IN-STREAM LOSSLESS COMPRESSION OF DIGITAL IMAGE SENSOR DATA

摘要

A method and system provide in-stream compression of bytes of digital image sensor data. A specified number of least significant bits of the byte of digital image sensor data is masked or dropped (54 of Figure 5) to reduce the amount of image data if a frame of image data. After masking, alternate bytes of digital image sensor data are subtracted to produce and entropy-reduced data model (56 & 64 of Figure 5). The difference bytes of digital image sensor data are split into a predetermined number of channels (65 of Figure 5), each channel having a bit width such that the sum of he bit widths of each channel equals a bit width of the byte of digital image sensor data. Each channel is operated upon by a distinct cumulative distribution function (66, 68, and 70 of Figure 5) before being multiplexed (72 of Figure 5). The multiplexed digital image sensor data is encoded by arithmetic compression encoding (74 of Figure 5). The method and system also utilize a division-free method of arithmetic encoding to simplify the hardware requirements of encoding. Lastly, the method and system utilize a round-robin removal approach for adaptively fixing a number of elements in a histogram.