Optimally isotropic Laplacian operator
Behrooz Kamgar-Parsi, Behrooz Kamgar-Parsi, Azriel Rosenfeld · IEEE Transactions on Image Processing · 1999
Laplacian operators used in the literature for digital image processing are not rotationally invariant. We examine the anisotropy of 3 x 3 Laplacian operators for images quantized in square pixels, and find the operator which has the minimum overall anisotropy.