快速FFT变换，复数形式！ 时间复杂度为O（n * log n）！ 很快！-fast FFT transform

一个用来处理简单pgm格式的小程序，比如对数变换、指数变换、直方图均衡化等等，功能不多，但是很有用-Pgm format to handle a simple little program, such as log transformation, exponential transform, histogram equalization, etc., function much, but useful

Compression using Burrows Wheeler Transform. Includes n*log(n) comparison tri-partite suffix array block sorting, Move-to-Front coding, dynamic canonical Huffman coding of Wheeler s run-length-coding.