这个是C制作的源代码。。。

对一幅图像进行DFT变换，分别对源图像在空间域和频域里进行二次抽样和差值，最后得出结果比较。- Get a grey level image which size is N*N. (For example, 256*256, however,

N = ), and partition to 8*8 sub images.

Apply DFT to these sub images, and get the fourier transformed image F.

3. Derive the proper subsampling function matrix S in spatial domain.

4. Multiplying proper 4*4 DFT matrix T to matrix S, derive the frequency version

　 of subsampling function matrix, S.

5. Similarly, derive the frequency version of interpolation matrix, I.

6. Apply these matrices to each sub image of F (which is DFT of original image),　

　 and get the final image, taking inverse DFT.

7. Apply subsampling/interpolation function matrix S/I to original image in spatial

　 domain and get the final image.