I have a collection of signal images with signal as a black line, grid of red lines in the background, and black letters and numbers that are of no importance to me.
I need to extract the black curvy signal line as a time series, and completely ignore the letters and numbers. Something like the graph below, but printed and scanned, therefore not so crisp.
Ideally, the output should be a CSV of the black line.
...26.931, 24.740, 25.806, 24.364, 24.477, 23.901, 23.175, 23.227...
Is there an off the shelf method? what is the simplest/easiest way?