Abstract

The biological hardware of the human visual system has been modeled by conformal retinocortical projections. Such a complex-log transformation implies certain invariances in the pattern of stimulation of the visual cortex, thus retaining the characteristic features of a scene to be reconstructed from primal sketches. Assuming the human visual system uses Fourier domain descriptions for image reconstruction, evaluation of the modulation transfer function (MTF) of the visual system (i.e., eye-retina brain) provides us with important clues to biological image processing. Experimental evaluation of human MTFs in the presence of local obscuration demonstrates the constraints on spatial frequency response imposed by local receptive-field structures of the retina. The effect of such constraints on spatial frequency response in image processing and image reconstruction are addressed.

© 1986 Optical Society of America