There is provided an image processing apparatus comprising: a first halftone processing unit configured to perform halftone processing on multilevel input image data; a first filter unit configured to perform smoothing filter processing on the first halftone image data; a second filter unit configured to perform smoothing filter processing on the multilevel input image data; a first difference evaluation unit configured to calculate a difference between the converted first and second filter-processed data for each pixel as a first moiré intensity; a third filter unit; a fourth filter unit; a second difference evaluation unit configured to calculate a difference between the converted third and fourth filter-processed data for each pixel as a second moiré intensity; and a moiré intensity selection unit configured to select one of the first moiré intensity and the second moiré intensity.