What you need is a digitized version of at least one analog trace. The overlaps of multiple traces of the same color make that difficult to do with an automatic algorithm applied to a digitized image. If you can get access to a drawing tablet with stylus and a t, you could (maybe*) tape the paper on the tablet and trace one or more traces with the stylus. (* assuming that paper does not block detection of the stylus.) But there would have to be software that would output stylus movement as a series of (x,y) points rather than as a pixel image (you already have that). Or you need a drawing program that will display the image above and capture mouse movements as positions. I don’t know if photoshop or anything similar In tkinter, one could display the image and move the mouse over the image and capture the movement with mouse_move events.
