Improved combined intra prediction for higher video compression efficiency

Author(s):  
Andre Seixas Dias ◽  
Saverio G. Blasi ◽  
Marta Mrak ◽  
Ebroul Izquierdo
Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2872
Author(s):  
Miroslav Uhrina ◽  
Anna Holesova ◽  
Juraj Bienik ◽  
Lukas Sevcik

This paper deals with the impact of content on the perceived video quality evaluated using the subjective Absolute Category Rating (ACR) method. The assessment was conducted on eight types of video sequences with diverse content obtained from the SJTU dataset. The sequences were encoded at 5 different constant bitrates in two widely video compression standards H.264/AVC and H.265/HEVC at Full HD and Ultra HD resolutions, which means 160 annotated video sequences were created. The length of Group of Pictures (GOP) was set to half the framerate value, as is typical for video intended for transmission over a noisy communication channel. The evaluation was performed in two laboratories: one situated at the University of Zilina, and the second at the VSB—Technical University in Ostrava. The results acquired in both laboratories reached/showed a high correlation. Notwithstanding the fact that the sequences with low Spatial Information (SI) and Temporal Information (TI) values reached better Mean Opinion Score (MOS) score than the sequences with higher SI and TI values, these two parameters are not sufficient for scene description, and this domain should be the subject of further research. The evaluation results led us to the conclusion that it is unnecessary to use the H.265/HEVC codec for compression of Full HD sequences and the compression efficiency of the H.265 codec by the Ultra HD resolution reaches the compression efficiency of both codecs by the Full HD resolution. This paper also includes the recommendations for minimum bitrate thresholds at which the video sequences at both resolutions retain good and fair subjectively perceived quality.


1999 ◽  
Vol 35 (17) ◽  
pp. 1453 ◽  
Author(s):  
E.A. Edirisinghe ◽  
J. Jiang ◽  
C. Grecos

2020 ◽  
pp. 599-609
Author(s):  
Hajar Touzani ◽  
Ibtissem Wali ◽  
Fatima Errahimi ◽  
Anass Mansouri ◽  
Nouri Masmoudi ◽  
...  

New and stronger video compression standard was developed during the last years, called H.265/HEVC (High Efficiency Video Coding). This standard has undergone several improvements compared to H.264/AVC (Advanced Video Coding). In intra prediction block, 33 directional intra prediction modes were included in H.265 to have an efficient coding instead of 8 modes that were used in H.264 in addition to planar and DC modes, which has generated computational complexities in the new standard. Therefore one of the most issues for embedded implementation of HEVC is time reduction of the encoding process. In this paper, an embedded implementation of a fast intra prediction algorithm is performed on ARM processors under the embedded Linux Operating System. Experimental results included the comparison between the original HM16.7 and the proposed algorithm show that the encoding time was reduced by an average of 61.5% with an increase of 1.19 in the bit rate and a small degradation in the PSNR of 0.05%.


Author(s):  
Umesh Kaware ◽  
Sanjay Gulhane

The emerging High Efficiency Video Coding (HEVC) standard is a new improved next generation video coding standard. HEVC aims to provide improved compression performance as compared to all other video coding standards. To improve the coding efficiency a number of new techniques have been used. The higher compression efficiency is obtained at the cost of an increase in the computational load. In HEVC 35 modes are provided for intra prediction to improve the compression efficiency. The best mode is selected by Rate Distortion Optimization (RDO) process. It achieves significant improvement in coding efficiency compared with previous standards. However, this causes high encoding complexity. This paper discuss the various fast mode decision algorithms for intra prediction in HEVC.


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