Yun Zhang, Xiaoxiang Yang, Xiangkai Liu, Yongbin Zhang, Gangyi Jiang, and Sam Kwong

IEEE Transactions on Image Processing (IEEE T-IP), Vol. 25, No. 12, Dec. 2016, pp.5877-5891

In 3D video systems, imperfect depth images often induce annoying temporal noise, e.g., flickering, to the synthesized video. However, the quality of synthesized view is usually measured with peak signal-to-noise ratio or mean squared error, which mainly focuses on pixelwise frame-by-frame distortion regardless of the obvious temporal artifacts. In this paper, a novel full reference synthesized video quality metric (SVQM) is proposed to measure the perceptual quality...

Linwei Zhu, Yun Zhang, Na Li, Gangyi Jiang, and Sam Kwong

Journal of Visual Communication and Image Representation (JVCI), Vol. 38, July. 2016, pp. 824–837

Video transcoding is to convert one compressed video stream to another. In this paper, a fast H.264/AVC to High Efficiency Video Coding (HEVC) transcoding method based on machine learning is proposed by considering the similarity between compressed streams, especially the block partition correlations, to reduce the computational complexity. This becomes possible by constructing three-level binary classifiers to predict quad-tree Coding Unit (CU) partition in HEVC...

Long Xu, Jia Li, Weisi Lin, Yun Zhang, Yongbing Zhang, and Yihua Yan

Displays, Elsevier, vol.2016, no.44, pp.21-26, Jun. 2016. (SCI IF 1.903)

To know what kinds of image features are crucial for image quality assessment (IQA) and how these features affect the human visual system (HVS) is still largely beyond human knowledge. Hence, machine learning (ML) is employed to build IQA by simulating the HVS behavior in IQA processes. Support vector machine/regression (SVM/SVR) is a major member of ML. It has been successfully applied to IQA recently. As to image quality rating, the human’s opinion about it is not always reliable.In fact, the subjects cannot precisely rate the small difference of image quality in subjective testing, resulting...

Zhaoqing Pan, Yun Zhang, Jianjun Lei, Long Xu, and Xingming Sun

IET Image Processing (IET IP), vol.10, no.1, Jan. 2016, pp.9-15

The exhaustive variable-block-size mode decision can efficiently remove the redundancies among the Multiview videos, while it also leads to significant increase of computational complexity in the Multiview video coding (MVC) encoder, and the high encoding complexity becomes a bottleneck for the MVC encoder to achieve real-time multimedia applications. To address this bottleneck, many fast mode decision methods have been proposed. However, most of them are only...

Yun Zhang, Linwei Zhu, Xiangkai Liu, Gangyi Jiang

IEEE International Symposium on Circuits and Systems (ISCAS’2016), Montreal, Canada, 2016.

Depth videos shall be efficiently compressed and transmitted to the client for view synthesis in Three-Dimensional (3D) video system. Since depth video may contain noise that reduce the coding efficiency, we propose a depth filtering algorithm for 3D depth coding, which exploits the Allowable Depth Distortion (ADD) in view synthesis and is able to improve the coding performance of the depth encoder. Firstly, the depth values has the same rendering...

Long Xu, Lin Ma, Yun Zhang, Yihua Yan

IEEE International Conference on Visual Communications and Image Processing (VCIP'2016), Chengdu, China, Nov.27, 2016.

HEVC is an emerging new standard for digital video compression, which is regarded as a successor to H.264/AVC standard. It still belongs to block-based hybrid video coding framework. The block patterns range from 4×4 to 64×64 blocks, and DCT is extended from 4×4 to 32×32. 2D-DCT for image is performed along the vertical and horizontal directions, so it is good at the energy compaction of residual block with vertical or horizontal edges. However, the edges are usually...

Baozhen Du, Mei Yu, Gangyi Jiang, Yun Zhang, Feng Shao, Zongju Peng, Tianzhi Zhu

IEEE International Conference on Visual Communications and Image Processing (VCIP'2016), Chengdu, China, Nov.27, 2016.

Existing perceptual researches on stereoscopic images mainly focus on the threshold of whole image distortion, rather than the effect of texture feature on the so-called threshold of just-noticeable distortion. Obviously, it is unreasonable to use a single unified perception threshold for natural stereoscopic images as the texture complexity typically...