Profile adjustment method, profile adjustment apparatus, and profile adjustment system

A profile adjustment apparatus that adjusts an adjustment target profile among a plurality of profiles including an input profile expressing a correspondence relationship between first coordinate values in a first device-dependent color space and device-independent coordinate values in a profile connection space and an output profile expressing a correspondence relationship between the device-independent coordinate values and second coordinate values in a second device-dependent color space, the profile adjustment apparatus comprising:

• the output profile including a first conversion table for converting the device-independent coordinate values into the second coordinate values and a second conversion table for converting the second coordinate values into the device-independent coordinate values;
• a target reception unit configured to receive an adjustment target at an adjustment point, using coordinates in a profile connection space as a reference;
• a conversion unit configured to convert the device-independent coordinate values at the adjustment point into the second coordinate values in accordance with the first conversion table, and convert the second coordinate values into adjustment target PCS values as the device-independent coordinate values, in accordance with the second conversion table;
• an optimizing unit configured to, when values obtained by adding relative values of the adjustment target using the coordinates in the profile connection space as a reference to the adjustment target PCS values are assumed as target PCS values, the second coordinate values at the adjustment point are assumed as adjustment target color values, and values added to the adjustment target color values are assumed as adjustment color values, obtain an optimal solution of the adjustment color values through an optimization process including an element that brings provisional PCS values, obtained by converting, according to the second conversion table, provisional color values obtained by adding the adjustment color values to the adjustment target color values, closer to the target PCS values;
• and
• a profile adjustment unit configured to adjust the adjustment target profile based on the optimal solution of the adjustment color values.

A profile adjustment system that adjusts an adjustment target profile among a plurality of profiles including an input profile expressing a correspondence relationship between first coordinate values in a first device-dependent color space and device-independent coordinate values in a profile connection space and an output profile expressing a correspondence relationship between the device-independent coordinate values and second coordinate values in a second device-dependent color space, the profile adjustment system comprising:

• the output profile including a first conversion table for converting the device-independent coordinate values into the second coordinate values and a second conversion table for converting the second coordinate values into the device-independent coordinate values;
• a printing apparatus configured to print a color chart including a patch;
• a colorimetric device configured to measure the patch;
• a target reception unit configured to receive an adjustment target at an adjustment point, using coordinates in a profile connection space as a reference;
• a conversion unit configured to convert the device-independent coordinate values at the adjustment point into the second coordinate values in accordance with the first conversion table, and convert the second coordinate values into adjustment target PCS values as the device-independent coordinate values, in accordance with the second conversion table;
• an optimizing unit configured to, when values obtained by adding relative values of the adjustment target using the coordinates in the profile connection space as a reference to the adjustment target PCS values are assumed as target PCS values, the second coordinate values at the adjustment point are assumed as adjustment target color values, and values added to the adjustment target color values are assumed as adjustment color values, obtain an optimal solution of the adjustment color values through an optimization process including an element that brings provisional PCS values, obtained by converting, according to the second conversion table, provisional color values obtained by adding the adjustment color values to the adjustment target color values, closer to the target PCS values;
• and
• a profile adjustment unit configured to adjust the adjustment target profile based on the optimal solution of the adjustment color values.