对数字图像处理中的离散傅里叶变换(DFT),离散余弦变换（DCT）进行了详细的分析。其中DFT包括log视觉处理，中心点移动等。DCT包括分块处理，和保留较少系数，并比较结果。-Digital image processing of the discrete Fourier transform (DFT), discrete cosine transform (DCT) for a detailed analysis. DFT which include the log of visual processing, the center of movement. Including sub-block DCT processing, and retention of small coefficients, and compare the results.