Patent ID: 7855809

Claim:
An image processing apparatus for executing an error diffusion process to color data having a plurality of density components including at least first and second density components, comprising: a processor and a memory; a first processing unit that modulates at least one of a quantization threshold value and a quantization diffusion coefficient on the basis of the first density component, and executes the error diffusion process to the first density component by using at least one of the modulated quantization threshold value and the modulated quantization diffusion coefficient; and a second processing unit that executes the error diffusion process to the second density component by using a fixed quantization threshold value and a fixed quantization diffusion coefficient, wherein the error diffusion process executed by the second processing unit requires a lighter processing load than the error diffusion process executed by the first processing unit, wherein a color reproduced by an image forming unit according to the first density component is similar to a color reproduced by the image forming unit according to the second density component, and wherein a highest density reproducible by the image forming unit according to the first density component is lower than a highest density reproducible by the image forming unit according to the second density component.