Title :
A transformation for ordering multispectral data in terms of image quality with implications for noise removal
Author :
Green, A.A. ; Berman, M. ; Switzer, Paul ; Craig, Maurice D.
Author_Institution :
CSIRO Div. of Miner. Phys. & Miner., North Ryde, NSW, Australia
fDate :
1/1/1988 12:00:00 AM
Abstract :
A transformation known as the maximum noise fraction (MNF) transformation, which always produces new components ordered by image quality, is presented. It can be shown that this transformation is equivalent to principal components transformations when the noise variance is the same in all bands and that it reduces to a multiple linear regression when noise is in one band only. Noise can be effectively removed from multispectral data by transforming to the MNF space, smoothing or rejecting the most noisy components, and then retransforming to the original space. In this way, more intense smoothing can be applied to the MNF components with high noise and low signal content than could be applied to each band of the original data. The MNF transformation requires knowledge of both the signal and noise covariance matrices. Except when the noise is in one band only, the noise covariance matrix needs to be estimated. One procedure for doing this is discussed and examples of cleaned images are presented
Keywords :
geophysical techniques; remote sensing; covariance matrices; image quality; maximum noise fraction; multispectral data; noise removal; remote sensing; smoothing; transformation; Aircraft; Australia; Covariance matrix; Image coding; Image quality; Linear regression; Noise reduction; Signal to noise ratio; Smoothing methods; Statistics;
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on