Notes on Steerable Filters Psych 267 / CS 348 D / EE 365
نویسنده
چکیده
The simplest illustration of a steerable function is the first-order directional derivative of a two-dimensional Gaussian. Although we will only consider Gaussians, the principle of steerability may be extended to any differentiable function. For notational simplicity we will consider a unit-variant Gaussian and ignore the 1 p2 scaling constant: g(x; y) = e (x2+y2)=2: (1) Lets begin by considering the first-order horizontal derivative (i.e., in x) of g(x; y), given by: gx(x; y) = @g(x; y) @x = xe (x2+y2)=2: (2)
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