I did this Finnish -> English translation of my B.Sc. thesis from 2007 in 2016-2017. Get it here. Sorry for the low res still graphics and receiver strain on this information on digital look-alikes. Just read the abstract and the conclusions if not interested in the technical stuff. Pictures are understandable. Digital look-alikes are disinformation weapons in wrong hands. Disinformation weapons technology thesis? Yeah, probably that.
Normal image in dot lighting (a)
Image of the diffuse reflection which is caught by placing a vertical polarizer in front of the light source and a horizontal in the front the camera (b)
Image of the highlight specular reflection which is caught by placing both polarizers vertically (c)
Subtraction of c from b, which yields the specular component(d)
Images are scaled to seem to be the same luminosity.