JP2001333287A - Color image recording device - Google Patents

Abstract

(57) [Summary] To satisfy these demands, it is possible to increase the resolution of only black-and-white image data without increasing the data amount of RGB color image data, thereby achieving higher image quality of the entire output image. It is another object of the present invention to provide a color image recording apparatus capable of improving the sharpness of a color character or the like while maintaining a low price and suppressing color misregistration to achieve high image quality. A color image recording apparatus includes: a printer engine unit for printing video data; and a printer controller unit for outputting video data obtained from the color image data to the printer engine unit. Color image data and black-and-white image data having a higher resolution than the color image data are input in parallel, and K
Generate the image data based on the input black-and-white image data.
It is generated based on the color image information input with the MC image data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color printer,
The present invention relates to a color image recording device used for a color copying machine, a video printer, and the like.

[0002]

2. Description of the Related Art In recent years, color image scanners, digital cameras, and the like have been rapidly spreading, and accordingly, a color image recording apparatus capable of reproducing color image data with high speed and high image quality has been demanded. Also,
By combining a color image scanner and a color image recording device, a multifunctional color image recording device configured to easily obtain color copy records in addition to color printing from a host device such as a PC. So-called multifunction printers are also becoming popular.

As described above, a color image recording apparatus capable of easily obtaining color printing and color copying records based on color image data from a host device such as a PC is composed of an image forming unit (printer engine unit), a printer controller unit, and the like. Can be divided into A feature of the printer controller constituting this color image recording apparatus is that raster processing is employed in order to process a large amount of color image data from a color image scanner, a digital camera or the like at a high speed and print it by a printer engine. Often. Hereinafter, a printer controller of a conventional color image recording apparatus that adopts a form of raster processing will be described with reference to the drawings.

FIG. 26 is a block diagram showing a printer controller of a conventional color image recording apparatus.

In FIG. 26, 1 is an interface unit for receiving RGB color image data from a color image scanner device or a host device 20 such as a PC, 2 is a filter unit for correcting the contour characteristics of the color image data, and 3 is a C unit.
A density conversion unit that converts reflection data handled by an RT display or a color image scanner into density data handled by an image recording device, and 4 can reproduce ink or toner that handles color image data in an RGB color space by the image recording device. A color conversion unit 5 for converting to a YMC color space calculates an appropriate amount of black component from the Y'M'C 'color data output from the color conversion unit 4, outputs K image data, and outputs Y'. Y "M" C "obtained by subtracting K from M'C '
A page memory for temporarily storing color image information converted into four colors of Y "M" C "K";
Is a gamma correction unit in which a gamma value is set according to the characteristics of the printer engine unit 30 described later. Reference numeral 8 converts image data read from the page memory 6 and subjected to gamma correction to binarized video data. The screen processing unit 30 sends the image data to the printer engine unit 30. The image processing unit 30 is an image forming unit (printer engine unit).

[0006] The printer controller of the conventional color image recording apparatus having the above-described configuration will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 27 is a data diagram showing input color image data, and FIGS.
FIG. 29 is a filter coefficient diagram showing filter coefficients in the filter unit 2, FIG. 29 is a graph showing characteristics of the density conversion unit 3, and FIG.
0 is a block diagram showing the color conversion unit 4, FIG. 31A is a graph showing R spectral characteristics and ideal spectral characteristics of C ink and toner, and FIG. 31B is a G spectral characteristic and ideal spectral characteristics of M ink and toner. FIG. 31C is a graph showing the characteristic, and FIG. 31C is a graph showing the ideal spectral characteristic of the Y ink and toner, and FIG.
FIG. 32A is a graph showing the actual spectral characteristics of the C ink and toner, FIG. 32B is a graph showing the actual spectral characteristics of the M ink and toner, and FIG. 32C is the actual spectral characteristics of the Y ink and toner. 33 is a graph showing characteristics, FIG. 33 is a block diagram showing the UCR unit 5, FIG. 34 (a) is a graph showing the maximum UCR amount and the ink amount for each image data C ′, M ′, Y ′, and FIG. 34 (b). Is each image data K in 100% UCR,
FIG. 3 is a graph showing ink amounts for C ", M", and Y ";
5A is a graph showing the maximum UCR amount and the ink amount for each of the image data C ′, M ′, and Y ′ as in FIG. 34A, and FIG. 35B is a graph showing each image data K at 75% UCR. , C ″, M ″, Y ″, a graph showing the ink amount,
36 (a), (b), (c) and (d) show C, M, Y,
FIG. 37A is a memory diagram showing a K area page memory;
(B), (c), (d), (e), (f), and (g) are P
SYSNC, HSYNC, VCLK, C image data, M
FIG. 4 is a timing chart showing image data, Y image data, and K image data.

First, a color image scanner, a PC
The print data for one page or a plurality of pages is received from the host device 20 via the interface unit 1. The print data handled by the host device 20 includes character information, bitmap information such as photographs, graphic information, and the like. In a color image recording apparatus using a raster processing printer controller, character information and graphic information are raster-processed by the host device 20 and input to the printer controller as bitmap information. The image information of the document read by the color image scanner is output as bitmap information.

FIG. 27 shows an example of bitmap information subjected to raster processing. Here, the character "P" in the input image will be described as an example. Here, the upper part of the character “P” is divided into lines of the designated resolution, and each line is divided into pixels of the designated resolution in the main scanning direction. The image data of each divided pixel is The data is sequentially output from line 1 to line n from left to right in the main scanning direction. In the case of bitmap image information, red (R)
The three primary colors of green (G) and blue (B) are color-separated and output, and the black and white image information included in the color image information is also output as a part of the RGB color image information. Therefore, all the color image data received by the raster processing printer controller is input in the form of RGB bitmap information. At this time, the attribute data of the image information such as characters / photos is recorded in the header part of the received data and received at the same time as the image data.

[0009] The received bitmap image data is
Appropriate processing is performed according to the image attribute of the header portion. Here, a description will be given assuming that color image data obtained by reading a document from a color image scanner is input.

[0010] As shown in FIG.
The color is separated into B3 planes and received in the form of RGB color image data. The image data read by the color image scanner is based on the lens MTF (Modulati
on Transfer Function) and CC
Due to the influence of the response characteristics of the D image sensor, the contour information of the portion where the spatial frequency is high, that is, the edge portion is deteriorated.
Therefore, next, contour enhancement is performed by the filter unit 2 to compensate for a high spatial frequency component of the image data. FIG.
Shows the coefficients of these filters. The filter is a 5 × 5 Laplacian that performs a product-sum operation around the pixel of interest.
Make up the filter. Here, when the coefficient of the peripheral pixel with respect to the target pixel is increased, a strong filter is obtained, and when the coefficient is reduced, a weak filter is obtained. When the coefficient for the peripheral pixels is set to a minus value, an outline emphasis filter is obtained.
Positive values result in an unsharp filter that blurs image information. FIG. 28 shows the specific set values. As can be seen, when the image data is a photographic paper photograph, a weak contour emphasis filter is set in accordance with the optical characteristics of the image reading device (FIG. 28A). Also, in the case of character data, a strong contour emphasis filter is set particularly to improve the sharpness (FIG. 28B), and in the case of a printed photograph, a weak unsharp filter is set to suppress the moire phenomenon. (FIG. 28 (c)). As described above, the filter unit 2 performs the filtering process adapted to the attribute information of the input image.

