Alan Valev Tonisson

Image scaling with aliasing cancellation

This paper describes a novel image scaling algorithm based on a simple orientation adaptive anti-aliasing filter. The Projection-Slice theorem of Fourier theory is applied to characterize the structure of aliasing errors along edges in scaled images. This structure is used to explain the operation of our anti-aliasing filter which removes the dominant Fourier component of the aliasing error. It is shown that edge detail may be recovered from an aliased image by applying the anti-aliasing filter to the output of a separable wide-band interpolating filter. We also describe a simple one-dimensional inverse filter that may be combined with our anti-aliasing filter to restore further detail. Comparison of our scaling algorithm with other methods demonstrates that our scaling method is generally superior to other methods in removing visible aliasing artifacts along edges. Our method also competes favorably with state-of-the-art methods in recovering edge detail, without introducing sharpening artifacts exhibited by other methods.