摘要 |
Image processing, compressing, decompressing, transmitting, sending and receiving devices and methods, their programs and a displaying device, in which a bit plane number is increased again after the bit plane number is first reduced to enable it to largely improve or remove granular quality deterioration in a mild gradation area and a plain gradation area within an image. For data compression, a first image processor includes a block coder for executing a reversible compression of image data of pixels of a raster image and a bit plane compressor for conducting an irreversible compression of the image data. For data decompression, a second image processor includes a bit plane decompressor for carrying out an irreversible decompression of the compressed data and a block decoder for executing a reversible decoding of the compressed data, to output decompressed image data to a display for displaying a reproduced raster image. The compressed data is once stored in a memory.
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