Tuesday, 20 July 2004, 2pm:
Visual patterns with matching subband statistics

Joshua Gluckman
Dept. of Computer Science, Brooklyn Polytechnic University

Statistical representations of visual patterns are commonly used in computer vision, image processing and pattern recognition. One such representation is a statistical distribution measured from the output of a bank of filters (Gaussian, Laplacian, Gabor, wavelet etc). Both marginal and joint distributions of filter responses have been advocated and effectively used for a variety of vision tasks including: image retrieval, object recognition, texture analysis and texture synthesis. We begin by examining the ability of these statistical representations to discriminate between an arbitrary pair of visual stimuli. Examples of patterns are derived that provably possess the same statistical properties, yet are visually distinct. We further analyze these representations by studying classes of patterns with matching statistical properties. In particular, we show that these representations are effectively blind to certain phase correlations. Finally, we derive higher order whitening transformations that remove statistical redundancies from images. These transformations effectively remove any information from the marginal and joint subband statistics. Thus, they demonstrate what image properties these subband statistics dont see.