MDSI range camera calibration

An MDSI (Multiple Double Short-Time Integration) range camera consists of a grid of pixels which are utilized to measure the near infrared laser intensity back-scattered from an illuminated scene. For each pixel two consecutive intensity measurements are conducted which encode the time-of-flight as well as the reflectance of the illuminated objects. From these two intensity values the distance to the object in the observed solid angle element can be computed. Estimation of range camera parameters which are essential for accurate range reconstruction can be performed using a coordinate-measuring device. The corresponding calibration procedure, however, is tedious and inflexible. In this paper we therefore present a new, simple and flexible approach to range camera calibration based on separate representations of viewing rays corresponding to the range pixels. Our approach uses range reconstruction superiority of a calibrated gray-value camera for planar calibration patterns. The resulting range information is given in the coordinate system of the gray-value camera.