SYSTEM AND METHOD FOR FIXED-RATE BLOCK-BASED IMAGE COMPRESSION WITH INFERRED PIXEL VALUES

摘要

An image processing system (205) includes an imageencoder system (220) and an image decoder system (230) thatare coupled together. The image encoder system (220) includesan image decomposer (315) and a block encoder (318) thatare coupled together. The block encoder (318) includes acolor quantizer (335) and a bitmap construction module (340).The image decomposer (315) breaks an original image intoblocks. Each block (260) is then processed by the block encoder(318a-nth). Specifically, the color quantizer (335) selects somenumber of base points, or codewords, that serve as referencepixel values, such as colors, from which quantized pixel valuesare derived. The bitmap construction module (340) then mapseach pixel colors to one of the derived quantized colors. Thecodewords and bitmap are output as encoded image blocks(320). The decoder system (230) includes a block decoder(505a-mth). The block decoder (505a-mth) includes a blocktype detector (520), one or more decoder units, and an outputselector (523). Using the codewords of the encoded data blocks,the comparator and the decoder units determine the quantizedcolors for the encoded image block and map each pixel to oneof the quantized colors. The output selector (523) outputs theappropriate color, which is ordered in an image composer withthe other decoded blocks to output an image representative ofthe original image. A method for encoding an original imageand for decoding the encoded image to generate a representationof the original image is also disclosed.