Hi Gianluca,
oh I forgot to mention that there are curved lines too in my images.
l = {Line[{{0, 0}, {0, 1}, {1, 1}, {0, 0}}], Circle[{0.5, 0.5}, 0.5]};
i = Graphics[l, ImageSize -> 300]
Show[ImageGraphics[Rasterize[Graphics[l, ImageSize -> 100]]], ImageSize -> 300]
Show[ImageGraphics[Rasterize[Graphics[{Thickness[0.05], l}, ImageSize -> 100]]], ImageSize -> 300]
HighlightImage[i, ImageLines[ColorNegate[i], 1/3]]
HighlightImage[i, ImageLines[ColorNegate[i], 1/15]]
ImageLines only works for straight line segments, but I want a vectorization of the whole image.
Max