Patent ID: 9729757
Date: 2017-08-08
CPC Classifications: H04N

Claim:
1. An image processing apparatus that outputs as an output pixel value a binarized pixel value obtained by binarization of an input pixel value for each component color of an image, comprising: a filter processing unit configured to perform a bandpass filter process for a difference between the output pixel value and the input pixel value of an adjacent pixel to a target pixel; an error diffusion unit configured to perform an error diffusion process of a quantization error for output of the filter processing unit; and a quantizer configured to perform quantization for a value obtained by the error diffusion process and thereby determine the output pixel value of the target pixel; wherein the filter processing unit performs the bandpass filter process with characteristics different from each other (a) in respective ones of a primary scanning direction and a secondary scanning direction and (b) for respective ones of the component colors of the image; and a filter coefficient of the bandpass filter process independently for each one of the component colors of the image is corrected for banding reduction with a correction coefficient corresponding to an angle from the primary scanning direction.