二维图像信号的去噪步骤：

（1）二维图像信号的小波分解。选择合适的小波与恰当的分解层次N，并对待压缩的二维图像信号进行N层分解计算。

（2）对分解后的每一层高频系数，选择一个恰当的阈值，并对该层高频系数进行软阈值量化处理。

（3）二维图像信号的小波重构。用小波分解后的第N层近似（低频系数）和经过阈值量化处理后的各层细节（高频系数），对二维信号进行小波重构。-Two-dimensional image signal denoising steps: (1) two-dimensional image signal wavelet decomposition. Select the appropriate wavelet decomposition level and the appropriate N, and treatment of compressed N-layer two-dimensional image signal decomposition calculations. (2) of the decomposition of high-frequency coefficients of each layer, select an appropriate threshold, and high-frequency coefficients of the layer of soft threshold quantification. (3) Wavelet two-dimensional image reconstruction. Wavelet decomposition of the first N-layer approximation (low frequency factor) and through the quantification of threshold levels after the details (high frequency coefficients), two-dimensional wavelet reconstruction signal.