JP2007015394A - Printing apparatus, printing program, printing method, image processing apparatus, image processing program, image processing method, and recording medium recording the program - Google Patents

Abstract

Provided are a printing apparatus and program, a printing method, an image processing apparatus, a program, and a method capable of making white stripes and dark stripes generated due to a flying bend phenomenon inconspicuous.
In an inkjet printing apparatus, when dots smaller than a predetermined size are continuous, the dot size of any one of the pixels is changed to a size larger than the predetermined size. As a result, the size of dots involved in the banding phenomenon is automatically adjusted to eliminate white stripes and dark stripes, so that the banding phenomenon caused by the so-called flight curve phenomenon can be eliminated or hardly noticeable.
[Selection] Figure 1

Description

  The present invention relates to a printing apparatus typified by a facsimile machine, a copying machine, a printer for OA equipment, a printing program, a printing method, an image processing apparatus, an image processing program, an image processing method, a recording medium on which the program is recorded, and the like. In particular, a so-called inkjet type printing apparatus, printing program, printing method, and image in which fine particles of liquid ink of a plurality of colors are ejected onto a printing paper (printing medium) to draw predetermined characters and images. The present invention is suitable for a processing apparatus, an image processing program, an image processing method, and a recording medium on which the program is recorded.

The following describes a printing apparatus, particularly a printer that employs an inkjet method (hereinafter referred to as an “inkjet printer”).
Ink jet printers are generally inexpensive and can easily obtain high-quality color prints, and are widely used not only in offices but also in general users with the spread of personal computers and digital cameras.

  In such an ink jet printer, generally, a movable body called a carriage integrally provided with an ink cartridge and a print head is reciprocated on a print medium (paper) in a direction perpendicular to the paper feed direction. By ejecting (jetting) liquid ink particles from the nozzles of the print head in the form of dots, a desired printed matter is created by drawing predetermined characters and images on the print medium. The carriage is equipped with ink cartridges of four colors (black, yellow, magenta, cyan) including black (black) and the print heads of each color, so that not only monochrome printing but also full-color printing combining each color is easy. (Furthermore, 6 colors, 7 colors, or 8 colors in which light cyan, light magenta, etc. are added to these colors are also put into practical use).

  In addition, in an ink jet printer that performs printing while reciprocating the print head on the carriage in a direction perpendicular to the paper feed direction, the print head is moved several tens of times in order to print the entire page cleanly. Since it is necessary to reciprocate 100 times or more from the beginning, there is a disadvantage that it takes much printing time compared with other types of printing apparatuses, for example, laser printers using electrophotographic technology such as copying machines. . This type of inkjet printer is generally called a “multi-pass printer” or a “serial printer”.

  On the other hand, in an ink jet printer of a type in which a long print head having the same (or long) dimension as the width of the print paper is used and a carriage is not used, it is not necessary to move the print head in the width direction of the print paper. Since printing in so-called one scanning (one pass) is possible, high-speed printing similar to the laser printer is possible. In addition, since a carriage for mounting the print head and a drive system for moving the print head are not required, the printer housing can be reduced in size and weight, and the quietness can be greatly improved. Yes. This type of ink jet printer is generally called a “line head printer”.

  By the way, a print head indispensable for such an ink jet printer has one row of fine nozzles having a diameter of about 10 to 70 μm at a certain interval, or a plurality of rows in a direction perpendicular to the nozzle arrangement direction of the print head. As a result of manufacturing errors, the ink ejection direction of some nozzles is tilted, or the nozzle positions are shifted from the ideal position, and dots formed by the nozzles are formed. In some cases, a so-called “flight bend phenomenon” occurs in which the landing position is deviated from the target point.

  As a result, a printing defect referred to as a so-called “banding phenomenon” may occur in a portion printed using the defective nozzle, and the print quality may be significantly reduced. That is, when the “flying curve phenomenon” occurs, the distance between dots ejected by adjacent nozzles becomes non-uniform, and “white stripes (printing paper is white In the case where the distance between dots ejected by adjacent nozzles is short, a “dark streak” occurs.

  In particular, the banding phenomenon is more likely to occur in the “line head type printer” in which the print head or print medium is fixed (one pass printing) than in the case of the “multi-pass type printer” (serial printer) as described above. (In a multi-pass type printer, there is a technique that makes banding inconspicuous by using the print head reciprocating many times).

Therefore, in order to prevent a kind of printing failure due to such "banding phenomenon", research and development in the so-called hardware part, such as improvement in print head manufacturing technology and design improvement, has been earnestly advanced, It is difficult to provide a print head in which 100% “banding phenomenon” does not occur due to manufacturing costs, technical aspects, and the like.
Therefore, in addition to the improvement in the hardware part as described above, a technology that reduces such “banding phenomenon” by using a so-called software method such as printing control as described below is used in combination. Has been.

For example, in “Inkjet recording apparatus and inkjet recording method” of Patent Document 1 below, the dot size in the nozzle array direction of the print head is the same, while the drive direction of the print head (perpendicular to the nozzle array direction). (Banding) extending in the direction perpendicular to the nozzle arrangement direction is reduced by irregularly changing the size of the dots in the (direction).
JP-A-6-340094

However, in the above prior art, since the dot size is determined irregularly, in some cases, it is difficult to reduce “white streaks” generated in the vicinity of small dots when they are consecutive. Further, when printing with the same density, density unevenness occurs, that is, the density of a region that should have a uniform density may partially change, resulting in a decrease in print quality.
Accordingly, the present invention has been devised in order to effectively solve such problems, and the object thereof is a novel printing apparatus capable of eliminating or almost inconspicuous the banding phenomenon caused by the flight bending phenomenon. A printing program, a printing method and an image processing apparatus, an image processing program, an image processing method, and a recording medium on which the program is recorded are provided.

  Another object of the present invention is to provide a novel printing apparatus, a printing program, a printing method and an image processing apparatus, an image processing program, an image processing method, and a recording medium on which the program is recorded. is there.

[Mode 1] In order to solve the above problems, a printing apparatus according to mode 1
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; A print data generating unit that generates print data in which a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generating unit is set; and the print data generated by the print data generating unit Printing means for executing printing based on
The print data generation means generates print data in which the dot size corresponding to any one of the continuous dots is changed when the dot size within a predetermined range is continuous in the print data. It is characterized by being.
As a result, dots having a predetermined range of sizes do not continue, so that the banding phenomenon caused by the so-called flight bend phenomenon can be effectively eliminated or made almost inconspicuous.

  Here, “dot” in the present embodiment is a basic unit representing characters and figures of printed matter, and refers to one area where ink ejected from one or more nozzles has landed on the medium. In addition, the “dot” is not “zero” in area but has a certain size (area), and there are a plurality of types for each size. In addition, the shape of the dot is not necessarily a perfect circle, and includes a shape other than a true circle such as an ellipse. In this case, the diameter is not uniform, so the area occupied by the dot or It is assumed that the dot size is determined based on the average diameter (form relating to “printing apparatus” below, form relating to “printing program”, form relating to “printing method”, form relating to “image processing apparatus”, The same applies to the description relating to the “image processing program”, the “image processing method”, the “recording medium on which the program is recorded”, the best mode for carrying out the invention, and the like.

  If this “dot diameter” is defined more strictly, a perfect circle equivalent dot having an area equal to the area of a dot formed by ejecting a certain amount of ink is assumed, and the equivalent dot diameter is set to the dot size. The diameter. In general, since the ink absorption rate and the like vary depending on the print medium, it is a matter of course that the dot diameter to be formed varies variously if the print medium changes even if the ink amount is the same. In addition, this “dot” is not necessarily limited to one formed by one ink droplet by one discharge, but a combination of two or more ink droplets by discharge as in the case of a maximal dot. Including those formed in this way.

  “N value (N ≧ 2)” is described in detail later in the embodiment, and image data of M value (M> N) (for example, 8 bits, 256 gradations) is based on a certain rule. In addition to the so-called “binary” in which dots are shot or not shot, the dot size is changed in several stages according to the size of the pixel value. (Forms relating to the following “printing apparatus”, forms relating to “printing program”, forms relating to “printing method”, forms relating to “image processing apparatus”, forms relating to “image processing program”, “image processing method”) This is the same in the description of the form relating to "the recording medium on which the program is recorded", the best mode for carrying out the invention, and the like.

  The reason why the value of “N” is set to (N ≧ 2) is that it is necessary to at least define binarization regarding whether or not dots are hit in order to generate print data. (Forms relating to “printing device”, “printing program”, “printing method”, “image processing device”, “image processing program”, “image processing method”, In addition, the same applies to the description relating to the “recording medium on which the program is recorded” and the column of the best mode for carrying out the invention.

  “Banding phenomenon” refers to a printing defect in which “white streaks” or “dark streaks” are generated due to “flight bend phenomenon” (hereinafter referred to as “printing device”, “printing” Form relating to "Program", Form relating to "Printing Method", Form relating to "Image Processing Apparatus", Form relating to "Image Processing Program", Form relating to "Image Processing Method", Form relating to "Recording Medium on which said Program is Recorded", Invention This is the same in the description of the column of the best mode for carrying out.

  In addition, as described above, the “flight bend phenomenon” is different from the non-ejection phenomenon of some nozzles, as described above. Although ink is ejected, the ejection direction of some of the nozzles is inclined and the dots are positioned at the target position. Phenomenon that is formed more deviated (forms relating to “printing apparatus”, forms relating to “printing program”, forms relating to “printing method”, forms relating to “image processing apparatus”, forms relating to “image processing program”, The same applies to the description relating to the “image processing method”, the description relating to the “recording medium on which the program is recorded”, the best mode for carrying out the invention, and the like.

  Also, “white streaks” are parts where the distance between adjacent dots continuously increases due to the “flying curve phenomenon” and the background color of the print medium stands out in a streak shape. The “dark streaks” are the same as the “flying bend phenomenon”, in which the phenomenon in which the distance between adjacent dots is continuously shorter than a predetermined distance and the color of the background of the print medium is changed. It becomes invisible or appears darker as the distance between the dots becomes shorter, and some of the dots that are separated from each other overlap normal dots, and the overlapped part becomes conspicuous in a dark streak shape A part (area) is referred to (a form relating to “printing apparatus” below, a form relating to “printing program”, a form relating to “printing method”, a form relating to “image processing apparatus”, “ Embodiment concerning the image processing program ", a mode relating to an" image processing method ", and various types of 'a recording medium storing the program", is the same in the description, such as the best mode column for carrying out the invention).

  The “predetermined range of dot sizes” means, for example, that there are 16 types of dot sizes including “no dot”, “no dot” is “1”, “smallest dot” is “2”, “ If “next largest dot” is “3”,..., “Largest dot” is “16”, the predetermined range is “3” to “10”, or “1” to “6”, etc. In the case of “10” or less, “12” or less or the like (the following “printing device”, “printing program”, “printing method”, “image processing device”, “image processing” The same applies to the description relating to the "program", the "image processing method", the "recording medium on which the program is recorded", the best mode for carrying out the invention, and the like.

  The term “continuous” refers to a case where two or more dots are continuous (a form relating to “printing apparatus”, a form relating to “printing program”, a form relating to “printing method”, and a form relating to “image processing apparatus”. The same applies to the description relating to the "image processing program", the "image processing method", the "recording medium on which the program is recorded", the best mode for carrying out the invention, and the like.

  Here, “one of the pixels” means, for example, one of the pixels when two are continuous, or one of the three pixels when three are continuous. (Forms relating to “printing device”, “printing program”, “printing method”, “image processing device”, “image processing program”, “image processing method”) As well as the description of the form relating to the “recording medium on which the program is recorded” and the column of the best mode for carrying out the invention.

