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How to calibrate OTCamera

OTCamera gives you the opportunity to receive distinctive camera parameters. These include intrinsics, extrinsics and distortion coefficients. By using our web browser based program and multiple images of a calibration pattern, like a chessboard you can calculate a camera matrix and distortion coefficients. You will be able to evaluate your calibration with a reprojection error which is used to quantify how closely you can recreate true projection. In other words: You can undistort pictures, trajectories or any other pixel coordinates.

First step

  • First you need to download a chessboard pattern (you can search for calibration board).
  • The pattern size and dimension will play no big role for now, so feel free to use any chessboard.
  • Attach your printout to a solid object. The image should be as flat as possible.
  • For best results its unavoidable to let your calibration pattern be manufactured by professionals.


  • Start the calibration application on your raspberrypi.
  • Create a new calibration with a self-chosen CamID.
  • Enter the number of chessboardcolumns, -rows and the squaresize in mm.
  • Choose a number of wanted successful calibration pictures and resolution.
  • Start the calibrationprocess.
  • By clicking on "receive coefficients" your camera parameters will be stored as json-file on your raspberrypi.
  • Evaluate the reprojection error displayed in the userinterface.


Last update: August 26, 2021