Liu Zaide£¬Zheng Nanning£¬Liu Yuehu£¬Lan Xuguang
(School of Electronics and Information Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract:Based on the binary representation for real number, the lifting coefficients of the 9/7 biorthogonal wavelet filter pair of CDF(Cohen, Daubechies and Feauveau) are expressed in binary representation.A simple shift-add operation is used to substitute for the multiplier with complicated architecture operating on floatingª²point, so that the 9/7 discrete wavelet transform in JPEG2000 is implemented through fixed-point computing. Compared with the floating-point computing method, the shift-add operation is simpler,and can be implemented easily by VLSI, which enables the real-time image processing to be realized by hardware. The simulation results show that, in the case of low compression ratio, the PSNR(peak signal-to-noise ratio) of the reconstructed image by the shift-add operation is only 0.1dB lower than the floating-point computing method. When the compression ratio is high, our method is a little superior to the latter.
Keywords:discrete wavelet transform£»fixedª²point computing;floating-point-computing method;lifting;shift-add operation