[Mode 2] The printing apparatus of mode 2
N-valued data generating means for generating N-value image data by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel, and Based on the print data generation unit that generates print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation unit is set, and the print data generated by the print data generation unit Printing means for executing printing,
When the print data generation unit has dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. It is characterized by generating data.
As a result, dots smaller than the predetermined size do not continue, so that the banding phenomenon caused by the so-called flight curve phenomenon can be effectively eliminated or made almost inconspicuous.

[Mode 3] The printing apparatus of mode 3
N-valued data generating means for generating N-value image data by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel, and A print data generating unit that generates print data by setting a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generating unit, and a print data generated by the print data generating unit Printing means for executing printing based on
The print data generating means is a dot size changing unit that changes the dot size of any one of the continuous dots when the dots smaller than the predetermined size are continuous in the print data to a size larger than the predetermined size. The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that has propagated the error by the error propagation unit. And a dot size resetting unit to be set.

That is, in this embodiment, not only the dot size is changed so that dots smaller than the predetermined size do not continue as in the first embodiment, but also the error of the pixel value caused by the change in the dot size is as follows. It is used by propagating to unprocessed pixels such as scan lines.
As a result, the area gradation of the peripheral area subjected to dot size conversion can be maintained at the same level as the original area gradation, and a high-quality printed matter with less density unevenness can be obtained.

  Here, the “unprocessed pixel” means an unprocessed pixel adjacent to a pixel to be processed (a form related to “printing apparatus”, a form related to “printing program”, and a form related to “printing method” below) , A form relating to “image processing apparatus”, a form relating to “image processing program”, a form relating to “image processing method”, a form relating to “recording medium on which the program is recorded”, a column of the best mode for carrying out the invention, etc. The same in the description).

[Form 4] The printing apparatus of form 4
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; Based on the print data generating means for generating print data by setting the dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generating means, and the print data generated by the print data generating means Printing means for executing printing,
The N-value data generation unit includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when adjacent to each other so that a dot size corresponding to the pixel value is equal to or less than a predetermined size, And an error propagation unit that propagates an error of a pixel value generated when the N-value process is performed by the adjustment unit to an unprocessed pixel.

That is, in this embodiment, when M-value image data is converted to N-values, if dots of a predetermined size or smaller are consecutive, the N-value is adjusted so that dots of a predetermined size or smaller are not consecutive, and the adjustment causes the N-value image data to be generated. The error is propagated to adjacent unprocessed pixels.
As a result, it is possible to avoid the occurrence of banding due to continuous dots having a predetermined size or less as in the second embodiment, and to maintain the area gradation of the peripheral area after the dot size conversion at the same level as the original area gradation. This makes it possible to obtain a high-quality printed matter with little density unevenness. Further, by adjusting the pixel value in consideration of the dot size during the N-ary processing, it becomes unnecessary to change the dot size when generating the print data, so that the processing efficiency is improved.

[Form 5] The printing apparatus of form 5 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; Based on the print data generating means for generating print data by setting the dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generating means, and the print data generated by the print data generating means Printing means for executing printing,
The N-value data generation means includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when the dot size corresponding to the pixel value is adjacent to a predetermined range, and the N-value adjustment adjustment And an error propagation unit that propagates an error of a pixel value generated when the N-value process is performed by the unit to an unprocessed pixel.

In other words, in the present embodiment, when dots in a predetermined range continue when converting N-value image data into N values, the N value is adjusted so that the dots in the predetermined range do not continue, and errors caused by the adjustment are adjusted. It is intended to propagate to adjacent unprocessed pixels.
As a result, it is possible to avoid the occurrence of banding due to continuous dots in a predetermined range, and it is possible to maintain the area gradation of the peripheral area after dot size conversion at the same level as the original area gradation. It is possible to obtain a high-quality printed matter with a small amount of ink. Further, by adjusting the pixel value in consideration of the dot size during the N-ary processing, it becomes unnecessary to change the dot size when generating the print data, so that the processing efficiency is improved.

[Mode 6] A printing apparatus according to mode 6 includes:
In the printing apparatus according to Mode 4 or 5, the N-valued data generation unit diffuses an error in pixel value to unprocessed pixels around the target pixel when the target pixel of the image data is subjected to N-value processing. And an error diffusion unit.
As described above, when N-value processing of the target pixel is performed, an error diffusion method which is one of well-known halftone processing methods is used in combination, so that errors generated by the N-value processing can be reduced to surrounding pixels according to a predetermined error diffusion matrix. In the subsequent processing, the influence as a whole can be taken into consideration in the subsequent processing, so that a high-quality printed matter faithfully expressing the intermediate gradation can be obtained.

  Here, the “error diffusion process” in the present invention is the same as that normally used in the field of image processing, and an error caused by the binarization process of a certain pixel is determined according to a predetermined error diffusion matrix. This is a process for allocating to surrounding pixels and minimizing the error as a whole by considering the influence in subsequent processes. For example, if the pixel value of the pixel of interest is larger than the intermediate value of half the number of gradations of the image, it is classified as black, and if it is smaller, it is classified as white, and then the error between the pixel value before classification and the pixel value after processing This is a method of distributing and adjusting to surrounding pixels at a proper ratio (the following forms related to “printing apparatus”, forms related to “printing program”, forms related to “printing method”, forms related to “image processing apparatus”, “image processing” The same applies to the description relating to the "program", the "image processing method", the "recording medium on which the program is recorded", the best mode for carrying out the invention, and the like.

Similar to the “error diffusion method”, even if a dither method, which is one of the well-known halftone processing methods, is used, a high-quality printed matter that faithfully represents the intermediate gradation can be obtained with certainty.
This “dither method” is the same as that normally used in the field of image processing. For example, a pixel value of a target pixel of an image and a numerical value corresponding to each pixel of a dither matrix prepared in advance are used. In comparison, this is a processing method in which if the pixel value of the target pixel is larger, it is determined to be black, and if it is smaller, it is determined to be white, and the pixel is distributed to white and black.

[Form 7] The print program of form 7 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And function as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
The print data generation unit functions to generate print data in which the dot size corresponding to any one of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. It is characterized by this.

As a result, the banding can be reduced in the same manner as in the first aspect, and the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost inconspicuous.
In addition, most printing devices on the market such as inkjet printers have a computer system including a central processing unit (CPU), a storage device (RAM, ROM), an input / output device, and the like. Since each means can be realized by software, it can be realized more economically and easily than a case where dedicated means is created to realize each means.
Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Embodiment 8] The printing program of Embodiment 8 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And function as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
When the print data generation unit continuously prints dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. It is characterized by functioning to generate data.

As a result, similar to the second aspect, the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost inconspicuous.
In addition, as in the case of the seventh aspect, each means can be realized by software by using a computer system provided in most printing apparatuses currently on the market as it is. This can be realized more economically and easily than in the case where the above means are realized. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 9] The printing program of mode 9 is
N-valued data generating means for generating image data of N values by converting image data, which is a set of pixel values of M values (M> N) constituting an image, into N values (N ≧ 2) for each pixel. And functioning as print data generation means for setting the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means and generating print data,
A dot size changing unit that changes the dot size of any one of the consecutive dots when the dots smaller than the predetermined size are continuous in the print data, the print data generating unit changing the dot size to a size greater than or equal to the predetermined size The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that is propagated the error by the error propagation unit. It functions as a dot size resetting unit to be set.

As a result, the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost inconspicuous as in the third mode.
In addition, as in the case of the seventh aspect, each means can be realized by software by using a computer system provided in most printing apparatuses currently on the market as it is. This can be realized more economically and easily than in the case where the above means are realized. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 10] The print program of mode 10 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
An N-value adjusting unit that adjusts N-value conversion of the pixel value when the N-value data generation unit is adjacent so that a dot size corresponding to the pixel value is a predetermined size or less; It is characterized by functioning as an error propagation unit that propagates an error of a pixel value generated when N-value processing is performed by an adjustment unit to an unprocessed pixel.

As a result, the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost inconspicuous as in the case of the fourth aspect.
In addition, as in the case of the seventh aspect, each means can be realized by software by using a computer system provided in most printing apparatuses currently on the market as it is. This can be realized more economically and easily than in the case where the above means are realized. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Form 11] The print program of form 11 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
When the N-valued data generating means is adjacent so that the dot size corresponding to the pixel value falls within a predetermined range, an N-valued adjusting unit that adjusts the N-valued value of the pixel value, and the N-valued adjustment It is characterized by functioning as an error propagation unit that propagates an error of a pixel value generated when an N-value process is performed by a unit to an unprocessed pixel.

As a result, as in the fifth aspect, the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost inconspicuous.
In addition, as in the case of the seventh aspect, each means can be realized by software by using a computer system provided in most printing apparatuses currently on the market as it is. This can be realized more economically and easily than in the case where the above means are realized. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 12] The printing program of mode 12 is
In the printing program according to mode 10 or 11, when the N-valued data generation unit performs N-value processing on the target pixel of the image data, an error in pixel value is diffused to unprocessed pixels around the target pixel. It functions as follows.
As a result, as in the sixth aspect, the error generated during the N-value processing of the target pixel can be diffused to the surrounding unprocessed pixels and the area gradation of the peripheral region can be maintained at the same level as the original area gradation. It is possible to reliably obtain a high-quality printed material that faithfully represents the intermediate gradation.

  In addition, as in the case of the seventh aspect, each means can be realized by software by using a computer system provided in most printing apparatuses currently on the market as it is. This can be realized more economically and easily than in the case where the above means are realized. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 13] The computer-readable recording medium of mode 13 is
A computer-readable recording medium on which the printing program according to any one of forms 7 to 12 is recorded.
Accordingly, the printing program according to any one of the above embodiments 7 to 12 can be easily and easily transmitted to a consumer such as a user via a computer-readable storage medium such as a CD-ROM, a DVD-ROM, an FD, or a semiconductor chip. It can be reliably provided.

[Form 14] The printing method of form 14 includes:
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; Based on the print data generation step for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set, and the print data generated in the print data generation step Printing step for performing printing, and
The print data generation step generates print data in which the dot size corresponding to any one pixel of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. To do.

As a result, dots of a predetermined range of sizes do not continue in the same manner as in the first mode, and therefore, “white streaks” due to the banding phenomenon caused by the so-called flight bending phenomenon can be effectively eliminated or made almost inconspicuous.
Here, the operating subject of the N-ary data generation step and the print data generation step is, for example, a CPU (Central Processing Unit) of a computer system, and the operation step of the printing step is a printer. An output device such as a printing mechanism (in the following description of the form relating to “printing method”, the form relating to “image processing apparatus”, the form relating to “image processing method”, the best mode for carrying out the invention, etc.) The same).

[Form 15] The printing method of form 15 includes:
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel; A print data generation step for generating print data by setting a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step, and a print data generated in the print data generation step. Printing step to perform printing based on,
The print data generation step includes a step of changing a dot size of any one of the consecutive dots when the dots smaller than the predetermined size are continuous in the print data to a size larger than the predetermined size; An error propagation step of propagating a pixel value error of the pixel caused by the dot size change process to an unprocessed pixel, and a step of resetting a dot size of the pixel propagated with the error, To do.
As a result, dots smaller than the predetermined size do not continue as in the case of Form 2, so that the banding phenomenon caused by the so-called flight bending phenomenon can be effectively eliminated or made almost inconspicuous.

