MULTIDIMENSIONAL RANGE MAPPING WITH PATTERN PROJECTION AND CROSS CORRELATION

A range camera is provided for the determination of range to an object through the utilization of a system which projects a limited depth of field light pattern onto an object and measures the blurring of the pattern on the object. In one embodiment an anisotropic aperture or astigmatic optics are used in combination with an isotropic pattern to eliminate system error introduced by the camera. The anisotropic aperture provides that blurring takes place only in a given direction, with measurement of blurring in an orthogonal direction providing an output only responsive to the blurring associated with the camera. This blurring can then be subtracted out to eliminate system error from the range measurement. The range camera is operative to produce a range picture or map, with optional outputs providing localized albedo and a conventional brightness image. In another embodiment, the direction of the blur, either in front of or in back of the plane of best focus of the projected pattern, is provided through the utilization of a mask having an aperture devoid of point symmetry. In a further embodiment, direction of blur can be ascertained through the utilization of astigmatic optics.