JPH09200547A - Color picture recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for a color conversion processing during a color picture recording processing by simply and effectively holding a color converted result, retrieving it at a high speed and reutilizing it. SOLUTION: At the time of converting first color information in color picture data to second color information, a position inside a color converted result holding area 1011 where the first color information is to be held is obtained by a holding position calculation means and whether or not the first color information is held at the position is judged. In the case that it is held, a value after conversion held at the position is used as the second color information. In the case that the converted result is not held, the first color information is converted to the second color information and registered in the color converted result holding area 1011 further.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image recording device. More specifically, the present invention relates to a color image recording apparatus for processing color image data input from an information generating source such as a host computer, converting the color image data into color information for recording a color image, and recording the color information.

[0002]

2. Description of the Related Art In a conventional color image recording apparatus, R (red), G (green), B in input image data is used.
There is one that converts color information represented by (blue) or the like into color information of Y (yellow), M (magenta), C (cyan), and K (black) for recording a color image and records the color information. It was In such a color image recording device,
In particular, when processing color image data, it is necessary to perform color conversion processing for all the pixels forming the image data, so that the time required for the color conversion processing alone is considerably large.

Therefore, each time the color conversion is performed, the color conversion result is held in the color conversion result holding area, and when the color conversion of the next color is performed, is the color conversion result already held? There was one that searched for and used the color conversion result without performing color conversion again if it was held.

[0004]

However, if it takes time to search for and register the color conversion result that needs to be performed every time the color conversion process is performed, even if the color conversion result is held, It may happen that the effect is not obtained.

That is, even if the color conversion result for the color designated value to be converted is held, if the processing time required to retrieve the conversion result becomes long, the actual color conversion process is performed. Even if it can be omitted, the overall processing time will not be shortened so much, and conversely color conversion will be faster.

Therefore, the main object of the present invention is to solve the above-mentioned problems, to simply and effectively hold the color conversion result, and to search and reuse it at high speed.
An object of the present invention is to provide a color image recording apparatus capable of shortening the time required for color conversion processing during color image recording processing.

Another object of the present invention is, in addition to the above-mentioned main object, that when a color conversion result is held, color space identification information for indicating a color space to which the color information before conversion belongs is added and held. It is to provide a color image recording apparatus capable of performing the above.

[0008]

In order to achieve the above-mentioned object, the present invention converts the first color information contained in the color image data received from the information source into the second color information, In a color image recording apparatus that records an image based on the converted second color information, a color that is large enough to hold N color conversion results and that holds color information before and after the conversion in association with each other. From the holding means having the conversion result holding area and the first color information, the maximum prime number S not exceeding N is obtained.
Holding position calculating means for calculating a position in the color conversion result holding area using, and judging means for judging whether or not a desired color conversion result is held in the storage position calculated by the holding position calculating means. When the determination unit determines that the desired color conversion result is not held, an update unit that updates the color conversion result at that position with a new color conversion result, and When it is determined by the determining means that the desired color conversion result is held, the color conversion means that reads out the color conversion result held at that position and uses it as the conversion result is provided. Further, when the color conversion result is held, it is possible to further include a means for adding and holding color space identification information for indicating the color space to which the color information before conversion belongs. Alternatively, it is possible to further comprise a means for obtaining a maximum prime number S that does not exceed the number N of colors that can be held in the color conversion result holding area, according to the capacity of the color conversion result holding area.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION When converting the first color information in the color image data into the second color information, in the color conversion result holding area where the first color information should be held by the holding position calculating means. Is determined, and it is determined whether or not the first color information is held at that position. If it was held,
The converted value held at that position is used as the second color information. When the conversion result is not held, the first color information is converted into the second color information and further registered in the color conversion result holding area.

When holding the color conversion result, the first
By additionally registering the identification information for identifying the color space of the color information, the color information in a plurality of different color spaces can be mixed and processed.

Further, in accordance with the conversion of the capacity of the color conversion result holding area, a prime number S that does not exceed the number N of colors that can be held in the color conversion result holding area is obtained, and this value is used hereafter. And calculate the position in the color conversion holding area.

