Compute extrinsic parameters for a given kinect intrinsic camera parameters

Question

I have to calculate the Extrinsic parameters based on Kinect V2 intrinsic parameter. In kinectV2 sensor, we could get intrinsic parameters like fx,fy,cx,cy coefficients. But i want to find extrinsic parameter values based on my kinect intrinsic parameters.

I saw so many methods available in opencv to calculate extrinsic parameters,but all these are related to chessboard as a base.

Please suggest me how you find the extrinsic parameter such as rotation and translation for a given intrinsic parameter.

Answer 1

You can use calibrateCamera function with your initial intrinsic parameters by using CV_CALIB_USE_INTRINSIC_GUESS option. Whether you use a checkerboard or any other tool, you have to provide at least three 3d point coordinates in the real world and corresponding 2d coordinates on the image plane. Calculation of extrinsics without any correspondences is not an option.

If you don't want to use a checkerboard, track a spherical object in time, record 3d real world and 2D image coordinate of the center of sphere to generate the dataset you need to use this function. However, you should keep in mind that then you are limited with the accuracy of your kinects depth sensor.