[Mode 16] The printing method of mode 16 is
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel; Based on the print data generation step for generating print data by setting the dot size corresponding to the pixel value of the N-value image data generated in the N-value data generation step, and the print data generated in the print data generation step Printing step for executing printing,
The N-value data generation step includes an N-value adjustment step for adjusting the N-value conversion of the pixel value when adjacent to each other so that a dot size corresponding to the pixel value is equal to or smaller than a predetermined size, And an error propagation step for propagating an error of the pixel value generated when the N-value process is performed in the adjustment step to the next unprocessed pixel.
As a result, it is possible to maintain the area gradation of the peripheral region that has been dot-sized converted to the same level as the original area gradation as in the third aspect, and a high-quality printed matter with less density unevenness can be obtained.

[Form 17] The printing method of form 17 includes:
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel; A print data generation step for generating print data by setting a dot size corresponding to the pixel value for each pixel of interest for the N-value image data generated in the N-value data generation step, and the print data generation step. A printing step for executing printing based on the printed data,
The N-value data generation step includes an N-value adjustment step for adjusting N-value conversion of the pixel of interest when a dot size corresponding to an adjacent pixel in the print data is equal to or smaller than a predetermined size; And an error propagation step for propagating an error of the pixel value generated when the N-value processing is performed in the conversion adjustment step to an unprocessed pixel.

  As a result, it is possible to maintain the area gradation of the peripheral area that has been dot-sized converted as in the fourth aspect, in the same way as the original area gradation, and it is possible to obtain a high-quality printed matter with little density unevenness. In addition, by adjusting the pixel value in consideration of the dot size during the N-ary processing, it is not necessary to change the dot size when generating the print data, thereby improving the processing efficiency.

[Form 18] The printing method of form 18 includes:
In the printing method according to the seventeenth aspect, the N-valued data generation step diffuses an error of the pixel value to unprocessed pixels around the target pixel when the target pixel of the image data is N-valued. It is characterized by this.
As a result, the error caused by the N-value conversion process is assigned to the surrounding pixels in accordance with a predetermined error diffusion matrix in the same manner as in the sixth aspect, and the overall error can be minimized in consideration of the influence in the subsequent process. Therefore, it is possible to reliably obtain a high-quality printed material that faithfully represents the intermediate gradation.

[Mode 19] An image processing apparatus according to mode 19
N-valued data generating means for generating N-value image data by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel, and Print data generating means for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generating means is provided,
The print data generation means generates print data in which the dot size corresponding to any one of the continuous dots is changed when the dot size within a predetermined range is continuous in the print data. It is characterized by being.
As a result, dots of a predetermined range of size do not continue as in the first mode, so that the banding phenomenon caused by the so-called flight bending phenomenon can be effectively eliminated or made almost inconspicuous. Further, since each means can be realized on software, it can be realized by an information processing apparatus such as a general-purpose personal computer.

[Mode 20] An image processing apparatus according to mode 20
N-valued data generating means for generating N-value image data by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel, and Print data generating means for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generating means is provided,
When the print data generation unit has dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. It is characterized by generating data.
As a result, dots smaller than the predetermined size do not continue, so that the banding phenomenon caused by the so-called flight curve phenomenon can be effectively eliminated or made almost inconspicuous. Further, since each means can be realized on software, it can be realized by an information processing apparatus such as a general-purpose personal computer.

[Mode 21] An image processing apparatus according to mode 21
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; Print data generation means for setting the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means and generating print data;
The print data generating means is a dot size changing unit that changes the dot size of any one of the continuous dots when the dots smaller than the predetermined size are continuous in the print data to a size larger than the predetermined size. The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that has propagated the error by the error propagation unit. And a dot size resetting unit to be set.

  As a result, the area gradation of the peripheral area subjected to dot size conversion can be maintained at the same level as the original area gradation, and a high-quality printed matter with less density unevenness can be obtained. Further, since each means can be realized on software, it can be realized by an information processing apparatus such as a general-purpose personal computer.

[Mode 22] An image processing apparatus according to mode 22
N-valued data generating means for generating image data of N values by converting image data into N values (N ≧ 2) for each pixel of image data that is a set of pixel values of M values (M> N) constituting an image And print data generation means for setting the dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means and generating print data,
The N-value data generation unit includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when adjacent to each other so that a dot size corresponding to the pixel value is equal to or less than a predetermined size, And an error propagation unit that propagates an error of a pixel value generated when the N-value process is performed by the adjustment unit to an unprocessed pixel.
As a result, the area gradation of the peripheral area subjected to dot size conversion can be maintained at the same level as the original area gradation, and a high-quality printed matter with less density unevenness can be obtained. Further, since each means can be realized on software, it can be realized by an information processing apparatus such as a general-purpose personal computer.

[Form 23] An image processing apparatus of form 23 is
N-valued data generating means for generating image data of N values by converting image data into N values (N ≧ 2) for each pixel of image data that is a set of pixel values of M values (M> N) constituting an image And print data generation means for setting the dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means and generating print data,
The N-value data generation means includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when the dot size corresponding to the pixel value is adjacent to a predetermined range, and the N-value adjustment adjustment And an error propagation unit that propagates an error of a pixel value generated when the N-value process is performed by the unit to an unprocessed pixel.
As a result, the area gradation of the peripheral area subjected to dot size conversion can be maintained at the same level as the original area gradation, and a high-quality printed matter with less density unevenness can be obtained. Further, since each means can be realized on software, it can be realized by an information processing apparatus such as a general-purpose personal computer.

[Mode 24] An image processing apparatus according to mode 24
In the image processing device according to form 22 or 23, the N-valued data generating means converts an error of a pixel value to an unprocessed pixel around the target pixel when the target pixel of the image data is N-valued. It further has an error diffusing unit for diffusing.
As a result, the error caused by the N-value conversion processing is assigned to the surrounding pixels according to a predetermined error diffusion matrix in the same manner as in the fifth embodiment, and the overall error can be minimized in consideration of the influence in the subsequent processing. Therefore, it is possible to reliably obtain a high-quality printed material that faithfully represents the intermediate gradation. Further, since each means can be realized on software, it can be realized by an information processing apparatus such as a general-purpose personal computer.

[Mode 25] The image processing program of mode 25 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And function as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
The print data generation unit functions to generate print data in which the dot size corresponding to any one of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. It is characterized by this.

As a result, the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost unnoticeable.
Moreover, since each means can be realized by software using a general-purpose computer system such as a personal computer (PC), it is more economical and easier than the case where the means are realized by creating dedicated hardware. Can be realized. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 26] The image processing program of mode 26 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And function as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
When the print data generation unit continuously prints dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. It is characterized by functioning to generate data.

As a result, the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost unnoticeable.
In addition, since each means can be realized by software using a general-purpose computer system such as a personal computer (PC), as in the case of the form 25, compared to a case where dedicated hardware is created and each means is realized. Economically and easily. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 27] The image processing program of mode 27 is
N-valued data generating means for generating image data of N values by converting image data, which is a set of pixel values of M values (M> N) constituting an image, into N values (N ≧ 2) for each pixel. And functioning as print data generation means for setting the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means and generating print data,
A dot size changing unit that changes the dot size of any one of the consecutive dots when the dots smaller than the predetermined size are continuous in the print data, the print data generating unit changing the dot size to a size greater than or equal to the predetermined size The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that is propagated the error by the error propagation unit. It functions as a dot size resetting unit to be set.

As a result, “white streaks” and “dark streaks” are reduced, and the banding phenomenon due to the flight bending phenomenon can be eliminated or made almost inconspicuous.
In addition, since each means can be realized by software using a general-purpose computer system such as a personal computer (PC), as in the case of the form 25, compared to a case where dedicated hardware is created and each means is realized. Economically and easily. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 28] The image processing program of mode 28 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
An N-value adjusting unit that adjusts N-value conversion of the pixel of interest when the N-value data generation unit is adjacent so that a dot size corresponding to the pixel value is equal to or smaller than a predetermined size; It is characterized by functioning as an error propagation unit that propagates an error of a pixel value generated when N-value processing is performed by an adjustment unit to an unprocessed pixel.

This makes it possible to maintain the area gradation of the peripheral area after dot size conversion at the same level as the original area gradation, and not only can obtain a high-quality printed matter with little density unevenness, but also N-value conversion. By adjusting the pixel value in consideration of the dot size during processing, it is not necessary to change the dot size when generating print data, thereby improving processing efficiency.
In addition, since each means can be realized by software using a general-purpose computer system such as a personal computer (PC), as in the case of the form 25, compared to a case where dedicated hardware is created and each means is realized. Economically and easily. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 29] The image processing program of mode 29 is
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel. And functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
An N-value adjustment unit for adjusting N-value conversion of the pixel of interest when the N-value data generation unit is adjacent so that a dot size corresponding to the pixel value falls within a predetermined range; and the N-value adjustment It is characterized by functioning as an error propagation unit for propagating an error of a pixel value generated when the N-value processing is performed by the unit to an unprocessed pixel.

This makes it possible to maintain the area gradation of the peripheral area after dot size conversion at the same level as the original area gradation, and not only can obtain a high-quality printed matter with little density unevenness, but also N-value conversion. By adjusting the pixel value in consideration of the dot size during processing, it is not necessary to change the dot size when generating print data, thereby improving processing efficiency.
In addition, since each means can be realized by software using a general-purpose computer system such as a personal computer (PC), as in the case of the form 25, compared to a case where dedicated hardware is created and each means is realized. Economically and easily. Furthermore, it is possible to easily upgrade the version by modifying or improving the function by rewriting a part of the program.

[Mode 30] The image processing program of mode 30 is
30. In the image processing method according to mode 28 or 29, when the N-valued data generation step performs N-value processing on a target pixel of the image data, an error of the pixel value is determined as an unprocessed pixel around the target pixel. It is characterized by diffusing into
As a result, similarly to the fifth aspect, the error generated during the N-value processing of the target pixel can be diffused to the surrounding unprocessed pixels, and the area gradation of the peripheral region can be maintained at the same level as the original area gradation. It is possible to reliably obtain a high-quality printed material that faithfully represents the intermediate gradation.

[Mode 31] The computer-readable recording medium of mode 31 is
A computer-readable recording medium on which the image processing program according to any one of forms 25 to 30 is recorded.
Accordingly, the image processing program according to any one of the above embodiments 25 to 30 can be easily provided to users such as users via a computer-readable storage medium such as a CD-ROM, DVD-ROM, FD, or semiconductor chip. And can be provided reliably.

[Mode 32] An image processing method according to mode 32 includes:
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; A print data generation step for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set;
The print data generation step generates print data in which the dot size corresponding to any one pixel of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. To do.
As a result, dots do not continue, so that “white streaks” due to the banding phenomenon caused by the so-called flight curve phenomenon can be effectively eliminated or made almost inconspicuous. Further, since no printing means or the like is used, it can be realized on software by a general-purpose computer system such as a personal computer.

[Mode 33] An image processing method according to mode 33 is
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting the image into N values (N ≧ 2) for each pixel; A print data generation step for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set;
In the print data generation step, when dots smaller than a predetermined size are continuous in the print data, printing in which the dot size of a pixel corresponding to one of the continuous dots is changed to a size larger than the predetermined size It is characterized by generating data.
As a result, dots smaller than a predetermined size do not continue, so that “white streaks” due to the banding phenomenon caused by the so-called flight curve phenomenon can be effectively eliminated or made almost inconspicuous. Further, since no printing means or the like is used, it can be realized on software by a general-purpose computer system such as a personal computer.

[Form 34] An image processing method according to form 34 includes:
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel; A print data generation step of generating print data by setting a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step;
The print data generation step includes a dot size change step of changing the dot size of any one of the consecutive dots when the dots smaller than the predetermined size continue in the print data to a size greater than or equal to the predetermined size. And an error propagation step for propagating the pixel value error of the pixel generated by the dot size change process of the dot size change step to an unprocessed pixel, and a dot size of the pixel propagated with the error at the error propagation step. And a dot size resetting step to be set.

