JP2005057527A - Image processor and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processor for forming and managing a look-up table itself according to the individual difference of a printer or an ink head and a secular change, etc. <P>SOLUTION: In a system which has a file of an original LUT different from a file of a module using the LUT and uses the LUT as a database file, the processor newly creates a database file by calibration and utilizes the created file as a new LUT. It has a calibration database having the new LUT; a means for switching the original database file having the original LUT to create printing data; and an image processing means which incorporates calibration on/off-information in the database file, acquires the calibration on/off-information from a database name managing file and the original database file when acquiring the database name, and processes images based on the original database or the calibration database, when the calibration is on or off. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus and an image processing method.

  For example, when an image to be synthesized on a personal computer is output by a printer, luminance signals R (red), G (green), and B (blue) as data of the image are used as color signals Y (yellow), M (magenta), C (cyan) Further, it is necessary to perform color conversion to K (black) as necessary, but the input space by the luminance signal and the output space by the color signal in this color conversion have a non-linear relationship. It is common. As described above, in the data conversion, when the correspondence between the input and the output has a non-linear relationship, it is not easy to perform the calculation by modeling the conversion strictly, and even if a certain degree of modeling is possible. The amount of calculation required for the conversion itself may be enormous. In order to solve such a problem in data conversion, a method is known in which data conversion is simply performed by previously converting output data corresponding to each input data into a lookup table.

The look-up table obtained in advance differs only for each printing mode, and the same type of printer always uses the same look-up table regardless of the conditions of the head and printer.
JP 2002-001939 A

  However, an optimal print result cannot always be obtained with a lookup table obtained in advance, due to individual differences between printer bodies and ink heads, changes with time, and the like. For example, when magenta is strong, the color becomes red overall, and the gray balance may not be maintained.

  Therefore, the present invention has been made from such a viewpoint, and an object of the present invention is to provide an image processing apparatus that creates and manages a look-up table itself based on individual differences of printers and ink heads, changes over time, and the like. There is to do.

  In particular, an object of the present invention is to provide an image processing apparatus that can be used by switching between an original lookup table and a new database file after calibration. A further object is to reduce the database file size.

  In the conventional example shown in FIG. 8, a gradation correction table having the same contents is used in print modes A (calibration ON) and D (calibration OFF). However, when calibration is executed, only A is changed, and only the calibration database file is used. That is, when the original database file is viewed, it can be seen that the same data is duplicated in the database file.

  In order to achieve the above object, the image processing apparatus of the present invention is characterized by the following configuration.

  That is, in a system using the original lookup table (LUT) and the module that uses the LUT as separate files, and using the LUT as a database file, a database file is newly created by performing calibration, and the created file is created as a new LUT. In the image processing apparatus to be used as the above, a means for creating print data by switching between the calibration database having the new LUT and the original database file having the original LUT, incorporating calibration ON / OFF information into the database file, and the database name At the time of acquisition, calibration ON / OFF information is acquired from the database name management file and the original database. And having an image processing means for performing image processing in the calibration database when. As a result, for example, as shown in FIG. 9, it is possible to reduce the gradation correction table of o403 in FIG. 8 by holding the calibration ON / OFF information.

  As described above, according to the present invention, it is possible to always obtain an optimum printing result by creating and editing a database file including a look-up table due to individual differences between printer bodies and ink heads and changes with time. Can do. For example, when magenta is strong, the overall color becomes reddish, and the inability to maintain gray balance is considerably reduced. Furthermore, the LUT to be referred to can be reduced by holding the calibration ON / OFF information for each print mode in the database file.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of an image processing system showing an embodiment of a data conversion apparatus of the present invention.

  The output device 205 can be in the form of a color printer, for example, and uses four colors of ink of yellow (Y), magenta (M), cyan (C), and black (K) to output a color print on a print sheet. Is what you do. However, the output of the color printer may be three colors, five colors, six colors, and seven colors, but in this embodiment, description will be made with four colors. The print data composed of the density data of Y, M, C, and K used in the output device 205 is obtained by image processing executed by the control device 201. The image processing includes color correction described below. Color conversion, tone correction and quantization processing are included.

  The control device 201 has a CPU, and executes data processing related to the present system, such as color conversion described later and initial processing therefor, and operation control of mechanical components of each part. The storage device 203 is composed of a memory such as ROM and RAM, a hard disk, and an external storage device such as a floppy (registered trademark) disk as a whole. Is stored.

  For example, an image read by a scanner is stored in the storage device 203, and the operator of this system operates an operation from the input device 202 such as a keyboard or a mouse on an image displayed on the display device 204 such as a CRT. An image to be printed out by the output device 205 can be produced by performing desired processing or the like by input.

  The image produced by this system is generally gradation data of each of the luminance signals R, G, and B, and color correction, color conversion, and gradation correction are performed in order to use the data as print data of the output device 205. Quantization processing is performed.

  Of course, the application of the present invention is not limited to the system as described above. For example, it is well known that color conversion processing is performed in an apparatus such as a copying machine, and it is obvious that the present invention can be applied to such an apparatus or system.

  In this color correction process, color correction from 8 bits for each color of RGB to 8 bits for each color of R′G′B ′ is performed. Further, the color conversion process performs color conversion from 8 bits for each color of R′G′B ′ to 8 bits for each color of CMYK. Further, the gradation correction processing corrects C′M′Y′K ′ 8 bits for each color to 8 bits for C ″ M ″ Y ″ K ″. In addition, the quantization process performs quantization from 8 bits for each color of C "M" Y "K" to 1 bit for each color of cmyk. Color correction, color conversion, gradation correction, and quantization processing at this time use a look-up table (hereinafter also referred to as LUT).

  FIG. 2 is a conceptual diagram of the present invention.

