Social Icons

Featured Posts

November 17, 2014

The maturity of H.265/HEVC video compression on the study of X265 v.1.4

In this post I share my test results on x265 coding efficiency to track the development progress. The x265 version 1.4 was used for this test, as well as the JCT-VC test sequences. It is worth mentioning that the Class E sequence set has changed, as described in JCTVC-O0022. However, for backward compatibility of the test results I still use the old test sequences set.

July 23, 2014

Xiph's Daala Compression Efficiency Update

Nine months have passed since my last comparisson of the HEVC, VP9 and Daala compression efficiency. Daala was in the development stage and is still being developed. Recently I've updated the codec to see the changes.
My apologies to the haters of PSNR and the lovers of SSIM. I'm still using PSNR.

December 9, 2013

Intra Compression Efficiency in VP9 and HEVC

In this paper we get into detailed overview of intra compression data-flow in HEVC and VP9. We describe common and unique stages of both standards. Then we carry out experiments with JCT-VC HM and WebM VP9 encoders on intra compression efficiency.
We also turn some of the HEVC features off to get its dataflow as close to VP9 as possible. Finally we get into discussion of the efficiency of both codecs, the corresponding standards and their intra compression algorithms.

November 16, 2013


This post is a useful link to Tampere Image Database (TID) and visual quality metric test suite, that I would like to have close at hand.
TID is intended for evaluation of full-reference image visual quality assessment metrics. TID allows estimating how a given metric corresponds to mean human perception. For example, in accordance with TID2008, Spearman correlation between the metric PSNR (Peak Signal to Noise Ratio) and mean human perception (MOS, Mean Opinion Score) is 0.525.

October 22, 2013

Next Generation Video Codecs: HEVC, VP9, Daala

Nowadays video services (digital television, Internet video etc.) are a common part of our live. According to Cisco [1] mobile video traffic was 51 percent of the entire global Internet traffic by the end of 2012 and it is expected to be 66 percent by 2017.
The demand on video and its quality is very high. Since the appearance of VoIP in 1984 video resolution has increased from QCIF (176×144 pixels) to Full HD (1920×1080). Now it is evolving to 4K (3840×2160) and 8K (7680×4320) UHD. But the higher the resolution and quality is, the higher bitrate it takes.
This paper contains a general review of new video compression standards HEVC, VP9 and Daala. Their compression efficiency is studied and compared to AVC.
The paper was reported at the XI International Theoretical and Practical Conference of Students and Young Scientists "Youth and Contemporary Information Technolodies". The report can be found here.