Journal ArticleDOI
Theory of Edge Detection
David Marr,Ellen C. Hildreth +1 more
TLDR
The theory of edge detection explains several basic psychophysical findings, and the operation of forming oriented zero-crossing segments from the output of centre-surround ∇2G filters acting on the image forms the basis for a physiological model of simple cells.Abstract:
A theory of edge detection is presented. The analysis proceeds in two parts. (1) Intensity changes, which occur in a natural image over a wide range of scales, are detected separately at different scales. An appropriate filter for this purpose at a given scale is found to be the second derivative of a Gaussian, and it is shown that, provided some simple conditions are satisfied, these primary filters need not be orientation-dependent. Thus, intensity changes at a given scale are best detected by finding the zero values of delta 2G(x,y)*I(x,y) for image I, where G(x,y) is a two-dimensional Gaussian distribution and delta 2 is the Laplacian. The intensity changes thus discovered in each of the channels are then represented by oriented primitives called zero-crossing segments, and evidence is given that this representation is complete. (2) Intensity changes in images arise from surface discontinuities or from reflectance or illumination boundaries, and these all have the property that they are spatially. Because of this, the zero-crossing segments from the different channels are not independent, and rules are deduced for combining them into a description of the image. This description is called the raw primal sketch. The theory explains several basic psychophysical findings, and the operation of forming oriented zero-crossing segments from the output of centre-surround delta 2G filters acting on the image forms the basis for a physiological model of simple cells (see Marr & Ullman 1979).read more
Citations
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Journal ArticleDOI
A Representation for Shape Based on Peaks and Ridges in the Difference of Low-Pass Transform
James L. Crowley,Alice C. Parker +1 more
TL;DR: A multiple resolution representation for the two-dimensional gray-scale shapes in an image is defined by detecting peaks and ridges in the difference of lowpass (DOLP) transform and the principles for determining the correspondence between symbols in pairs of such descriptions are described.
Journal ArticleDOI
The Hermite transform-theory
TL;DR: It is demonstrated that the Hermite transform is in better agreement with human visual modeling than Gabor expansions, and therefore the scheme is presented as an analysis/resynthesis system.
Journal ArticleDOI
Surface-based labeling of cortical anatomy using a deformable atlas
S. Sandor,Richard M. Leahy +1 more
TL;DR: The approach the authors take is to model a prelabeled brain atlas as a physical object and give it elastic properties, allowing it to warp itself onto regions in a preprocessed image.
Journal ArticleDOI
Integration of depth modules: stereo and shading
TL;DR: This data show that disparate shading (even in the absence of disparate edges) yields a vivid stereoscopic depth perception, and is compared with computer-vision algorithms for both single cues and their integration for three-dimensional vision.
References
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Journal ArticleDOI
Receptive fields, binocular interaction and functional architecture in the cat's visual cortex
David H. Hubel,Torsten N. Wiesel +1 more
TL;DR: This method is used to examine receptive fields of a more complex type and to make additional observations on binocular interaction and this approach is necessary in order to understand the behaviour of individual cells, but it fails to deal with the problem of the relationship of one cell to its neighbours.
Journal ArticleDOI
Receptive fields and functional architecture of monkey striate cortex
David H. Hubel,Torsten N. Wiesel +1 more
TL;DR: The striate cortex was studied in lightly anaesthetized macaque and spider monkeys by recording extracellularly from single units and stimulating the retinas with spots or patterns of light, with response properties very similar to those previously described in the cat.
Book
The Fourier Transform and Its Applications
TL;DR: In this paper, the authors provide a broad overview of Fourier Transform and its relation with the FFT and the Hartley Transform, as well as the Laplace Transform and the Laplacian Transform.
Book
Digital Picture Processing
Azriel Rosenfeld,Avinash C. Kak +1 more
TL;DR: The rapid rate at which the field of digital picture processing has grown in the past five years had necessitated extensive revisions and the introduction of topics not found in the original edition.
Journal ArticleDOI
Application of fourier analysis to the visibility of gratings
F. W. Campbell,John G. Robson +1 more
TL;DR: The contrast thresholds of a variety of grating patterns have been measured over a wide range of spatial frequencies and the results show clear patterns of uniformity in the response to grating noise.