Industrial inspection, law enforcement, and museum preservation professionals all need to capture digital representations of real objects. These digital representations are later used for evidence and analysis that allows more efficient product manufacturing, faster criminal investigations, and preservation of priceless cultural objects. Existing cameras can capture a single view under a single lighting condition, and 3D scanners can capture the shape, but existing devices do not capture the surface reflectance properties. In this proposal, the team has developed a method to capture photographs which allow the lighting to be interactively changed after they are captured. In addition, computation on the data can reveal details which are not visible to the naked eye.
A wide variety of sensors have been investigated in research labs and commercially. These include cameras that fundamentally measure light intensity, as well as depth sensors that fundamentally measure 3D object geometry. This proposal regards a related but different kind of sensor that fundamentally measures surface reflectance, how that surface reacts to light from different incident angles. This is important because the surface reflectance properties of an object may contain important information, even when the surface has no apparent detail when measured with a standard camera or depth sensor. In addition to surface reflectance, this new sensor can directly observe small changes in surface orientation which are below the noise threshold when measuring the surface shape with triangulation or time-of-flight based 3D depth sensors.
