Improvements to image magnification

The main limitation of state-of-the-aft magnifying techniques is that they do not introduce any new information to the original image. This lack of information, more precisely the absence of high spatial frequency components is responsible for the perceptible degradation of the enlarged image. The idea underlying this work is to estimate the phases and frequencies of absent waveforms of absent frequencies from the original low resolution image and then to synthesize them in the high resolution image. The developed technique takes advantage of sub-pixel edge estimations from the low resolution image to direct the subsequent polynomial interpolation step. To improve perceptible image quality, the n-degree polynomial interpolating curve is user-controllable allowing both sharp and smooth edges to be synthesized. The proposed approach has been applied both to gray-level images and to color images. (C) 2001 Pattern Recognition Society. Published by Elsevier Science Ltd. All rights reserved.