What if the original graph has grid lines?
Although grid lines can confuse the Automatic Line Follow mode there are generally some simple solutions. The UN‑SCAN‑IT software has grid line filters that can recognize (and ignore) grid lines based upon the intensity, thickness, or horizontal/vertical nature of the grid lines. In addition, if the grid lines are thinner or a lighter color than the data line, most scanners (or photocopy machines) can be adjusted to drop out the grid lines while retaining the data line. If the grid lines are particularly difficult, you can erase the grid lines just where they touch the top surface of the data line, or use Manual Mode (Auto-x-Increment) where UN‑SCAN‑IT moves automatically in the x direction and the user controls the y movement.
