Coding images in the frequency domain: Filter design and energy processing characteristics of the human visual system

Questions concerning the number, tuning widths, and phase sensitivity of two-dimensional narrow-band energy processing units, particularly in central vision, are reviewed. Results with grating and two-dimensional images are discussed, particularly within the context of energy processing and information reduction strategies for the human observer. Finally, a consequent principle of invariance is defined and shown to hold with such filter units.