Patent ID: 8139090

Claim:
An image processor that corrects image data representing a gray-scale value of each of pixels of an image, based on a change in the gray-scale value of each pixel, the image processor comprising: an encoding unit that divides a current-frame image into a plurality of blocks and outputting first encoded image data, corresponding to the current-frame image, the first encoded image data including a representative value denoting a magnitude of pixel data of each of the blocks and a quantized value of pixel data in each of the blocks, the quantized value being obtained by quantizing the pixel data in each blocks based on the representative value; a decoding unit that decodes the first encoded image data thereby outputting first decoded image data corresponding to the current-frame image; a delay unit that delays the first encoded image data for a period equivalent to one frame, thereby outputting second encoded image data corresponding to the image preceding the current frame by one frame; a decoding unit that decodes the second encoded image data, thereby outputting second decoded image data corresponding to the image preceding the current frame by one frame; an encoded data discrimination unit that calculates variations of the representative value and the quantized value between the current-frame image and the image preceding by one frame by referring to the first and the second encoded image data, the encoded data discrimination unit determining whether each pixel of the current frame represents a still picture or a motion picture based on the variations of the representative values and the quantized value, and generating a control signal which has a first value for a pixel which determined to represent the still picture and has a second value for a pixel which determined to represent the motion picture; a one-frame-preceding-image calculation unit that generates one-frame-preceding image data by selecting the current-frame image data or the second decoded image data on a pixel to pixel basis, based on the control signal; and an image data compensation unit that compensates a gray-scale value of the current-frame image, based on the current-frame image data and the one-frame-preceding image data.