Patent ID: 8890952
Filing Date: 2014-11-18
Classification: G01S

Abstract:
1. An imaging system comprising: a light source for illuminating a scene with a known intensity light; a camera having an optic axis and center that images the scene responsive to light reflected by surface elements in the scene from the illuminating, known intensity light; a range finder controllable to determine distances to the surface elements of the scene imaged by the camera; a controller configured to determine an imaging direction for respective ones of the surface elements imaged by the camera along which imaging direction the camera images light from the respective ones of the surface elements, define normals to the surface elements of the scene imaged by the camera based on the distances to the surface elements, the controller configured to determine reflectivities of the surface elements based on respective distances of the surface elements from the camera, a dot product of the normal to the respective surface elements and a vector parallel to the imaging direction for respective ones of the surface elements, the known intensity of illuminating light, and light from the surface elements imaged by the camera, the controller is configured to provide an image of the scene comprising image pixels whose gray levels are based on the determined reflectivities of the surface elements, the controller configured to identify candidates for a feature in the scene by determining whether the determined reflectivities of the surface elements match a particular reflectivity of the feature, wherein ones of the surface elements being considered as a candidate for the feature have a value of Rcosθ that satisfies a constraint: R*≧R cosθ≧R′cosθ