Method, system and computer program product for optimization of data compression

A data processing system for compressing a sequence of n coefficients by determining a cost-determined sequence of n coefficient indices represented by a cost-determined sequence of (run, index derivative) pairs under a given quantization table and run-index derivative coding distribution, wherein each sequence of (run, index derivative) pairs defines a corresponding sequence of coefficient indices such that each index in the corresponding sequence of coefficient indices is a digital number, the corresponding sequence of coefficient indices includes a plurality of values including a special value, and each (run, index derivative) pair defines a run value representing a number of consecutive indices of the special value, and an index-based value derived from a value of the index following the number of consecutive indices of the special value, the data processing system comprising:

• (a) an initialization module for using the given quantization table and run-index derivative coding distribution to formulate a cost function for a plurality of possible sequences of (run, index derivative) pairs;
• (b) a calculation module for applying the cost function to each possible sequence in the plurality of possible sequences of (run, index derivative) pairs to determine an associated cost of each of the plurality of possible sequences of (run, index derivative) pairs, and for selecting the cost-determined sequence of (run, index derivative) pairs from the plurality of possible sequences of (run, index derivative) pairs based on the associated cost of each of the plurality of possible sequences of (run, index derivative) pairs;
• and encoding the cost-determined sequence of (run, index derivative) pairs using arithmetic coding, with a plurality of context models, based on the given run-index derivative coding distribution.

A computer program product for use on a computer system to compress a sequence of n coefficients by determining a cost-determined sequence of n coefficient indices represented by a cost-determined sequence of (run, index derivative) pairs under a given quantization table and run-index derivative coding distribution, wherein each sequence of (run, index derivative) pairs defines a corresponding sequence of coefficient indices such that each index in the corresponding sequence of coefficient indices is a digital number, the corresponding sequence of coefficient indices includes a plurality of values including a special value, and each (run, index derivative) pair defines a run value representing a number of consecutive indices of the special value, and an index-based value derived from a value of the index following the number of consecutive indices of the special value, the computer program product comprising a non-transitory computer readable recording medium, and instructions recorded on the recording medium for instructing the computer system to perform the steps of:

• (a) using the given quantization table and run-index derivative coding distribution to formulate a cost function for a plurality of possible sequences of (run, index derivative) pairs;
• (b) applying the cost function to each possible sequence in the plurality of possible sequences of (run, index derivative) pairs to determine an associated cost of each of the plurality of possible sequences of (run, index derivative) pairs;
• and,
• (c) selecting the cost-determined sequence of (run, index derivative) pairs from the plurality of possible sequences of (run, index derivative) pairs based on the associated cost of each of the plurality of possible sequences of (run, index derivative) pairs;
• and,
• (d) encoding the cost-determined sequence of (run, index derivative) pairs using arithmetic coding, with a plurality of context models, based on the given run-index derivative coding distribution.