Modern transform design for advanced image/video codingapplications

摘要

This paper offers an overall review of recent advances in the design of modern transforms for image and video codingapplications. Transforms have been an integral part of signal coding applications from the beginning, but emphasis hadbeen on true floating-point transforms for most of that history. Recently, with the proliferation of low-power handheldmultimedia devices, a new vision of integer-only transforms that provide high performance yet very low complexity hasquickly gained ascendency. We explore two key design approaches to creating integer transforms, and focus on asystematic, universal method based on decomposition into lifting steps, and use of (dyadic) rational coefficients. Thismethod provides a wealth of solutions, many of which are already in use in leading media codecs today, such as H.264,HD Photo/JPEG XR, and scalable audio. We give early indications in this paper, and more fully elsewhere.