IMAGE PROCESSING APPARATUS AND IMAGE PROCESSING METHOD

Abstract

An object of an input print job is discriminated, and color conversion processing is applied to the object of the print job based on the discrimination result and information which is set in correspondence with the print job and is used to designate color conversion processing. When the object is a transparent object, the color conversion processing is executed on a rendering color space, and when the object is a gradation object, the color conversion processing is executed on a device color space.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing principal processing associated with color processing in a conventional printer;

FIG. 2 is a view for explaining composition processing for combining two graphic data;

FIG. 3 is a view showing an example for executing color matching processing (color space compression) before composition of transparent graphics;

FIG. 4 is a view showing an example for executing color matching processing (color space compression) after composition of transparent graphics;

FIGS. 5A and 5B are views for explaining gradation processing;

FIGS. 6A and 6B are views showing quantization errors in the gradation processing, and CMYK rendering processing;

FIG. 7 is a view showing a method of processing a print job by a multi-color printing apparatus (printer) according to the first embodiment;

FIG. 8 is a block diagram showing an example of the arrangement of the printer according to the first embodiment;

FIG. 9 shows an example of the arrangement of a print processing block and a setting dialog according to the first embodiment;

FIG. 10 is a flowchart showing the division processing of a gradation object;

FIG. 11 is a view showing a method of processing a print job by a printer according to the second embodiment;

FIG. 12 shows an example of the arrangement of a print processing block and setting dialogs according to the second embodiment;

FIG. 13 shows a sequence for determining the number of divisions based on the number of grids of an LUT of a profile upon selection of an automatic setting;

FIG. 14 is a view for explaining an example of inversion of values which are to monotonically change in a color change of gradation upon making interpolation calculations;

FIG. 15 is a view showing a state wherein gradation data enters a color cube from an entrance and leaves the color cube from an exit;

FIG. 16 shows a state wherein one gradation data passes over a plurality of color cubes;

FIG. 17 is a view for explaining correction processing inside a color cube on an upward trend;

FIG. 18 is a view for explaining correction processing inside a color cube on an upward trend;

FIG. 19 is a flowchart showing inversion correction processing according to the third embodiment;

FIG. 20 shows an example of the arrangement of a print processing block and a setting dialog of a UI setting unit according to the third embodiment; and

FIG. 21 shows a setting dialog of a UT setting unit according to the fourth embodiment.

Claims

1. An image processing apparatus comprising: discrimination means for discriminating an object of an input print job; andcolor conversion processing means for performing color conversion processing to the object based on a result of said discrimination means and information which designates color conversion processing set for each print job,wherein, when the object is a transparent object, said color conversion processing unit executes the color conversion processing on a rendering color space, and when the object is a gradation object, said color conversion processing unit executes the color conversion processing on a device color space, andwhen the object is the gradation object, the object is divided into a plurality of objects, color matching processing is applied to end points of the divided objects, and intermediate pixels are formed on the device color space.

2. The apparatus according to claim 1, further comprising processing means for processing the print job in multi-threads, wherein the information which designates the color conversion processing is issued for each job thread.

3. The apparatus according to claim 1, wherein, when the object is a gradation object, a parameter used to designate the gradation object is inputs a data group of the gradation object is formed by color matching processing based on the parameter and a trend changing of color values of the data group is inspected, andintermediate pixel values are calculated by an interpolation calculation from the data group, and when the intermediate pixel values do not monotonically increase or decrease according to the trend changing, the intermediate pixel values are corrected to monotonically increase or decrease.

4. The apparatus according to claim 3, wherein the parameter includes at least color information of a start point of the gradation object, color information of an end point of the gradation object, and the number of pixels to be generated in the gradation object.

5. The apparatus according to claim 3, wherein the interpolation calculation used to calculate the intermediate pixel values is executed by increasing precision.

6. The apparatus according to claim 1, wherein an interpolation calculation method to be applied in the color conversion processing is switched in accordance with a print mode and whether or not to prioritize image quality of the gradation object.

7. An image processing method of an image processing apparatus comprising: a discrimination step of discriminating an object of an input print job; anda color conversion processing step of applying color conversion processing to the object based on a result in the discrimination step and information which designates color conversion processing set for each print job,wherein the color conversion processing step includes a step of executing, when the object is a transparent object, the color conversion processing on a rendering color spacer and executing, when the object is a gradation object, the color conversion processing on a device color space, andwhen the object is the gradation object, the object is divided into a plurality of objects, color matching processing is applied to end points of the divided objects, and intermediate pixels are formed on the device color space.

8. A program, recorded on a computer-readable recording medium, for making a computer execute respective steps of a processing method of an image processing apparatus according to claim 7.

9. A computer-readable recording medium recording a program according to claim 8.

10. An image processing apparatus comprising: means for performing color matching processing to a data group corresponding to a gradation object;means for detecting a trend changing of color to the data group based on a result of the color matching processing, and for obtaining an intermediate pixel by an interpolation calculation from the data group; andmeans for correcting a value of the intermediate pixel when the value of the intermediate pixel does not monotonically increase or decrease according to the trend changing.

11. The apparatus according to claim 10, wherein the color matching processing is performed in accordance with a color ticket issued by an instruction from a user interface.

12. The apparatus according to claim 10, wherein an interpolation calculation method to be applied in the color matching processing is switched in accordance with a print mode and whether or not to prioritize image quality of the gradation object.

13. An image processing method comprising: a step of performing color matching processing to a data group corresponding to a gradation object;a step of detecting a trend changing of color to the data group based on a result of the color matching processing to obtain an intermediate pixel by an interpolation calculation from the data group; anda step of correcting a value of the intermediate pixel when the value of the intermediate pixel does not monotonically increase or decrease according to the trend changing.

14. The method according to claim 13, wherein the color matching processing is performed in accordance with a color ticket issued by an instruction from a user interface.

15. The method according to claim 13, wherein the interpolation calculation method to be applied in the color matching processing is switched in accordance with a print mode and whether or not to prioritize image quality of the gradation object.