| 摘要 |
PROBLEM TO BE SOLVED: To correct an image taken against the sun or in a dark place to the extent that it is easily viewable and determinable. SOLUTION: A video signal processor comprises: an image feature detection part 1 that divides the luminance component in a determination region fa from the minimum luminance value to the maximum luminance value of an input video signal screen f into 16 blocks by luminance level, and generates a histogram data showing the distribution of each luminance level; an arithmetic part 2 that finds an average luminance value APL in the determination region fa, and generates an average luminance gain Gapl of the property in which the gain is larger in a case where the average luminance value APL is low than a case where the average luminance value APL is high; and a grey level correction part 3 that provides the lower limit DwLimit of the luminance level in a predetermined low luminance region, and, based on the DwLimit, the histogram data H[i], and the average luminance gain Gapl, corrects the grey level in the determination region fa by generating a grey level correction curve of the property in which the luminance level in the predetermined low luminance region does not fall below the lower limit DwLimit. COPYRIGHT: (C)2008,JPO&INPIT
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