  As a result, the area gradation of the peripheral area subjected to dot size conversion can be maintained at the same level as the original area gradation, and high-quality print data with little density unevenness can be obtained. Further, since no printing means or the like is used, it can be realized on software by a general-purpose computer system such as a personal computer.

[Mode 35] An image processing method according to mode 35 is
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel; A print data generation step for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated in the N-value data generation step;
The N-value data generation step includes an N-value adjustment step for adjusting the N-value conversion of the pixel value when adjacent to each other so that a dot size corresponding to the pixel value is equal to or smaller than a predetermined size, An error propagation step of propagating an error of a pixel value generated when the N-value process is performed in the adjustment step to an unprocessed pixel.

  This makes it possible to maintain the area gradation of the peripheral area after dot size conversion at the same level as the original area gradation, and not only can obtain a high-quality printed matter with less density unevenness, but also N-value conversion. By adjusting the pixel value in consideration of the dot size during the process, it is not necessary to change the dot size when generating the print data, thereby improving the processing efficiency. Further, since no printing means or the like is used, it can be realized on software by a general-purpose computer system such as a personal computer.

[Mode 36] An image processing method according to mode 36 includes:
An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel; A print data generation step for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated in the N-value data generation step;
The N-value conversion data generation step includes an N-value adjustment step for adjusting N-value conversion of the pixel value when the dot size corresponding to the pixel value is adjacent to a predetermined range, and the N-value adjustment adjustment And an error propagation step for propagating an error of a pixel value generated when the N-value process is performed in steps to an unprocessed pixel.

  This makes it possible to maintain the area gradation of the peripheral area after dot size conversion at the same level as the original area gradation, and not only can obtain a high-quality printed matter with less density unevenness, but also N-value conversion. By adjusting the pixel value in consideration of the dot size during the process, it is not necessary to change the dot size when generating the print data, thereby improving the processing efficiency. Further, since no printing means or the like is used, it can be realized on software by a general-purpose computer system such as a personal computer.

[Mode 37] The image processing method according to mode 37 includes:
37. In the image processing method according to mode 35 or 36, when the N-valued data generation step performs N-value processing on a target pixel of the image data, an error of the pixel value is determined as an unprocessed pixel around the target pixel. It is characterized by diffusing into
As a result, the error generated by the N-value processing can be allocated to surrounding pixels according to a predetermined error diffusion matrix, and the overall error can be minimized in consideration of the influence in the subsequent processing. High-quality print data that is faithfully expressed can be obtained.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.
1 to 15 show a first embodiment of a printing apparatus 100, a printing program, a printing method, an image processing apparatus, an image processing program, an image processing method, and a computer-readable recording medium according to the present invention. It is.
FIG. 1 is a functional block diagram showing a first embodiment of a printing apparatus 100 according to the present invention.

  As shown in the figure, the printing apparatus 100 includes a print head 200 having a plurality of nozzles and image data (hereinafter referred to as appropriate) that is a set of pixel values of M values (M> N) that constitute an image to be printed. Image data acquisition means 10 for acquiring "multi-value image data" and the multi-value image data acquired by the image data acquisition means 10 along the nozzle arrangement direction of the print head 200 with N values (N ≧ 2) N-valued data generating means 20 for generating N-valued image data and a dot size corresponding to each pixel value of the N-valued image data generated by the N-valued data generating means 20 is set. Print data generating means 30 for generating print data and ink jet printing for executing printing based on the print data generated by the print data generating means 30 using the print head 200 And the stage 40, are mainly composed of.

First, the print head 200 applied to the present invention will be described.
FIG. 3 is a partially enlarged bottom view showing the structure of the print head 200, and FIG. 4 is a partially enlarged side view thereof.
As shown in FIG. 3, the print head 200 has a long structure extending in the paper width direction of printing paper used in a so-called line head type printer, and has a nozzle N for discharging black (K) ink exclusively. A plurality (18 in the drawing) of the black nozzle modules 50 arranged in a straight line and a plurality of nozzles N for discharging yellow (Y) ink exclusively are arranged in a straight line in the same direction as the black nozzle module 50. A yellow nozzle module 52, a plurality of nozzles N that specifically eject magenta (M) ink, a magenta nozzle module 54 that is linearly arranged in the same direction as the black nozzle module 50, and cyan (M) ink. Cyan nozzle module in which a plurality of nozzles N are discharged in a straight line in the same direction as the black nozzle module 50 Which are arranged integrally in the direction perpendicular to the four nozzle modules 50, 52, 54, 56 nozzle array direction such Lumpur 56. In the case of a print head intended for monochrome, only black (K) is used. In the case of a print head targeted for a high-quality image, ink of 6 colors or 7 colors including light magenta or light cyan is added. Sometimes used.

  FIG. 4 shows, for example, the black nozzle module 50, which is one of these four nozzle groups 50, 52, 54, and 56, from the side, and the sixth nozzle N6 from the left is the flight bend phenomenon. In this state, the ink is ejected obliquely from the nozzle N6 and dots are formed in the vicinity of the landing position of the ink ejected by the normal nozzle N7 adjacent thereto.

  Therefore, when printing is performed using the black nozzle module 50, as shown in FIG. 5, in the state where no flying curve occurs, all the dots are printed at a predetermined landing position (ideal As shown in FIG. 6, for example, when the sixth nozzle N6 from the left has undergone a flight curve phenomenon, the dot ink landing position is normal next to the target landing position by a distance a. As a result, the dot ink ejected by the nozzle N7 is printed shifted to the landing position side. The characteristics of the print head 200 are fixed to some extent at the manufacturing stage, and it is considered that it is relatively rare to change after manufacturing, except for ejection failures due to ink clogging.

Next, the image data acquisition means 10 network multi-valued color image data to be used for printing sent from a printing instruction device (not shown) such as a personal computer (PC) or a printer server connected to the printing device 100. Etc., or a function to read and acquire directly from an image (data) reading device such as a scanner or a CD-ROM drive (not shown), and to obtain a multi-valued color image If the data is multi-value RGB data, for example, image data in which the gradation (luminance value) for each color (R, G, B) per pixel is expressed by 8 bits (0 to 255), this is converted into color. The function of processing and converting into multivalued CMYK (for four colors) data corresponding to each ink of the print head 200 is also exhibited at the same time.
The N-value data generation unit 20 converts the multi-value image data acquired by the image data acquisition unit 10 into N values (N ≧ 2) along the nozzle arrangement direction of the print head 200 to generate N-value image data. It is supposed to provide the function to do.

FIG. 7 shows N-value conversion and dot size conversion showing the relationship between the pixel value and the N value, and the relationship between the N value and the dot size, which is referred to in the N-value conversion performed by the N-value data generation means 20. An example of the table 300A is shown.
In the example shown in the figure, when N = “4” is set to quaternarization and “luminance value” is selected as the pixel value, the pixel value relating to the luminance of the acquired multi-valued image data is 8 bits, 256 (0 to 255). ) In the case of gradations, four threshold values “35”, “110”, and “200” are assigned to four types of N values.

That is, the range where the luminance value is “255” to “201” is converted to N value = “1”, and the range where the luminance value is the first threshold value “200” to “111” is N value = “2”. The range of the brightness value from the second threshold “110” to “36” is converted to N value = “3”, and the range of the brightness value from the third threshold “35” to “0” is N value = “4” is converted.
When a “density value” is adopted as the pixel value, each pixel value is converted into an N value having a reverse relationship to the “luminance value”.

Next, as shown in FIG. 1, a print data generation unit 30 for generating print data from N-value image data generated by the N-value data generation unit 20 includes a dot size setting unit 30a, a dot size, It comprises a changing unit 30b, an error propagation unit 30c, and a dot size resetting unit 30d.
The dot size setting unit 30a provides a function of setting dots corresponding to the N value for each pixel generated by the N-valued data generation means 20, for example, N-value conversion and dot size shown in FIG. According to the conversion table 300A, dots corresponding to the N value for each pixel are set.

That is, in the example of the figure, when N value = “1”, “no dot” is selected as the dot size, and when N value = “2”, “small dot” with the smallest area is selected, When the N value = “3”, the “medium dot” with the next largest area is selected, and when the N value = “4”, the “large dot” with the largest area is selected for each pixel. Will be set as a dot corresponding to.
The dot size changing unit 30b provides a function of changing the dot size of one of the pixels to a size equal to or larger than the predetermined size when dots smaller than the predetermined size are continuous in the nozzle arrangement direction of the print head 200. It is like that.

  For example, when there are four types of dot sizes including “no dot” (“small dot”, “medium dot”, “large dot”), when two or more dots smaller than “medium dot” continue, , “Medium dot” → “medium dot”, “medium dot” → “small dot”, “small dot” → “small dot”, “small dot” → “medium dot”, the four patterns of the print head 200 The dot size on the rear side in the nozzle arrangement direction is forcibly changed from “medium dot” or “small dot” to “large dot”.

  In addition, there are many dot sizes including “no dot”, for example, 16 types, “no dot” is “1”, “smallest dot” is “2”, “next largest dot” is “3”,. When “the largest dot” is “16”, the plurality of dot sizes are grouped into predetermined ranges such as “1” to “5”, “6” to “10”, “10” or more. And you may make it handle collectively.

Although the specific example will be described in detail later, the error propagation unit 30c provides a function of propagating an error in the pixel value of the target pixel generated by the dot size changing process by the dot size changing unit 30b to the adjacent unprocessed pixels. It is supposed to do.
For example, if the dot of the pixel of interest before the dot size is changed is a “medium dot” and this is forcibly increased to a “large dot”, as shown in FIG. Becomes “4” and its luminance value also becomes “0”. As a result, an error of the luminance value “70” is generated. Therefore, the error of “70” is changed to the pixel of the next line, that is, the print head 200. When the nozzle arrangement direction is the vertical direction, it propagates to the unprocessed pixel on the right or left side.

The dot size resetting unit 30d provides a function of resetting the dot size of the pixel whose error has been propagated by the error propagation unit 30c.
For example, as described above, the dot of the target pixel to which the error is propagated by the error propagation unit 30c is a “medium dot” (pixel value: “70”), and the error propagation unit 30c causes an error of the luminance value “70”. Is propagated, the pixel value becomes “70” + “70” = “140”, and is reset to “small dot” which is the dot size corresponding to the pixel value. That is, the dot size is changed from “medium dot” to “small dot”.

Here, the technique of dividing the dot size in one printed material as described above is a conventionally well-known technique, and is a technique that is frequently used especially for obtaining a printed material that achieves a high balance between printing speed and printing image quality. is there.
In other words, high image quality can be obtained by reducing the dot size, but high performance is required for machine accuracy when the dot size is reduced, and it is necessary to hit many dots to form a solid image with small dots. There is. Therefore, the printing speed and the image quality are realized with a high balance by using a dot size sorting technique such as reducing the dot size for a high-detail image portion and increasing the dot size for a solid image portion.

In addition, as a technical method for realizing the dot size sorting in this way, for example, in the case of a method using a piezo actuator for a print head, the voltage applied to the piezo element is changed to eject ink. It can be easily realized by controlling the amount.
Next, the printing unit 40 ejects ink from the nozzle modules 50, 52, 54, and 56 formed on the print head 200 while moving one or both of the print medium (paper) S and the print head 200, respectively. In addition to the above-described print head 200, the print head 200 is formed on the print medium S in the width of the ink jet printer so as to form a predetermined image composed of a large number of dots on the print medium S. A print head feed mechanism (not shown) that reciprocates in the direction (in the case of a serial type), a paper feed mechanism (not shown) for moving the print medium S, and ink ejection of the print head 200 are controlled based on the print data. It is composed of known components such as a print controller mechanism (not shown).

