Coding Algorithms in JPEG2000 Standard
Tinku Acharya, Ajoy Kumar Ray · 2005
Entropy coding in JPEG2000 is not as straightforward as in the baseline JPEG standard. We decided to present a separate chapter completely on the coding algorithms for JPEG2000 standard because of its vast nature and better understanding of the audience. The encoding of the transformed coefficients in JPEG2000 has two stages – Tier 1 coding and Tier 2 coding. The Tier-1 coding essentially involves the entropy encoding technique which is combination of a fractional bit-plane coding (BPC) and binary arithmetic coding (BAC). The “embedded block coding with optimized truncation (EBCOT)” algorithm has been adopted for the fractional bit-plane coding in JPEG2000 standard. The binary arithmetic coding is implemented based on the principle of MQ-coder. In JPEG2000 standard, the Tier-2 coding engine is responsible for efficiently representing layer and block summary information for each code-block. In this chapter, we have discussed in great detail the principles and the algorithms for Tier-1 coding with some examples for better understanding by the readers. We have briefly described the importance of the Tier-2 algorithm as well.