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

摘要

An image processing system (205) includes an image encoder system (220) and an image decoder system (230) that are coupled together. The image encoder system (220) includes an image decomposer (315) and a block encoder (318) that are coupled together. The block encoder (318) includes a color quantizer (335) and a bitmap construction module (340). The image decomposer (315) breaks an original image into blocks. Each block (260) is then processed by the block encoder (318a-nth). Specifically, the color quantizer (335) selects some number of base points, or codewords, that serve as reference pixel values, such as colors, from which quantized pixel values are derived. The bitmap construction module (340) then maps each pixel colors to one of the derived quantized colors. The codewords 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 block type detector (520), one or more decoder units, and an output selector (523). Using the codewords of the encoded data blocks, the comparator and the decoder units determine the quantized colors for the encoded image block and map each pixel to one of the quantized colors. The output selector (523) outputs the appropriate color, which is ordered in an image composer with the other decoded blocks to output an image representative of the original image. A method for encoding an original image and for decoding the encoded image to generate a representation of the original image is also disclosed.