The color image data whose optical characteristics have been corrected by the filter unit 2 are then input to a density conversion unit 3. The input RGB color image data is reflection type data proportional to the intensity of the reflected light of the original, and is converted into density type data proportional to the layer pressure of a recording material such as ink or toner which is usually handled in a color image recording apparatus. Convert. The data conversion from the reflection system to the density system is a logarithmic conversion, and as shown in FIG. 29, the RGB color image data is handled by 8 bits.
Assuming a value from 0 to 255, when the data is 25, the density (D) is about 1.0, and when the data is 2, the density (D) is about 2.1.

The RGB color image data converted into the density data by the density conversion unit 3 is then input to the color conversion unit 4.
The primary color RGB color space is converted into complementary color YMC color space data handled by the printer engine unit 30. FIG.
As shown in FIGS. 1 (a) to 1 (c), the complementary color of R is C, the complementary color of G is M, and the complementary color of B is Y.
After normalizing the RGB density system data from 0 to 1, respectively, it is performed by executing the calculations of the equations (1) to (3).

C = (1-R) (1) M = (1-G). . . (2) Y = (1−B) (3) The normalization and the complement operation are performed by the first complement operation unit 100, the second complement operation unit 101, and the third complement operation unit shown in FIG. This is performed at 102. Further, as shown in FIGS. 32A to 32C, the spectral characteristics of the YMC recording material for performing color reproduction by a color image recording apparatus such as ink and toner have an ideal YM
A large amount of color crosstalk component is included in the C spectral characteristics, and the characteristics are far from ideal. Therefore, the data subjected to the YMC color conversion is input to the color masking processing unit 103 shown in FIG. 30, and the color crosstalk component of the recording material such as toner or ink is corrected. This operation is performed by the operations of equations (4) to (6) by a product-sum operation in a primary matrix.

C ′ = 1.5C−0.3M−0.2Y (4) M ′ = − 0.3C + 1.4M−0.1Y (5) Y ′ = − 0.2C− 0.5M + 1.7Y (6) Each coefficient of the matrix depends on the characteristics of the recording material. In recent years, the number of cases where correction of a non-linear component which is insufficient with a primary matrix has been increasing by interpolation between a three-dimensional lookup table and a table has increased.

The Y'M 'color-corrected in this manner
Next, the C ′ density system image data is input to the UCR unit 5.
The UCR unit 5 is configured as shown in FIG. First, the minimum value of Y ′, C ′, and M ′ is detected by the minimum value detection unit 104 as the maximum UCR amount. Next, based on the given UCR coefficient (UCR rate), a value obtained by multiplying the maximum UCR amount by the UCR rate in multiplier 105 is calculated as black component data (K image data). 34 and 35 show examples where the UCR rate is 100% and 75%. The black component data thus calculated is output to the next page memory 6 as black plate data K, and C ′, M ′, Y ′
, The black component data to be printed as the black plate K is subtracted by the first subtractor 106, the second subtractor 107, and the third subtractor 108, respectively.
It is output as M plane data M ″ and Y plane data Y ″. Here, of the black components included in the CMY image data, the UCR rate, which is the ratio subtracted as the black plate K, is varied according to the image attribute of the input image data. Generally, in the case of character information, the UCR rate is set to a value close to 100% as shown in FIG. 34B, while emphasizing black character reproducibility. In the case of natural image information such as a photograph, FIG. As described above, in many cases, the UCR rate is reduced to about 75% to improve the tone reproducibility of the high density portion.

The C plane data C ″, M plane data M ″, Y plane data Y ″, and black plane data K obtained as described above
Respectively, temporarily store one page in the corresponding address of the page memory 6. As shown in FIGS. 36 (a) to 36 (d), a predetermined address of the C "M" Y "K image data is incremented each time one line is written, and n lines of image data for one page are stored in the prepared memory. When the image data for one page is stored in the page memory 6, the printer controller issues a print request to the printer engine.

As shown in FIG. 37, after the printer engine unit 30 is ready for printing, the page synchronizing signal PSYSNC (FIG. 37 (a)) for one page of data, 1
The horizontal synchronization signal HSYNC (FIG. 37 (b)) corresponding to the line data and the video clock VCLK (FIG. 37 (c)) corresponding to the video data of one pixel are transmitted, and the image data stored in the page memory 6 is transmitted. (FIG. 37 (d)-
(G)) is sequentially read for each VCLK. The image data read out from the page memory 6 in synchronization with the VCLK is input to the γ correction unit 7, and after the non-linearity with respect to the density reproduction of the printer engine unit 30 is corrected,
The screen processing unit 8 performs a binarization process, converts the video signal into a video signal, outputs the video signal to the printer engine unit 30 in synchronization with the input VCLK, and converts the signal into one page of Y "M" C "K". Printing will be performed.

[0018]

However, in the above-described conventional color image recording apparatus, when the resolution is increased for the purpose of improving the image quality, the amount of input RGB color image data increases exponentially. . According to the literature, 1
It is known that up to about 600 dpi, it is possible to visually improve the image quality with the increase in resolution. Therefore, for example, when the resolution is increased from 300 dpi to 600 dpi, A4 size image data is about 8.3 MB to about 33.2 MB for each color. Further 1200d
In the case of pi, it is about 132.8 MB. for that reason,
Simply increasing the resolution for the purpose of improving the image quality causes an increase in the processing time in the printer controller unit, and as a result, there is a problem that high-speed processing becomes difficult. Also, since the capacity of the page memory for storing the image data to be processed needs to be greatly expanded, the device cost becomes significantly higher, resulting in an increase in the data transfer speed by the interface. There is a problem that it becomes difficult to take countermeasures for the accompanying harmonic interference.

In this color image recording apparatus, it is possible to improve the quality of the entire output image without increasing the data amount of RGB color image data, and to remarkably improve the sharpness of color characters and the like while maintaining a low price. It is required that it can be improved.

The present invention satisfies these requirements,
By increasing the resolution of only the black and white image data without increasing the data amount of the GB color image data, it is possible to improve the overall image quality of the output image, and to improve the sharpness of color characters and the like while maintaining a low price. It is an object of the present invention to provide a color image recording apparatus capable of remarkably improving the image quality.

[0021]

According to the present invention, there is provided a color image recording apparatus for printing video data, and outputting video data obtained from the color image data to the printer engine. A color image recording apparatus comprising: a printer controller unit for inputting color image data and black-and-white image data having a higher resolution than the color image data in parallel; Is generated on the basis of color image information input with YMC image data.

As a result, it is possible to obtain a color image recording apparatus capable of increasing the resolution of only the black-and-white image data without increasing the data amount of the RGB color image data, thereby improving the image quality of the entire output image.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A color image recording apparatus according to a first aspect of the present invention includes a printer engine for printing video data and a printer controller for outputting video data obtained from the color image data to the printer engine. And a printer controller unit that inputs color image data and black-and-white image data having a higher resolution than the color image data in parallel, and based on the black-and-white image data input with the K image data. Generate, YM
This is to generate the color image information based on the input C image data.