[0012]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Embodiment 1 <Description of Apparatus Configuration> FIG. 1 is a block diagram showing the configuration of a color image recording apparatus according to this embodiment. 100 in the figure
Reference numeral 1 denotes a color image recording apparatus main body of this embodiment, which receives multi-valued color image data from a host computer and uses the color image data to obtain yellow (Y), magenta (M), cyan (C), black (K). ) Is a color image recording apparatus for generating a binary image pattern for each of the four colors and recording the image by superimposing the patterns of the four colors on a recording sheet.

Color image data processed by the color image recording apparatus of this embodiment is composed of various commands such as commands for instructing drawing of characters, figures and images, commands for specifying colors, and various data following each command. Shall consist of The recording color can be designated for each character or figure, and the designated color is designated by a value in the range of 0 to 255 for each of R, G, and B. The image data is RGB format image data, and each pixel forming the image is represented by 8 bits of RGB, that is, one pixel is represented by 24 bits.

A host computer 1002 supplies color image data to the color image recording apparatus of this embodiment.

Reference numeral 1003 is a reception buffer for temporarily storing the color image data sent from the host computer.

Reference numeral 1004 denotes a CPU that controls the main body of the image recording apparatus according to a program stored in the program ROM 1005.

A program RO 1005 stores a program having an algorithm shown in FIG. 2 for the CPU 1004 to control the main body of the color image recording apparatus.
M.

Reference numeral 1006 denotes a frame memory, which includes Y,
This is a memory that holds a binary image pattern generated for each of M, C, and K colors.

Reference numeral 1007 denotes a color image recording (output) section for recording an image in accordance with a binary image pattern for each color of Y, M, C and K in the frame memory 1006.

A color conversion unit 1008 converts the RGB format color data received as an input by the color image recording apparatus of this embodiment into density values of YMCK colors which are ink colors of the color image recording apparatus. It is a thing.

A color processing parameter storage unit 1009 stores parameters for the masking process used when the color conversion unit 1008 calculates YMCK color information based on RGB information.

Reference numeral 1010 is an output gamma table,
It is a table used for gamma conversion performed in the color conversion calculation process.

Reference numeral 1011 denotes a color conversion result holding area storage unit for holding the color conversion result in the color table converted by the color conversion unit 1008 together with the RGB color information before conversion.

Reference numeral 1012 is a work memory used in various processes of the color image recording apparatus including image data drawing processes.

<Explanation of Processing Operation> The image drawing processing in this embodiment having the above-mentioned structure will be described with reference to FIGS. 2 and 3.

FIG. 2 is a diagram showing a color conversion process of the color image recording apparatus of this embodiment. The color conversion processing according to the present embodiment is performed when a color is designated for a character or a graphic,
This is a process performed on the RGB color information of each pixel when the color image data of the B format is drawn. In this color conversion processing, RGB color information is converted into YMCK color information for image recording.

First, in step S2001, the prime number S is read. This prime number S is the color conversion result holding area (101
It is a value fixed in advance according to the size of 1). In this embodiment, the color conversion result holding area (1011)
Has a size that can hold the color conversion result of 1024 colors. In this case, the prime number S is the maximum prime number 1021 that does not exceed the maximum number of colors (1024) that can be held in the color conversion result holding area.

Next, in step S2002, the position in the color conversion result holding area (1011) is obtained from the RGB value to be color converted and the value of the prime number S. Specifically, when the RGB values (0 to 255) are r, g, and b, respectively,
The color conversion holding area (101
1) Find the position within.

[0030]

## EQU00001 ## Position = (r.times.65536 + g.times.256 + b)% (prime number S) (1) (% is an operator for finding a remainder) That is, as a position, color conversion is performed for a given RGB value. Any of the 0th to (S-1) th positions in the holding area corresponds uniquely.

Next, proceeding to step S2003, the RGB value at the position in the color conversion holding area (1011) just obtained is read.

In step S2004, step S20
The RGB value read in 03 and the RGB value to be converted now are compared to see if they are the same.
Although the position obtained in step S2002 is uniquely determined for each RGB, a plurality of Rs are set at the same position.
Since the GB values may correspond to each other, it is necessary to check whether or not the RGB value to be obtained now matches the RGB value held in the color conversion result holding area (1011).

