Research On Core Coding Algorithm Of JPEG2000 Standard And Implementation Of Encoder Based On DSP

JPEG2000 is the lasted generation of international still image compression standard. With excellent image compression performance and superior image quality, it not only addresses a number of weaknesses in the exiting JEPG standard, such as block effect, but also provides several features like image progressive transmission by pixel accuracy and resolution, scalable image quality, lossless/loss compression, region of interest coding, etc. Due to the excellent coding performance and attractive features, JPEG2000 has a large rang of applications such as digital camera, medical imaging, digital library, network transferring and so on. However, it needs high performance processing ability to implement JPEG2000 codec for its complexity algorithms (wavelet transform, embedded block coding with optimized truncation). As a result, a certain extent, the advanced technologies limit the JPEG2000 applications.Analyzed the necessity of still image encode, theoretical and the development of standard in technique completely. The paper researched the standard of JPEG2000 that includes the encoding process, algorithm, coding stream grammar and file format. Here, the main point was to research core algorithm discrete wavelet transform (DWT) and embedded block coding with optimized truncation (EBCOT) which decided the function of the encoder. First the paper realized DWT in VC6.0 on PC with lifting scheme. Then the paper given two methods to improve standard algorithm aim to 8 bit gray images which is eliding clean pass's scanning of lower bit plane and once scanning for higher bit plane. It realized in VC6.0 with C language. In the P4/2.4G/512M,the paper tested the lossy encoder and decoder with Barbara and Lena (512×512) images. In lower bit rate, the sense of vision felt good in the whole. With the necessary condition to ensure the coding image quality, the encoding of lossy compression time shortened by 8% to 12% and the decoding time shortened by 2% to 5%.Finally, transplanted the source code into the platform of DM642 to adjust and optimize. Then this paper paid attention to the new arithmetic medium processor DM642 as the hardware platform of the company of TI and realized the core algorithm on DSP.