Image analysis using anisotropic local contrast
This article describes a contrast measure inspired by findings from human vision. It takes into account the frequency and orientation selectivity of cortical cells in the mammalian visual system. The input image is decomposed into different spatial frequency bands and orientations using Gabor filters. Then, a local directional contrast measure is computed for each spatial frequency band by introducing a competition mechanism among the different orientations. The visual information conveyed by this new contrast measure, called local directional bandlimited contrast (LDBC), has been analyzed on real and synthetic images. Results based on a limited set of images are presented which confirm the consistency of this new measure with the subjective perception of contrasts in complex natural images.