Color conversion processing apparatus, color conversion processing method and storage medium

A color conversion processing method of converting a signal value of an input image into an output value of an actual color material used in an image forming apparatus, the method comprising the steps of:

• acquiring a printing setting for the input image;
• and
• converting the signal value of the input image into the output value of the actual color material in accordance with the acquired printing setting, wherein
• at the conversion step, the conversion is performed while maintaining a relationship between the signal value of the input image and output values of a virtual color material,
• the number of virtual color materials is smaller than the number of actual color materials and the respective virtual color materials have respective densities corresponding to respective wavelength bands obtained by dividing a wavelength range reproduced by the actual color materials being output into a plurality of wavelength bands,
• the output values of the plurality of virtual color materials are determined based on the respective densities corresponding to the respective wavelength bands, and
• the relationship is a relationship that increases monotonically and whose secondary differential does not become negative.

A non-transitory computer readable storage medium storing a program for causing a computer to perform a color conversion processing method of converting a signal value of an input image into an output value of an actual color material used in an image forming apparatus, the method comprising the steps of:

• acquiring a printing setting for the input image;
• and
• converting the signal value of the input image into the output value of the actual color material in accordance with the acquired printing setting, wherein
• at the conversion step, the conversion is performed while maintaining a relationship between the signal value of the input image and output values of a virtual color material,
• the number of virtual color materials is smaller than the number of actual color materials and the respective virtual color materials have respective densities corresponding to respective wavelength band obtained by dividing a wavelength range reproduced by the actual color materials being output into a plurality of wavelength bands,
• the output values of the plurality of virtual color materials are determined based on the respective densities corresponding to the respective wavelength bands, and
• the relationship is a relationship that increases monotonically and whose secondary differential does not become negative.