JP2003283851A5

JP2003283851A5 -

Info

Publication number: JP2003283851A5
Application number: JP2002078025A
Authority: JP
Filing date: 2002-03-20
Publication date: 2005-08-11
Anticipated expiration: 2022-03-20

Claims

First image data representing the colors of a plurality of pixels constituting an image with a plurality of element colors used in a first image device is acquired, and the colors of the pixels are converted into a plurality of element colors used in a printing apparatus. A print control apparatus that executes printing on a printing apparatus while performing color conversion on the expressed second image data,
When the result of printing with the second image data after color conversion is measured under a plurality of light sources, the average of the color values obtained by each color measurement corresponds to the color represented by the first image data. A printing control apparatus characterized by that.

First image data representing the colors of a plurality of pixels constituting an image with a plurality of element colors used in a first image device is acquired, and the colors of the pixels are converted into a plurality of element colors used in a printing apparatus. A print control apparatus that executes printing on a printing apparatus while performing color conversion on the expressed second image data,
When the specific color expressed by the first image data is color-converted into the second image data, the coordinates of the specific color in the predetermined color space indicate the print result of the color-converted second image data as a specific light source. Color conversion means for performing color conversion so as to be closer to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources than the coordinates in the predetermined color space obtained by color measurement below. A printing control apparatus characterized by that.

The color conversion means includes coordinates in a predetermined color space of at least one specific color and a center of gravity of each coordinate in the predetermined color space obtained by measuring the print result of the second image data under a plurality of light sources. The print control apparatus according to claim 2, wherein the color conversion is performed so that the values are substantially equal.

4. The print control apparatus according to claim 2, wherein the plurality of light sources include at least two of a D system, an A system, and an F system of CIE standard light.

5. The light source according to claim 2, wherein the plurality of light sources include at least two of a CIE standard light ordinary fluorescent lamp, a high color rendering fluorescent lamp, and a three-wavelength fluorescent lamp. The printing control apparatus according to 1.

6. The print control apparatus according to claim 2, wherein the predetermined color space is a uniform color space.

The printing control apparatus according to claim 6, wherein the coordinates of the specific color and the coordinates of the center of gravity are within a distance of 3 or less in the uniform color space.

7. The color conversion apparatus according to claim 6, wherein the color conversion unit performs color conversion so that the specific color and the gravity center are close to each other in a state where the specific color and the center of gravity are projected on a constant brightness plane in a uniform color space. Item 8. The print control apparatus according to any one of Items 7 to 8.

The color conversion means is stored in advance in a predetermined storage medium and performs an interpolation operation with reference to a color conversion table in which the first image data and the second image data are associated with each other for a plurality of representative colors. Color conversion can be performed, and the same color conversion table has data for converting coordinates in the predetermined color space of the specific color into coordinates close to the center of gravity of the coordinates in the predetermined color space. The printing control apparatus according to any one of claims 2 to 8.

The color conversion table includes the coordinates in a predetermined color space obtained by measuring the print result of the second image data under the specific light source and the coordinates in the predetermined color space of the color indicated by the first image data. It is created by correcting the first image data for the original table created by associating both image data. In this correction, the first image data is converted into the second image data and printed by referring to the original table. In this case, the measurement result is measured under a plurality of light sources, the center of gravity of each coordinate in a predetermined color space is obtained, the first image data referred to is changed, and the first image data after the change indicates The printing control apparatus according to claim 9, wherein the coordinates of the color in a predetermined color space are brought close to the coordinates of the center of gravity.

The color conversion table includes the coordinates in a predetermined color space obtained by measuring the print result of the second image data under the specific light source and the coordinates in the predetermined color space of the color indicated by the first image data. It is created by correcting the second image data for the original table created while associating the two image data. In the correction, the second image data of the original table is changed, and the second image data after the change is printed. The center of gravity of the coordinates obtained by measuring the result under a plurality of light sources approaches the coordinates in the predetermined color space of the specific color indicated by the first image data associated with the second image data before the change in the original table. The print control apparatus according to claim 9, wherein the print control apparatus is configured as described above.

The above correction is a result of converting each color corresponding to the vertex in the color space having each element color of the first image data of the original table as an axis variable and a color indicating an achromatic color in the first image data by the original table and printing. Is measured as a first correction for at least one of the colors having the maximum saturation in the predetermined color space when the color is measured under a specific light source, and the first correction is performed for the other image data. The coordinates in the predetermined color space obtained by measuring the color of the second image data indicating the color between the specific color and the specific color corresponding to the vertex in the color space under a specific light source are substantially linear. The print control apparatus according to claim 10, wherein the second correction is performed so as to line up.

The print control apparatus according to claim 2, wherein the specific color is a substantially achromatic color.

The printed material printed based on the input RGB values corresponding to several colors included in the color reproducible range by the printing apparatus is color-measured under the D50 light source, the A light source, and the F light source to obtain the Lab value, Further, when the respective relative Lab values are obtained from the Lab point values of the white point and the black point, the difference between the RGB value corresponding to the average value of the respective relative Lab values and the input RGB value is the RGB corresponding to the relative Lab value of the D50 light source. A printing control apparatus characterized by being smaller than a difference between a value and an input RGB value.

