New algorithms for processing images in the transform-compressed domain

摘要

Abstract: Future multimedia applications involving images and video will require technologies enabling users to manipulate image and video data as flexibly as traditional text and numerical data. However, vast amounts of image and video data mandate the use of image compression, which makes direct manipulation and editing of image data difficult. To explore the maximum synergistic relationships between image manipulation and compression, we extend our prior study of transform-domain image manipulation techniques to more complicated image operations such as rotation, shearing, and line-wise special effects. We propose to extract the individual image rows (columns) first and then apply the previously proposed transform-domain filtering and scaling techniques. The transform-domain rotation and line-wise operations can be accomplished by calculating the summation of products of nonzero transform coefficients and some precalculated special matrices. The overall computational complexity depends on the compression rate of the input images. For highly-compressed images, the transform-domain technique provides great potential for improving the computation speed.!14