Image rectification

A camera (red) rotates about the blue axis by 5° to 90° (green), as the images are rectified by projection to the virtual image plane (blue). The virtual plane must be parallel to the stereo baseline (orange) and for visualization is located in the center of rotation. In this case, rectification is achieved by a virtual rotation of the red and green image planes, respectively, to be parallel to the stereo baseline.

Image rectification is a transformation process used to project images onto a common image plane. This process has several degrees of freedom and there are many strategies for transforming images to the common plane. Image rectification is used in computer stereo vision to simplify the problem of finding matching points between images (i.e. the correspondence problem), and in geographic information systems (GIS) to merge images taken from multiple perspectives into a common map coordinate system.