With this configuration, if high-resolution black-and-white image data is input, it has the effect of generating K image data from the black-and-white image data and improving the quality of the entire output image.

According to a second aspect of the present invention, there is provided a color image recording apparatus.
2. The color image recording apparatus according to claim 1, wherein the printer controller comprises: a UCR section for generating new K image data from the YMC image data; and a high resolution monochrome image data and a UCR section inputted in parallel with the color image data. And a black data replacement unit that replaces the new K image data generated in step (1).

With this configuration, when high-resolution black-and-white image data is input, black-and-white image data input as K image data is used, and when high-resolution black-and-white image data is not input, YMC image data is used. This has the effect that the generated K image data is used.

According to a third aspect of the present invention, there is provided a color image recording apparatus.
According to a second aspect of the present invention, in the color image recording apparatus, the black data replacement unit includes a multiplier that provides a UCR rate based on image attribute data input in parallel with the YMCK image data.

According to this configuration, the character portion has the effect of increasing the UCR rate and the natural image portion performing the process of decreasing the UCRRITU, whereby the outline of the character becomes clear and the gradation of the natural image is improved.

A color image recording apparatus according to claim 4 is
The color image recording apparatus according to claim 2, wherein
The page memory for storing the replaced high-resolution black-and-white image data and the YMC image data, and the black-and-white image data and the YMC image data corresponding to the same position of the image in the page memory are read. An edge detection unit that detects each edge of the YMC image data, an edge closed region detection unit that detects a closed region closed by the detected edge, and a closed region of the read monochrome image data and a read YMC image data, respectively. An image comparison / correction unit that compares a closed area with each other and corrects a difference between the read black-and-white image data and each of the read YMC image data is provided.

With this configuration, the timing of the YMC image data is corrected based on the black and white image data, and the color shift is corrected.

A color image recording apparatus according to claim 5 is
According to a fourth aspect of the present invention, in the color image recording apparatus, the edge detection unit includes one or more Sobel filters and a threshold value determination circuit.

This configuration has the effect that the edge portion is reliably detected.

A color image recording apparatus according to claim 6 is
The color image recording apparatus according to claim 4, wherein
The edge closed region detection unit receives a weighting filter that weights the edge information output from the edge detection unit, a threshold determination circuit that detects the weighted edge information with a predetermined threshold, and output data of the threshold determination circuit. And a binarization processing circuit for binarizing the image data. The toggle circuit is enabled and controlled according to the output level of the binarization processing circuit.

With this configuration, the configuration has an effect that the edge closed area is reliably detected.

A color image recording apparatus according to claim 7 is
7. The color image recording apparatus according to claim 4, wherein when converting the YMC image data stored in the page memory into a video signal, the monochrome image data corresponding to the same position of the image of each page. And a pseudo resolution conversion unit for adding or deleting dots with reference to the edge information.

With this configuration, dots are added or deleted from the YMC image data. In particular, for character information whose contour needs to be sharpened, high-resolution monochrome image data is used as basic data for low-resolution RGB color data. The resolution of the image data can be increased in a pseudo manner, the sharpness of the color characters can be remarkably improved, and only the edge area needs to be detected, so that high image quality can be achieved while maintaining a low price. Have.

The color image recording apparatus according to claim 8 is
8. The color image recording apparatus according to claim 7, wherein the pseudo-resolution conversion unit performs YMC on the processing clock of the monochrome image data.
The edge information of the monochrome image data is simultaneously compared with reference to the edge information of the image data, and the edge position of the YMC image data is corrected based on the comparison result.

With this configuration, the YMC image data can be corrected for the correct position, and the color shift can be corrected more accurately.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a block diagram showing a printer controller of a color image recording apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 1 denotes an interface unit for receiving RGB color image data, Bk monochrome image data and image attribute information from a color image scanner device or a host device 20 such as a PC, and 2 denotes an outline characteristic of the received image data. A density conversion unit for converting reflection-type image data handled by a PC or a color image scanner into density-type image data handled by an image recording device; and 4, an image recording device for converting image data in an RGB color space. A color conversion unit 5 for converting image data Y ', M', and C 'in a YMC color space in which ink or toner handled by the printer can be reproduced has a more suitable amount of black than input Y'M'C' image data. UC to calculate components and obtain black plate, that is, K color output
R and 9 are high-resolution Bk monochrome data input in parallel with the RGB color image data from the interface unit 1 and U
A black data replacement unit 6 for replacing the K color output generated by the CR unit 5 is a color image of four colors of Y ″, M ″, C ″, and K ″ obtained by the UCR unit 5 and the black replacement unit 9. A page memory for temporarily storing data, a gamma value set in accordance with the characteristics of the printer engine unit (image forming unit) 30 by sequentially reading out Y, M, C, and K color image data stored in the page memory 6 The gamma correction unit 8 that performs correction in step (1) converts the image data read from the page memory 6 and subjected to gamma correction into binarized video data, and sends the data to the printer engine unit 30 in synchronization with a clock. Screen processing unit.

The printer controller of the color image recording apparatus configured as described above will be described with reference to FIGS. FIG. 2 is an explanatory diagram showing RGB image data and pixels, FIG. 3 is an explanatory diagram showing Bk black-and-white image data and pixels, FIG. 4 is a block diagram showing a black data replacing unit, and FIGS. b), (c), (d), (e),
(F) is a timing chart showing LSYNC, WCLK, Y "M" C "image data, LSYNC2, WCLK4, K" image data, and FIGS. 6 (a), (b), (c) and (d) show page K Memory, C page memory, M page memory, Y
FIG. 7A is a memory diagram showing a page memory, and FIG.
(C), (d), (e), (f) are HSYNC, VCL
K, Y “M” C ”video data, HSYNC2, VCL
FIG. 8 is a timing diagram showing K4, K ″ video data, FIG. 8 is an explanatory diagram of a color print recording mode, and FIG. 9 is a graph showing gradation with respect to resolution on visual characteristics.

First, as in the prior art, one page of image data is received from the host device 20 such as a color image reading device or a PC via the interface unit 1. As in the prior art, all image data received by the printer controller is input in the form of bitmap information. At this time, the attribute data of the image information is recorded in the header of the received data, and is received simultaneously with the image data. Here, the description will be made assuming that the image data is input by the color image reading apparatus.

The input read color image data of the color photograph is received via the interface unit 1 in the form of RGB image data shown in FIG. At this time, Bk monochrome image data of the same document shown in FIG. 3 is also received in parallel. In the image data of the document read by the color image scanner, the contour information of the portion having a high spatial frequency, that is, the edge portion is deteriorated due to the influence of the MTF characteristics of the lens and the response characteristics of the CCD image sensor. Therefore, next, the filter unit 2 performs contour enhancement to compensate for a component having a high spatial frequency of the image data. Since the operation of the filter unit 2 is the same as that of the conventional technology, the description is omitted.

The RGB color image data and the Bk black and white data whose optical characteristics have been corrected by the filter unit 2 are then input to the density conversion unit 3. RGB color image data and B
Since the k-black and white image data is reflection-type data proportional to the intensity of the reflected light of the original, it is converted here to density-type data proportional to the layer pressure of the recording material such as ink or toner normally used in a color image recording apparatus. After that, the color conversion unit 4 converts the primary color system RGB color space into the complementary color system YMC color space and performs a color masking process. The corrected color correction data Y ′, M ′, and C ′ are output as image data. The operation up to this point is the same as the conventional technique.

