| 摘要 |
PROBLEM TO BE SOLVED: To provide an image transforming device capable of compressing a dynamic range without painting out a dark part black, without making noise of the dark part conspicuous and without graying a white large object (or the area). SOLUTION: By a luminance Y1 of respective pixels of a source image, the luminance Y2 of the pixel of a low frequency image and functions C1 and C2 of the luminance Y2 , the luminance Y3 of the pixel of a transformed image is obtained by Y3 =C1 Y1 +C2 Y2 . Since C1 +C2 is fixed at Y2 <=T2 , contrast decline of low frequency components is prevented. The low frequency image is emphasized in a part where the luminance Y2 is low in the low frequency image and the low frequency image is suppressed in the part where the luminance Y2 is high in the low frequency image. Thus, an image transforming method or the image transforming device can compress the dynamic range without making the noise of the dark part conspicuous and without graying the white large object (or the area, a light part). |
