The Sequoia Calibration Report is provided with every Sequoia shipped by Pix4D. It includes the following sections:
- Bundle Block Adjustment Details
- Internal Camera Parameters
- Camera Rig Relatives
- 2D Keypoints and Matches
- Geolocation details
This step includes the optimization of the camera position and orientation values, as well as the creation of the Automatic Tie Points. For more information: 202558679.
This section shows the difference between the Initial Values as coming from the camera database and the Optimized Values obtained at the end of the calibration process. For more information: 202558679.
A vector field is also displayed. This corresponds to the average reprojection error for each block of pixels. An error of less than 1 pixel is to be expected. If patterns are detected (upper left corner all pointing in the same directions), this should be investigated.
This table contains the information concerning the rig geometry, i.e. the geometry between the different sensors of Sequoia. In particular, it shows the offset between the different sensors and the Reference Camera. By default, the translation is not optimized as it has precisely measured, while the rotation angles are optimized since they can vary slightly.
The tables in this section give statistics concerning the number of keypoints per image for the different sensors. The number of (matched) keypoints is an indicator of how well the different images are connected together. For more information: 202558679.
During the calibration process for Sequoia, over 100 GCPs were extracted automatically. This table displays some statistics concerning this process: the average, the variance and the RMS error for each direction.