title: L/M-fold image resizing in block-DCT domain using symmetric convolution.
abstract: Image resizing is to change an image size by upsampling or downsampling of a digital image. Most still images and video frames on digital media are given in a compressed domain. Image resizing of a compressed image can be performed in the spatial domain via decompression and recompression. In general, resizing of a compressed image in a compressed domain is much faster than that in the spatial domain. We propose a novel approach to resize images with L/M resizing ratio in the discrete cosine transform (DCT) domain, which exploits the multiplication-convolution property of DCT (multiplication in the spatial domain corresponds to symmetric convolution in the DCT domain). When an image is given in terms of its 8 x 8 block-DCT coefficients, its resized image is also obtained in 8 x 8 block-DCT coefficients. The proposed approach is computationally fast and produces visually fine images with high PSNR.
authors.affiliation: Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea. hwpark@athena.kaist.ac.kr
authors.forename: HyunWook
authors.initials: H
authors.lastname: Park
authors.forename: YoungSeo
authors.initials: Y
authors.lastname: Park
authors.forename: Seung-Kyun
authors.initials: SK
authors.lastname: Oh