Image/video scaling algorithm based on multirate signal processing

This paper presents an approach for image and video scaling using multirate signal processing. The main objective is to scale images with an arbitrary rational scaling ratio without visible aliasing or distortion artifact. The approach can be applied to grey scale images, color images and video signals in both spatial domain and time domain. Cosine modulation is used to minimize the required on-chip memory since only a prototype filter is stored with some cosine modulation factors. The filters are shown to have comparable regularity for each scaling factor. An efficient structure is proposed for limited bit length filter coefficients which has no imaging artifact after the filter coefficients are quantized. Simulations on still image and video scaling are presented.