小波变换方法被广泛应用于图像处理,但由于其不具有平移不变性以及较少的方向选择,因而限制了它的应用范围。四叉树复小波变换,是对Malla算法的一种改进,通过奇偶滤波器的对称使用,在四棵数上分别实现分解和重构。与一般复小波一样,四叉树复小波算法具有较好的方向选择性和平移不变性,并且容易实现完全重构。采用四叉树复小波变换和基于子带噪声的自适应阈值方法,对一幅卫星图像进行了去噪处理,仿真实验表明该方法具有较好的去噪效果。 Wavelet transform method is widely used in image processing, but its limited range of applications because it does not have translational invariance and less direction selection. Quadtree complex wavelet transform is an improvement on Malla algorithm. Through the symmetrical use of parity filter, it can decompose and reconstruct four trees respectively. As with general complex wavelet, quadtree complex wavelet algorithm has good direction selectivity and translational invariance, and it is easy to realize complete reconstruction. A quadtree complex wavelet transform and adaptive thresholding based on sub-band noise are used to denoise a satellite image. The simulation results show that this method has a good denoising effect.