The C'M'Y 'density-based image data obtained in this way is then input to the UCR unit 5, where the C', M ', Y' image data is obtained at a UCR rate corresponding to the image attribute. , A black component is subtracted from the data to be output as C plane data C ″, M plane data M ″ and Y plane data Y ″, and black plane data K is obtained. Here, the black plane data K and density conversion The Bk black and white data output from the unit 3 are both input to the black data replacement unit 9. The black data replacement unit 9
As shown in FIG. 4, a multiplier 200, a clock doubling circuit 201, a clock doubling circuit 202, a multiplexer 2
The multiplier 200 outputs Bk black-and-white data at the same ratio as the UCR rate (UCR coefficient) given to the UCR unit 5 as K ′ data. The replacement is performed by the multiplexer 203 to obtain black plate data K ″.
Reference numeral 03 denotes replacement of black data only when the image attribute is in the four-color mode, that is, only when four colors of RGB color image data and Bk monochrome image data are input simultaneously. Otherwise, the black plate data K becomes black plate data K ".

The C plane data C ″, M plane data M ″, Y plane data Y ″, and black plane data K ″ thus obtained are temporarily stored in the corresponding addresses of the page memory 6 for one page. The LSYNC signal (FIG. 5A), which is a one-line write start signal to the page memory 6, is clock 2
The multiplying circuit 201 converts the signal into an LSYNC2 signal (FIG. 5D) having a cycle of 1/2, and a WCLK signal (FIG. 5B) which is a write clock for each pixel is divided by a clock quadruple circuit 202 into 1 /. It is converted into a WCLK4 signal (FIG. 5 (e)) having a period of 4. FIG. 5 shows the relationship between these write signals to the page memory 6. C "M"
The Y "color image data is written with a WCLK signal, and the K" monochrome image data is written with a WCLK4. for that reason,
As shown in FIG. 6, for the three colors of C "M" Y ", image data of n lines for one page is written into the page memory 6 as in the conventional technique (FIGS. 6B to 6D), and K" Color one
Since the resolution of the image data for the page is double, 2n
The number of pixels per line is doubled for each line, that is, C "
Writing of image data four times as large as M "Y" is performed.

When the image data for one page of the four colors C, M, Y, K is stored in the page memory 6,
The printer controller issues a print request to the printer engine 30. After preparation for printing, the printer engine unit 30 converts the page synchronization signal PSYNC for one page of data, the horizontal synchronization signal HSYNC corresponding to one line of data (FIG. 7A), and video data for one pixel. The corresponding video clock VCLK (FIG. 7)
(B)) is sent to the page memory 6, and the image data stored in the page memory 6 is sequentially read for each VCLK. The image data read out from the page memory 6 in synchronization with VCLK is input to the γ correction unit 7, where the non-linearity with respect to the density reproduction of the printer engine unit 30 is corrected. The digital signal is subjected to a binarization process, converted into a video signal, output to the printer engine unit 30 for one page of C "M" Y "K" in synchronization with the input VCLK, and printed. At this time,
Regarding the image data of K ″ color, the one-line synchronization signal HSY
The cycle of the NC signal is の of that of the other C “M” and “Y” colors, VCL
The K signal is output at a cycle of 1/4.

By such an operation, as shown in FIG. 8, a high-resolution black-and-white image obtained by multiplying the image data obtained by converting the low-resolution RGB reflection type data of the original into YMC density type data by a predetermined UCR rate is used. The data and the data are combined by the printer engine unit 30. As is generally known, it is known that, as shown in FIG. 9, as shown in FIG. 9, in a portion having a high resolution, that is, a high spatial frequency, the gradation property and the associated color information cannot be identified for a while. I have. That is, the outline information is finely reproduced only in the black and white image in the high resolution part, so that even if the color image is rough, a high-resolution and high-quality color image reproduction output can be obtained.

As described above, according to the present embodiment, the printer controller unit inputs color image data and black-and-white image data having higher resolution than the color image data in parallel, Is generated based on color image information input with YMC image data. If high-resolution black-and-white image data is input, K image data is generated from black-and-white image data. As a result, the quality of the entire output image can be improved. The printer controller is a UCR unit 5 for generating new K image data from the YMC image data.
And a black data replacement unit 9 for replacing the high-resolution black and white image data input in parallel with the color image data and the new K image data generated by the UCR unit 5, so that the high-resolution black and white image data is When input, black-and-white image data input as K image data can be used, and when high-resolution black-and-white image data is not input, K image data generated from YMC image data can be used. Since it is possible, any image data can be handled. Furthermore, the black data replacement unit 9 can perform data processing according to the characteristics of the input image data by providing a multiplier that provides a UCR rate based on image attribute data input in parallel with the YMCK image data.

(Embodiment 2) FIG. 10 is a block diagram showing a printer controller of a color image recording apparatus according to Embodiment 2 of the present invention, and FIG. 11 shows details from a page memory to a gamma correction unit. It is a block diagram.

10 and 11, an interface unit 1, a filter unit 2, a density conversion unit 3, a color conversion unit 4, a UC
The R unit 5, the black data replacement unit 9, and the page memory 6 are shown in FIG.
Therefore, the same reference numerals are given and the description is omitted.
The following will be described from the page memory 6. Reference numeral 10 denotes an edge detection unit which detects edge information of C "M" Y "K" color image data read from the page memory 6 and outputs it as an edge detection signal. Reference numeral 11 denotes a closed space region surrounded by the detected edge information. The edge closed area detection unit to be detected, 12 is C "
The edge closed areas of each of the M, Y, and K colors are compared, and the edges of the other C, M, and Y color image data are corrected based on the closed area of the black and white image data, and each of the corrected data Y1, M is corrected.
An image comparison / correction unit 13 for outputting 1, C1 is provided for each resolution correction data by deleting or adding dots to the Y1, M1, C1 color image data whose edge information has been corrected, based on monochrome image data K ″ = K1. A pseudo-resolution conversion unit that outputs Y2, M2, and C2 together with the black-and-white image data K1 = K2.
Y "K" color image data is sequentially read out, and the Y2, M2, C2 color image data and the K2 monochrome image data whose edge information has been corrected are output to the printer engine unit 30.
The gamma correction unit 8 performs correction with a gamma value set according to the characteristics of C2, M2, Y2, and K that have been subjected to gamma correction.
This is a screen processing unit that converts two image data into binarized video data and sends it to the printer engine unit 30 in synchronization with a clock. The γ correction unit 7 and the screen processing unit 8 are the same as those in the related art.

