Skeletonize petioles images

I extracted petioles by mathematic morphology and want now to skeletonize at 1 pixel wide for measure it.
There are some petiole image examples : Index of /temp/petioles
Please help me !
Best regards

I precise that the petioles may be curved, double-curved, triple-curved, etc horizontal, vertical or oblique

noone has an answer ?

this first algorithm is for one non-ramified petiole and for several ramified petioles please ?

I make the skeleton but there are artefacts around, how to remove them please ?
This is the image :

noone has an answer please ?

hello, I do an up please

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nobody has an answer please ?

noone has a solution ?