If it is determined in step S2004 that the RGB values are the same, the flow advances to step S2007 to read the YMCK value held at the position just examined in the color conversion result holding area (1011), and read this value. Is used as the conversion result for the RGB value to be converted. That is, in this case, the conversion result can be obtained without performing a complicated calculation for obtaining the YMCK value from the RGB value.

On the other hand, if it is determined in step S2004 that the RGB values do not match, step S2005.
Proceed to. In this case, the color conversion result holding area (101
This means that different RGB color conversion results are held at the same position in 1). Therefore, since the color conversion result held here cannot be used, step S200
Go to No. 5, YM for the requested RGB color information
CK color information is calculated and obtained.

The conversion (calculation) process for converting RGB into YMCK in step S2005 is performed according to the flow shown in FIG. First, RGB received as input
C obtained by converting the density of each value of
The values of 1, M1 and Y1 are further subjected to undercolor removal processing, and K2
And generate C1, M1, Y1 as C2, M2, Y
Convert to 2. Next, C2, M2 and Y2 are converted into C3, M3 and Y3 by masking conversion. The masking variable performed here is a calculation using a 3 × 3 matrix as shown below.

[0036]

[Equation 2]

After that, gamma (γ) conversion is performed on each of C3, M3, Y3 and K2. These gamma conversion processes are performed using the output gamma table.

After the YMCK value is calculated in step S2005, the process proceeds to step S2006.

In step S2006, the RGB value before conversion and the YMCK value after conversion are stored in the positions obtained in step S2002 in the color conversion holding area (1011). At this time, even if the conversion result of RGB having different values is already stored in the same position, the converted R
The values of GB and YMCK are stored.

As described above, according to the present embodiment, the process of retrieving the color conversion result when performing the color conversion process can be simplified, and the registration process when holding the newly converted color information is also performed. It can be simplified and the processing time required for the color conversion processing can be shortened.

Embodiment 2 In the above embodiment, the color information in the color image data input from the host computer is called RGB format.
There was only color information of the type.

In this embodiment, R is included in the color image data.
Processing in the case where not only GB but also two types of color information of RGB and L ^* a ^* b ^* are mixed will be described.

FIG. 5 is a block diagram showing the arrangement of a color image recording apparatus according to this embodiment. Since the configuration of the color image recording apparatus shown in FIG. 5 is almost the same as the configuration of the apparatus shown in FIG. 1, the same apparatus reference numerals are given to the same apparatus components and the description thereof will be omitted. Here, only the constituent elements characteristic of this embodiment will be described.

This color image recording apparatus processes color image data in which color information of a plurality of color spaces is mixed. Specifically, in addition to the RGB format color information,
It is capable of processing color information in the L ^* a ^* b ^* format. Therefore, as shown in FIG. 7, in the second color conversion result holding area storage unit 1013, in addition to one type of color information such as RGB, conversion results of a plurality of color information can be stored separately. The color information identification information is stored together with the color information.

As the color conversion unit, in addition to the RGB color conversion unit 1008, the second color conversion unit 1 for L ^* a ^* b ^{* is} used.
014 is provided. Color conversion unit 101 for L ^* a ^* b ^*
As shown in FIG. 8, the color conversion performed in No. 4 is first performed as L ^*.
A ^* b ^* is converted into RGB, and thereafter, conversion is performed in the same process as the RGB color conversion unit 1008. At this time, the same color processing parameters and conversion tables as those used by the RGB color conversion unit 1008 are commonly used for conversion.

FIG. 6 is a diagram showing the color conversion processing in this embodiment. When calculating the storage position in step S2002, it was calculated from the respective values of r, g, and b in the first embodiment, but the storage position is obtained by the same calculation formula here. However, the color information to be converted is calculated using each value of L ^* a ^* b ^* .

After that, steps S2008 and S2
In step 003, the color information identification information and the color information value stored in the position just calculated are read. In step S2009, it is determined whether or not both the color space information and the color information value match what is about to be converted. Even if only the color information values match, if the color information identification information does not match,
The stored color conversion result is not available. If both match, the process advances to step S2007 to use the stored color conversion result value as the YMCK conversion value. On the contrary, if they do not match, the YMCK value is calculated again in step S2005. Then, in step S2010, the value of the color space information is stored as the color information identification information together with the YMCK conversion result.