The operation of the printer controller of the color image recording apparatus constructed as described above is shown in FIG.
This will be described with reference to FIGS. FIG. 12A is a data diagram showing pixels and lines of K ″ monochrome image data.
2 (b) is a data diagram showing pixels and lines of C "M" Y "color image data, FIG. 13 (a) is a timing diagram showing K" monochrome image data in the main scanning direction, and FIG. FIG. 14 is a timing diagram showing C "M" Y "color image data in the scanning direction, FIG. 14 is a block diagram showing the edge detecting unit 10, and FIG. 15A is a data diagram showing edge information of K" monochrome image data of the character P. FIG. 15 (b) shows C "M" Y "of the character P.
FIG. 16 is a data diagram showing edge information of color image data.
16A is a block diagram showing the edge closed area detection unit 11, FIG. 16B is a data diagram showing coefficient values of the weighting filter 304, and FIG. FIG. 17 (b) is a data diagram showing C "
FIG. 18 is a data diagram showing a closed area of M "Y" color image data, FIG. 18 is a block diagram showing the image comparison / correction unit 12, and FIG.
19A is a data diagram showing pixels and lines of K1 monochrome image data, FIG. 19B is a data diagram showing pixels and lines of C1M1Y1 color image data, and FIG. 20A is K1 monochrome image data in the main scanning direction. FIG. 20 is a timing chart showing
FIG. 21B is a timing diagram showing C1M1Y1 color image data in the main scanning direction, FIG. 21 is a block diagram showing the pseudo resolution conversion unit 13, and FIG. 22A is a data diagram showing pixels and lines of K2 monochrome image data. 22 (b) is C2M2Y
FIG. 23A is a timing chart showing K2 monochrome image data in the main scanning direction, and FIG. 23B is a timing chart showing C2M2Y2 in the main scanning direction.
FIG. 24A is a timing chart showing color image data;
(B), (c), (d), (e), (f), (g),
(H) is a timing diagram showing HSYNC, VCLK, Y2M2C2 image data, VCLK2, Y2M2C2 image data with false resolution conversion error, HSYNC2, VCLK4, and K2 image data, and FIGS.
(D), (e), (f), (g) are PSYSNC, HS
YNC, VCLK2, Y2M2C2 video data, HS
FIG. 5 is a timing chart showing YNC2, VCLK4, and K2 video data.

First, as in the prior art, one page of image data is received from the host device 20 such as a color image reader or a PC via the interface unit 1. As in the prior art, all image data received by the printer controller is input in the form of bitmap information. At this time, the attribute data of the image information is recorded in the header of the received data and is received at the same time as the image data. Here, the description will be made assuming that the image data is input by the color image reading apparatus. The read color image data of the input color photograph is received via the interface unit 1 in the form of RGB image data. At this time, Bk monochrome image information of the same document is also received in parallel. In the image data of the document read by the color image scanner, the contour information of the portion having a high spatial frequency, that is, the edge portion is deteriorated due to the influence of the MTF characteristics of the lens and the response characteristics of the CCD image sensor. Therefore, next, the filter section 2 performs contour emphasis to compensate for a component having a high spatial frequency of the image data. The operation of the filter unit 2 is the same as that of the prior art, and therefore will not be described. The RGB color image data and the Bk black and white data whose optical characteristics have been corrected by the filter unit 2 are then input to the density conversion unit 3. Since the RGB color image data and the Bk monochrome image data are reflection data proportional to the intensity of the reflected light of the original, the density is proportional to the layer pressure of the recording material such as ink or toner normally used in a color image recording apparatus. After being converted into system data, the color conversion unit 4 converts the primary color system RGB color space into a complementary color system YMC color space and performs a color masking process on the color separation characteristics of ink, toner, and the like. It is output as color correction data Y'M'C 'image data in which the color crosstalk component has been corrected. The operation up to this point is the same as the conventional technique.

The C-M-Y-density-based image data obtained in this manner is then input to the UCR unit 5, and the C'M'Y 'is calculated at a UCR rate (UCR coefficient) corresponding to the image attribute. A certain black component is subtracted from the image data and output as C plane data C ″, M plane data M ″ and Y plane data Y ″, and black plane data K is obtained.
The Bk black and white data output from the density converter 3 are also input to the black data replacing unit 9. As shown in FIG. 4, the black data replacing unit 9 includes a multiplier 200, a clock doubling circuit 201, a clock doubling circuit 202, and a multiplexer 203, and the multiplier 200 transmits K ′ data to the UCR unit 5. Bk black-and-white data is output at the same ratio as the given UCR rate, and black plate data K output from UCR unit 5 is replaced by multiplexer 203 to obtain black plate data K ″.
No. 3 replaces black data only when the image attribute is in the four-color mode, that is, only when four colors of RGB color image data and Bk monochrome image data are input simultaneously.

The C plane data C ″, M plane data M ″, Y plane data Y ″, and black plane data K ″ thus obtained are temporarily stored in the corresponding addresses of the page memory 6 for one page. The LSYNC signal, which is a one-line write start signal to the page memory 6, is supplied to the clock doubling circuit 20.
The signal is converted into an LSYNC2 signal having a cycle of 1/2 by 1;
The WCLK signal, which is a write clock for each pixel, is processed by a clock quadrupler circuit 202 to generate a 1/4 cycle of WCLK4.
It is converted into a signal (see FIG. 5). Writing to these page memories 6 is performed in the same manner as in the first embodiment, and Y ″
As for the M “C” three colors, n for one page as in the prior art
The line image data is written to the page memory 6,
Since the resolution of the image data for one page of the K ″ color is twice, the writing of the image data is performed twice as many as the number of pixels per line for 2n lines, that is, four times as large as C ″ M ″ Y ″. Will be. When the image data for one page of the four colors C, M, Y, and K is stored in the page memory 6, the printer controller unit operates the printer engine unit 30.
Issues a print request to

After the printer engine unit 30 is ready for printing, the C "M"
The Y, K, and four color image data are read. Here, FIG.
2. A description will be given by taking as an example the letter "P" in a part of the input image as shown in FIG. As shown in FIGS. 12 and 13,
For three colors of C "M" Y ", n lines of image data are read out in synchronization with the read clock VCLK. For K" monochrome data, image data of 2n lines is read out in synchronization with the four times read clock VCLK4. Image data four times as large as C "M" Y "is read (see FIG. 7).
The image data read from the page memory 6 in this manner is then input to the edge detection unit 10.

As shown in FIG. 14, the edge detector 10 includes an averaging circuit 302 for averaging the outputs of the first Sobel filter 300, the second Sobel filter 301, and the two Sobel filters, and an averaging circuit. It comprises a first threshold value detection circuit 303 which receives an output of the circuit 302 and detects a threshold value above a certain level. When image data is sequentially read and input to the edge detection unit 10, the first Sobel filter 300 detects an edge in the main scanning direction,
The second Sobel filter 301 detects an edge in the sub-scanning direction. The output of the two filters is added and averaged circuit 302
After averaging, an edge detection result is obtained by the first threshold detection circuit 303 which has set an appropriate threshold. With such a configuration, it is possible to detect oblique edges in addition to right / left / upper / lower edges.

In FIG. 15, the detected edge information (edge detection signal) for the character "P" is divided into high-resolution K "monochrome image data and low-resolution Y" M "C" color image data.
One example is shown. Here, the portion where the edge is detected is displayed as “1”. The image data in which the edge has been detected in this manner is input to the edge closed space detection unit 11 next.

