| 摘要 |
PROBLEM TO BE SOLVED: To reduce the capacity of a memory to be used and an operation quantity, to easily form into hardware, and to emphasize the contrast of an image subjected to proper gradation compression. SOLUTION: In a step S21, the luminance of a wide DR image L is subjected to logarithmic conversion. In a step S22, a logarithmic tone curve correction image logL<SB>c</SB>is generated. In step S23, a logarithmic reduction image logL<SB>cl</SB>is generated, and luminance logL<SB>cl</SB>(p) of a pixel of a logarithmic smoothed image is further calculated by interpolation operation. In step S24, a gain value g(p) is calculated for each pixel position. In a step S25, luminance logL<SB>u</SB>(p) of a pixel of a logarithmic gradation compressed image logL<SB>u</SB>(p) is calculated. In a step S26, the luminance logL<SB>u</SB>(p) is subjected to logarithmic inverse conversion. This apparatus is applicable to an image pickup device such as a digital video camera, and a reproducing device such as a display and a printer. COPYRIGHT: (C)2004,JPO&NCIPI |
