Digital halftoning method and method for constructing class tiling map
AssigneeNational Taiwan University of Science and Technology
InventorsJing-ming Guo, Yun-fu Liu
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Abstract
A digital halftoning method and a method for constructing a class tiling map are disclosed. The present invention utilizes to arrange class matrixes in a staggering form such that adjacent class matrixes exist a staggering shift. Also, the class tiling map is constructed in this way. Then, a dot diffusion procedure is performed to an original image with the class tiling map so as to generate a halftone image corresponding to the original image. The present invention is capable of solving the problem of a periodic appearance caused by traditional dot diffusion.
Claims10
A digital halftoning method, comprising steps of:
- (a1) providing a class matrix and a diffused matrix, the class matrix recording a sequence to process each pixel in an image block, the diffused matrix recording diffused weightings for propagating errors to neighbor pixels;
- (a2) performing a similarity operation to the class matrix for obtaining a plurality of similar class matrixes, the class matrix and the similar class matrixes constituting a class matrix set;
- (a3) selecting appropriate class matrixes from the class matrix set and arranging the selected class matrixes in a staggering form to construct a class tiling map, in which adjacent class matrixes exist a staggering shift;
- and
- (a4) processing an original image by performing a dot diffusion procedure with the class tiling map and the diffused matrix to generate a halftone image corresponding to the original image.
A method for constructing a class tiling map, comprising steps of:
- (d1) performing a similarity operation to a class matrix to obtain a plurality of similar class matrixes, the class matrix and the similar class matrixes constituting a class matrix set;
- and
- (d2) selecting appropriate class matrixes from the class matrix set and arranging the selected class matrixes in a staggering form to construct the class tiling map, in which adjacent class matrixes exist a staggering shift.
Dependencies are inferred from the claim text.