FAST LOSS LESS IMAGE COMPRESSION SYSTEM BASED ON NEIGHBORHOOD COMPARISONS

摘要

A fast loss less image compression system based on neighborhood comparisonscompares pixel value differences with neighboring pixels and replaces suchpixel values with the minimum of the differences. A marker is attached to ablock of pixels, such that all the pixels in that block are compared withneighbors of one direction. The marker indicates how of the pixels in thatblock are compared. Intermittent Huffman-tree construction is used such thatone tree is used for several frames. Huffman coding is used to compress theresulting frame. A single Huffman-tree is constructed once every predeterminednumber of frames. The frequency of Huffman-tree construction can be performedaccording to the instantaneous availability of processor time to perform theconstruction. When more processing time is available, the Huffman-trees arecomputed more frequently. Such frequency variation can be implemented by usingan input video frame buffer.