JP2006197415A - Color image processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently prepare a profile proper to the use application of a printer and a paper type by changing the color constitution of a color patch in a color chart, in response to the usage application of the printer and the paper type. <P>SOLUTION: This color image processor prepares a profile for reducing a variation in print color characteristics of the printer. The color image processor is provided with a color chart preparing means for determining the arrangement of color patches constituting a color chart and color constitution, a storing means for reading measured values of individual color patches and storing past measured results and new measured results, and a profile preparing means for preparing a profile on the basis of the measured results. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a color image processing apparatus that generates a profile for reducing variations in print color characteristics of a printer.

  In general, when a monitor image signal is output using a printer, color conversion or color correction image processing is performed so that the appearance on the monitor is close to the appearance of the printer output. In this case, color conversion and color correction often use a look-up table called a profile. The profile is created based on the measurement values of the color patches in the color chart output from the printer. However, the usage of the printer (for example, photo image / document image / specific color) and the type of paper (for example, normal) Depending on the paper / glossy paper, etc., a plurality of profiles may be created. Therefore, it is desirable to use a color chart in which colors are arranged efficiently.

As a conventional technique for creating a profile, Patent Document 1 uses a color chart composed of a print color characteristic measurement patch and a plurality of correction patches of the same color, and calculates variations and average values of colorimetric values. A color image processing apparatus that corrects colorimetric values and creates a profile is disclosed.
JP 2001-320592 A

  According to the color image processing apparatus described in Patent Document 1, there are a plurality of patches of the same color in the same sheet, and correction of the measured value with reference to the measured value variation makes it possible to prevent variations in the printer over time. It is possible to respond to this. However, in this apparatus, since the same color is measured a plurality of times, the measured value is estimated by interpolation processing for a color that has not been measured. For this reason, there is a problem that the gradation of the profile is easily broken.

  The present invention has been made in consideration of such problems, and by changing the color configuration of the color patch in the color chart according to the usage of the printer and the type of paper, the usage of the printer and the paper The purpose is to efficiently create a profile suitable for each type.

  According to a first aspect of the present invention, there is provided a color image processing apparatus for creating a profile for reducing variations in printing color characteristics of a printer, and determining the arrangement and color configuration of color patches constituting a color chart. It comprises a chart creation means, storage means for reading measured values of individual color patches, storing past measurement results and new measurement results, and profile creation means for creating a profile based on the measurement results, To do.

  The invention according to claim 2 is the color image processing apparatus according to claim 1, wherein the color chart creating means corresponds to a low / medium saturation portion when determining a color configuration of a color patch in the color chart. It is characterized in that more colors are arranged than the color corresponding to the high saturation portion.

  According to a third aspect of the present invention, there is provided the color image processing apparatus according to the first aspect, wherein the color chart creating means determines the color corresponding to the high saturation portion when determining the color configuration of the color patch in the color chart. It is characterized by arranging more than the colors corresponding to the low and medium saturation portions.

  According to a fourth aspect of the present invention, in the color image processing apparatus according to the first aspect, the color chart creating means determines the color composition of the color patch in the color chart when the specific color and the periphery of the specific color are determined. More specific colors are arranged than the specific color and colors not corresponding to the periphery of the specific color.

  A fifth aspect of the present invention is the color image processing apparatus according to any one of the second to fourth aspects, wherein the color chart creating means determines the color configuration of the color patches in the color chart. The color configuration is determined by referring to the measurement results for each paper type used in the past.

  A sixth aspect of the present invention is the color image processing apparatus according to the first aspect, wherein the storage means uses vector quantization when storing past measurement results and new measurement results. To do.

  According to the present invention, the color chart creating means determines the arrangement and color configuration of the color patches constituting the color chart, and the storage means reads the measured values of the individual color patches, and the past measurement results and new measurement results. Since the profile creation means creates a profile based on the measurement result, the color configuration of the color patch in the color chart can be changed according to the usage of the printer and the paper type. As a result, a profile suitable for the intended use of the printer and the paper type can be created efficiently.

  The color image processing apparatus of the present invention includes color chart creation means, storage means, and profile creation means. The color chart creation means determines the arrangement and color composition of the color patches constituting the color chart, and the storage means reads the measurement values of the individual color patches, stores the past measurement results and the new measurement results, The profile creation means creates a profile based on the measurement result. As a result, a profile corresponding to the characteristics of the printer can be created.

  Here, when determining the color configuration of the color patch in the color chart, the color chart creating means arranges more colors corresponding to the low and middle saturation portions than colors corresponding to the high saturation portions. As a result, the color reproducibility of an image that places importance on the low and medium saturation portions can be improved. At this time, the color chart creation means can determine the color configuration with reference to the measurement results for each paper type used in the past, and can thereby absorb the temporal variation of the low and medium saturation portions. It becomes.

  The color chart creation means can also arrange more colors corresponding to the high saturation portion than colors corresponding to the low and middle saturation portions when determining the color configuration of the color patch in the color chart. As a result, the color reproducibility of an image that places importance on the high saturation portion can be improved. At this time, the color chart creating means can determine the color configuration with reference to the measurement result for each paper type used in the past, and can thereby absorb the temporal variation of the high saturation portion. .

  Furthermore, when determining the color configuration of the color patch in the color chart, the color chart creating unit arranges more colors that correspond to the specific color and the specific color and the surrounding colors than the specific color and a color that does not correspond to the specific color and the surrounding area. It is possible. As a result, the color reproducibility of the specific color can be improved. At this time, the color chart creating means can determine the color configuration with reference to the measurement result for each paper type used in the past, and thereby absorbs the specific color and the temporal variation around the specific color. Is possible.

  Note that the storage means can use vector quantization when storing past measurement results and new measurement results, which enables automatic determination of color patch placement based on numerical criteria. It becomes.

