In this example a topview is generated using the calibration square that was added in the scene before taking the picture. Of course it's also possible to go to the scene and measure the positions of certain marks (long after the tiretracks have disappeared). Move your mouse over the image to see the result of warping. Note that after warping the sizes in the topview have also been calibrated using the reference points.
In this example indented writing becomes visible with oblique lighting.
Especially when you have more fragments of indented writing to visualize (keeping in mind their relative positions) it is good to be able to easily and precisely map those fragments onto the normal view of the document. Click on the image below to see the result.
The image is perfectly mapped (note the yellow bands that look golden with the oblique light).
The same method to overlay images can be very useful in demonstrating the overlap of a signature and its suspected reproduction, while removing possible distortion from the reproduction process.