Different DSP related source codes pertaining to FFT,Convolution,filtering,concatenation of signals in different frequencies,sampling including upsampling & downsampling

数组降采样，将有四十个元素的数组降采样成八个元素一组的五个小组-Downsampling the array, the array will have forty elements of a down-sampled into eight groups of five groups of elements

code for extracting features from cell images. downsampling included