Handling Distortion and Perspective Errors in Imaging Systems
Imaging errors introduced by lenses can limit the quality of an optical system. Both distortion and perspective errors, however, can be measured and corrected.
While all vision systems try to accurately reproduce an object's features, the degree of image resolution and contrast needed are determined by the specific application (see "Now You See It," Quality, May 2002, pg. 8). The application also will dictate the acceptable degree of distortion and perspective error. This begs the question, "What are these errors and what role do they play in determining sufficient image quality?"
Distortion
Distortion is an optical error or aberration, caused by the lens, which results in differences in magnification at different points in the image. Although distortion does limit the quality of the image, no image information is lost -- it is merely misplaced.