小波谱分析mallat算法经典程序，圆周卷积的快速傅里叶变换-small spectral analysis algorithm Mallat classic procedure, the circular convolution Fast Fourier Transform

针对图像进行快速傅里叶变换，方便进行频频分析与处理。-Fast Fourier transform for the image, to facilitate frequent analysis and processing.

快速傅里叶变换，可用于谐波分析等算法，用 C++编译-Fast Fourier transform, harmonic analysis method can be used with C++ compiler

快速傅里叶变换，主要用于时频分析，求取信号频谱，运算快捷方便。-failed to translate

当前信号处理中，对频谱的研究不断深入，本书中讲述如何使用快速傅里叶变化进行频谱变换，和图像相关性分析，信号处理- How to use FFT2 The note explains in detail how to apply the Matlab 2-dimensional FFT for filtering of two-dimensional signals, e.g. images. It is shown how to connect the output from fft2 to t