Initial Tangent Estimate
Convolve image with oriented Gaussian kernals.
-
Single Gaussian in the tangent direction
-
Difference of three Gaussians in the perpendicular direction
G(x,y) = LSF(x) * exp(-y2 /
sy2)
LSF(x) = exp(-x2 /
s12)
- B exp(-x2 / s22)
+ C exp(-x2 / s32)