Video denoising

October 16, 2008
Oscar Au | Hong Kong University of Science and Technology

It is well known that noise can be introduced into video during capturing, storage and transmission. It is especially bad in dark regions in the video where the signal-to-noise ratio is low. Such noise is typically visually disturbing and can cause serious problem to many video coding systems such as MPEG-1/2/4, and H.261/3/4. This is because many precious bits would need to be spent to encode this undesirable noise in the video. As MPEG-2, MPEG-4, H.263 and H.264 are used widely in consumer electronics such as DVD, Blu-ray, DVB-C/T/S/H, DMB, HDTV, PDA, IPTV, video conferencing and streaming, there is a great need for video denoising.

In this talk, we will introduce a class of optimal linear filter in temporal domain to suppress noise. Even when the filter length is very small, the denoising results can be very significant. In pre-filtering applications, these filters require robust motion estimation (in noisy condition) which requires much computation. We will show a class of fast motion estimation especially designed for denoising purpose. We will also introduce a formulation that can integrate the denoising filter seamlessly into the video encoders and decoders such as MPEG-1/2/4 and H.261/3/4. The resulting complexity is greatly reduced and the video coding performance greatly improved.

Speaker Details

Oscar C. Au received his B.A.Sc. from Univ. of Toronto in 1986, his M.A. and Ph.D. from Princeton Univ. in 1988 and 1991 respectively. After being a postdoctoral researcher in Princeton Univ. for one year, he joined the Dept. of Electrical and Electronic Engineering of the Hong Kong University of Science and Technology (HKUST) in 1992. He is now an Associate Professor, Director of Multimedia Technology Research Center (MTrec), and Advisor of the Computer Engineering (CPEG) Program in HKUST.His main research contributions are on video and image coding and processing, watermarking and steganography, speech and audio processing. Research topics include fast motion estimation for MPEG-1/2/4, H.261/3/4 and AVS, optimal and fast sub-optimal rate control, mode decision, transcoding, denoising, deinterlacing, post-processing, JPEG/JPEG2000 and halftone image data hiding, etc. He has published over 130 technical journal and conference papers. His fast motion estimation algo rithms were accepted into the ISO/IEC 14496-7 MPEG-4 international video coding standard and the China AVS-M standard. He has 2 US patents and is applying for 9 more on his signal processing techniques. He has performed forensic investigation and stood as an expert witness in the Hong Kong courts many times.Dr. Au is an active senior member of the Institute of Electrical and Electronic Engineering (IEEE). He has been an Associate Editor of the IEEE Transactions on Circuits and System, Part 1 (TCAS1) and the IEEE Trans. On Circuits and Systems for Video Technology (CSVT). He is the Chairman of the Technical Committee on Multimedia Systems and Applications and a member of the TC on Video Signal Processing and Communications and the TC on DSP of the IEEE Circuits and Systems (CAS) Society. He served on the organizing committee of the IEEE Int. Symposium on Circuits and Systems (ISCAS) in 1997, the IEEE Int. Conf. On Acoustics, Speech and Signal Processing (ICASSP) in 2003, the ISO/IEC MPEG 71st Meeting in 2004, Int. Conf. on Image Processing (ICIP) in 2010, and other conferences.