Links

Camera Intrinsic calibration

Calibrations Homepage

  • This page allows the users to view, create, launch, and delete calibration datasets. Admins can manage users’ access to these datasets on this page.
  • Click on New to create a new calibration dataset.

Calibration Selection

Select the Camera Intrinsic Calibration button to create a new Camera Intrinsic Calibration dataset.

Calibration Instructions Page

Upon selecting Camera Intrinsic Calibration, the user is welcomed to the instructions page. Click on Get started to start the calibration setup.

Configuration for Checkerboard

  • Target configuration = Checkerboard
  • Enable use EXIF metadata to use of EXIF metadata from images to optimize calibration. Recommended to disable it if using an External Lens for the Camera.
  • Camera lens model: For wide-angle cameras, use Fish-eye and Standard for the rest
  • Horizontal corners: Number of horizontal inner corners in the checkerboard
  • Vertical corners: Number of vertical inner corners in the checkerboard

Configuration for Charucoboard

  • Target configuration = Charuco Board
  • Enable use EXIF metadata to use of EXIF metadata from images to optimize calibration. Recommended to disable if using an External Lens for the Camera
  • Camera lens model: For wide-angle cameras, use Fish-eye and Standard for the rest
  • Charucoboard Dictionary: There are multiple types of aruco markers from which the charuco board can be made. We support four commonly used dictionaries of opencv, which are DICT_4X4_250, DICT_5X5_250, DICT_6X6_250, and DICT_7X7_250
  • Horizontal corners: Number of chessboard squares in the horizontal direction in charucoboard
  • Vertical corners: Number of chessboard squares in the vertical direction in charucoboard
  • Square size: The size of the square in the board in meters
  • Marker size: The size of the ArUco marker present inside the charucoboard in meters.

Calibration Pipeline

Add images

Upload the images taken from the camera for which intrinsics need to be calculated.

Run calibration

Click the Calibrate button at the bottom to trigger calibration. Upon completion, you can see the intrinsic parameters and the error statistics in the right panel.

Verify Results

Error Stats

The Reprojection error is in pixels. It is the mean of the Euclidean distance between the auto-detected checkerboard corners to the reprojected checkerboard corners. The closer the Reprojection error is to zero, the better the intrinsics are.

Undistorted Image

  • Users can visualize the Undistorted image to check the quality of the intrinsics
  • The side-by-side view can be used to check both the distorted and undistorted images simultaneously

Checkerboard Coverage

  • Checkerboard coverage shows the area covered by the checkerboard corners from all the images uploaded. Higher coverage results in higher calibration accuracy.
    • 0 - 50% is low coverage
    • 51 - 70% is moderate coverage
    • 71 - 100% is Good coverage
  • Users can see the individual reprojection error of all the checkerboard corner points. A color ramp is used to depict the reprojection error. A light red color shows a lower reprojection error, and a darker red indicates a higher reprojection error.

Save to profile

Camera Intrinsic parameters can be saved to the profile for easier import in other calibrations.