The present invention provides a method for digitally obtaining contours of fabricated polygons. A GDS polygon described in a Geographic Data System (GDS) file is provided. Based on the GDS polygon, a plurality of identical polygons is fabricated with the same fabrication process such that shapes of the plurality of identical polygons are altered by optical effects in the same or similar way. The plurality of identical polygons forms poly-silicon gates of a plurality of test transistors. The position of source and drain islands along a length of a poly-silicon gate for each of the plurality of test transistors is different. Using Automated Test Equipment (ATE), a digital test is performed on a circuit including the plurality of test transistors to obtain test responses, the test responses being raw digital data. The test responses may be displayed in a histogram reflecting a contour of the plurality of identical polygons or post-processed to reconstruct a contour of the plurality of identical polygons.