Over 100Mpixels Real Time JPEG-XR Encoder Design

• Main Authors: Ding, Chien-Shan, 丁建杉
• Other Authors: Chang, Tian-Sheuan
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/68727607689142825895

碩士 === 國立交通大學 === 電機學院電子與光電學程 === 100 === In modern industry, although high resolution and wide dynamic range images had be used with in several applications like digital camera sensors, web display devices, so the compression of visual information becomes more and more important. JPEG XR [1] is an new image coding standard, based on high definition (HD) Photo developed by Microsoft [3]. It supports high compression performance higher than JPEG and JPEG2000. Entropy coding was the throughput bottleneck in previous architectures. There are three feedback loops in entropy coding stage; (1) Control of ModelBits, (2) Updating of the scanning order, and (3) Decision of the Huffman table to be used. Therefore, how to design a pipelined module in a straightforward implementation or processing Macroblocks in parallel structure becomes main design challenge. We generalized the characteristic of Normalization (Update ModelBits) and took advent -age of reduction of Levels. Our propose pipeline controller can optimal the encoding forward steps to decrease un-necessary data processing. We could safely pipeline all the encoding processes including the entropy coding and achieves higher throughput than those of related works. After our optimization, estimation of the encoding speed in our implementation is measured. The four images with same size but different manner are tested and represent quite similar results. The calculated throughput in terms of pixel/cycle shows that our implementation can achieve more than 1 pixel/cycle. The architecture is synthesized by Synposys Design Compiler with 0.18 um CMOS standard cell library. The result shows that the gate count of the designed JPEG XR encoder with 100MHz as target frequency is 235,377, number of used SRAMs is required by 992 × 3 channels. An over 100Mpixels real time JPEG XR encoder is designed.