| 摘要 |
To eliminate artifacts resulting from the quantization of images by means of an error diffusion process, a determination is made whether a current pixel being processed is within a shadow or highlight region of an image. If so, a dot of a complementary value is placed in the region only if a distance constraint between the current pixel and neighbor dots is satisfied. If the distance constraint is not satisfied, the placement of the dot is postponed. The distance constraint is based upon the grayscale level of the current pixel. A road map for determining the distance to other dots is defined in a manner such that it expands further from the location of the current pixel as the grayscale value of that pixel approaches the extreme limits of the grayscale range. As a result, a homogenous distribution of dots in highlight and shadow regions of an image is produced.
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