  The printer driver module main body 206 in FIG. 2 calls the calibration module 208 to create a new database file 212 based on the original database file 211. The calibration activation method may be a driver utility, or may be issued when a print start command is issued, a driver is installed, or a head is replaced.

  Here, the original database file 211 is a database 220 of the printer as shown in FIG. 3, and is used for command and margin information as model information, an LUT (interpolation table) necessary for color correction / color conversion, and tone correction processing. The proposed LUT (tone correction table), dither matrix required for quantization processing, and various information for each print mode that matches the driver UI information are included. In this proposal, calibration is turned on for each print mode. / OFF information is included (FIG. 6).

  As a calibration method, a database file is created based on individual differences of printers and ink heads, changes with time, and the like. For example, the head ID and head rank information (for example, C: +2, M: 0, Y: -1, K: +1) is picked up from the printer main body, and the information is notified to the calibration module. A database file including an LUT (tone correction table 223 in FIG. 4) matching the head rank is created. Alternatively, calibration may be performed with the head rank determined by the user's judgment by having the user perform test printing.

  The calibration module creates a new database file and creates a database name management file 213 for managing the file name as shown in FIG. The database management file 213 according to the present invention has a correspondence between the head ID 221 and the new database table name 222. Therefore, when a new head is mounted, it must be registered in the database management file.

  Next, the printer driver module calls a module 207 that returns the original database file name. When printing is actually performed from the printer driver, 214 is called to obtain a new database file name created by calibration. At this time, calibration ON / OFF information (FIG. 6) is acquired from the original database file according to the print mode that matches the setting of the driver UI. If the ON / OFF information is ON, the calibration database name corresponding to the head ID is acquired from 213, and if it is OFF, the original database name is acquired and returned to the printer driver module.

  Then, by calling the color correction / color conversion module and the quantization / gradation correction module with the database file name and performing processing, the optimum print result is obtained using the optimum LUT.

  As shown in FIG. 6, it can be seen that the gradation correction table can be diverted by calibration ON / OFF with the above configuration. That is, the calibration ON / OFF information for each print mode included in the original database is referred to. If OFF, the gradation correction table included in the original database is used. If it is ON, the gradation correction table of the calibration database is used. Here, if there is no calibration information for each printing mode, the calibration database is always referred to, and a new table is provided for positions where calibration is not desired. In FIG. 6, this means that the same gradation correction table cannot be used in the print modes 01 and 04.

  The original database file is also used when the printer driver fails to acquire the head ID, when the new database file is not created normally, or when the database management file is not created successfully. FIG. 7 shows the flow of processing for using the original database file during the exception processing as described above.

  First, the printer driver module obtains an original database name (224). Next, when the print destination port is a file, image processing is performed according to the LUT of the original database file (229). If the print destination port is a printer, the printer head ID is acquired (225). If the head ID acquisition fails, image processing is performed according to the LUT of the original database file (229). If the head ID is successfully acquired, a new database file name corresponding to the head ID is obtained (226). At this time, if the database management file has not been created normally, an accurate database file name cannot be determined, and image processing is performed according to the LUT of the original database file (229). If the database file corresponding to the head ID is not registered, calibration processing is performed, and the new database file name is registered in the database management file (227). If the new database file is not normally created at this time, image processing is performed according to the LUT of the original database file (229). If the new database file is normally created, the process proceeds to the next step, and calibration ON / OFF information is acquired according to the driver UI setting (print mode). If calibration is ON, image processing is performed according to the LUT of the new database file (228). If a new database file corresponding to the head ID already exists, image processing is performed according to the LUT of the new database file without performing calibration processing (228). If the calibration is OFF, image processing is performed according to the original database table (229).

  In addition, the calibration database file is configured to be edited after copying the original database file. However, if the calibration module sets the calibration table to a set of tables only when calibration is ON, the size of the calibration database file Can be reduced.

It is a block diagram which shows the structure of the image processing system which shows one Embodiment of the data converter of this invention. 1 illustrates the concept of the present invention. It shows the concept of a database file. The concept of adjusting the LUT of the gradation correction table according to the head rank is shown. The concept of the database file name corresponding to the head ID is shown. The concept of various information for each print mode is shown. The flow of this invention is shown. FIG. 5 shows the same gradation correction table held in the conventional example. FIG. 6 shows an improved example of the present invention in which the same gradation correction table is not held.

Claims (6)

In a system that uses the original lookup table (LUT) and the module that uses the LUT as separate files, and uses the LUT as a database file, a new database file is created by performing calibration, and the created file is used as a new LUT In the image processing apparatus to
Means for generating print data by switching between the calibration database having the new LUT and the original database file having the original LUT;
Calibration ON / OFF information is incorporated in the database file, and calibration ON / OFF information is acquired from the database name management file and the original database when the database name is acquired. An image processing apparatus comprising image processing means for performing image processing using a database.   The image processing apparatus according to claim 1, wherein the calibration database is a set of tables only when calibration is ON.   The image processing apparatus according to claim 1, wherein when the head ID information of the printer cannot be acquired, print data is created using an original database file having the original LUT.   The image processing apparatus according to claim 1, wherein when a new LUT cannot be normally created, print data is created using an original database file having the original LUT.   2. The image processing apparatus according to claim 1, wherein when a correct name cannot be obtained from a database management file, print data is created using an original database file having the original LUT. In a system that uses the original lookup table (LUT) and the module that uses the LUT as separate files, and uses the LUT as a database file, a new database file is created by performing calibration, and the created file is used as a new LUT In the image processing method to
Print data is created by switching between the calibration database having the new LUT and the original database file having the original LUT,
Calibration ON / OFF information is incorporated in the database file, and calibration ON / OFF information is acquired from the database name management file and the original database when the database name is acquired. An image processing method characterized by performing image processing on a database.

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