The edge-closed space detecting section 11 performs the operation shown in FIG.
As shown in FIG. 5, a 5 × 5 weighting filter 304 in which predetermined coefficients are set, and a second threshold value detection circuit 305 for detecting the output of the weighting filter 304 at a certain threshold value, the edges are connected and the isolated edges are connected. That is, the erroneous detection result is removed, and accurate edge information is obtained. Toggle circuit 3 based on the obtained accurate edge information
06, the space between edges is detected as a closed space.
In order to further suppress the malfunction of the toggle, the binarization processing circuit 3
The result of binarizing the image data by using the switching circuit 3
By inputting to the reset terminal 06, a white background portion of the image is removed, and only the portion where the image data exists is detected as the edge closed space.

FIG. 17 shows a high resolution K ″ for the edge closed space of the image detected by the edge closed space detecting section 11.
Two examples of black-and-white image data and low-resolution Y "M" C "color image data are shown, where a portion where a closed space is detected is displayed as" 1 ".

The high-resolution K "monochrome image data and the low-resolution Y" M "C" color image
Comparing the types of edge closed spaces at the same position, as shown in FIG. 20, a slight color shift, that is, color registration occurs due to a position shift at the time of reading and a difference in filter processing. This color registration is corrected by the image comparison and correction unit 12.

FIG. 18 shows the image comparison / correction unit 12. In FIG. 18, 308 is a first comparator, 309 is a second comparator, and 310 is a third comparator. 311 is a first shift register, 312 is a second shift register,
313 is a third shift register, and 314 is a fourth shift register. 315 is a first data selector,
316 is a second data selector, and 317 is a third data selector. The operation of the image comparison / correction unit 12 thus configured will be described below.

First, the K detection result signal and the C detection result signal are input to the first comparator 308 together with the K image data and the C image data. That is, the image data is input as image data with a detection flag (see FIG. 11). When the value of the K detection result signal is “1” and the value of the C detection result signal is “0”, A> B is at the H level, the value of the K detection result signal is “1”, and the value of the C detection result signal is also “1”. When the value of the “1” or K detection result signal is “0” and the value of the C detection result signal is “0”, A = B becomes H level. Further, if the value of the K detection result signal is “0” and C
When the value of the detection result signal is “1”, the output of A <B becomes H level. Next, signals A> B, A = B, and A <B are input as selection signals to the first data selector 315, and outputs Q0 and Q of the first shift register 311 are input as input signals.
1, Q2 has been input. First shift register 31
1 receives the C image data and the VCLK signal as the shift clock, so that Q0, Q1, Q2
The C image data delayed by one pixel each is output. Here, in the case of A> B, the C image data is missing from the K image data, so that Q0 which is data preceding by one pixel is output. If A = B, the values of the detection result signals match, so that reference Q1 is output. In the case of A <B, since the image is protruding, Q2 delayed by one pixel is output. In this way, the Q2 output delayed by one pixel and the Q
By switching and outputting 0 output according to the determination result, FIG.
As indicated by the arrow at 0 (b), the color shift component of the C image data can be corrected based on the K image data.
The operation of the M image data and the Y image data is the same as that described above, and the description is omitted.

Next, the operation of the pseudo resolution converter 13 will be described with reference to FIG. In FIG. 21, reference numeral 318 denotes VCLK4 which is a read clock for K image data and C
A fifth shift register 319 for holding the correction data and sequentially shifting the data, 319 is a sixth shift register for holding the M correction data and sequentially shifting the data, and a seventh shift register 320 is also used for holding the Y correction data and shifting the data. Shift register, 32
Reference numeral 1 denotes an eighth shift register that holds the K correction data and performs a shift. Reference numeral 322 denotes a fourth data selector which receives the C comparison data from the image comparison / correction unit 12 and selects and outputs Q0, Q1, and Q2 of the fifth shift register 322. A fifth data selector 324 for selecting and outputting Q0, Q1 and Q2 of the shift register 323 of the third shift register 323 similarly outputs the seventh shift register based on the Y comparison result.
Is a sixth data selector for selecting and outputting Q0, Q1, and Q2 of the shift register 324 of FIG.

The pseudo-resolution conversion unit 1 configured as described above
The processing content of No. 3 will be described with reference to FIGS.

FIGS. 22 and 23 refer to image data at the same position of high-resolution K1 monochrome image data and low-resolution C1 image data for the character "P". Here, with respect to the low-resolution C1 image data, the high-resolution K1
When reading is performed at the same four times the reading clock as the monochrome image data, low-resolution C1 image data naturally outputs the same data for two addresses engraved in the main scanning direction. Here, the image comparison and correction unit 1
Reference is made to the C1 comparison data output by (2). A> B
Is output, Q0 is output for the K1 image data because the C1 image data is missing. In the case of A = B output, it is determined that the K1 image data and the C1 image data match, and Q1 data is output. In the case of A <B output, it is determined that one pixel has run out, and Q2 data delayed by one pixel is output. In this way, by switching and outputting the Q2 output delayed by one pixel and the Q0 output advanced by one pixel based on the Q1 output, high-resolution image dot information is added to or deleted from the low-resolution C1 image data. It can be seen that an effect equivalent to the above is obtained. For example, when jaggies (jaggies) occur at edge portions, the jagged portions are twice as fine (120 in case of 600 dpi).
Since the resolution is smoothed at 0 dpi), the resolution is equivalently (pseudo) increased. Since the same operation is performed for the M image data and the Y image data, the description is omitted.

As described above, the read clock VCL
The low-resolution C1M1Y1 color image data stored and read in the page memory 6 on the basis of K is V, which is a read clock for K1 monochrome image data having double the resolution.
After the resolution is pseudo-converted to a high resolution in synchronization with CLK4 and output, the result is input to the γ correction unit 7, and the nonlinearity with respect to the density reproduction of the printer engine unit 30 is corrected.
The video signal is converted into a video signal by the binarization processing by the screen processing unit 8, and the VCL is applied to all four colors of Y2M2C2K2.
The video signal is converted into a video signal synchronized with K4, output to the printer engine unit 30, and printed over one page of Y2M2C2K2.

As described above, according to the present embodiment, the page memory 6 for storing the replaced high-resolution black-and-white image data and the YMC image data, and the black-and-white image data corresponding to the same position of the image in the page memory 6 And an YMC image data, and detects an edge of the read monochrome image data and an edge of the read YMC image data, and an edge closed area detection unit 11 that detects a closed area closed by the detected edge. When,
Closed area of read monochrome image data and read YMC
An image comparison / correction unit 12 that compares each of the closed areas of the image data with each other and corrects a deviation between the read black-and-white image data and each of the read YMC image data provides a timing for the YMC image data. Since the correction can be made based on the image data, the color shift can be corrected. In addition, since the edge detection unit 10 includes one or a plurality of Sobel filters 300 and 301 and the threshold value determination circuit 303, an edge portion can be reliably detected. Further, the edge closed area detection unit 11 includes a weighting filter 304 that weights the edge information (edge detection signal) output from the edge detection unit 10, and a threshold determination circuit 305 that detects the weighted edge information at a predetermined threshold. And a toggle circuit 306 to which the output data of the threshold value judgment circuit is input, and a binarization processing circuit 307 for binarizing the image data, and the toggle circuit 306 is provided in accordance with the output level of the binarization processing circuit 307. In this case, the edge closed area can be reliably detected. Further, when converting the YMC image data stored in the page memory 6 into a video signal, a pseudo resolution for adding or deleting dots by referring to edge information of monochrome image data corresponding to the same position of the image of each page. By providing the conversion unit 13, dots can be added or deleted from the YMC image data. In particular, high-resolution black-and-white image data is used as basic data for character information whose contour needs to be sharpened. Since the resolution of the low-resolution RGB color image data can be artificially increased, the sharpness of the color characters can be significantly improved, and only the edge area needs to be detected. Can be achieved. Further, the pseudo-resolution conversion unit 13 refers to the edge information of the YMC image data at the processing clock of the black and white image data, compares the edge information of the black and white image data simultaneously, and corrects the edge position of the YMC image data based on the comparison result. By doing so, the YMC image data can be further corrected to an accurate position, so that the color shift can be corrected more accurately.

