说明：  使用db1小波对图像进行三层平稳小波分解SWT，在重建过程中，保证其他各项系数为零来避免iswt的合成运算。
(The three-layer smooth wavelet decomposition SWT is used to reconstruct the image using db1 wavelet. In the reconstruction process, the other coefficients are zero to avoid the synthesis of iswt.)