【摘要】 基于实数的二进制表示法,把CDF(Cohen,DaubechiesandFeauveau)9/7双正交小波基的提升系数化为二进制,采用简单的移位-加操作代替结构复杂的浮点乘法器,从而实现了JPEG2000中9/7离散小波变换的定点计算.相对于浮点计算法,移位-加操作最大的优点是计算简单,特别易于超大规模集成电路实现,因而使硬件实时处理图像信号成为可能.实验仿真结果表明:在低压缩比的情况下,用移位-加操作重构的图像,其峰值信噪比(PSNR)只比浮点法低0.10dB,当压缩比增大时,其PSNR值略好于浮点法.更多还原

【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 floating-point, 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.更多还原