Orthocam

Weak Perspective Camera Calibration

Orthocam provides camera calibration tools for cameras in the weak perspective regime. This regime occurs when Δz << z, usually occurring when the camera's angle of view is <10° (according to doi:10.1088/0957-0233/26/9/095203). In this regime, the standard camera model has one too many degrees of freedom relative to the perspective information available, and optimizations can fail to converge.

This software is integrated with (and requires) the Stereo Camera Calibration App in MATLAB R2016b specifically. Orthocam is working software and has not been polished for ease of use.

Orthocam was developed by Allen Lee, Stephen Huston, and Kristin Branson in the Branson Lab at HHMI/Janelia Research Campus for use with the Animal Part Tracker.

Requirements and Setup

1. Orthocam calibration requires MATLAB R2016b specifically, as well as the MATLAB Computer Vision Toolbox.
2. Clone the repo or download the code.
3. Start MATLAB and navigate to the repo directory.
4. Run getVisionFiles in MATLAB. This will copy a few MATLAB toolbox files into a vision directory underneath the repo.
5. A patchfile diffs.patch has been supplied in this repo that specifies updates to these toolbox files. See patch.cmd for a command you should run in a unix shell (eg on Windows, use WSL2) while in the repo directory.
6. Run setupPaths in MATLAB. This will add the modified toolbox files to your MATLAB path. These modified toolbox files will shadow their built-in counterparts. Don't save your MATLAB path if you also need to use the standard MATLAB Stereo Calibration App. Note that your original toolbox files are safe and unmodified in their usual locations.
7. Follow the recipe in README_Calibration_Recipe.md to perform your calibrations.

Good luck! May your optimizations converge and your reprojections be faithful!