In flicker correction of a moving picture consisting of a plurality of frames, moving averages of accumulative histograms are calculated for each frame on image data. Then, gamma tables for correcting the image data of a frame in the plurality of frames are made such that the accumulative histograms after corrected with the gamma tables match with the moving averages of the accumulative histograms. Then, the image data of the frame in the plurality of frames is corrected with the gamma tables. In some cased, each frame is divided into areas, and the flicker correction is performed for each area if necessary.