Introduction - If you have any usage issues, please Google them yourself
From the above experiment, we can see the image change, after Fourier transform and inverse transform and DCT discrete cosine transform and inverse transform, the images have changed a lot, first of all, is a 2-D Fourier transform, the image data emergence of high-frequency frequency-domain data, low-frequency data in the four weeks of the phenomenon, and then after a 2-D Fourier transform inverse transform, the image again to restore the original map. And 2-D discrete cosine transform on the impact of images is also true.