To provide a threshold matrix, which can obtain a visually preferable output image even in the case that a very high image quality is required by a simple processing method of an organized dither method, and a method and device for gradation reproduction using it.
The threshold matrix is generated by performing processing which giving a repulsion potential to each dot of a dot pattern of each gradation to determine the dot position for determination of a dot pattern representing an adjacent gradations and when this threshold matrix is used to perform gradation conversion processing of an input image having a uniform density corresponding to the size of the threshold, it has an isotropic and acyclic dot pattern of less low frequency components and has an anisotropic and cyclic or pseudo- periodic dot pattern at least in the vicinity of the lowest gradation or the highest gradation.
HIRAI SHINYA
SUZUKI TAKASHI
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