Patent ID: 7505631
Filing Date: 2009-03-17
Classification: H03M,H04N

Abstract:
1. An image coding method in which variable length coding process is performed to transform coefficients by referring to a variable length code table comprising a plurality of reference events, wherein each reference event comprising Last, Run and Level, is paired with a reference variable length code, wherein the variable length coding process comprises: obtaining an input event comprising Last, Run, Level, corresponding to said transform coefficients, comparing said input event with each reference event in said table, and if said input event accords with one of said reference events, outputting a variable length code corresponding to said reference event, and if said input event does not accord with any reference events in said table, obtaining a first transformed event, by transforming the Level value of said input event, comparing said first transformed event with each of the reference events in said table, and if said first transformed event accords with one of said reference events, outputting a control code and a second mode code followed by variable length code corresponding to said reference event, and if said first transformed event does not accord with any reference events in said table, obtaining a second transformed event, by transforming the Run value of said input event, comparing said second transformed event with each of the reference events in said table, and if said second transformed event accords with one of said reference events, outputting a control code and a third mode code followed by a variable length code corresponding to said reference event, and outputting a control code and a first mode code followed by a fixed length code corresponding to said input event if said second transformed event does not accord with any reference events in said table.