Patent ID: 8917425

Claim:
An image processing apparatus comprising: a halftone processor configured to apply halftone processing to input image data, and to output halftone image data; an error detector configured to detect errors of respective pixels generated by the halftone processing of said halftone processor by evaluating differences between the input image data and the halftone image data, and to output the errors as error data; a first processor configured to apply correction processing to the halftone image data using the error data, and to output first image data; a second processor configured to apply halftone processing of a higher resolution than the halftone processing of said halftone processor to the input image data, and to output second image data; a change detector configured to detect, from a pixel value of a pixel of the input image data and pixel values of pixels in a first range with reference to that pixel, a change amount of a pixel value at that pixel, and to output change data including change amounts of pixel values at respective pixels; a decision unit configured to decide, for each pixel, a mixing ratio of that pixel using a value based on a sum of an error of the pixel detected by said error detector and a change amount of a pixel value at that pixel detected by said change detector; and a mixing unit configured to mix pixel values of the first image data and the second image data according to the mixing ratios to generate output image data, wherein when the value based on the sum is increased, the mixing ratio of the second image data decided by said decision unit remains the same or is increased.