The creation of realistic digital faces plays a very important role in digital effects for movies, for instance to create the digital double of an actor. Besides acquiring a faithful geometry of the face, recreating a realistic appearance of human skin is extremely important.
In fact, human perception creates a strong revulsion toward things that appear almost human, but not quite: a phenomenon named the “uncanny valley”.
Human skin has a complex structure, with several layers containing blood vessels, connective tissues, fat and hair follicles. However, skin color is mostly due to the concentration of some molecules (skin chromophores), such as melanin and hemoglobin. Both can be present in two different variants, and their relative ratio has different effects on the color of the skin. A further complication is that their concentration changes with time, and depends on the emotional state. As a result, facial skin color and appearance undergo continuous changes.
Our project, in collaboration with experts in computer graphics at Imperial College London, will extend the state of the art on both acquisition and rendering of facial appearance and human skin, in both static and dynamic conditions.
We will use novel spectral image acquisition devices available at NTNU and at Imperial College to measure important skin data, which will be used to create a new skin appearance model for computer graphics applications, thus increasing the photo-realism of digital faces in movies and video games.
Furthermore, novel techniques to estimate skin chromophores from images will be devised. Potentially, this will have additional applications in cosmetology, such as the selection of the appropriate colors to personalize makeup, or the selection of the most suitable sunscreen lotion. More important, the accurate estimation of some skin chromophores could find applications in medicine, since it has important consequences on skin cancer.
