How to Correct Nonlinear Distortion in Images Captured by a Pin-Hole Camera Model
1. What are the causes of nonlinear distortion in images captured by pinhole cameras?
In the context of a pinhole camera model, nonlinear distortion refers to the optical imperfections and irregularities that occur during the image capture process. It results from deviations between the idealized pinhole camera model and the real-world characteristics of the camera (replacing the ideal pinhole with a lens). Here’s an explanation of nonlinear distortion in a pinhole camera model:
(1) Radial Distortion: One common form of nonlinear distortion in pinhole cameras is radial distortion. This distortion occurs because the lens system used in real cameras does not always precisely obey the idealized pinhole model. Radial distortion can be of two types:
- Barrel Distortion: In barrel distortion, straight lines appear to curve outward from the center of the image. It is more common in wide-angle lenses.
- Pincushion Distortion: In pincushion distortion, straight lines appear to curve inward toward the center of the image. It is more common in telephoto lenses.