Adaptive down-sampling video coding

Down-sampling coding, which sub-samples the image and encodes the smaller sized images, is one of the solutions to raise the image quality at insufficiently high rates. In this work, we propose an Adaptive Down-Sampling (ADS) coding for H.264/AVC. The overall system distortion can be analyzed as the sum of the down-sampling distortion and the coding distortion. The down-sampling distortion is mainly the loss of the high frequency components that is highly dependent of the spatial difference. The coding distortion can be derived from the classical Rate-Distortion theory. For a given rate and a video sequence, the optimum down-sampling resolution-ratio can be derived by utilizing the optimum theory toward minimizing the system distortion based on the models of the two distortions. This optimal resolution-ratio is used in both down-sampling and up-sampling processes in ADS coding scheme. As a result, the rate-distortion performance of ADS coding is always higher than the fixed ratio coding or H.264/AVC by 2 to 4 dB at low to medium rates.

[1]  Michael Elad,et al.  Down-Scaling for Better Transform Compression , 2001, Scale-Space.

[2]  Aggelos K. Katsaggelos,et al.  Toward a new video compression scheme using super-resolution , 2006, Electronic Imaging.

[3]  Sebastián López,et al.  Low-Cost Super-Resolution Algorithms Implementation Over a HW/SW Video Compression Platform , 2006, EURASIP J. Adv. Signal Process..

[4]  Ishfaq Ahmad,et al.  Power-rate-distortion analysis for wireless video communication under energy constraints , 2005, IEEE Transactions on Circuits and Systems for Video Technology.

[5]  Aggelos K. Katsaggelos,et al.  Region-based super-resolution for compression , 2007, Multidimens. Syst. Signal Process..

[6]  Michael Elad,et al.  Improved high-definition video by encoding at an intermediate resolution , 2004, IS&T/SPIE Electronic Imaging.

[7]  Lap-Pui Chau,et al.  The realization of arbitrary downsizing video transcoding , 2006, IEEE Transactions on Circuits and Systems for Video Technology.

[8]  T. Berger.  Rate-Distortion Theory , 2003 .

[9]  Weisi Lin,et al.  Adaptive downsampling/upsampling for better video compression at low bit rate , 2008, 2008 IEEE International Symposium on Circuits and Systems.