Abstract
Conventional techniques for obtaining both spectroscopic and pictorial information of incoherent objects are first reviewed and then the principle and implementations of a new method called Fourier transform spectral imaging [K. Itoh and Y. Ohtsuka, J. Opt. Soc. Am. A 3 (1986) 94.] are illustrated by referring to experimental results obtained recently. The critical considerations resulted in classification of the conventional techniques into nine categories, the new method being included in one of the most advanced algorithms. The principle is illustrated from the view point of the power spectrum estimation of a homogeneous random field rather than that of propagation of the spatial coherence.
