Patent ID: 7672523

Claim:
A method, comprising: respectively encoding, by a computing system, collections of coefficients of source data according to a global coding order and an overall target bit rate; calculating, by the computing system, for a current one of a plurality of coding units of a particular one of the collections of coefficients, an adaptive threshold, wherein said calculating comprises determining a fractional number, wherein said fractional number comprises a denominator derived from at least a relationship between the overall target bit rate and a total amount of bits used to encode previously-encoded coding units of the source data according to at least the global coding order, and wherein said fractional number comprises a numerator equal to an amount of distortion that would be caused by terminating said encoding of the particular one of the collections of coefficients at the current coding unit or by terminating said encoding of the particular one of the collections of coefficients at a neighboring coding unit of the current coding unit; and terminating, by the computing system, said encoding of the particular one of the collections of coefficients upon determining that a rate-distortion value of the current one of the plurality of coding units is less than the calculated adaptive threshold of the current coding unit.