Vision threads: a novel approach to generic camera calibration

Optical metrology techniques such as fringe projection technology and phase-measuring deflectometry, which use cameras as image sensors for 3D coordinate measurement and inspection, are becoming increasingly demanding. The necessary precise and at the same time robust calibration of image sensors of these systems is offered by so called vision ray calibration. This generic approach is a model-free description of a vision ray and are determined for each imaging sensor pixel. Numerous images of the sinusoidal fringe images displayed on the active calibration target (LCD) are captured in different poses. This generates a large amount of data and consequently leads to time-consuming evaluation for the camera calibration. In this paper, we propose a new optimization method that uses “vision threads" instead of vision rays to enhance the computation efficiency associated with conventional vision ray calibration. We present MATLAB simulation results in to validate our novel approach.