Joint Calibration of Time-of-Flight Depth Camera and Color Camera

Depth sensor such as Time-of-Flight (TOF) depth camera can get depth information in real time and accurately, which attracts the extensive attention in the computer vision field. To gain the color and depth information of the same scene, a joint calibration method of TOF depth camera and color camera based on traditional chessboard calibration methodis proposed, aiming at the low resolution and high radial distortion of the TOF camera, using the chessboard planar with sparse corners to improve the precision of the corner detection. First, calibrate the color and TOF depth camera separately, the intrinsic parameters of the color camera was gained through the traditional chessboard calibration method, the undistorted intensity images from TOF camera were used to get the intrinsic parameters of the TOF camera. Then, several experiments were conducted to get the relative position of the two cameras, the final result was the value after the least square optimization. Experiments show that the precision of the calibration is high, which means the reprojection error of color camera can be reduced 0.15 pixels mostly and error of depth sensor can be reduced 0.09 pixels and the depth image at the color image position acquired by the calibration parameters and the original depth image can be well aligned with the color image.