[0070]

As described above, according to the color image recording apparatus of the first aspect of the present invention, a printer engine for printing video data and a printer engine for printing video data obtained from the color image data. And a printer controller for outputting color image data and black-and-white image data having a higher resolution than the color image data in parallel. If high resolution black and white image data is to be input by generating the image data based on the color image information to which the YMC image data is input, the K image data is generated from the black and white image data. The advantageous effect that the whole output image can be improved in image quality can be obtained.

According to the color image recording apparatus of the second aspect, in the color image recording apparatus of the first aspect,
The printer controller section includes a UCR section for generating new K image data from the YMC image data, and a high-resolution black-and-white image data input in parallel with the color image data.
And a black data replacement unit that replaces the new K image data generated by the unit, so that when high-resolution black and white image data is input, the black and white image data input as the K image data is used. When black and white image data having a resolution is not input, K image data generated from YMC image data can be used, so that it is possible to cope with any device that generates and inputs image data. Effects can be obtained.

According to the color image recording apparatus of the third aspect, in the color image recording apparatus of the second aspect,
The black data replacement unit has a multiplier that provides a UCR rate based on image attribute data input in parallel with the YMCK image data, so that the character part increases the UCR rate and the natural image part performs a process of decreasing the UCR rate. Therefore, the advantageous effect that the outline of the character can be made clear and the gradation of the natural image can be improved can be obtained.

According to the color image recording apparatus of the fourth aspect, in the color image recording apparatus of the second or third aspect, a page memory for storing the replaced high-resolution black-and-white image data and YMC image data is provided. , Black and white image data and YMC corresponding to the same position of the image in the page memory
An edge detector for detecting image data and detecting an edge of the read black-and-white image data and an edge of the read YMC image data; an edge closed region detector for detecting a closed region closed by the detected edge; An image comparison / correction unit that compares the closed area of the black-and-white image data with the respective closed areas of the read YMC image data and corrects a deviation between the read black-and-white image data and each of the read YMC image data. As a result, the timing of the YMC image data can be corrected based on the black and white image data, so that the advantageous effect that the color shift can be accurately corrected can be obtained.

According to the color image recording apparatus of the fifth aspect, in the color image recording apparatus of the fourth aspect,
Since the edge detection unit includes one or more Sobel filters and a threshold value determination circuit, an advantageous effect that an edge portion can be reliably detected can be obtained.

According to the color image recording apparatus of the sixth aspect, in the color image recording apparatus of the fourth or fifth aspect, the edge closed area detecting section weights the edge information output from the edge detecting section. A weighting filter to perform;
A toggle circuit including a threshold value determination circuit that detects weighted edge information at a predetermined threshold value, a toggle circuit to which output data of the threshold value determination circuit is input, and a binarization processing circuit that binarizes image data Is controlled in accordance with the output level of the binarization processing circuit, so that an advantageous effect that an edge closed region can be reliably detected can be obtained.

According to the color image recording apparatus of the present invention, the YMC image data stored in the page memory is converted into a video signal in the color image recording apparatus of any one of the fourth to sixth aspects. In this case, a pseudo-resolution conversion unit that adds or deletes dots with reference to the edge information of the black and white image data corresponding to the same position of the image of each page is provided. It can be deleted, and especially for character information whose contour needs to be sharpened, the resolution of low-resolution RGB color image data can be artificially increased by using high-resolution monochrome image data as basic data. Character reproducibility including color characters with little jaggy can be improved, sharpness of color characters can be significantly improved, and Since the Tsu di regions may only detect advantageous effect can be achieved while high image quality maintaining the low cost can be obtained. Furthermore, accurate dot addition can be performed without preparing a large number of patterns for performing the pseudo-resolution improving process in the screen processing unit. Has an advantageous effect that the visual resolution can be significantly improved.

According to the color image recording apparatus of the eighth aspect, in the color image recording apparatus of the seventh aspect,
The pseudo resolution conversion unit refers to the edge information of the YMC image data at the processing clock of the black and white image data, compares the edge information of the black and white image data at the same time, and determines the YMC
By correcting the edge position of the image data, Y
Since the MC image data can be corrected to an accurate position, an advantageous effect that color shift can be corrected more accurately can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a printer controller of a color image recording apparatus according to a first embodiment of the present invention;

FIG. 2 is an explanatory diagram showing RGB image data and pixels.

FIG. 3 is an explanatory diagram showing Bk monochrome image data and pixels.

FIG. 4 is a block diagram showing a black data replacement unit.

5A is a timing chart showing LSYNC. FIG. 5B is a timing chart showing WCLK. FIG. 5C is a timing chart showing Y "M" C "image data. FIG. 5D is a timing chart showing LSYNC2. (F) Timing diagram showing K ″ image data

6A is a memory diagram showing a K page memory. FIG. 6B is a memory diagram showing a C page memory. FIG. 6C is a memory diagram showing a M page memory.

7A is a timing chart showing HSYNC. FIG. 7B is a timing chart showing VCLK. FIG. 7C is a timing chart showing Y "M" C "video data. FIG. 7D is a timing chart showing HSYNC2. Figure (f) Timing diagram showing K "video data

FIG. 8 is an explanatory diagram of a color print recording mode.

FIG. 9 is a graph showing gradation with respect to resolution on visual characteristics.

FIG. 10 is a block diagram illustrating a printer controller of a color image recording apparatus according to a second embodiment of the present invention;

FIG. 11 is a detailed block diagram showing details from a page memory to a γ correction unit;

12A is a data diagram showing pixels and lines of K ”monochrome image data. FIG. 12B is a data diagram showing pixels and lines of C” M ”Y” color image data.

13A is a timing chart showing K "monochrome image data in the main scanning direction. FIG. 13B is a timing chart showing C" M "Y" color image data in the main scanning direction.

FIG. 14 is a block diagram illustrating an edge detection unit.

15A is a data diagram showing edge information of K "monochrome image data of a character P. FIG. 15B is a data diagram showing edge information of C" M "Y" color image data of a character P.

16A is a block diagram illustrating an edge closed region detection unit. FIG. 16B is a data diagram illustrating coefficient values of a weighting filter 304.

FIG. 17A is a data diagram showing a closed region of K ”monochrome image data of a character P. FIG. 17B is a data diagram showing a closed region of C” M ”Y” color image data of a character P.

FIG. 18 is a block diagram illustrating an image comparison and correction unit.

19A is a data diagram showing pixels and lines of K1 monochrome image data. FIG. 19B is a data diagram showing pixels and lines of C1M1Y1 color image data.

