JPEG2000全通道并行EBCOT-Tier1编码器结构设计

新一代静止图像压缩标准JPEG2000采用了EBCOT算法。该算法Tier1部分在上下文生成过程中需要对位平面进行多次通道扫描，效率很低，难以满足高质量图像实时压缩的要求。目前已有多种改进方案被相继提出，主要基于PS/GOCS和多窗口通道并行扫描。该文设计出一种适用于硬件实现的单窗口全通道并行编码结构，目前已通过FPGA验证。实验表明，该结构下Tier1编码速度明显优于现有几种优化方案。同时，本设计所采用的编码逻辑在解码过程中亦可使用，便于进行编解码复用设计。

Full Pass-Parallel Architecture for EBCOT-Tier1 Encoder in JPEG2000

EBCOT algorithm is an essential part of the new image compression standard, JPEG2000. The Tier1 part of EBCOT requires each bit-plane be scanned for three times in order to generate entropy contexts. Therefore the scanning efficiency is unacceptable,which fails to fulfill real-time compression of high quality images. So far some improvements have already been made, mainly based on PS/GOCS, and multi-window/pass-parallel coding technique. In this paper, a hardware-oriented, full pass-parallel coding architecture is presented, based on only one scanning window. This architecture is verified on FPGA. Experimental results show that its coding speed is superior to the other two main improvements. Furthermore, the coding logic adopted can be reused on the decoding stage, which facilitates sharing code/decode architecture.