3D Free-Form Object Material Identification by Surface Reflection Analysis with a Time-of-Flight Range Sensor

The main objective in this research is to estimate 3D free-form real objects surface characteristics to identify the material based on surface reflectance analysis. To investigate the surface micro-structural detail, we use a time-of-flight range sensor to obtain the orientation of object local surface patches and the intensity of infrared scattering light reflected from those patches. A modified Torrence-Sparrow light reflection model is used to analyze the reflected infrared light. The surface roughness parameter, which represents the microstructure characteristics of object surface and can be an indicator of object material, is determined from the reflection model. We also have demonstrated the feasibility of the method through experiments. Since the original function of the sensor is to obtain 3D shapes of objects, we can develop an object recognition system with this sensor that can consider object material as well as shape.