US Patent 7869092 Image processing apparatus, printing apparatus, and image processing method

In an image processing for printing a monochrome image, color deviation can be suppressed to print a favorable monochrome image. Specifically, the printing of a monochrome image is performed by using black ink in all of a color reproduction region (color gamut) including a gray axis and regions other than the gray axis. This avoids the use of C, M, and Y for the expression of the monochrome image to suppress the color deviation due to slight imbalance among amounts of three colors of inks.