图象变换　从傅立叶变换的频谱图中可以看出，提高分辨率以后，其边缘更加平滑，锯齿状明显减弱。但其傅立叶变换后的图像没有明显改变。
3》DC系数移动
其系数移动以后，频谱分量都集中到了频谱的中间。
4》滤波器频率响应(Image transform,As can be seen from the spectrum diagram of Fourier transform, the edge is smoother and the serrated is significantly reduced after improving the resolution. But the image of the Fourier transform did not change significantly.
3. The DC coefficient moves.
When the coefficients are moved, the spectral components are concentrated in the middle of the spectrum.
4) filter frequency response.)