| 摘要 |
PROBLEM TO BE SOLVED: To easily and accurately calculate, for a distribution curve by histogram of reproduction page data, SNR of reproduction data without referring to original page data before recording even if respective distribution of white and black elements are mutually overlapped. SOLUTION: In separation of white and black signal distributions, the higher luminance side from a high luminance-side peak position of the distribution curve is taken as section A, a lower luminance side from a low luminance-side peak position as section C, and the space between the sections A and C as section B. The distribution of the section A and the distribution of the section C are composed of only white signal and only black signal, respectively. Dispersionσ2 and average valueμare determined respectively for white signal and black signal from the respective sections, and SNR value is calculated using these parameters. COPYRIGHT: (C)2008,JPO&INPIT
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