【摘要】 提出了在频域设计M带非采样二维金字塔变换的方法.首先描述了完全重构的2带非采样二维金字塔变换.采用级联2带滤波器组的方法设计出完全重构的M带非采样二维金字塔变换.每个级联的滤波器可通过设置通带和阻带的截止频率来计算.所设计的变换取代Contourlet变换中的拉普拉斯金字塔变换,在获得一定冗余度的同时可对频域进行更精细的分解.实验证实了提出的变换去噪方法可获得较好的效果.更多还原

【Abstract】 The design of M-band nonsampled 2D pyramid transform defined in frequency domain is proposed.Firstly,2-band nonsampled pyramid transform satisfying perfect reconstruction condition is described.Then,the M-band nonsampled 2D pyramid transform with perfect reconstruction is designed by cascade of 2-band filter bank.Each cascade filter can be calculated by setting the cutoff frequencies of passband and stopband.Substituting the proposed nonsampled pyramid transform for laplacian pyramid in original Contourlet transform can achieve a new transform,which has much finer frequency decomposition as well as some redundancy.Numerical experiments show that the denoising method based on the proposed transform is effective.更多还原