Correcting sharing ratios of nozzle groups in overlapping image region and correcting color conversion table based thereon

An image processing device for generating, based on image data, printing data used to cause a printing apparatus to execute printing, the printing apparatus being configured to cause a first nozzle group and a second nozzle group to discharge ink droplets to form dots on a printing medium to print a print image based on the image data, the image processing device comprising:

• a sharing ratio correction unit configured to correct, in accordance with a degree of reduction in a dot coverage below a predetermined dot coverage in an overlapping image region that undergoes printing by the first nozzle group and the second nozzle group, at least either of a first sharing ratio for the first nozzle group sharing positions of the dots to be formed in the overlapping image region and a second sharing ratio for the second nozzle group sharing positions of the dots to be formed in the overlapping image region to allow a total ratio of the first sharing ratio and the second sharing ratio to exceed 100%;
• and
• a color correction unit configured to correct a color conversion table used to convert color space data of the image data corresponding to the overlapping image region into color space data of the printing data to correct color of a print image of the overlapping image region printed based on the first sharing ratio and the second sharing ratio after the correcting of at least either of the first sharing ratio and the second sharing ratio by the sharing ratio correction unit.

A printing system comprising:

• a printing apparatus configured to cause a first nozzle group and a second nozzle group to discharge ink droplets to form dots on a printing medium to print a print image based on image data;
• and
• an image processing device that includes
• a sharing ratio correction unit configured to correct, in accordance with a degree of reduction in a dot coverage below a predetermined dot coverage in an overlapping image region that undergoes printing by the first nozzle group and the second nozzle group, at least either of a first sharing ratio for the first nozzle group sharing positions of the dots to be formed in the overlapping image region and a second sharing ratio for the second nozzle group sharing positions of the dots to be formed in the overlapping image region to allow a total ratio of the first sharing ratio and the second sharing ratio to exceed 100%, and
• a color correction unit configured to correct a color conversion table used to convert color space data of the image data corresponding to the overlapping image region into color space data of printing data to correct color of a print image of the overlapping image region printed based on the first sharing ratio and the second sharing ratio after the correcting of at least either of the first sharing ratio and the second sharing ratio by the sharing ratio correction unit,
• wherein the image processing device is configured to generate, based on the image data, the printing data used to cause the printing apparatus to execute printing.

A color conversion table creation method for creating a color conversion table used to convert color space data of image data into color space data of printing data used to cause a printing apparatus to perform printing, the printing apparatus being configured to cause a first nozzle group and a second nozzle group to discharge ink droplets to form dots on a printing medium, the color conversion table creation method comprising:

• performing first printing for forming a first print image based on image data having a single concentration, based on a color conversion table before correction, in an overlapping image region that undergoes printing by the first nozzle group and the second nozzle group and a non-overlapping image region that undergoes printing by the first nozzle group or the second nozzle group;
• correcting, in accordance with a degree of reduction in a dot coverage in the first print image formed in the overlapping image region relative to a dot coverage in the first print image formed in the non-overlapping image region, at least either of a first sharing ratio for the first nozzle group sharing positions of the dots to be formed in the overlapping image region and a second sharing ratio for the second nozzle group sharing positions of the dots to be formed in the overlapping image region to allow a total ratio of the first sharing ratio and the second sharing ratio to exceed 100%;
• performing second printing for forming a second print image based on image data having a single concentration, based on the color conversion table before correction and the first sharing ratio and the second sharing ratio after the correcting of at least either of the first sharing ratio and the second sharing ratio, in the overlapping image region and the non-overlapping image region;
• and
• correcting the color conversion table before correction based on the second print image to create a color conversion table used to convert color space data of image data corresponding to the overlapping image region into color space data of printing data corresponding to the overlapping image region.