thin — thinning by border deletion
out = thin(img)
Function thin performs thinning of binary objects. It uses the Zhang-Suen, a de facto standard and simple technique. The resulting image, the skeleton, is not always connected and is very sensible to noise. It is also slower than a good skeletonization algorithm (see skel). For thin shapes, it should work faster and provide better quality. You will need some pruning criterium to eliminate spurs.
im=gray_imread(SIPDIR+'images/r.gif');
imshow(im,2);
skl = thin(im);
xbasc();
imshow(im+skl,[]);
// Quality is definitely inferior to that of good skeletonization
// methods, as in the following test
im=gray_imread(SIPDIR+'images/escher.png');
skl = thin(im); // Ordinary thinning
xbasc();
xset('wdim',400,500);
subplot(1,2,1);
imshow(im+skl,[]);
xset('wdim',800,400);
skl = skel(im); // multiscale euclidean skeletonization
subplot(1,2,2);
imshow(im+(skl >= 10),[]);
xset('wdim',800,400);