Review Article A review of multi-channel indices of class separability

Abstract

Abstract An increasingly common question arising in processing digital multi-channel data from spacecraft and aircraft scanner systems is “which channels contain the best information to separate the classes of interest to the user?”. This may be to identify the best single channel for separating classes in a black and white photographic or line printer output product, or the best three channels for a colour photographic presentation of the data, or the best ‘n’ channels to enter into a classification (being mindful of the ‘trade off’ between improved sub-class separability and increasing usage of computer space and time resources). The only valid way to approach separability using more than one channel is to consider it in multi-channel space utilizing the inter-channel relationship terms. Having defined the classes using some form of hierarchical ordering approach, such as that proposed by Anderson et al. (1972), the user may compile the statistical profiles of the classes of interest from the sensor mul...