红外与毫米波学报2009，Vol.28Issue(4)：316-320,5.
对数变换与小波变换用于野外采集植物波谱降噪
FIELD COLLECTED PLANT SPECTRUM DENOISING BY LOGARITHM TRANSFORM AND WAVELET TRANSFORM
摘要
Abstract
The objects' spectrum is often contaminated by noise when it is collected in the open air. According to the principle of the spectrum collection, the noise was considered as one kind of multiplicative compound noise. By theoretical derivation, the combination of logarithm transform and wavelet transform was introduced into noise reduction. Multiplicative noise simulation test was carried out. And the results show that the spatial correlation algorithm is best suited for spectral data denoising, modulus maxima algorithm is inferior to it. Threshold shrinking rule is unsuitable for spectrum denoising. The wild plants spectrum were processed based on spatial correlation algorithm. Results show that the noise near 1450 nm in the spectrum is perfectly denoised, while near 1800 ~ 1900 nm strong noise can not be removed perfectly. The reason is the limited records accuracy of the spectrometer. When the theoretical ratio is far greater than 1, the spectrometer will accurately record them. While the theoretical ratio is far less than 1, the record will be 0. So serious system errors will be generated in strong noise band and will be retained after the wavelet transform was applied because they are considered as signal singularity. Experiments prove that spatial correlative filtering with the combination of logarithm transform and wavelet transform is feasible for multiplicative-noise-contaminated spectrum denoising.关键词
对数变换/小波变换/野外采集波谱/空域相关滤波Key words
logarithm transform/wavelet transform/field collected spectrum/spatial correlative filtering分类
信息技术与安全科学引用本文复制引用
周广柱,王翠珍,杨锋杰,李寅明..对数变换与小波变换用于野外采集植物波谱降噪[J].红外与毫米波学报,2009,28(4):316-320,5.基金项目
国家"863"计划(2009AAl22147)、国家自然科学基金(40842003)和山东省软科学(2007RKA071)资助项目 （2009AAl22147）
