Patent ID: 7973976

Claim:
A dither matrix generator, comprising: a main-cluster generator that generates at least one main-cluster in a matrix, the matrix including a plurality of cells, the main cluster area including a predetermined number of cells; a sparsest searcher that searches for a sparsest area in the matrix, the sparsest area being the area other than the area of the main-cluster; a sub-cluster generator that generates at least one sub-cluster area in the sparsest area of the matrix, the sub-cluster area including a smaller number of cells than that of the main-cluster, the sub-cluster being generated in a part of the matrix other than that of the main cluster; and a dither value allocator that allocates dither values to the plurality of cells of the matrix, the cells in the main-clusters having smaller dither values than those in the sub-cluster areas, the cells in the sub-cluster areas having smaller dither values than those in the areas other than the main-cluster and the sub-cluster areas.