  FIG. 1 shows the configuration of a color image processing apparatus according to an embodiment of the present invention. The color image processing apparatus 1 includes a server 2 that performs arithmetic processing, a monitor 4, a measuring instrument 5, a printer 6, and a client 3 that interfaces with the printer 6.

  The server 2 includes a CPU 7, a calculation unit 8, a data unit 9, and a data processing unit 10, and the client 3 uses a personal computer or the like, and includes a CPU 11 and a printer driver 12. The printer driver 12 receives input color data (for example, RGB) from an application on the color image processing apparatus 1, and based on the printer profile generated by the color image processing apparatus 1, the data is converted into a format that can be interpreted by the printer 6. The data is converted and transmitted to the printer 6.

  FIG. 2 shows a flowchart of the entire processing procedure in this embodiment, and FIG. 3 shows a data storage format.

  As shown in FIG. 2, the usage of the profile of the printer to be created and the paper type (paper type) used are selected (step S1). Here, in use applications, for example, when outputting a photographic image, a low / medium saturation portion is selected, and when outputting a graph or character image, a high saturation portion is selected, and a photographic image is selected. When a specific color (for example, human skin) is output, the specific color and the vicinity of the specific color are selected. For the paper type used, for example, glossy paper is selected when outputting a photographic image, and plain paper is selected when outputting a graph or character image.

  After selecting the above usage and paper type, the color configuration of the color patch is determined (step S2). From the data part 9, the low medium saturation part / high saturation part / specific color component values for each paper type are acquired. In FIG. 2, the data structure is configured as an upper layer of paper type in FIG. 2, but the data structure may be changed according to the number and capacity of data.

  FIG. 3 shows a storage format of data in the data section 9. Measurement data is stored in a format in which a vector obtained by concatenating measurement values (for example, common color signals L, a, and b), a sign of a representative vector having the closest distance, and an error between the measurement value vector and the representative vector Has been. Here, the L value in the common color signal indicates the brightness, the a and b values indicate the hue, and when both the a and b values are 0, the color is achromatic, and the red increases as the a value increases. , The more negative the green becomes. Yellow becomes stronger as the b value becomes positive, and blue becomes stronger as the value becomes negative.

  The representative vector is stored in advance in the data section 9 when the system is constructed, and the number of patches that can be arranged in the color chart when only the low saturation part / high saturation part / specific color is used for each paper type. Just prepare. The representative vector is determined so as to divide the target color space (for example, L, a, b) equally. However, the representative vector may be nonlinearly divided according to the characteristics of the printer. When determining the code for the measurement data, the data processing unit 10 calculates the distance to all the representative vectors, and applies the code of the representative vector with the shortest distance.

  When determining the color composition data of the color patch, acquisition is performed from data having a large quantization error when the colorimetric values are vector-quantized. Further, data is acquired so that the data of the saturation part / specific color selected at the time of selecting the application is larger than the data of the saturation part / specific color not selected at the time of selecting the application (for example, a ratio of 2: 1). .

  After the color configuration data is determined, color patches are arranged (step S3). The patch is arranged based on the above-described error and use at the time of vector quantization, but the saturation part / specific color data selected at the time of use selection is placed at the center of the chart, and the vector quantization error The process is performed so that the one with a large is placed in the center of the chart. Also, patches are arranged with priority on the result of use selection / paper type over vector quantization error. After the patch placement is completed, the placement and color configuration information is stored in the buffer of the data section 9.

  After the arrangement process is completed, a color chart is created (step S4), and the color chart is output from the printer 6 that is a profile creation target. Thereafter, the output color chart is measured by the measuring instrument 5 (step S5), and the data is stored (step S6). The data is saved by acquiring the patch arrangement and color configuration information from the buffer of the data unit 9, capturing the relationship with the measurement result, performing vector quantization by the data processing unit 10, and saving the new measurement result. . After saving the data, a profile creation process is performed using the measurement result (step S7). Through the above processing, the color configuration of the color patch in the color chart can be changed according to the usage and paper type of the printer, and a profile suitable for the usage and paper type of the printer can be efficiently created. .

It is a block diagram which shows the structure in one Embodiment of this invention. It is a flowchart which shows a process sequence. It is explanatory drawing which shows the preservation | save format of data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color image processing apparatus 2 Server 3 Client 4 Monitor 5 Measuring instrument 6 Printer 7 CPU
8 Calculation part 9 Data part 11 CPU
12 Printer driver

Claims (6)

In a color image processing apparatus that creates a profile that reduces variations in the printing color characteristics of a printer,
Arrangement of color patches constituting the color chart, color chart creating means for determining the color composition, and
Storage means for reading the measurement values of individual color patches and storing past measurement results and new measurement results;
A color image processing apparatus comprising profile creating means for creating a profile based on the measurement result.   The color chart creation means arranges more colors corresponding to the low and medium saturation portions than colors corresponding to the high saturation portions when determining the color configuration of the color patches in the color chart. The color image processing apparatus according to 1.   The color chart creation means arranges more colors corresponding to the high saturation portion than colors corresponding to the low and medium saturation portions when determining the color configuration of the color patch in the color chart. The color image processing apparatus according to 1.   The color chart creation means, when determining the color configuration of the color patch in the color chart, arranges more colors corresponding to the specific color and the specific color surroundings than colors not corresponding to the specific color and the specific color periphery. The color image processing apparatus according to claim 1.   3. The color chart creating means, when determining a color configuration of a color patch in a color chart, determines a color configuration with reference to a measurement result for each paper type used in the past. 5. A color image processing apparatus according to any one of items 1 to 4.   The color image processing apparatus according to claim 1, wherein the storage unit uses vector quantization when storing past measurement results and new measurement results.

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