OpenCV's calibrateCamera function enables automatic intrinsic and extrinsic calibration of projector-camera systems within TouchDesigner

Harvey Moon’s Next Level Calibration talk documents using OpenCV’s calibrateCamera within TouchDesigner to calibrate cameras and projectors automatically, eliminating manual corner-picking. The workflow: structured light (patterns projected by a projector, captured by camera), OpenCV finds correspondences, computes the camera/projector intrinsic matrix (focal length, principal point, distortion) and extrinsic pose. CamSchnappr (Moon’s TD component) implements this for projector-to-VR-world calibration. Extension: fiber optic arrays for automatic calibration of physical scale models; multi-projector calibration using cameras and structured light patterns.

Examples

Calibrating three projectors to a curved screen: project a checkerboard pattern from each projector, capture with a camera, run calibrateCamera to get warp maps for each projector. Auto-calibrating a scale city model with fiber optic sensors after physical adjustments.

Assessment

Describe the sequence of OpenCV operations needed to compute the homography between a projector and a camera viewing a flat surface. Identify where Ret Error output from CamSchnappr fits in the feedback loop.