Spatial resolution enhancement of images using nonlinear interpolation

A nonlinear interpolation scheme for image-resolution enhancement is presented. The algorithm is based upon a source model emphasizing edges and incorporates a hybrid local edge-fitting operator which has been developed for this application. A small neighbourhood about each pixel in the low-resolution image is first mapped to a best-fit continuous-space step-edge. This bilevel approximation serves as a local template upon which the higher-resolution sampling grid can then be superimposed. Disputed values in regions of overlap are averaged to smooth errors. The result is an image of increased resolution with noticeably sharper edges and lower reconstruction error than produced by linear techniques