What does intrinsics mean?

The numbers that describe what a camera does to a ray, independent of where the camera is: the focal lengths fx and fy in pixels and the principal point (cx, cy). They are found by calibration and often written as the intrinsic matrix K.

Also written as: intrinsic matrix, intrinsic parameters

In a lesson

Two cameras with the same 3.6 mm lens and different sensors have completely different intrinsics. And if you rescale an image, the intrinsics scale with it: halve the width and fx and cx both halve. Forgetting that is a classic bug, and it shows up as a system that works on full frames and mysteriously mis-aims on thumbnails.

Learn it

• Taught in U11.2 Intrinsics and calibration Vision, University

Used in

• U11.5 Colour, and why it breaks

All glossary terms