Temporal Flicker Reduction and Denoising in Video usingSparse Directional Transforms

摘要

The bulk of the video content available today over the Internet and over mobile networks suffers from manyimperfections caused during acquisition and transmission. In the case of user-generated content, which is typicallyproduced with inexpensive equipment, these imperfections manifest in various ways through noise, temporalflicker and blurring, just to name a few. Imperfections caused by compression noise and temporal flicker arepresent in both studio-produced and user-generated video content transmitted at low bit-rates. In this paper,we introduce an algorithm designed to reduce temporal flicker and noise in video sequences. The algorithm takesadvantage of the sparse nature of video signals in an appropriate transform domain that is chosen adaptively basedon local signal statistics. When the signal corresponds to a sparse representation in this transform domain, flickerand noise, which are spread over the entire domain, can be reduced easily by enforcing sparsity. Our results showthat the proposed algorithm reduces flicker and noise significantly and enables better presentation of compressedvideos.