This volume presents an integrated view of how we perceive the spatial relations in our visual world, covering anatomical, physiological, psychophysical, and perceptual aspects. The authors discuss the visual system primarily in terms of spatial frequency analysis using a linear systems approach. They review evidence supporting a local, patch-by-patch spatial frequency filtering of visual information rather than the global Fourier analysis other researchers have proposed. A separate chapter addresses the special issues surrounding color vision, and a brief, nonmathematical introduction to linear systems analysis is included for the uninitiated reader.