A noiseless code length method (NCLM) to estimate dimensionality of hyperspectral data

Hyperspectral image analysis has been subjected to many improvements made in past decade. Yet the accurate estimation of dimensionality is still a challenge. Since dimension estimation of the hyperspectral data is the first step in analysis of an image, the accuracy of analysis results highly depends on the accuracy of the dimension estimation step. Mostly, existing methods isolate the process of dimension estimation and process of denoising which leads to an inaccurate estimation of constituent components in the signal. In this paper, the problem of estimating the dimensionality of hyperspectral data using the concept of ldquonoiseless code lengthrdquo is addressed. In our proposed method, NCLM, a set of nested subsets including the hyperspectral data is generated first and then an error comparison approach is utilized by estimating the noiseless data error rather than noisy data error used by the existing methods to find the optimum subset. It has been shown that the estimated noiseless error has a minimum that represents the accurate estimation of the dimensionality of hyperspectral data. The comparison of NCLM to other methods shows a substantial improvement in estimation of dimensionality in hyperspectral imagery.