Edge direction

Is there a function to check if an edge changes direction?

I have used bwlabel to work on connected edges, but now I only want to work on the ones that do not follow around corners. More clearly, they can be vertical, horizontal, or diagonal, but they cannot be a mixture of 2 or more...

Answer 1

[Wolfgang Schwanghart]

Hi,

to extract edges of any direction, you just need to choose the right structuring element for a morphological opening. E.g. to extract vertical edges:

BWv = imopen(BW,[1 1 1]');

horizontal:

BWh = imopen(BW,[1 1 1]);

top left to lower right

BWd = imopen(BW,[1 0 0; 0 1 0; 0 0 1]);

and so on.

Hope this helps, W.

[Philip]

You helped immensely, as always! Thanks!