| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reader capable of keeping the continuity of the tone of images and effectively suppressing noise components of image data outputted from a read sensor without lowering a resolution. SOLUTION: The image reader includes: a color difference calculation part 16 for calculating the difference of luminance values for respective colors from image data of the respective colors R, G and B read by a CIS sensor 11; an inclination calculation part 17 for calculating the inclination of a gamma curve in the luminance values of the image data of the respective colors; a correction value calculation part 18 for calculating a correction value for correcting the image data using a coefficient changed corresponding to the inclination of the gamma curve and the difference of the luminance values; a color difference correction part 14 for correcting the image data using the correction value and the difference of the luminance values for the image data of the respective colors when the difference of the luminance values is equal to or smaller than a threshold; and a gamma correction processing means 15 for executing correction processing using the gamma curve to the corrected image data. COPYRIGHT: (C)2010,JPO&INPIT
|
