主权项 |
1. An image processing apparatus comprising:
a first halftone processing unit configured to perform halftone processing on multilevel input image data to generate first halftone image data; a first filter unit configured to perform smoothing filter processing on the first halftone image data to generate first filter-processed data, which processing is performed for each pixel of interest referring to a neighboring first region including the pixel of interest; a second filter unit configured to perform smoothing filter processing on the multilevel input image data to generate second filter-processed data, which processing is performed for each pixel of interest referring to the first region; a first difference evaluation unit configured to convert the first filter-processed data, from the first filter unit, and the second filter-processed data, from the second filter unit, to equalize the number of tones per pixel, and calculate a difference between the converted first and second filter-processed data, respectively from the first and second filter units, for each pixel as a first moiré intensity; a third filter unit configured to perform smoothing filter processing on the first halftone image data to generate third filter-processed data, which processing is performed for each pixel of interest referring to a neighboring second region including the pixel of interest, and wherein the second region is smaller than the first region; a fourth filter unit configured to perform smoothing filter processing on the multilevel input image data to generate fourth filter-processed data, which processing is performed for each pixel of interest referring to the second region; a second difference evaluation unit configured to convert the third filter-processed data, from the third filter unit, and the fourth filter-processed data, from the fourth filter unit, to equalize the number of tones per pixel, and calculate a difference between the converted third and fourth filter-processed data, respectively from the third and fourth filter units, 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 based on a feature amount in the multilevel input image data in a predetermined region including the pixel of interest, and output the selected moiré intensity.
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