Closed-Form Correlation Model of Oriented Bandpass Natural Images
Most prevalent statistical models of natural images characterize only the univariate distributions of divisively normal- ized bandpass responses or wavelet-like decompositions of them. However, the higher-order dependencies between spatially neigh- boring responses are not yet well understood. Towards filling this gap, we propose a new closed-form spatial-oriented correlation model that captures statistical regularities between perceptually decomposed natural image luminance samples. We validate the new correlation model on a variety of natural images. Experi- mental results demonstrate the robustness of the new correlation model across image content. A software release that implements the new closed-form spatial-oriented correlation model is available at http://live.ece.utexas.edu/research/3dnss/bicorr_release.zip. Index Terms—Bivariate model, closed-form, natural scene sta- tistics (NSS), spatial-oriented correlation model.