Color material usage estimating image processing apparatus, image forming apparatus, image processing method, and computer-readable recording medium on which image processing program is recorded

An image processing method executed in an image processing apparatus connected to an image display device capable of displaying an image so as to perform data communication with each other, the image processing method comprising:

• a two color process step of generating, based on input image data of RGB inputted by reading an original document, image data of CMY for outputting a two-color image formed of two colors of a chromatic color and an achromatic color;
• a color material usage estimation and calculation step of calculating, based on the image data of CMY generated in the two color process step, a usage of color materials used in outputting the two-color image and generating information concerning the usage of color materials from a result of the calculation;
• and
• a color correction step of generating, based on the input image data of RGB, image data of CMY for outputting a full-color image,
• the color-material-usage estimation and calculation step including outputting the generated information concerning the usage of color materials to the image display device, and
• the color material usage estimation and calculation step including calculating, based on the image data of CMY generated in the color correction step, a first usage that is a usage of color materials used in outputting the full-color image, calculating, based on the image data of CMY generated in the two color process step, a second usage that is a usage of color materials used in outputting the two-color image, and generating, from results of the calculations, as information concerning a usage of color materials, information representing a comparison of the first usage and the second usage.