Sharp Kabushiki Kaisha Corporation

Kensaku Kagechi

Hisashi Saiga

Keisuke Iwasaki

Yoichiro Yahata

The object of the present invention is to provide an image encoding device and decoding device which allows the maximum compression rate to be achieved with a visually uniform level of picture quality. The present invention has a characteristic pixel extractorwhich encodes input images by small region unit in accordance with an irreversible compression method, decodes the encoded data which is created, and utilizes the input image and decoded image obtained after decoding to extract characteristic pixels, a characteristic distortion calculatorwhich utilizes characteristic pixels to calculate characteristic distortion of the decoded image in relation to the input image, and an encoding parameter controllerwhich controls parameter values determining the degree of data compression in line with the extent of characteristic distortion. The regions of picture quality of a visually uniform level thus obtained are all compressed using an image compression method with a high compression efficiency, thus allowing the maximum compression rate to be achieved.

Image encoding device

An input image is subjected to image region determination in a unit of prescribed block. Based on a result of image region determination, two or more pieces of layer data, of which validity or invalidity at the time of reproduction of the image is defined in a unit of prescribed block are generated by using data of the input image. Then, each of the two or more pieces of layer data is subjected to coding processing under a coding condition suitable for each of the generated two or more pieces of layer data, in a unit of block suitable for each of the two or more pieces of layer data.

Image coding apparatus, image coding method, and recording medium, capable of creating highly versatile data

An image compression apparatus capable of efficiently encoding an image without causing color deviation to the eye compresses luminance element image data and two types of chrominance element image data each consisting of a plurality of blocks. The image compression apparatus includes: a resolution determination processing section () adaptively setting a resolution of each block during reduction according to a predetermined criterion for each of the luminance element image data and the two types of chrominance element image data, and creating resolution information; a data creation processing section () connected to the resolution determination processing section (), and creating data having each block reduced based on the resolution information for each of the luminance element image data and the two types of chrominance element image data; and an encoder (A,B) connected to the resolution determination section () and the data creation processing section (), and encoding an output of each of the resolution information and the data creation processing section ().

Image compression device and image decompressing device, and computer-readable recorded medium on which program for allowing computer to execute image compressing method and image decompressing method

An image coding apparatus corresponding to a standard scheme of binary image compression and having the compression efficiency of a gray scale image improved includes: a bit plane generator () dividing unitary image data into a plurality of bit planes determined according to the number of bits forming each pixel, an image preprocessor () connected to the bit plane generator () to arrange bit data of the same position forming a plurality of bit planes in close proximity to combine into a single bit plane, and a data compressor () connected to the image preprocessor () to compress an image of the single bit plane.

Image encoding device and method therefor, image decoding apparatus and method therefor, and computer-readable recorded medium on which image encoding program and image decoding program are recorded

The object of the present invention is to provide an image encoding device and decoding device which allows the maximum compression rate to be achieved with a visually uniform level of picture quality. The present invention has a characteristic pixel extractorwhich encodes input images by small region unit in accordance with an irreversible compression method, decodes the encoded data which is created, and utilises the input image and decoded image obtained after decoding to extract characteristic pixels, a characteristic distortion calculatorwhich utilises characteristic pixels to calculate characteristic distortion of the decoded image in relation to the input image, and an encoding parameter controllerwhich controls parameter values determining the degree of data compression in line with the extent of characteristic distortion. The regions of picture quality of a visually uniform level thus obtained are all compressed using an image compression method with a high compression efficiency, thus allowing the maximum compression rate to be achieved.

Growing community of inventors

Nara, Japan

Kensaku Kagechi