  Here, the printing apparatus 100 is a computer for realizing various controls for printing, the image data acquisition means 10, the N-value data generation means 20, the print data generation means 30, the printing means 40, etc. on software. As shown in FIG. 2, the hardware configuration includes a central processing unit (CPU) 60 that is responsible for various controls and arithmetic processing, and a main storage device (Main Storage). Between a RAM (Random Access Memory) 62 and a ROM (Read Only Memory) 64 which is a read-only storage device, a PCI (Peripheral Component Interconnect) bus or an ISA (Industrial Stan) An external storage device 68 such as an HDD (Hard Disk Drive) 70 is connected to the bus 68 via an input / output interface (I / F) 66. , An output device 72 such as a printing means 22, CRT, LCD monitor, etc., an input device 74 such as an operation panel, a mouse, a keyboard and a scanner, and a network L for communicating with a print instruction device (not shown). .

  When the power is turned on, a system program such as BIOS stored in the ROM 64 or the like is stored in various dedicated computer programs stored in the ROM 64 in advance, or in a CD-ROM, DVD-ROM, flexible disk (FD), or the like. Various dedicated computer programs installed in the storage device 70 via the medium or the communication network L such as the Internet are similarly loaded into the RAM 62, and the CPU 60 performs various operations according to instructions described in the program loaded in the RAM 62. Each function of each means as described above can be realized on software by performing predetermined control and arithmetic processing by making full use of resources.

Next, an example of the flow of the printing process using the printing apparatus 100 configured as described above is mainly shown in the flowcharts of FIGS. 8 and 9 and the schematic diagram showing the flow of the dot size changing process in FIGS. 10 and 11. This will be described with reference to FIG.
As described above, the print head 200 for printing dots is generally capable of printing dots of a plurality of types of colors such as four colors and six colors almost simultaneously, but in the following example, the description is easy to understand. Therefore, it is assumed that each dot is printed by any one (single color) print head 200 (monochrome image).

First, when a predetermined initial operation for printing processing is completed after the power is turned on, the printing apparatus 100 is connected to a printing instruction terminal (not shown) such as a personal computer. It is monitored whether there is an explicit print instruction from the print instruction terminal, and when it is determined that this print instruction and multi-value image data to be processed have been sent, processing is performed according to the target pixel determination flow shown in FIG. While sequentially determining target pixels of interest, dot conversion processing as shown in FIG. 9 is executed for each target pixel.
At this time, when the image data acquired by the image data acquisition means 10 is multi-value RGB data, as described above, this is converted into multi-value CMYK data corresponding to the ink used based on a predetermined conversion algorithm. Then, the multivalued CMYK data is handled as image data to be processed.

The flowchart of FIG. 8 shows an example of a flow for determining a target pixel to be processed, and FIG. 9 shows an example of a dot conversion processing flow for the target pixel determined according to this determination flow.
As shown in FIG. 8, the flow of determination processing for each pixel of interest constituting multi-valued image data to be processed is as follows. First, in the first step S100, the uppermost pixel on the line in the nozzle arrangement direction. The second pixel excluding the pixel is determined as the first pixel of interest, and then the process proceeds to the next step S102 to determine whether the dot conversion processing for the pixel of interest has ended, and to determine that the processing has not ended (No), the process waits until the process for the target pixel is completed. However, when it is determined that the process is completed (Yes), the process proceeds to the next step S104, and The pixel immediately below (on the downstream side in the nozzle arrangement direction) is determined as the next pixel of interest.

  For example, as shown in FIG. 10A, in the case of image data in which a large number of pixels are arranged vertically and horizontally, if the upper left pixel 1a is considered as the starting point of processing, the pixel 1b immediately below this pixel 1a When the processing of the first pixel of interest 1b is completed, the pixel 1c immediately below it is determined as the next pixel of interest and sequentially moved to the pixels (1d, 1e ...) immediately below it. The pixels are determined one after another as the target pixel.

  Then, when it moves to the next step 106 and determines that the processing for the target pixel has been completed (Yes), the process further proceeds to the next step S108 and the target pixel is the last (bottom end) pixel of the line. If it is determined that the pixel is not the last pixel (No), the process returns to step S104 and the next pixel is determined as the pixel of interest sequentially. When it is determined that the pixel is the (bottom end) pixel (Yes), the process proceeds to step S110.

  In step S110, it is determined whether or not a line exists next to the line. When it is determined that the line does not exist (No), the processing is terminated as it is, but when it is determined that the line exists (Yes). Then, after moving to step S112 and moving to the next line, the process returns to the first step S100 and the same processing is performed on the pixels on the line to sequentially determine the target pixel. This process is repeated until the last pixel of the last line is reached.

  In the example of FIG. 10A, when the processing of all the pixels on the first line “1” is completed, the process proceeds to the next line “2” and the second from the top on the line “2”. Are determined as the first pixel of interest in the line, and then the pixels on the line “2” are sequentially determined in the order of the pixels 2c, 2d, 2e..., And all the pixels on the line “2” are determined. When the processing is completed, the target pixel is determined as the next line “3”, line “4”, etc., and when the last pixel nn of the last line “n” is determined, the target pixel is determined. Processing will be terminated.

Next, an example of the dot conversion processing flow for the target pixel determined according to the target pixel determination flow will be described with reference mainly to the flowchart of FIG. 9 and the schematic diagrams of FIGS.
First, when performing the dot conversion process as shown in FIG. 9, a provisional dot size is set for each pixel in advance by the dot size setting unit 30 a of the print data generation unit 30.

  That is, as shown in FIG. 1, the multivalued image data to be processed is acquired by the image data acquisition means 10 and then converted into N values by the N-valued data generation means 20. Then, provisional print data in which a provisional dot size is set for each pixel is generated by the dot size setting unit 30a of the print data generation unit 30 based on the N-value data. Note that it is needless to say that a known halftoning technique such as an error diffusion process or a dither method may be used in combination as appropriate in the N-value conversion processing of multi-value image data by the N-value data generation means 20. Absent.

Then, if the first pixel of interest is determined as shown in the flow of FIG. 8 for the print data in which the provisional dot size is set for each pixel in this way, the pixel of interest of FIG. The dot conversion process is performed.
That is, as shown in the first step S200 of FIG. 9, when the target pixel to be processed is determined, the pixel immediately above the target pixel is directly observed, and the dot size of the pixel immediately above is detected. Control proceeds to the next step S202.

In step S202, it is determined whether or not the pixel immediately above the target pixel is a “large dot”. If it is determined that the pixel is a “large dot” (Yes), the process jumps to step S212. When it is determined that it is not “large dot” (No), the process proceeds to the next step S204.
In the present embodiment, the N-value conversion is set to “4” as in the above-described example, and the types of dots to be used are “no dot”, “small dot”, “medium dot” corresponding to each N value. ”And“ Large dots ”.

  In step S204, it is determined whether or not the pixel directly above determined to be a “large dot” is a “medium dot”. If it is determined to be a “medium dot” (Yes), the process proceeds to step S214. If it is determined that the pixel is not “medium dot” (No), the process proceeds to the next step S206 to determine whether or not the pixel of interest is “small or medium dot”. When it is determined that the pixel is not “small or medium dot” (Yes), the process proceeds to step S212. When it is determined that the pixel of interest is “small or medium dot” (Yes), After shifting to step S208 and changing the dot size of the target pixel from “small or medium dot” to “large dot”, the process proceeds to next step S210.

In step S210, the error (pixel value) generated by the dot size conversion process in step S208 is propagated to the unprocessed pixel (right pixel) of the next line adjacent to the target pixel.
Then, if the error is propagated to the unprocessed pixel on the next line in this way, the process proceeds to the last step S212, the process proceeds to the next target pixel, and the same process is repeated.

  On the other hand, if it is determined in step S204 that the pixel immediately above is a “medium dot” (Yes) and the process proceeds to step S214, whether or not the target pixel is a “medium dot” in step S214. When it is determined that it is not “medium dot” (No), the process jumps to step S212. However, when it is determined that it is “medium dot” (Yes), the process proceeds to step S208. Thus, the dot of the target pixel is converted into a “large dot”.

An example of the flow of such a dot conversion processing flow will be specifically described with reference to the schematic diagrams of FIGS.
FIG. 10A shows an example of print data in which a large number of pixels are arranged in the nozzle arrangement direction and in the vertical direction, and provisional dots (all “medium dots”) are set for each pixel. Is.

In the case of such provisional print data, as shown in FIG. 1A, first, when the second pixel 1b from the top of the first line is determined as the first pixel of interest, the pixel of interest 1b is selected. The dot size of the pixel 1a immediately above is detected (step S200).
In the example shown in the figure, since the dot size of the pixel 1a immediately above is “medium dot”, the process proceeds to step S214 through steps S202 and S204, and it is determined whether or not the target pixel 1b is “medium dot”. .

In the example shown in the figure, the target pixel 1b is a “medium dot”, so that the process proceeds to step S208 and the target pixel 1b is changed from “medium dot” to “large dot” as shown in FIG. Size conversion will be done.
When such dot size conversion is performed, an error corresponding to the dot size is generated with respect to the original pixel value. Therefore, as shown in FIG. Propagate to.

In the example shown in the figure, by converting “medium dot” to “large dot”, an error of “70” is generated as shown in FIG. 7, and this error “70” is directly used as the adjacent unprocessed pixel in the second line. Propagate to 2b.
As a result, the unprocessed pixel 2b is newly added with the error “70” to the original pixel value “70”, so that the pixel value becomes “140”, and as shown in FIG. The dot size is converted from “medium dot” to “small dot”.

As shown in FIG. 4, the pixel value of “small dot” is “150”, and this dot conversion causes an error of “−10”. It is propagated to an adjacent unprocessed pixel 3b on a certain third line.
Next, when the dot conversion process for the first target pixel 1b is completed in this way, the target pixel is moved to the next pixel 1c and the same process is performed.

In the example of FIG. 10C, since the pixel 1b immediately above the target pixel 1c is a “large dot”, the target pixel is moved to the next pixel 1d while maintaining the dot size as it is. .
Since the next pixel of interest 1d has a dot size of “medium dot” and the pixel 1c immediately above it is also a “medium dot”, it is converted to a “large dot” as shown in FIG. The error “70” is propagated to the unprocessed adjacent pixel 2d on the second line as described above.

As a result, as shown in FIG. 5 (5), the dot size of the unprocessed adjacent pixel 2d of the second line is converted to “small dot”, and the error “−10” is the next line, ie, three lines It is propagated to the unprocessed adjacent pixel 3d of the eye.
In this way, when the pixel of interest is sequentially moved downward and the dot conversion process for the pixel located at the lowermost end is completed, the pixel of interest is the next line 2 as shown in FIG. Moving to the line, the second pixel 2b from the top of the line is determined as the first pixel of interest on the line.

  As shown in FIG. 10 (6), the first pixel of interest 2b has a “medium dot” size immediately above the pixel 2a, and thus reaches step S202, step S204, and step S214 in FIG. Since the dot size is not “small dot”, that is, “medium dot”, the pixel of interest is moved to the next pixel 2c without performing the dot conversion process as it is (step s212).

