Theory of spatiochromatic image encoding and feature extraction

Andrew McCabe, Terry Caelli, Geoff West, Adam Reeves
2000 Optical Society of America. Journal A: Optics, Image Science, and Vision  
We consider how to interpret, filter, and cross-correlate complex-value color (hue and saturation) images by using a single discrete Fourier transform: the spatiochromatic discrete Fourier transform. The model defines new types of spatiochromatic oriented sinusoidal gratings, termed rainbow gratings, which encode the variation of color over space. We demonstrate how color-opponent detectors observed within the vertebrate visual system can be easily defined by linear filters within this
more » ... ation. This model also allows us to filter and detect both spatial and chromatic patterns in images by using a single cross-correlation procedure. In doing so, we explore a new form of the Cauchy-Schwartz inequality applied to complex-valued scalar products. Results demonstrate the power of this form of spatiochromatic matched filtering in detecting signals embedded in such a significant amount of noise that they are not visible to the unaided human eye.
doi:10.1364/josaa.17.001744 pmid:11028522 fatcat:3axkkuusezaf3au2a6fnbsoa44