Method and apparatus for changing the spatial resolution of a digital image

摘要

A method and apparatus for changing the spatial resolution of a digital image are disclosed. A feature vector (Y) for a pixel (101) in the digital image (102) is obtained. The pixel (101) is classified so that the pixel (101) is allocated to one or more context classes by comparing the feature vector (Y) of the pixel (101) with a prototype of each of said context classes. Each context class has one or more interpolation filters associated therewith. The pixel (101) is filtered using the one or more interpolation filters associated with the one or more context classes to which said pixel (101) is allocated, thereby to generate one or more pixels of the final digital image. The feature vector (Y) for the pixel (101) is a function of differences between selected adjacent pairs of pixels in the first digital image, at least one of said adjacent pairs of pixels in the first digital image not including said pixel (101).