  As shown in FIG. 10 (6), the next pixel of interest 2c is a “medium dot” and the pixel 2b immediately above it is a “small dot”, so that it goes through steps S202, S204, and S206. At step S208, as shown in FIG. 11 (7), the size of the target pixel 2c is converted from “medium dot” to “large dot”, and the error is adjacent to the third line as the next line. Propagate to the unprocessed pixel 3c. Since the adjacent unprocessed pixel 3c is a “medium dot” as shown in FIG. 8 (8), the error “70” is received from the target pixel 2c, and the dot is changed to the “small dot” as described above. The size is converted, and the error “−10” is propagated to the adjacent unprocessed pixel 4c on the fourth line, which is the next line.

When the dot conversion process for the target pixel 2c is completed, as shown in FIG. 9 (9), the target pixel moves to the pixel 1d immediately below, and the same dot conversion process is performed on the target pixel 2d. Although the pixel 2c immediately above the target pixel 2d is a “large dot”, the target pixel moves to the next pixel 2e without performing the conversion process as it is.
Since the next pixel of interest 2e has a dot size of “medium dot” and a dot size of the immediately above pixel 2d of “small dot” as shown in FIG. Similarly, it is converted into a “large dot” and its error is propagated to the unprocessed adjacent pixel 3e on the third line. As a result, as shown in FIGS. The dot size of the adjacent pixel 3e is converted from “medium dot” to “small dot”.

When the dot conversion processing for the lowermost pixel of the second line is completed in this way, the same processing is repeated for the third line as shown in FIG. The process ends when the lowermost pixel is reached.
Note that the error generated in the dot conversion processing of the last line is discarded as it is because there is no pixel to propagate.

FIG. 12 shows changes in dot patterns before and after such dot conversion processing is performed. The dot pattern on the left side of the diagram is before the dot conversion processing is performed, and the dot pattern on the right side of the diagram is dot conversion. The dot pattern after implementing a process is shown.
As shown in the figure, it can be seen that in the dot pattern before the dot conversion processing is performed, two white stripes stand out in parallel with the direction perpendicular to the nozzle arrangement direction due to two flight curve phenomena. However, since the “small or medium dots” are not continuous in the nozzle arrangement direction in the dot pattern after the dot conversion process is performed, the two white stripes that occurred between the “medium dots” It can be seen that both have disappeared almost completely.

In addition, the dots adjacent to the “large dots” are “small dots” or “medium dots”, and the “large dots” are not continuous vertically and horizontally, so the gradation of the entire image is not greatly increased. It can be seen that the same gradation as the original gradation is maintained.
As described above, according to the present invention, when dots smaller than the predetermined size are continuous in the nozzle arrangement direction of the print head, the dot size of any one of the pixels is changed to a size larger than the predetermined size. As a result, dots smaller than the predetermined size do not continue in the nozzle arrangement direction of the print head, so that the banding phenomenon caused by the so-called flight bending phenomenon can be effectively eliminated or made almost inconspicuous.

  As shown in FIG. 7, the dot size to be divided by the present invention and the normal print head 200 includes four patterns of “large dot”, “medium dot”, “small dot”, and “no dot”. However, the type of the dot size is not limited to this, and it is sufficient that there are at least two patterns other than “no dot”, and it is preferable that the number of patterns is larger.

Further, the print head 200 in the present embodiment corresponds to the print head in the printing apparatus such as the first form of means for solving the problem, and the N-ary data generation unit 20, the print data generation unit 30, the printing unit. Reference numeral 40 corresponds to an N-ary data generation unit, a print data generation unit, a printing unit, and the like in the printing apparatus of mode 1 or the like.
In addition, the present invention is characterized in that the image data is converted into print data in accordance with the print head characteristics with little modification to the existing print head 200 and the printing means 40 itself. In addition, it is not necessary to prepare a dedicated one as the printing unit 40, and the existing inkjet print head 200 and the printing unit 40 (printer) can be used as they are.

Therefore, if the print head 200 and the printing means 40 are separated from the printing apparatus 100 of the present invention, the function can be realized only by a general-purpose information processing apparatus (image processing apparatus) such as a personal computer.
Further, it goes without saying that the printing apparatus 100 of the present invention is not limited to a form in which all of the functions are housed in the casing, and a part of the functions, for example, N-valued data generation means. The configuration may be such that only 20 is realized on the personal computer side and the print data generating means 30 and the printing means 40 are functionally divided so as to be realized on the printer side.

Further, the present invention is not limited to the flight bend phenomenon, but the ink ejection direction is vertical (normal), but the nozzle formation position is deviated from the normal position. As a result, the dots formed are the same as the flight bend phenomenon. Of course, the present invention can be applied in exactly the same manner.
Furthermore, the present invention can be similarly applied to a problem in which ink is not discharged from a specific nozzle due to ink clogging or the like.

  The printing apparatus 100 of the present invention is applicable not only to a line head type ink jet printer but also to a multi-pass type ink jet printer (serial printer). It is possible to obtain a high-quality printed matter with almost no noticeable white or dark streaks in one pass even if there is a problem, and a serial printer can reduce the number of reciprocating operations. High-speed printing is also possible. For example, when a desired image quality can be realized by one printing, the printing time can be shortened to 1 / K as compared with the case where printing is performed by K reciprocating printing.

FIG. 13 shows respective printing methods using a line head type ink jet printer and a serial printer.
In contrast to the image data shown in FIG. 6A, in the line head type ink jet printer, the print head 200 has a length corresponding to the paper width of the printing paper S as shown in FIG. The printing head 200 is fixed, and the printing paper S is moved in a direction perpendicular to the nozzle arrangement direction with respect to the printing head 200, so that printing is completed in a so-called one scan (one pass). It is also possible to perform printing while fixing the printing paper S as in a so-called flatbed scanner and moving the print head 200 side in the direction perpendicular to the nozzle arrangement direction, or moving both in the opposite direction. It is.

  On the other hand, as shown in FIG. 3C, the serial printer positions the print head 200 that is much shorter than the length of the paper width in the direction perpendicular to the nozzle arrangement direction of the line head type print head 200. The printing paper S is moved in a direction perpendicular to the nozzle arrangement direction of the line head type print head 200 by a predetermined pitch while being reciprocated many times in the nozzle arrangement direction of the line head type print head 200. Printing is executed. Therefore, in the case of a serial printer, the printing head 200 can be repeatedly positioned at an arbitrary position, but the banding phenomenon as described above is disadvantageous in that the printing time is longer than that of the line head type ink jet printer. Among them, it is possible to cope to some extent with respect to the reduction of the white streak phenomenon.

In this embodiment, an ink jet printer that performs printing by ejecting ink in dots has been described as an example. However, the present invention is another printing apparatus that uses a print head in which printing mechanisms are arranged in a line. For example, the present invention is also applicable to a thermal head printer called a thermal transfer printer or a thermal printer.
In FIG. 3, each nozzle module 50, 52, 54, 56 provided in each color of the print head 200 has a form in which the nozzles N are linearly continuous in the longitudinal direction of the print head 200. As shown in FIG. 14, each of these nozzle modules 50, 52, 54, 56 is composed of a plurality of short nozzle units 50a, 50b,... 50n, which are arranged before and after the movement direction of the print head 200. You may comprise. In particular, if each of the nozzle modules 50, 52, 54, 56 is composed of a plurality of short nozzle units 50a, 50b,... 50n, the yield is greatly improved compared to the case of using a long nozzle unit. To do.

  Each means for realizing the above-described printing apparatus 100 of the present embodiment can be realized on software using a computer system incorporated in most existing printing apparatuses. Is stored in a semiconductor ROM in advance in a product or distributed via a network such as the Internet, or a computer-readable record such as a CD-ROM, DVD-ROM, or FD as shown in FIG. By using the medium R, it can be easily provided to a desired user or the like.

Next, FIGS. 16 to 21 show a second embodiment relating to the printing apparatus 100 and the printing program, printing method, image processing apparatus, image processing program, and image processing method of the present invention.
First, FIG. 16 is a functional block diagram showing a second embodiment of the printing apparatus 100 according to the present invention.

  As shown in the figure, the printing apparatus 100 includes a print head 200 having a plurality of nozzles and image data acquisition means 10 for acquiring multivalued image data to be used for printing in substantially the same manner as in the first embodiment. N-valued data for generating N-value image data by converting the multi-value image data acquired by the image data acquisition means 10 into N values (N ≧ 2) along the nozzle arrangement direction of the print head 200. A generation unit 20; a print data generation unit 30 that generates a print data by setting a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation unit 20; and the print head 200. And an ink jet type printing unit 40 that performs printing based on the print data generated by the print data generation unit 30.

Among these, the basic functions of the print head 200, the image data acquisition unit 10, and the print data generation unit 30, and the configuration and function of the printing unit 40 are the same as those of the printing apparatus 100 in the first embodiment. Therefore, the description is omitted, and the N-ary data generation unit 20 will be mainly described.
As shown in the figure, the N-valued data generating means 20 in the present embodiment is more specifically, an N-valued processing unit 20a, an N-valued adjustment unit 20b, an error propagation unit 20c, and an error diffusion unit 20c. It is composed of

  This N-value conversion processing unit 20a provides the most basic function as the N-value conversion data generation means 20, and the multivalue acquired by the image data acquisition means 10 is the same as in the first embodiment. 7 is converted into N values (N ≧ 2) along the nozzle arrangement direction of the print head 200 based on the conversion table 300 showing the relationship between pixel values and N values as shown in FIG. A function for generating image data is provided.

  As described above, the N value of the N-value conversion processing for multi-valued image data in the N-value conversion processing unit 20a is not particularly limited, but in the present embodiment, the first implementation is performed. Similarly to the form, when N = “4” is set to quaternarization and “luminance value” is selected as the pixel value, the pixel value related to the luminance of the acquired multivalued image data is 8 bits, 256 (0 to 255). ) In the case of gradations, four threshold values “35”, “110”, and “200” are assigned to four types of N values. That is, the range where the luminance value is “255” to “201” is converted to N value = “1”, and the range where the luminance value is the first threshold value “200” to “111” is N value = “2”. The range of the luminance value from the second threshold “110” to “36” is converted to N value = “3”, and the range of the luminance value from the third threshold “35” to “0” is N value = “4” is converted.

The N-value adjusting unit 20b provides a function of adjusting the N-value conversion of the pixel of interest when the dot size corresponding to the pixel adjacent in the nozzle arrangement direction is equal to or smaller than a predetermined size. The description will be described later.
The error propagation unit 20c provides a function of propagating the pixel value error generated when the N-value adjustment processing unit 20b performs N-value processing to unprocessed adjacent pixels on the next line. As will be described later, the gradation change caused by the N-value adjustment can be avoided.

The error diffusion unit 20d provides a function of diffusing an error of a pixel value to unprocessed pixels around the target pixel when the target pixel is subjected to N-value processing. The halftone can be expressed faithfully by effectively utilizing the error generated by the conversion processing.
FIG. 17 is a flowchart showing an example of the flow of printing processing according to the present embodiment. The present embodiment will be described with reference mainly to this drawing. Unless otherwise specified, other assumptions and configurations are the same as those in the first embodiment.

  As shown in the figure, first, when the printing apparatus 100 is turned on and a predetermined initial operation for printing processing is completed, if a printing instruction terminal such as a personal computer is connected, the image data acquisition means 10 monitors whether there is an explicit print instruction from the print instruction terminal, and when there is a print instruction, the process proceeds to the first step S300 and the first attention on the multi-value image data to be processed After determining the pixel, the process proceeds to the first determination step S302.

Note that the pixel-of-interest determination method in the present embodiment is also determined according to the pixel-of-interest determination flow in FIG. 8 as in the above-described embodiment.
In step S302, it is determined whether or not there is a pixel immediately above the target pixel, that is, whether or not the pixel is located at the uppermost position in the nozzle arrangement direction of each line. (No) jumps to the next step S304 and proceeds to step S308, but if it is determined that it is not the uppermost pixel (Yes), it proceeds to the next step S304.

