Patent ID: 7212681

Claim:
A method of image compression comprising: dividing an image into blocks; for each block transforming the block to form transform coefficients for the block; quantizing the transform coefficients of the block; ordering the quantized coefficients of the block along a two-dimensional path to form a series of quantized transform coefficients; forming events from the series of quantized transform coefficients, each event being a run of none or more zero-valued coefficients followed by a run of one of a predefined set of sequences, each sequence in the set being either a single coefficient of amplitude greater than one, or a sequence of 1's and 0's starting with a coefficient of amplitude 1; forming a codeword for each formed event, such that relatively short codewords are formed to represent events that are relatively more likely to occur, and relatively long codewords are formed to represent events that are relatively less likely to occur.