As described above, according to this embodiment, even when the image data in which the color information of a plurality of color spaces is mixed is processed as the color information, the color conversion result is obtained when the color conversion processing is performed. Can be simplified, and the registration processing for holding the newly converted color information can be simplified, and the processing time required for the color conversion processing can be shortened.

Embodiment 3 In the above two embodiments, the size of the area for holding the color conversion result and the prime number S used when retrieving the color conversion result were fixed in advance.

In this embodiment, a process when the size of the color conversion result holding area (1011) changes in page units will be described.

FIG. 9 is a block diagram showing the arrangement of a color image recording apparatus according to this embodiment. Since the configuration of the color image recording apparatus shown in FIG. 9 is almost the same as the configuration of the apparatus shown in FIG. 1, common device constituent elements are designated by the same device reference numerals, and description thereof will be omitted. Here, only the constituent elements characteristic of this embodiment will be described.

In FIG. 9, reference numeral 1015 denotes a color conversion result management area storage unit, which has a memory capacity secured as a color conversion result holding area, the maximum number N of colors that can be stored in the color conversion result holding area, and N. This is an area for storing the largest prime number S that does not exceed. These pieces of information are set at the time of initialization processing for color conversion. The memory capacity secured as the color conversion result holding area is 12 depending on the memory availability at the time of initialization processing for color conversion.
It shall be any of 8K, 64K, 16K, 4K and 1K bytes.

In FIG. 9, 1016 is a prime number table,
It is a table in which a maximum prime number S corresponding to a size assigned as a color conversion result holding area is stored.

FIG. 10 is a flow chart showing the contents of the initialization processing for color conversion. By this initialization processing, the color conversion result holding area and the color conversion result management area are initialized.

First, if the color conversion result holding area is already secured in step S3001, the area is released. After that, the process advances to step S3002,
Determine the size of the color conversion result storage area. In particular,
128K, 64 depending on the amount of free memory at this point
The maximum capacity that can be secured is selected from among K, 16K, 4K, and 1K bytes. The size information determined here is stored in the color conversion result management area.

Next, in step S3003, the color conversion result storage area is actually reserved from the free memory. afterwards,
In step S3004, the color conversion result storage area is initialized. Further, the process proceeds to step S3005, in which the prime number S corresponding to the size of the color conversion result storage area is obtained from the prime numbers stored in advance in the prime number table, and this value is stored in the color conversion result management area. deep.

The prime number S and the color conversion result storage area set as described above are used in the subsequent color conversion processing.

The procedure for performing the color conversion process is basically the same as that shown in the above embodiment. However, instead of storing the RGB color information in the color conversion result holding area, it is also possible to hold and process the value after density conversion in the color conversion process shown in FIG. 4 (see FIG. 11). less than,
The procedure of the color conversion process in this case will be described with reference to FIG.

In FIG. 12, steps S2001 and S200.
In 2, the prime number S stored in the color conversion result management area
Is used to find the position where the color information is stored. next,
In step S2011, the RGB values to be converted are subjected to density conversion. In step S2012, the density value at a predetermined position in the color conversion result holding area is read, and the flow advances to step S2013.

In step S2013, step S20
It is determined whether or not the density value obtained in 11 matches the density value read in step S2012. If they match, the YMC stored in step S2007.
The K value is read and this is used as the conversion value. On the other hand, if the two density values do not match, step S2014
Proceed to. Here, the value of YMCK is calculated, but since the density conversion in the conversion processing shown in FIG. 4 is performed in step S2011, the value at this time is used to perform the conversion after the undercolor removal.

In step S2015, the value after density conversion and the finally obtained YMCK value are held in the color conversion result holding area.

As described above, the RG in the image data
By storing the color information after density conversion instead of the B information, especially when the total number of combinations of density values after density conversion is smaller than the total number of combinations of RGB values, color conversion is performed. The probability that the value after color conversion is stored in the result holding area is improved, and as a result, the time required for color conversion processing can be shortened.

Also, when the size of the color conversion result holding area (1011) is changed in response to the downloading of a large number of fonts or the registration of overlay pages, the efficiency of memory usage can be improved as compared with the case of a fixed size. Similarly, the process of holding and retrieving the color conversion result can be simplified.