In step S304, it is determined whether or not the pixel immediately above the target pixel is a “large dot”, and when it is determined that the pixel is not a “large dot” (No), on the other hand, the “large dot” is displayed on the step S306 side. When it is determined that there is (Yes), each moves to the step S308 side.
In step S306, the target pixel is subjected to N-value conversion using the converted threshold value as shown in FIGS. 18 and 19, and then the process proceeds to step S310 where all of the errors generated by the N-value conversion are processed. After propagating to the right pixel, that is, the adjacent unprocessed pixel of the next line, the process proceeds to step S314.

On the other hand, on the side of step S308, N-value conversion with a normal threshold value, that is, N-value conversion with a normal threshold value as shown in FIG. 7, is performed. After the generated error is diffused to the surrounding unprocessed pixels according to the error diffusion matrix employed in the normal error diffusion process, the process proceeds to step S314 in the same manner.
In step S314, a dot having a size corresponding to the N value determined in this way is set (assigned), and then the process is performed for all the pixels by sequentially passing through steps S316 and S318.

20 and 21 are schematic diagrams specifically showing an example of the flow of such processing for each pixel.
First, as shown in FIG. 20 (1), it is assumed that the multivalued image data to be processed has a pixel value (luminance value) of all the pixels of 8 bits and 256 tones, “70”.
When such multi-valued image data is N-valued by a normal threshold based on the conversion table 300 as shown in FIG. 7, and a dot corresponding to the N value is determined, the multi-valued image data shown in FIG. Thus, the dot size corresponding to all the pixels is “medium dot”.

As described above, when N-value conversion using a normal threshold value is performed, if all pixel values are the same or similar, all the dots are converted to the same size dot. As shown in the figure, white streaks are conspicuous when a flight curve occurs in some nozzles.
On the other hand, in the present embodiment, as shown in FIG. 3 (3), since there is no pixel immediately above the first pixel of interest 1a, step 300, step S302, step 308, step Through 312 and step 314, an N-value conversion process is performed using a normal threshold value as it is, and a dot corresponding to the N value is set.

In the example in the figure, the pixel value of the first target pixel 1a is “70”, which is a so-called “3” value, and therefore, a “medium dot” that is a dot size corresponding to the “3” value is assigned. In the example shown in the figure, no error occurs, and in this case, error diffusion processing is not necessary.
Next, when the processing of the first target pixel 1a is completed in this way, the target pixel is moved to the next pixel 1b as shown in FIG. Perform the process.

In the example in the figure, there is a pixel immediately above the target pixel 1b, but the pixel immediately above it is not a “large dot”, and therefore the N value based on the threshold value converted through step S302 and step S306 is executed.
That is, the pixel value of the pixel of interest 1b is “70”, and when the N-value conversion process is performed using the normal threshold value, the “medium dot” that is the dot size corresponding to the “3” value becomes the “3” value. In this case, it is forcibly converted to “large dots” by the N-value conversion table 300B based on the converted threshold values as shown in FIG.

As a result, the pixel value of the pixel of interest becomes “0” and an error of “70” is generated. Therefore, as shown in FIG. 4 (4), all the errors “70” are adjacent unprocessed pixels in the next line, that is, , The pixel value of the adjacent unprocessed pixel 2b is converted to “140 (70 + 70)”.
Next, when the processing of the second target pixel 1b is completed in this way, as shown in FIG. 5 (5), the target pixel moves to the next pixel 1c, and the same applies to the target pixel 1c. Will be carried out.

In the example of the figure, since the pixel immediately above the target pixel 1c is a “large dot”, the target pixel 1c is subjected to N-value processing from a normal threshold value. As a result, the target pixel 1c is It will be converted to “medium dot”.
Further, when the processing of the third target pixel 1c is completed in this way, as shown in FIG. 6 (6), the target pixel moves to the next pixel 1d, and the same applies to the target pixel 1d. Processing will be carried out.

In the example of the figure, since the pixel immediately above the target pixel 1d is a “medium dot”, the target pixel 1d is subjected to N-value conversion processing using the converted threshold value. As a result, the target pixel 1d Is converted to “large dot” and the generated error is propagated to the adjacent unprocessed pixel 2d, whereby the pixel value of the adjacent unprocessed pixel 2d changes to “140”.
Then, when the processing for all the pixels in the first line is completed in this way, as shown in FIG. 21 (7), the process moves to the next line, and for each pixel in the second line, The same process is repeated.

  In the example shown in the figure, the first target pixel 2a in the second line is subjected to N-value conversion using a normal threshold value. As a result, “medium dot” is set for the first target pixel 2a. Also, since the pixel immediately above the next target pixel 2b is not a “large dot”, N-value conversion using the converted threshold value shown in FIG. 18 is performed through steps S302, S304, and S306. .

  In the example of the figure, the pixel value of the target pixel 2b is “140”. Therefore, even if N-value conversion using the converted threshold value is performed as illustrated in FIG. 2 ”value, and“ small dot ”is set. Further, the pixel value of “small dot” is “150”, and an error of “−10” occurs compared to the original pixel value “140”. In such a case, although not shown in the flowchart of FIG. 17, there is no difference from N-value conversion according to a normal threshold value, so that the error “−10” is converted into a normal error diffusion matrix as shown in FIG. 21 (7). Accordingly, the pixel is diffused to the unprocessed pixels around the target pixel 2b.

  In the example shown in the figure, a typical error diffusion matrix called a so-called Floyd & Steinberg type is adopted, and the error generated by the N-value conversion is divided into 16 equal parts, of which 7 equal parts are the target pixel. In the unprocessed pixel 2c immediately below 2b, 1 equal part is assigned to the unprocessed pixel 3c diagonally to the lower right of the target pixel 2b, and 5 equal parts are assigned to the unprocessed pixel 3b right next to the target pixel 2b. As a result of diffusion to the unprocessed pixel 3a on the upper right side of the target pixel 2b, the pixel value changes from “70” to “66” in the unprocessed pixel 2c, and from “70” to “70” in the unprocessed pixel 3c. "Rounding up by rounding off") indicates that the unprocessed pixel 3b is converted from "70" to "67", and the unprocessed pixel 3a is converted from "70" to "69".

Next, when the processing for the second target pixel 2b is completed in this way, as shown in FIG. 8 (8), the target pixel moves to the pixel 2c immediately below, and the same processing is performed for the target pixel 2c. Perform appropriate processing.
In the illustrated example, the pixel value of the target pixel 2c is “66”, but the pixel immediately above it is not a “large dot”. As a result, N-value conversion is performed using the converted threshold value, as shown in FIG. Then, it is converted to “large dot”, and all of the pixel value “66” is propagated to the adjacent unprocessed pixel 3c on the adjacent line, and the processing is completed.

Further, as shown in FIG. 9 (9), as a result of performing the same processing after moving to the next target pixel 2d, the pixel 2c immediately above the target pixel 2d is a “large dot”. N-value conversion is performed using a threshold value and converted into “small dots”, and the error is diffused to surrounding unprocessed pixels.
After that, when the same processing is repeated and the processing for all the pixels on the second line is completed, as shown in FIG. 10 (10), the processing proceeds to the third line, which is the next line, and the uppermost pixel 3a. The same processing is repeated in order.

When printing is performed based on the print data obtained in this way, “small or medium dots” do not continue in the nozzle arrangement direction, as in FIG. 12 described in the first embodiment. Therefore, both of the two white lines generated between “small or medium dots” are almost completely eliminated.
In addition, the adjacent dots of “Large dots” are “Small or medium dots” and the “Large dots” are not continuous vertically and horizontally, so the overall gradation of the image does not become large, and the original gradation It can be seen that the same gradation is maintained.

  As described above, according to the present invention, when N-valued multi-valued image data is normally converted into N-values, when dots of a predetermined size or smaller are consecutive, the N-value is set so that dots of a predetermined size or smaller are not consecutive. Since the error generated by the adjustment is propagated to the unprocessed adjacent pixels on the next line, white streak caused by continuous dots of a predetermined size or less as in the first embodiment. It is possible to avoid the occurrence and to maintain the area gradation of the dot size converted portion in the same manner as the original area gradation, and it is possible to obtain a high-quality printed matter with less density unevenness.

Further, since the error is distributed at the stage of the N-value conversion process, a process for changing the dot size is not necessary, and the processing efficiency is improved.
In this embodiment, an example in which a luminance value is used as a pixel value has been described. However, an N-value conversion table based on a converted threshold value when a density value is used as a pixel value is as shown in FIG. The N-value conversion table 300B in which “small dots” do not exist is adopted.

In the present embodiment, as in the first embodiment, the existing ink jet type print head 200 and printing means 40 (printer) can be used as they are.
Therefore, if the print head 200 and the printing means 40 are separated from the configuration of FIG. 16, the function can be realized only by a general-purpose information processing apparatus (image processing apparatus) such as a personal computer.

  Further, the present invention is not limited to the flight bend phenomenon, but the ink ejection direction is vertical (normal), but the nozzle formation position is deviated from the normal position. As a result, the dots formed are the same as the flight bend phenomenon. Of course, the present invention can be applied in the same manner, and can also be applied to a problem in which ink is not ejected from a specific nozzle due to ink clogging.

Further, the present embodiment can be applied not only to a line head type ink jet printer but also to a multi-pass type ink jet printer.
The N-value data generation unit 20 in the present embodiment corresponds to the N-value data generation unit such as the form 3 described in the means for solving the problem, and includes an N-value adjustment unit 20b, an error The adjusting unit 20c and the error diffusing unit 20d respectively correspond to an N-valued adjusting unit, an error adjusting unit, and an error diffusing unit such as in the form 3 described in the means for solving the same problem.

  Also, in the present embodiment, as in the first embodiment, image data is converted into print data according to the characteristics of the print head 200 with little modification to the existing print head 200 and the printing means 40 itself. Since the conversion process is performed, it is not necessary to prepare a special print head 200 or printing means 40, and the existing ink jet type print head 200 or printing means 40 (printer) can be used as it is. Therefore, if the print head 200 and the printing means 40 are separated, the function can be realized only by a general-purpose information processing apparatus (image processing apparatus) such as a personal computer.

  Each means for realizing the printing apparatus 100 of the present embodiment can also be realized on software using a computer system incorporated in most existing printing apparatuses, and the computer program is stored in advance. In addition to being incorporated into a product stored in a semiconductor ROM or distributed via a network such as the Internet, a computer-readable recording medium R such as a CD-ROM, DVD-ROM, or FD as shown in FIG. It can be easily provided to a desired user or the like.

