Description
Note
At the moment this node can not directly be connected to the SfM pipeline in the UI. That would be obviously a nice feature to have. The camera models and parameters can be manually copied to the CameraInit settings. This node just needs a bit more work before using it directly into the Meshroom graph. If someone is interested to contribute to this feature, we would be glad to provide assistance.
The internal camera parameters can be calibrated from multiple views of a checkerboard. This allows to retrieve focal length, principal point and distortion parameters. A detailed explanation is presented in OpenCVcameraCalibration.
| Name | Description |
|---|---|
| Input | Input images in one of the following form: - folder containing images - image sequence like "/path/to/seq.@.jpg" - video file |
| Pattern | Type of pattern (camera calibration patterns) - CHESSBOARD - CIRCLES - ASYMMETRIC CIRCLES - ASYMMETRIC CCTAG |
| Size | (Size of the Pattern) - Number of inner corners per one of board dimension like Width (7) Height (5) (0-10000) |
| Square Size | Size of the grid's square cells (0-100mm) (1) |
| Nb Distortion Coef | Number of distortion coefficient (0-5) (3) |
| Max Frames | Maximal number of frames to extract from the video file (0-5) (0) |
| Max Calib Frames | Maximal number of frames to use to calibrate from the selected frames (0-1000) |
| Calib Grid Size | Define the number of cells per edge (0-50) |
| Min Input Frames | Minimal number of frames to limit the refinement loop (0-100) |
| Max Total Average Error | Max Total Average Error (0-1) |
| Debug Rejected Img Folder | Folder to export delete images during the refinement loop |
| Debug Selected Img Folder | Folder to export debug images |
| Output | Output filename for intrinsic [and extrinsic] parameters (default filename cameraCalibration.cal) |
Details
Patterns
CHESSBOARD https://github.com/artoolkit/artoolkit5/blob/master/doc/patterns/Calibration%20chessboard%20(A4).pdf
Chessboard calibration video sample https://vimeo.com/141414129
CIRCLES
ASYMMETRIC_CIRCLES https://nerian.com/support/resources/patterns/
ASYMMETRIC_CCTAG https://github.com/alicevision/CCTag
A list with other camera calibration tools and patterns can be found here https://github.com/natowi/CameraCalibTools