Ｂit-width Tradeoffs in Hardware Discrete Wavelet Transform Architecture

• Main Authors: Tzu-yang Lin, 林子揚
• Other Authors: Ching-wei Yeh
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/79629371605516007911

碩士 === 國立中正大學 === 電機工程所 === 94 === Abstract Discrete Wavelet Transform is an efficient signal analysis technique. The newly announced image compressing technique JPEG2000 is adopting DWT as the core technology. DWT is performed by convoluting the image with designed filter banks in order decompose the digital signals into the signals in the subbands. The hardware implementation for DWT has progressed in recent year. An important progress in DWT architecture is called Lifting-based DWT. This architecture has the same performance with only half the area of the original DWT architecture. At 2002, C. Huang, P. Tseng, and L. Chen proposed a “Flipping” structure for the Lifting-based DWT, in which the multiplication positions were changed to reduce the number of registers. With this structure, the same performance can be reached with even less area. The aim is comparison of the Peaks Signal of Noise Ratio under the difference between the Bit-width of the Flipping structure and the Lifting-based structure. Implementing Flipping structure and Lifting-based structure is the way to compare the difference in the different floating bits. The PSNR of the Flipping in our experiment is 60.64dB under the 7 bits of the floating. The PSNR of the Lifting-based structure is 62.27dB under the 7 bits of the floating. The optimum floating Bit-width of the Flipping structure’s PSNR is 7 Bits. The PSNR of the Lifting-based structure’s PSNR is better with the longer Bit-width. The outcome of PSNR is enough for us under the 7 Bits of two kind’s DWT structures. Under the 7 floating Bits, the total Bit-width of Flipping structure is shorter than them of the Lifting-based structure and lack 1.6dB in the PSNR. The outcome of the Flipping structure is better than the Lifting-based structure.