1 is a functional block diagram showing a first embodiment of a printing apparatus according to the present invention. It is a block diagram which shows the hardware constitutions of the computer system which implement | achieves the printing apparatus which concerns on this invention. FIG. 4 is a partially enlarged bottom view showing the structure of the print head according to the present invention. It is a partial enlarged side view showing the structure of the print head according to the present invention. It is a conceptual diagram which shows an example of the ideal dot pattern in which a flight bending phenomenon does not generate | occur | produce. It is a conceptual diagram which shows an example of the dot pattern formed by the flight curve phenomenon of one nozzle. It is a figure which shows the conversion table which showed the relationship between the pixel value and N value referred in the case of N value conversion, and the N value and dot size. It is a flowchart figure which shows an example of the flow of an attention pixel determination process. It is a flowchart figure which shows an example of the flow of a dot conversion process. It is a 1st schematic diagram which shows an example of the flow of the dot conversion process which concerns on 1st Embodiment. It is a 2nd schematic diagram which shows an example of the flow of the dot conversion process which concerns on 1st Embodiment. It is a figure which shows an example of the dot pattern before and behind the process of 1st Embodiment. It is explanatory drawing which shows the difference in the printing system by a multipass type | mold inkjet printer and a line head type inkjet printer. It is a conceptual diagram which shows the other example of the structure of a print head. It is a conceptual diagram which shows an example of the computer-readable recording medium which recorded the program which concerns on this invention. It is a functional block diagram which shows 2nd Embodiment of the printing apparatus which concerns on this invention. It is a flowchart figure which shows an example of the flow of the process which concerns on 2nd Embodiment. It is a figure which shows the 1st example of the N-value conversion table by the converted threshold value. It is a figure which shows the 2nd example of the N-value conversion table by the converted threshold value. It is a 1st schematic diagram which shows an example of the flow of N-value conversion and the dot conversion process which concern on 2nd Embodiment. It is a 2nd schematic diagram which shows an example of the flow of N-value conversion and the dot conversion process which concern on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Printing apparatus, 200 ... Print head, 10 ... Image data acquisition means, 204 ... N-valued data generation means, 30 ... Print data generation means, 30a ... Dot size setting part, 30b ... Dot size change part, 30c ... Error Propagation unit 40 ... printing means 60 ... CPU 62 ... RAM 64 ... ROM 66 ... interface 70 ... storage device 72 ... output device 74 ... input device 50 ... black nozzle module 52 ... yellow nozzle module 54 ... Magenta nozzle module, 56 ... Cyan nozzle module, 300A ... Normal N-value conversion and dot conversion table, 300B ... converted first N-value conversion and dot conversion table, 300C ... converted second N Quantization and dot conversion table, P ... pixel, S ... print medium (paper), N ... nozzle, R ... notation Media.

Claims (32)

N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for generating print data in which dot sizes corresponding to the respective pixel values of the N-value image data generated by the N-valued data generation means are set;
Printing means for executing printing based on the print data generated by the print data generation means,
The print data generation unit generates print data in which the dot size corresponding to any one of the continuous dots is changed when the dot size within a predetermined range is continuous in the print data. A printing apparatus. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generating means for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generating means is set;
Printing means for executing printing based on the print data generated by the print data generation means,
When the print data generation unit has dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. A printing apparatus characterized by generating data. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for setting the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means and generating print data;
Printing means for executing printing based on the print data generated by the print data generation means,
The print data generation means is a dot size changing unit that changes the dot size of any one of the consecutive dots when the dots smaller than the predetermined size are continuous in the print data to a size larger than the predetermined size. The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that is propagated the error by the error propagation unit. A printing apparatus comprising: a dot size resetting unit for setting. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means;
Printing means for executing printing based on the print data generated by the print data generation means,
The N-value data generation unit includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when adjacent to each other so that a dot size corresponding to the pixel value is equal to or less than a predetermined size, An error propagation unit that propagates an error of a pixel value generated when an N-value process is performed by an adjustment unit to an unprocessed pixel. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means;
Printing means for executing printing based on the print data generated by the print data generation means,
The N-value data generation unit includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when the dot size corresponding to the pixel value is adjacent to a predetermined range, and the N-value adjustment An error propagation unit that propagates an error of a pixel value generated when an N-value process is performed by a unit to an unprocessed pixel. The printing apparatus according to claim 4 or 5,
The N-valued data generating means further includes an error diffusion unit that diffuses an error of a pixel value to unprocessed pixels around the target pixel when the target pixel of the image data is subjected to N-value processing. Printing device to do. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
The print data generation unit functions to generate print data in which the dot size corresponding to any one of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. A printing program characterized by that. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
When the print data generation unit continuously prints dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. A printing program characterized by functioning to generate data. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data by setting a dot size corresponding to each pixel value of N-value image data generated by the N-valued data generation means,
A dot size changing unit that changes the dot size of any one of the consecutive dots when the dots smaller than the predetermined size are continuous in the print data, the print data generating unit changing the dot size to a size greater than or equal to the predetermined size The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that is propagated the error by the error propagation unit. A printing program that functions as a dot size resetting unit to be set. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
An N-value adjusting unit that adjusts N-value conversion of the pixel value when the N-value data generation unit is adjacent so that a dot size corresponding to the pixel value is a predetermined size or less; A printing program that functions as an error propagation unit that propagates an error of a pixel value generated when an N-value process is performed by an adjustment unit to an unprocessed pixel. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means;
While functioning as a printing unit that executes printing based on the print data generated by the print data generation unit,
When the N-valued data generating means is adjacent so that the dot size corresponding to the pixel value falls within a predetermined range, an N-valued adjusting unit that adjusts the N-valued value of the pixel value, and the N-valued adjustment A printing program that causes an error propagation unit to propagate an error of a pixel value generated when an N-value process is performed by a unit to an unprocessed pixel.   The computer-readable recording medium which recorded the printing program of any one of Claims 6-11. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set;
A print step for executing printing based on the print data generated in the print data generation step,
The print data generation step generates print data in which the dot size corresponding to any one pixel of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. How to print. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set;
A printing step for executing printing based on the print data generated by the print data generation means,
In the print data generation step, when dots smaller than a predetermined size are consecutive in the print data, printing in which the dot size corresponding to any one pixel of the continuous dots is changed to a size greater than or equal to the predetermined size A printing method characterized by generating data. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step of generating print data by setting a dot size corresponding to each pixel value of the N-value image data generated in the N-valued data generation step;
A print step for executing printing based on the print data generated in the print data generation step,
The print data generation step includes a step of changing a dot size of any one of the consecutive dots when the dots smaller than the predetermined size are continuous in the print data to a size larger than the predetermined size; An error propagation step of propagating the pixel value error of the pixel caused by the dot size change process to the next unprocessed pixel, and a step of resetting the dot size of the pixel propagated with the error. Characteristic printing method. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated in the N-valued data generation step;
A print step for executing printing based on the print data generated in the print data generation step,
The N-value data generation step includes an N-value adjustment step for adjusting the N-value conversion of the pixel value when adjacent to each other so that the dot size corresponding to the pixel value is equal to or smaller than a predetermined size; An error propagation step of propagating a pixel value error generated when the N-value processing is performed in the adjustment step to the next unprocessed pixel. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated in the N-valued data generation step;
A printing step for executing printing based on the print data generated by the print data generation means,
The N-value data generation means adjusts the N-value conversion of the pixel value when adjacent so that the dot size corresponding to the pixel value falls within a predetermined range, and the N-value adjustment adjustment An error propagation step for propagating an error of a pixel value generated when performing N-value processing in steps to an unprocessed pixel. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set;
The print data generation unit generates print data in which the dot size corresponding to any one of the continuous dots is changed when the dot size within a predetermined range is continuous in the print data. An image processing apparatus. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set;
When the print data generation unit has dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. An image processing apparatus characterized by generating data. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generating means for generating print data by setting a dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generating means,
The print data generating means is a dot size changing unit that changes the dot size of any one of the continuous dots when the dots smaller than the predetermined size are continuous in the print data to a size larger than the predetermined size. The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that has propagated the error by the error propagation unit. An image processing apparatus comprising: a dot size resetting unit for setting. N-valued data generating means for generating image data of N values by converting image data into N values (N ≧ 2) for each pixel of image data that is a set of pixel values of M values (M> N) constituting an image When,
Print data generation means for setting the dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means and generating print data;
The N-value data generation means includes an N-value adjustment unit that adjusts the N-value conversion of the pixel value when adjacent to each other so that the dot size corresponding to the pixel value is a predetermined size or less, and the N-value conversion An image processing apparatus comprising: an error propagation unit that propagates an error of a pixel value generated when an N-value process is performed by an adjustment unit to an unprocessed pixel. N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
Print data generation means for setting the dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means and generating print data;
The N-value data generation means includes an N-value adjustment unit that adjusts N-value conversion of the pixel value when the dot size corresponding to the pixel value is adjacent to a predetermined range, and the N-value adjustment adjustment An error propagation unit that propagates an error of a pixel value generated when the N-value process is performed by the unit to an unprocessed pixel. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
The print data generation unit functions to generate print data in which the dot size corresponding to any one of the continuous dots is changed when a predetermined range of dot sizes is continuous in the print data. An image processing program characterized by that. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data in which the dot size corresponding to each pixel value of the N-value image data generated by the N-valued data generation means is set,
When the print data generation unit continuously prints dots smaller than a predetermined size in the print data, the dot size corresponding to any one of the continuous dots is changed to a size larger than the predetermined size. An image processing program that functions to generate data. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data by setting a dot size corresponding to each pixel value of N-value image data generated by the N-valued data generation means,
A dot size changing unit that changes the dot size of any one of the continuous dots when the dots smaller than the predetermined size are continuous in the print data to the print data generation unit, the dot size changing unit The error propagation unit that propagates the error of the pixel value of the pixel generated by the dot size change process of the dot size change unit to the unprocessed pixel, and the dot size of the pixel that has propagated the error by the error propagation unit. An image processing program that functions as a dot size resetting unit to be set. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
An N-value adjusting unit that adjusts the N-value conversion of the pixel of interest when the N-value data generation unit is adjacent so that a dot size corresponding to the pixel value is equal to or smaller than a predetermined size; An image processing program that functions as an error propagation unit that propagates an error of a pixel value generated when an N-value process is performed by an adjustment unit to an unprocessed pixel. Computer
N-valued data generating means for generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
In addition to functioning as print data generation means for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated by the N-valued data generation means,
When the N-valued data generating means is adjacent so that the dot size corresponding to the pixel value falls within a predetermined range, an N-valued adjusting unit that adjusts the N-valued value of the pixel value, and the N-valued adjustment An image processing program for causing an error propagation unit to propagate an error of a pixel value generated when an N-value process is performed by a unit to an unprocessed pixel. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set;
The print data generation step generates print data in which the dot size corresponding to any one pixel of the continuous dots is changed when the predetermined range of dot sizes is continuous in the print data. Image processing method. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data in which a dot size corresponding to each pixel value of the N-value image data generated in the N-value data generation step is set;
In the print data generation step, when dots smaller than a predetermined size are continuous in the print data, printing in which the dot size of a pixel corresponding to one of the continuous dots is changed to a size greater than or equal to the predetermined size An image processing method characterized by generating data. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data by setting a dot size corresponding to each pixel value of the N-value image data generated in the N-valued data generation step,
The print data generation step includes a dot size change step of changing the dot size of any one of the consecutive dots when the dots smaller than the predetermined size continue in the print data to a size greater than or equal to the predetermined size. And an error propagation step for propagating the pixel value error of the pixel generated by the dot size change process of the dot size change step to an unprocessed pixel, and a dot size of the pixel propagated with the error at the error propagation step. An image processing method comprising: a dot size resetting step for setting. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step for generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated in the N-valued data generation step;
The N-value data generation step includes an N-value adjustment step for adjusting the N-value conversion of the pixel value when adjacent to each other so that a dot size corresponding to the pixel value is equal to or smaller than a predetermined size, And an error propagation step for propagating an error of the pixel value generated when the N-value process is performed in the adjustment step to an unprocessed pixel. An N-valued data generation step of generating image data of N values by converting image data that is a set of pixel values of M values (M> N) constituting an image into N values (N ≧ 2) for each pixel;
A print data generation step of generating print data by setting a dot size corresponding to the pixel value of the N-value image data generated in the N-valued data generation step,
The N-value data generation means adjusts the N-value conversion of the pixel value when adjacent so that the dot size corresponding to the pixel value falls within a predetermined range, and the N-value adjustment adjustment An image processing method comprising: an error propagation step of propagating an error of a pixel value generated when performing N-value processing in steps to an unprocessed pixel.

Images