How to convert a morphological skeleton from 8-connected to 4-connected?

Hello,

Using the image processing toolbox, I was able to obtain a skeleton of cell membranes in a tissue. As expected, the diagonal lines in my binary image are "1-pixel wide". However, in order for my binary image to be compatible with a third-party script, my diagonal lines must be in a "staircase pattern" i.e. they must be 4-connected.

The result obtained with bwmorph's 'diag' operator is close to what I'd like but it produces lines that are too "thick".

I used the following code to obtain my image:

I(I < 250) = 0; % threshold the image
I = imclose(I, strel('disk', 5)); % remove small components
I = bwmorph(I,'skel',Inf); % diagonal lines too thin
I = bwmorph(I,'diag'); % diagonal lines too thick

You will find below images that further illustrate my case.

Any help would be immensely appreciated. Thank you.

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Skeleton Image:

Thick Image:

Ideal Diagonal Lines (4-connected):

Answer 1

[Image Analyst]

Use bwhitmiss() to identify places where the pattern is a diagonal. Then add a pixel to the left of right of it. Give it a try and let's see your code if you have trouble.

Answer 2

[martlet]

Thanks a lot Image Analyst, your answer put me on the right track.