Image processing apparatus, image processing method, and storage medium that convert an input luminance signal included in image data into an output signal for printing by using a conversion parameter

An image processing method comprising:

• obtaining image data;
• converting an input luminance signal included in the image data into an output luminance signal for an image printing apparatus by using a conversion parameter such that a dynamic range of luminance of the converted image data is narrower than that of the image data;
• and
• generating image data printable by the image printing apparatus,
• wherein, in a case when the input luminance signal indicates an input black reference luminance value, the output luminance signal indicates an output black reference luminance value, and,
• in a case when the input luminance signal indicates a predetermined reference input luminance value, the output luminance signal indicates a reference output luminance value, the reference output luminance value being a value calculated based on the predetermined reference input luminance value and the output black reference luminance value for observing a print product to be printed by the image printing apparatus.

A non-transitory computer readable storage medium storing a program that causes a computer to perform the functions of an image processing method, the image processing method comprising:

• obtaining image data;
• converting an input luminance signal included in the image data into an output luminance signal for an image printing apparatus by using a conversion parameter such that a dynamic range of luminance of the converted image data is narrower than that of the image data;
• and
• generating image data printable by the image printing apparatus,
• wherein, in a case when the input luminance signal indicates an input black reference luminance value, the output luminance signal indicates an output black reference luminance value, and,
• in a case when the input luminance signal indicates a predetermined reference input luminance value, the output luminance signal indicates a reference output luminance value, the reference output luminance value being a value calculated based on the predetermined reference input luminance value and the output black reference luminance value for observing a print product to be printed by the image printing apparatus.