[0064]

As described above, according to the present invention,
By simplifying the process of holding and retrieving the result of conversion into the color information for image recording, it is possible to shorten the time required for the color conversion process during image processing when recording a color image.

More specifically, according to the present invention, even when the image data in which the color information of a plurality of color spaces are mixed as the color information is processed, the color conversion result is obtained when the color conversion processing is performed. Can be simplified, and the registration processing for holding the newly converted color information can be simplified, and the processing time required for the color conversion processing can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a flowchart showing a color conversion process executed by a CPU (1004) shown in FIG.

FIG. 3 is a diagram illustrating the contents of a color processing result holding area according to the first embodiment.

FIG. 4 is a diagram illustrating a conversion (calculation) process from RGB to YMCK.

FIG. 5 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is a flowchart showing a color conversion process executed by a CPU (1004) shown in FIG.

FIG. 7 is a diagram illustrating the contents of a color processing result holding area according to the second embodiment.

FIG. 8 is a diagram illustrating a conversion (calculation) process from L ^* a ^* b ^* to YMCK.

FIG. 9 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 10 is a flowchart showing an initialization process for color conversion.

FIG. 11 is a diagram illustrating the contents of a color processing result holding area according to the third embodiment.

FIG. 12 is a flowchart showing a color conversion process according to the third embodiment of the present invention.

[Explanation of symbols]

 1001 color image recording apparatus main body 1002 host computer 1003 reception buffer 1004 CPU 1005 program ROM 1006 frame memory 1007 color image recording unit 1008 color conversion unit 1009 color processing parameter storage unit 1010 output gamma table 1011 color conversion result holding area storage unit 1012 work memory 1013 Second color conversion result holding area storage unit 1014 Second color conversion unit

Claims (10)

[Claims] 1. The first color information included in the color image data received from the information source is converted into second color information,
In a color image recording device for recording an image based on the converted second color information, a color having a size capable of holding N color conversion results and holding color information before and after the conversion in association with each other. Holding means having a conversion result holding area; holding position calculating means for calculating a position in the color conversion result holding area from the first color information using a maximum prime number S not exceeding N; A determination unit that determines whether or not the desired color conversion result is stored in the storage position calculated by the calculation unit, and if the determination unit determines that the desired color conversion result is not stored, An updating unit that updates the color conversion result at the position with a new color conversion result, and the position when the determination unit determines that the desired color conversion result is held. In Color image recording apparatus characterized by comprising a color converter to be used as the conversion result read the color conversion result being. 2. The method according to claim 1, further comprising means for adding and holding color space identification information for indicating a color space to which the color information before conversion belongs when holding the color conversion result. Color image recording device. 3. The method according to claim 1, further comprising means for determining a maximum prime number S that does not exceed the number N of colors that can be held in the color conversion result holding area, in accordance with the capacity of the color conversion result holding area. Characteristic color image recording device. 4. The color image recording apparatus according to claim 1, wherein multi-valued color image data is received from a host computer, and yellow (Y), (magenta (M), cyan (C), A color image recording apparatus, wherein a binary image pattern for each of the four colors of black (K) is generated, and an image is recorded by superimposing the pattern of the four colors on a recording sheet. 5. The color image data according to claim 4, wherein the color image data is a command for instructing drawing of characters, figures, and images.
In addition, a color image recording apparatus including a command for specifying a color and various data following each command. 6. The color image recording apparatus according to claim 1, wherein the holding unit having the color conversion result holding area holds the color conversion result together with the RGB color information before conversion. 7. A color image recording apparatus according to claim 6, wherein in the color conversion processing, RGB color information is converted into YMCK color information for image recording. 8. The color image recording apparatus according to claim 1, wherein the color image recording apparatus processes color image data in which color information of a plurality of color spaces is mixed. 9. The color conversion result holding area according to claim 8, wherein color information identification information capable of separately storing conversion results of a plurality of color information other than RGB or other type of color information is stored together with the color information. A color image recording apparatus characterized by: 10. A color image recording apparatus according to claim 1, further comprising means for variably setting the value of said prime number S.