此代码，可以完成matlab下的小波软阈值图像去噪，可以做不同阈值下的图像去噪，并通过峰值信噪比psnr的比对来说明阈值选取的方法-Wavelet threshold denoising compared soft threshold and hard threshold and the current method of calculating the various thresholds and thresholds approach the performance of function, through the signal to noise ratio and mean square deviation of the comparison, the various algorithms advantages and disadvantages.