Look up Table (LUT) Method for Image Halftoning
نویسندگان
چکیده
Recently we have applied Look Up Table (LUT) Method for inverse halftoning. We also proposed tree-structure LUT inverse halftoning in order to reduce memory requirements of the LUT method. In this paper we introduce LUT based halftoning method. Pixels from a causal neighborhood and the contone value of the current pixel will be included in the LUT. The LUT halftoning will require no arithmetic operations other than memory access. For any halftoning method, a sample set of images and halftones of these images will be used. We will then introduce tree-structure LUT (TLUT) halftoning. Even though this method is more complex than LUT halftoning it produces better halftones and it requires much less storage than LUT halftoning. We will demonstrate how error diffusion characteristics can be achieved with this method. Afterwards, our algorithm will be trained on halftones obtained by Direct Binary Search (DBS) images. The complexity of tree-structure LUT halftoning is higher than error diffusion algorithm but much lower than DBS algorithm. Also, the halftone quality of TLUT halftoning increases if the size of TLUT gets bigger. Thus, halftone image quality between error diffusion and DBS will be achi– eved depending on the size of tree-structure in TLUT algorithm.
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Look-up table (LUT) method for inverse halftoning
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