The technology has produced startling revelations: Names on gravestones that seemed lost to time. Unnoticed text and mechanical details on the celebrated ancient Greek Antikythera Mechanism, considered the world's first computer. Even the self-incriminating notes of a murderer – uncovered when the suspect’s writing was found imprinted on a blank page in his notebook.

Interactive Relighting is a way of capturing and viewing images of three-dimensional objects that can reveal hidden details. It does this by combining multiple still photographs of the subject to create a single, composite 'image' over which you can move a virtual light.

The result? Previously illegible or invisible marks, scratches, colors and textures become amazingly clear.

The technology relies on a technique invented by HP researchers to create a Polynomial Texture Map (PTM).

To create a PTM, users take multiple digital photos of an object, each time moving the light source to a different position. These pictures are merged into a file containing information about the reflectance of the object under varying lighting conditions.

Knowing that information, it is possible to map how the object responds to light, and from that, to ‘relight’ the object virtually, bringing out surface details that can’t be seen in normal light.

Interactive Relighting is used by some of the world’s foremost archeologists, paleontologists, art historians, geologists and forensic scientists. The technique is available for anyone to use on a non-commercial basis.

To see some of the results, click on the image LINK TO IMAGE and move your cursor to change the angle of the light. A right click allows you to change the reflectance of an object – making it seem more or less shiny than it is in real life. You can see more results here. For faster viewing, download the PTM Viewer.