to provide an image processor , an image processing method , and an image processing program which make it possible to perform high - speed image correction suitable for motion pictures while reducing a memory resource , etc ., an image processor that corrects input image data having a predetermined grayscale range is provided . the image processor includes a coefficient holding device to hold correction coefficients of a correction curve that corresponds to the entire grayscale range or a portion of the grayscale range and includes one or more correction points and a combination portion that is formed of a combination of a plurality of specific curve pattern portions , a correction amount determination device to determine a correction amount based on statistical information of grayscale values of pixels in the image input data , and a correction device to correct the input image data by adding the product of the correction amount and the correction coefficients determined by the input image data to the input image data .