title: A space-variant differential operator for visual sensitivity.
abstract: All the elements of a Fourier analysis can be derived from the experiments of Graham and Robson on contrast sensitivity. Once their experiment is posed as an eigenvalue problem, a complete orthonormal set of eigenfunctions results from solving the associated differential equation. Neither sine and cosine nor Gabor functions result. Instead, the Hermite functions arise as the eigenfunctions of a space-variant differential operator used to model the contrast sensitivity of human observers. These functions, up to a constant, are their own Fourier transforms, and in principle can be used to exactly represent the Fourier transform of naturally occurring visual images.
authors.affiliation: Stevens Institute of Technology, Hoboken, NJ 07030.
authors.forename: A L
authors.initials: AL
authors.lastname: Stewart
authors.forename: R
authors.initials: R
authors.lastname: Pinkham
mesh_terms: D015350:Contrast Sensitivity / Q000502:physiology*; D003491:Cybernetics; D005583:Fourier Analysis; D006801:Humans; D008960:Models, Psychological