spectra preprocess

代码说明：

  实现光谱数据的预处理，去除背景和基线漂移，具有非常好的效果，已经试验成功。(To achieve the preprocessing of spectral data, removing background and baseline drifts with very good results, and it has been successfully tested.)

文件列表：

spectra preprocess\DETREND.m
spectra preprocess\DOSC.m
spectra preprocess\MSC.m
spectra preprocess\NIRMAF.m
spectra preprocess\NORMALIZ.m
spectra preprocess\OFFSET.m
spectra preprocess\SNV.m
spectra preprocess