20A is a timing chart showing K1 monochrome image data in the main scanning direction. FIG. 20B is a timing chart showing C1M1Y1 color image data in the main scanning direction.

FIG. 21 is a block diagram showing a pseudo resolution conversion unit;

22A is a data diagram showing pixels and lines of K2 monochrome image data. FIG. 22B is a data diagram showing pixels and lines of C2M2Y2 color image data.

23A is a timing chart showing K2 monochrome image data in the main scanning direction. FIG. 23B is a timing chart showing C2M2Y2 color image data in the main scanning direction.

24A is a timing chart showing HSYNC, FIG. 24B is a timing chart showing VCLK, FIG. 24C is a timing chart showing Y2M2C2 image data, FIG. 24D is a timing chart showing VCLK2, and FIG. (F) Timing diagram showing HSYNC2 (g) Timing diagram showing VCLK4 (h) Timing diagram showing K2 image data

(A) Timing diagram showing PSYNCS (b) Timing diagram showing HSYNC (c) Timing diagram showing VCLK2 (d) Timing diagram showing Y2M2C2 video data (e) Timing diagram showing HSYNC2 (f) VCLK4 (G) Timing diagram showing K2 video data

And FIG. 26 is a block diagram showing a printer controller of a conventional color image recording apparatus.

FIG. 27 is a data diagram showing input color image data.

28A is a filter coefficient diagram showing a filter coefficient in a filter unit. FIG. 28B is a filter coefficient diagram showing a filter coefficient in a filter unit.

FIG. 29 is a graph showing characteristics of a density conversion unit.

FIG. 30 is a block diagram illustrating a color conversion unit.

31A is a graph showing R spectral characteristics and ideal spectral characteristics of C ink and toner. FIG. 31B is a graph showing G spectral characteristics and ideal spectral characteristics of M ink and toner. FIG. 31C is a graph showing B spectral characteristics and Y ink. Graph showing ideal spectral characteristics of toner

32A is a graph showing actual spectral characteristics of C ink and toner. FIG. 32B is a graph showing actual spectral characteristics of M ink and toner. FIG. 32C is a graph showing actual spectral characteristics of Y ink and toner.

FIG. 33 is a block diagram showing a UCR unit.

FIG. 34 (a) shows the maximum UCR amount and each image data C ′,
A graph showing the amount of ink with respect to M ′ and Y ′. (B) Each image data K, C ″,
Graph showing ink amounts for M "and Y"

FIG. 35 (a) shows the maximum UCR amount and each image data C ′,
A graph showing the amount of ink with respect to M ′ and Y ′. (B) Each image data K, C ″, and 75% UCR
Graph showing ink amounts for M "and Y"

36A is a memory diagram showing a C region page memory; FIG. 36B is a memory diagram showing an M region page memory; FIG. 36C is a memory diagram showing a Y region page memory;

(A) Timing diagram showing PSYNCS (b) Timing diagram showing HSYNC (c) Timing diagram showing VCLK (d) Timing diagram showing C image data (e) Timing diagram showing M image data (f) ) Timing diagram showing Y image data (g) Timing diagram showing K image data

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Interface part 2 Filter part 3 Density conversion part 4 Color conversion part 5 UCR part 6 Page memory 7 γ correction part 8 Screen processing part 9 Black data replacement part 10 Edge detection part 11 Edge closed area detection part 12 Image comparison correction part 13 Pseudo Resolution conversion unit 100 First complement operation unit 101 Second complement operation unit 102 Third complement operation unit 103 Color masking processing unit 104 Maximum value detection unit 105 Multiplier 106 First subtractor 107 Second subtracter 108 Third subtractor 109 Interface circuit 200 Multiplier 201 Clock doubling circuit 202 Clock doubling circuit 300 First Sobel filter 301 Second Sobel filter 302 Addition and averaging circuit 303 First threshold decision circuit 304 Weighting filter 305 Second threshold decision circuit 306 Toggle circuit 07 binarization processing circuit 308 first comparator 309 second comparator 310 third comparator 311 first shift register 312 second shift register 313 third shift register 314 fourth shift register 315 1 data selector 316 second data selector 317 third data selector 318 fifth shift register 319 sixth shift register 320 seventh shift register 321 eighth shift register 322 fourth data selector 323 fifth Data selector 324 Sixth data selector

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C262 AA24 AA25 AA26 AA27 AB13 AB15 AC02 AC04 AC07 BA02 BA07 BB03 DA03 DA16 5B057 BA30 CA01 CA08 CB01 CB08 CC03 CD05 CE16 CE17 DC17 5C076 AA21 AA22 BA06 BB04 BB40 5C019 MP17 MP0517 PP20 PP33 PP38 PP39 PP47 PQ18 PQ20 PQ22 RR02 TT02 5C079 HB02 HB03 HB12 LA01 LA21 LA24 LA34 LA37 LC11 MA02 MA11 NA04 NA05 NA29 PA02 PA03

Claims (8)

[Claims] 1. A color image recording apparatus comprising: a printer engine for printing video data; and a printer controller for outputting the video data obtained from color image data to the printer engine. The unit inputs the color image data and monochrome image data having a higher resolution than the color image data in parallel, generates K image data based on the input monochrome image data, and converts the YMC image data into the input color image data. A color image recording device, which is generated based on image information. 2. A printer control unit comprising: a UCR unit for generating new K image data from YMC image data; a high-resolution black and white image data input in parallel with the color image data; New K
2. The color image recording apparatus according to claim 1, further comprising a black data replacement unit that replaces the image data. 3. The black data replacement unit according to claim 1, wherein said black data replacement unit is a UCR based on image attribute data input in parallel with YMCK image data.
3. A color image recording apparatus according to claim 2, further comprising a multiplier for giving a ratio. 4. A page memory for storing the replaced high-resolution black-and-white image data and YMC image data, and black-and-white image data and YMC image data corresponding to the same position of the image in the page memory are read out. An edge detector that detects an edge of the monochrome image data and an edge of the read YMC image data; an edge closed region detector that detects a closed region closed by the detected edge; An image comparison / correction unit that compares the closed area with each of the read YMC image data and corrects a shift between the read monochrome image data and each of the read YMC image data. 4. A color image recording apparatus according to claim 2, wherein: 5. The color image recording apparatus according to claim 4, wherein said edge detecting section has one or more Sobel filters and a threshold value judging circuit. 6. The edge closed area detecting section includes a weighting filter for weighting edge information output from the edge detecting section, a threshold value determining circuit for detecting the weighted edge information at a predetermined threshold value, It has a toggle circuit to which the output data of the threshold value judgment circuit is input, and a binarization processing circuit for binarizing the image data, wherein the toggle circuit is enabled and controlled according to the output level of the binarization processing circuit. 6. A color image recording apparatus according to claim 4, wherein 7. When converting YMC image data stored in the page memory into a video signal, dots are added or deleted with reference to edge information of monochrome image data corresponding to the same position of the image of each page. The color image recording apparatus according to claim 4, further comprising a pseudo-resolution conversion unit that performs the conversion. 8. The pseudo-resolution conversion section refers to the edge information of the YMC image data at the processing clock of the black and white image data and simultaneously compares the edge information of the black and white image data. The color image recording apparatus according to claim 7, wherein the correction is performed.