Stereo-Camera Calibration

Overview: Stereo-Camera Calibration App is a software tool that makes the process of calibration of a Stereo-Camera simple and quick.
  1. Calibration List Page

This page contains the list of calibrations. You can launch an existing dataset, delete and even manage your access to these datasets.

2. Stereo-Camera Calibration Launch

You can select an existing stereo-camera calibration from the list page, or click on the “New Calibration” button on the top-right of the calibration list page and select the stereo-calibration in the window that pops.

3. Start Page

The page lists the important instructions and requirements that you need to follow in order to complete the calibration process.

  • Start the app by clicking on the “Get Started” button

  • Input the name you wish to give this calibration. This name will be shown on the calibration-list page. And then click on “Set Details”

4. Setup Stereo-Camera details

You can fill in the basic details for the Stereo-Camera and also specifically for the left and right camera of the Stereo-camera.

  • Camera name: Input the name for the Stereo-Camera sensor

  • Camera lens model: Select the lens model of your Stereo-Camera

  • Fill Camera intrinsic parameters manually: Check the box if you can input the intrinsic parameters for the left and right camera. Otherwise, uncheck it.

  • Left/Right Camera Intrinsic Parameters: The following parameters are common to both cameras.

  • Import Intrinsic Parameters: If you have calibrated the left and right cameras with the Deepen Camera-Intrinsic Calibration App and created profiles for your workspace, you can directly import the values using the dropdown menu.

  • Import from JSON: You can use JSON files to import the intrinsics parameters as well.

  • Once all the details are filled in, click the “Save Changes” button on the top right to save the changes. After that, click the “Continue” button on the bottom right.

5. Add Checkerboard images

You need to add the images taken from the left and right camera of the Stereo-Camera. This page allows you to pair them manually. Also, it has an “Auto Pair” button to pair the files automatically, based on their filename order. It is recommended to follow the file naming guidelines from the Stereo-Calibration Data collection doc.

  • Upload the images for the left camera

  • Upload the images for the right camera

  • Files are automatically paired based on the file name order.

  • Verify if the pairing is correct or not. If not, select the correct file pair on left and right, and pair them up using the “Add Pair” button on the bottom.

  • Delete any unpaired files, with the delete button that appears when hovered over a file.

  • Click on the “Save Changes” button to upload the files and save the pairing details for the files. After that, click on the “Continue” button.

6. Set checkerboard details

You need to fill in the checkerboard details like Horizontal Corners, Vertical Corners and Dimensions i.e. square size for the checkerboard and click on “Set Config”. Then click on “Save Changes” and then click on Continue.

7. Calibrate

On this page, you just have to click “Run Calibration” to get the calibration results. Once clicked, the images are processed and once done, the calibration results are shown on the right side of the page. Also, the Visualise button becomes enabled and allows you to visualise the calibration results.

8. Error stats

You can toggle the error stats and select individual errors or average errors. Individual Errors show the errors related to an image pair selected on the left pane.

  • Left Reprojection Error: The pixel error when the detected corners from the right image are projected onto the left image using the calibration results

  • Right Reprojection Error: The pixel error when the detected corners from the left image are projected onto the right image using the calibration results

  • Translation Error: The distance between the means of the 3d projections of the checkerboard in a 3d scene from the left images and right images

  • Rotation Error: The angle between the planes of the 3d projections in a 3d scene of the checkerboard from the left images and right images

9. Visualise

Clicking on the visualise button takes you to the visualisation screen. You can see the cameras and the selected image-pair checkerboard on the screen. You can move around in the 3d scene using the mouse left (for pan) or right (for orbit) button click-drag, to have a better sense of the view. Also, on the top-right, in the options dropdown, you have the option to show/hide all the checkerboards from all the image pairs at once.

10. Export

You can export the results of the calibration using the “Export” button on the top-right of the page. Fill in the name of the output file and click on Export.