3-D Perception With A Single Binary Coded Illumination Pattern

A new triangulation method for range image acquisition is presented. The scene is illu-minated with a fixed binary coded light pattern. The 64x63 range picture is determined from the information of a single camera image, which makes it possible to acquire moving scenes. The ambiguity inherent in multiple sample triangulation is solved by making each sample point identifiable by means of a binary signature, which is locally shared among its closest neighbours. The applied code is derived from pseudo-noise sequences. Analysis of an illumination-coded image yields the image coordinates of the detected sample points with sub-pixel accuracy, along with their assigned code bit. Exploration of the local topology around each sample retrieves its associated binary signature, by which it is identified. The corresponding spatial coordinates of an identified sample are determined by applying a linear transformation to its image coordinates, the appropriate matrix being selected by the identification result.