离散傅里叶变换DFT_学习笔记

程序参考：
https://blog.csdn.net/jameshater/article/details/50810613
主要了解magI.cols & -2，magI.rows & -2两条代码的原因

理解卷积的意义
https://blog.csdn.net/xueyedie1234/article/details/51577495
https://www.cnblogs.com/wuyuankun/p/4149499.html
https://www.cnblogs.com/freeblues/p/5738987.html

理解傅里叶变换在图像处理中的意义
https://blog.csdn.net/rubyboss/article/details/24178489
http://www.cnblogs.com/tenderwx/p/5245859.html
https://blog.csdn.net/z397164725/article/details/18734689