Under appropriate conditions zero-crossings of a bandpass signal are very rich in information. The authors examine here the relevance of this result to the early stages of visual information processing, where zero-crossings in the output of independent spatial-frequency-tuned channels may contain sufficient information for much of the subsequent processing.
© 1979 Optical Society of America
D. Marr, S. Ullman, and T. Poggio, "Bandpass channels, zero-crossings, and early visual information processing," J. Opt. Soc. Am. 69, 914-916 (1979)