An image processing apparatus may include a conversion unit, a determination unit, and a calculation unit to convert image data into color material data indicating a chromatic color material amount and an achromatic color material amount. The conversion unit converts image data of a pixel of interest into chromatic color material color material data. The determination unit determines achromatic color material color material data on the pixel of interest based on coloring information corresponding to the converted color material data of the chromatic color material and coloring information that occurs at surrounding pixels that surround the interest pixel. The calculation unit calculates coloring information that occurs at the interest pixel based on coloring information corresponding to a combination of the converted color material data of the chromatic color material and the determined color material data of the achromatic color material and the coloring information that occurs at the surrounding pixels.