Patent ID: 7808406

Claim:
A method for performing arithmetic encoding, comprising: performing arithmetic encoding on data to be encoded; mapping an interval update computation in arithmetic encoding to be performed in the original domain into the logarithm domain and implementing the interval update computation with add/subtract operations, wherein data conversions between the original domain and the logarithm domain are performed by approximations; and performing arithmetic encoding according to the interval update computation result; wherein the data conversion between the logarithm domain and the original domain for a data conversion from the logarithm domain to the original logarithm, comprises: deriving a value X in the original domain by shifting a parameter B by A bits to the left or to the right, or by dividing the parameter B by 2 raised to the power of A, wherein the parameters A and B are computed by decomposing Log X in the logarithm domain as Log_X=−A+B−1, where the parameter A is an integer, and the absolute value for the parameter B minus 1 is less than 1.