CameraCalibrator¶
in Lib.io.video
Calibrates a camera to determine its intrinsic parameters (like focal length and lens distortion) and to remove distortion from the video feed.
This operator analyzes images of a known chessboard pattern to calculate the camera's properties. This process is essential for many computer vision tasks, such as 3D reconstruction, augmented reality, and spatial mapping.
To use:
1. Set the ChessboardSize to match your physical chessboard pattern.
2. Show the chessboard to the camera.
3. Trigger CaptureImage multiple times from different angles and distances.
4. Trigger Calibrate to compute the camera parameters.
5. Switch Mode to 'LensCorrected' to see the corrected image on the TextureOut output.
6. Save the calibration to a file for later use.
AKA: lens calibration, camera intrinsics, undistort, computer vision, chessboard
Input Parameters¶
| Name (Relevancy & Type) | Description |
|---|---|
| Alpha (Single) | Controls the cropping of the undistorted image. 0 crops to show only valid pixels, while 1 shows all original pixels, potentially with black areas at the edges. |
| BorderInSquares (Int32) | The width of the border around the generated checkerboard pattern, measured in squares. |
| Calibrate (Boolean) | A trigger to start the calibration process using all the captured images. |
| CaptureImage (Boolean) | A trigger to capture the current frame showing the chessboard. Capture at least 10-15 images from various angles for a good calibration. |
| ChessboardSize (Int2) | The number of inner corners on your chessboard pattern (e.g., a 9x6 board has 8x5 inner corners). |
| DisplayResolution (Int2) | The resolution of the display that is showing the generated checkerboard pattern. This should match your projector or screen resolution. |
| FilePath (String) | The path to the file for saving or loading the camera calibration data (as a .json file). |
| Load (Boolean) | A trigger to load camera calibration data from the specified FilePath. |
| Mode (Int32) | Switches the operator's function between 'Passthrough' (raw video), 'Calibration' (for capturing and calculating), and 'LensCorrected' (for applying the correction to the live feed). |
| Reset (Boolean) | A trigger to clear all captured images and reset the current calibration. |
| Save (Boolean) | A trigger to save the current calibration data to the specified FilePath. |
| SquareInMm (Single) | The real-world side length of a single square on your physical chessboard, in millimeters. This is crucial for accurate 3D measurements. |
| TextureIn (Texture2D) | The live video feed from the camera that you want to calibrate. |
| UndistortMethod (Int32) | The algorithm used to undistort the image after calibration. 'Undistort' is generally simpler, 'Remap' offers more control. |
Outputs¶
| Name | Type |
|---|---|
| CheckerboardTexture | T3.Core.DataTypes.Texture2D |
| IsCalibrated | System.Boolean |
| StatusMessage | System.String |
| TextureOut | T3.Core.DataTypes.Texture2D |