isobel

Sobel edge detector

out = isobel(im) is an edge image computed using the Sobel edge operator applied to the image im. This is the norm of the vertical and horizontal gradients at each pixel. The Sobel horizontal gradient kernel is:

| -1  0  1|
| -2  0  2|
| -1  0  1|

and the vertical gradient kernel is the transpose.

[gx,gy] = isobel(im) as above but returns the gradient images rather than the gradient magnitude.

out = isobel(im,dx) as above but applies the kernel dx and dx' to compute the horizontal and vertical gradients respectively.

[gx,gy] = isobel(im,dx) as above but returns the gradient images rather than the gradient magnitude.

Notes

• Tends to produce quite thick edges.
• The resulting image is the same size as the input image.
• If the kernel DX is provided it can be of any size, not just 3x3, and could be generated using KDGAUSS.

See also

ksobel, kdgauss, icanny, iconv

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