快速傅里叶变换函数，对一维信号信息和二维图像信息进行快速傅里叶变换-Fast Fourier transform function, one-dimensional and two-dimensional image information signal information fast Fourier transform

用于灰度BMP图像的二维傅里叶变换，能够获取图像的频谱图-Corrosion calculation for grayscale images

用于灰度BMP图像的二维快速傅里叶反变换，将频谱信息转化为图像-Two-dimensional inverse fast Fourier transform for gray-scale BMP images, transforming spectral information into images