关键词: 近似系数, 细节系数, 9/7小波, 小波工具箱

Abstract: MATLAB directly uses orthogonal wavelet calculation model to process biorthogonal wavelet, leading to coefficients redundant problem. According to that, this paper proposes 9/7 wavelet prototype as the improved algorithm to hand the nonperiodic signal, compared with the given algorithm in MATLAB, for the signals which have the odd starting-even length and even starting-odd length, after wavelet transformation, two approximate coefficients and one detail coefficient can be saved, for the signals which have the odd starting-odd length and even starting-even length, one approximate coefficient can be saved. When using the improved algorithm to decompose the image with 512×512 points to 4th level, 4256 coefficients can be saved, and reconstruction image’s peak value signal-to-noise ratio is higher than the reconstruction image in MATLAB. So the improved algorithm not only reduces the computation time and data storage capacity, but also improves the quality of the reconstruction image.

Key words: approximate coefficient, detail coefficient, 9/7 wavelet, wavelet toolbox