| 摘要 |
PROBLEM TO BE SOLVED: To provide an image processor that conducts gamma correction with high accuracy, without having to use of a lookup table LUT. SOLUTION: A read section 1 reads the side of an original, an amplifier 14 adjusts the amplitude of a read image, an analog/digital converter 15 quantizes the image into digital image data. A shading correction section 16 applies shading correction processing to the generated digital image data and gives the data to an image processing section 2 where the image data are subjected to filter processing, gamma-correction processing and gradation processing or the like, and the resulting data are fed to an image forming section 3. Through the processing of a desired image signal, the processing of converting a quantization value of the digital image signal is conducted according to a tone curve. The tone curve is an approximated tone curve through the combination of linear functions, each having a different gradient. The processing of the image processor approximates the tone curve through the combination of the linear functions with different gradients and can conduct gamma correction with high accuracy, without having to use the LUT. |
