Research And Implementation Of DWT In JPEG2000

The latest still image compression standard JPEG2000 adopts Discrete Wavelet Transform(DWT) as its key arithmetic, which achieves much better coding efficiency and image quality than the traditional methods. With its excellent performance and prominent features, JPEG2000 has become the main-stream in the image compression field; therefore, high attention is paid to the VLSI realization for DWT. The objective of the dissertation is to implement the 2-D DWT for realtime processing images with large size and high resolution.The contents of the dissertation include two parts. In the first part of the dissertation, we discussed the wavelet theory. We focuse on the DWT algorithms such as convolutional filtering and lifting scheme. Then we discusse the implementation of the DWT of JPEG2000 in detail.In the second part, according to the key technologies in VLSI design and FPGA implement, the modified lifting scheme is introduced, such as the boundary extension issue, fixed-coefficient multipliers, fix point operation, inplace operation, 1-D DWT architecture and 2-D DWT architecture are discussed. Then, we describe this design with VHDL language and accomplish the timing analysis and synthesis in Quartus II 8.1 and Modelsim 6.0. Compared with Matlab simulation, The result proves that the proposed hardware structure is proper and feasible for the highly realtime processing image and system can work at high frequency.