Pinhole Camera Geometry
oh my god, all my lessons with Optics in high school is coming back…
- Learned from the Visual SLAM book, starting page 96
- I also have notes that I understand better in Camera Calibration, which I learned from Cyrill stachniss.
Let’s summarize the imaging process of a monocular camera:
- First, there is a point in the world coordinate system, and its world coordinates are .
- Since the camera is moving, its motion is described by or transform matrix . The camera coordinates for are .
- The components are , and they are projected onto the normalized plane to get the normalized coordinates: . Note that may be less than 1, indicating that the point is behind the normalization plane and it should not be projected on the camera plane.
- If the image is distorted, the coordinates of after distortion are calculated according to the distortion parameters.
- Finally, the distorted coordinates of pass through the intrinsics and we find its pixel coordinates: .