Extracting the MESA SR4000 Calibrations

Abstract

Time-of-flight range imaging cameras are capable of acquiring depth images of a scene. Some algorithms require these cameras to be run in `raw mode', where any calibrations from the off-the-shelf manufacturers are lost. The calibration of the MESA SR4000 is herein investigated, with an attempt to reconstruct the full calibration. Possession of the factory calibration enables calibrated data to be acquired and manipulated even in “raw mode.” This work is motivated by the problem of motion correction, in which the calibration must be separated into component parts to be applied at different stages in the algorithm. There are also other applications, in which multiple frequencies are required, such as multipath interference correction. The other frequencies can be calibrated in a similar way, using the factory calibration as a base. A novel technique for capturing the calibration data is described; a retro-reflector is used on a moving platform, which acts as a point source at a distance, resulting in planar waves on the sensor. A number of calibrations are retrieved from the camera, and are then modelled and compared to the factory calibration. When comparing the factory calibration to both the “raw mode” data, and the calibration described herein, a root mean squared error improvement of 51:3mm was seen, with a standard deviation improvement of 34:9mm. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.