累積濃度2次微分値に基づく濃淡画像のコントラスト変換 [in Japanese] Image Contrast Conversion Based on Accumulated Quadratic Differential Gray-Levels [in Japanese]
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This paper proposes a method for contrast improvement to generate an output image with a balance of higher contrast and visual naturalness. In the proposed method, not only a distribution of all gray-levels in an input image but also a distribution of quadratic differential values at all pixels are used for generating Look-Up-Table. Both a histogram to represent a distribution of gray-levels and a histogram to represent a distribution of quadratic differential values are generated. The frequency of a gray-level is divided by the frequency of the corresponding quadratic differential values to avoid from the increase of noises and from the too strong contrast enhancement with the saturation of brightness. The output images by the proposed method had good balance of higher contrast and visual naturalness without many noises and brightness saturation.
- IEEJ Transactions on Electronics, Information and Systems
IEEJ Transactions on Electronics, Information and Systems 128(4), 593-599, 2008-04-01
The Institute of Electrical Engineers of Japan