1 | initial version |
If your paper background is quite plain, you can do some simple binary thresholding to get the pencil lines. Then projecting the lines onto the y axis and doing a min for a range will give you the lowest point of a particular pencil line and you can set some predefined points in y that you are looking for to be logged. Whenever the min(projection(y)) is lower than your predefined line, you trigger the rest of the code. However the assumption is that the various pencil lines do not overlap in the projection space.