A METHOD AND APPARATUS FOR RE-SIZING AND CROPPING IMAGES BY OPERATING DIRECTLY ON THEIR DIGITAL ORTHOGONAL TRANSFORMS

摘要

Digital images are represented in the spatial domain by numbers that correspond to pixels and may be transformed to a transform domain image by means of a Transform Method. Other Transform Methods are used to transform t he transform domain image back to the original spatial domain image. In this invention, these other Transform Methods are modified in such a way that the Modified Transform Method yields spatial domain images that are re-sized versions of the original spatial domain image. Methods are disclosed for employing the Modified Transform Method to implement zoomed and panned versions of the re-sized images. The re-sized images do not require pixel- level smoothing filters and other methods for removing image distortions due to re-sizing.