Kyo-hyuk Lee

Fast sample adaptive offset encoding algorithm for HEVC based on intra prediction mode

This paper presents a fast sample adaptive offset (SAO) encoding algorithm in High Efficiency Video Coding (HEVC). The key idea of a proposed method is to simplify decision of the best SAO edge offset class by exploiting intra prediction mode information instead of exhaustive RD cost calculation for all classes. The proposed method reduces SAO encoding time about 77.3% only with 0.8% BD-rate degradation under common test condition of HEVC reference software version 10.0.

Analysis and complexity reduction of high efficiency video coding for low-delay communication

Bi-predictive motion compensation is an important coding tool in low-delay coding of HEVC. The proposed method reduces computational complexity about 30% by removing exhaustive bi-predictive motion estimation. The coding gain is about 6% in low-delay P coding.

Lossless embedded compression algorithm with context-based error compensation for video application

With the increase of image resolution in video application, the memory bandwidth is a critical problem in video coding. An embedded compression algorithm is a technique that can compress the frame data when stored in memory. It is possible to reduce memory requirements. In this paper, we propose a lossless embedded compression algorithm with context-based error compensation to reduce the memory bandwidth requirement. Experimental results have shown at least 50% memory bandwidth reduction on average and the data reduction ratio of the proposed algorithm is up to 5% higher than previously proposed lossless embedded compression algorithm [2].

Lossless image compression using valley transform

In this paper, a novel geometric transform, called the valley transform (VT), is proposed for robust compression of noisy images. The VT employs a nonlinear transform to convert random signals into regular ones. The proposed VT is able to change random pixels to regular one. For testing the compression performance, the VT is combined with the SPHIT method. The VT yields slightly better performance than the conventional image codecs such as JBIG, HD-photo and H.264 intra method in the lower bit-plane image compression.

Local interpolation filter estimation for fractional-pel displacement vector in video coding

ISO/IEC Motion Picture Experts Group (MPEG) and ITU-T Video Coding Experts Group (VCEG) have collaborated for development of new international video coding standard with high coding efficiency and network friendly video representation features. In 2003, JVT (collaboration group of MPEG and VCEG) published international standard H.264/MPEG-4 AVC which is the state of the art video coding technology. Several major technical progresses including precise fractional-pel displacement vector resolution with pre-fixed interpolation filter let H.264/MPEG-4 AVC have superior video coding efficiency compared to the previous standards such as MPEG-4, H.263 and etc. For recent years, many researches on interpolation filter for fractional-pel displacement vector have shown possibility for further improvements of video coding efficiency. Most investigations are on improvement of pre-fixed interpolation filters by transmitting texture dependent interpolation filter coefficients to decoder side. In this paper, we introduce a new approach for improvement of pre-fixed interpolation filter without transmitting filter information to decoder side, named as local interpolation filter estimation (LIFE). For generation of prediction signal with fractional-pel displacement vector, a local interpolation filter is estimated by exploitation of previously decoded spatial neighboring texture. Experimental results showed that we could get about 2 13% bit saving with LIFE compared to H.264 High Profile low delay condition.