Provided are a control apparatus, an image processing method and a non-transitory recording medium. A hardware processor of the control apparatus controls the amount of color materials to be used in printing a source image together with a white base by adjusting pixel values of multi-valued pixels forming the source image and white base, and converts the multi-valued pixels into two-valued pixels corresponding to colors of the color materials of the source image and two-valued white pixels. In controlling the amount of color materials, the hardware processor, for each multi-valued pixel of the white base, defines the pixel value such that colored two-valued white pixels exist in a coverage ratio being equal to or greater than the total coverage ratio of the color materials of the source image. The hardware processor rearranges the two-valued white pixels so that colored two-valued white pixels are located at all the colored pixel positions.