The measurement and use of registered reflectance and range data in scene analysis

The theory and use of a laser sensor designed to provide arrays of registered intensity and range data for three-dimensional scene analysis are described in this paper. Equations are derived to relate the mean and variance of both the intensity and the range data to the physical properties of the target and the parameters of the sensor. Experimental results that verify these equations are given. Adaptive data smoothing and normalization procedures are presented. These procedures reduce photon noise and correct the intensity data for inverse square-law effects. The resulting intensity data give the product of the diffuse surface reflectance and the cosine of the angle of incidence for each picture element in the scene. Simple procedures are given for finding outlines of occluding objects, obtaining normal views of obliquely sensed planar surfaces, and extracting the images of horizontal surface regions from a scene. These procedures demonstrate the advantages of having registered reflectance and range data for scene analysis.