The printed material printed based on the input RGB values corresponding to several colors included in the color reproducible range by the printing apparatus is color-measured under the D50 light source, the A light source, and the F light source to obtain the Lab value, Further, when the relative Lab values are calculated from the Lab point values of the white point and the black point, the difference between the average value of the relative Lab values and the Lab value corresponding to the input RGB value is the relative Lab value of the D50 light source and the input RGB value. Is smaller than the difference from the Lab value corresponding to the print control apparatus.

First image data representing the colors of a plurality of pixels constituting an image with a plurality of element colors used in a first image device is acquired, and the colors of the pixels are converted into a plurality of element colors used in a printing apparatus. A print control method for executing printing on a printing apparatus while performing color conversion on the expressed second image data,
When the specific color expressed by the first image data is color-converted into the second image data, the coordinates of the specific color in the predetermined color space indicate the print result of the color-converted second image data as a specific light source. A color conversion step of performing color conversion so as to be closer to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources than the coordinates in the predetermined color space obtained by performing color measurement below And a printing control method.

A print control program for controlling a printing apparatus according to an image printing instruction and printing the image,
A first image data acquisition function for acquiring first image data in which colors of a plurality of pixels constituting an image are expressed by a plurality of element colors used in a first image device;
A color conversion function for color-converting the color of each pixel expressed by the acquired first image data into second image data expressed by a plurality of element colors used in the printing apparatus;
When the computer realizes a print data output function for designating the color of each pixel in the converted second image data and generating and outputting print data for executing printing in the printing apparatus,
In the color conversion function, when the specific color expressed by the first image data is color-converted to the second image data, the coordinates of the specific color in the predetermined color space are represented by the second image data after the color conversion. Color conversion is performed so that the print result is closer to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources than the coordinates in the predetermined color space obtained by measuring the color under a specific light source. A print control program characterized by that.

A medium on which the print control program according to claim 17 is recorded.

First image data representing the colors of a plurality of pixels constituting an image with a plurality of element colors used in a first image device is acquired, and the colors of the pixels are converted into a plurality of element colors used in a printing apparatus. A color conversion device that performs color conversion to expressed second image data,
When the specific color expressed by the first image data is color-converted into the second image data, the coordinates of the specific color in the predetermined color space indicate the print result of the color-converted second image data as a specific light source. Color conversion means for performing color conversion so as to be closer to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources than the coordinates in the predetermined color space obtained by color measurement below. A color conversion device characterized by that.

First image data representing the colors of a plurality of pixels constituting an image with a plurality of element colors used in a first image device is acquired, and the colors of the pixels are converted into a plurality of element colors used in a printing apparatus. A color conversion method for performing color conversion on the expressed second image data,
When the specific color expressed by the first image data is color-converted into the second image data, the coordinates of the specific color in the predetermined color space indicate the print result of the color-converted second image data as a specific light source. A color conversion step of performing color conversion so as to be closer to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources than the coordinates in the predetermined color space obtained by performing color measurement below A color conversion method characterized by that.

Corresponding first image data in which a plurality of representative colors are expressed by a plurality of element colors used in the first image device and second image data in which the representative colors are expressed by a plurality of element colors used in the printing apparatus In addition, when a predetermined image is printed by a printing apparatus, a method for creating a color conversion table that is referred to when first image data representing the colors of a plurality of pixels constituting the image is converted into second image data is used. There,
Both image data are associated with coordinates in a predetermined color space obtained by measuring the print result of the second image data under the specific light source and coordinates in the predetermined color space of the color indicated by the first image data. A source table creation process for creating a source table;
Referring to the same table, the first image data indicating the specific color is converted into the second image data and printed, and the print result is measured under a plurality of light sources to obtain the coordinates in the predetermined color space. Multiple light source coordinate acquisition step;
A center-of-gravity calculating step of calculating the center of gravity of the coordinates in the predetermined color space obtained by measuring colors under the plurality of light sources;
When the first image data indicating the specific color is converted into the second image data and printing is performed, the coordinates of the specific color in the predetermined color space measure the print result under a specific light source. The first image data or the second image data in the original table is approximated to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources from the obtained coordinates in the predetermined color space. A color conversion table generation method comprising: a color conversion table generation step of correcting and generating a color conversion table.

Corresponding first image data in which a plurality of representative colors are expressed by a plurality of element colors used in the first image device and second image data in which the representative colors are expressed by a plurality of element colors used in the printing apparatus In addition, when a predetermined image is printed by a printing apparatus, the color conversion table is referred to when the first image data expressing the colors of a plurality of pixels constituting the image is converted into second image data.
When the first image data indicating the specific color is converted into the second image data and printing is performed, the coordinates of the specific color in the predetermined color space are obtained by measuring the print result under a specific light source. The correspondence relationship between the first image data and the second image data is defined so as to be closer to the center of gravity of each coordinate in the predetermined color space obtained by measuring colors under a plurality of light sources than the coordinates in the predetermined color space. The color conversion table characterized by being made.