• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.155-158
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• 2007

In this paper, we solved the underestimation problem of PSNR, which is caused by repeated frames, by easily synchronizing original and decoded frames using the proposed marks. Also we propose full-reference system which can be applied for measuring the quality of various kinds of video communication systems, e.g. wireless handsets, mobile phones and applications for PC. In addition, we propose a new video quality assessment metric using video communication parameters, i.e. frame rate and delay. According to the experiments, the proposed metric is not only appropriate for real-time video communication systems but also shows better correlation with the subjective video quality assessment than PSNR. The proposed measuring system and metric can be effectively used for measuring and standardizing the video quality of future communications.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.355-358
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• 2012

Although quality metrics for 2D video quality assessment have been proposed, the quality models on stereoscopic video have not been widely studied. In this paper, a new objective video quality metric for s tereoscopic video is proposed. The proposed algorithm consider three factors to evaluate stereoscopic video quality: blocking artifact, blurring artifact, and the difference between left and right view of stereoscopic vide o. The results show that the proposed algorithm has a higher correlation with DMOS than the others.

• ETRI Journal
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• v.38 no.6
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• pp.1114-1123
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• 2016

Multi-view video plus depth (MVD) has been widely used owing to its effectiveness in three-dimensional data representation. Using MVD, color videos with only a limited number of real viewpoints are compressed and transmitted along with captured or estimated depth videos. Because the synthesized views are generated from decoded real views, their original reference views do not exist at either the transmitter or receiver. Therefore, it is challenging to define an efficient metric to evaluate the quality of synthesized images. We propose a novel metric-the reduced-reference quality metric. First, the effects of depth distortion on the quality of synthesized images are analyzed. We then employ the high correlation between the local depth distortions and local color characteristics of the decoded depth and color images, respectively, to achieve an efficient depth quality metric for each real view. Finally, the objective quality metric of the synthesized views is obtained by combining all the depth quality metrics obtained from the decoded real views. The experimental results show that the proposed quality metric correlates very well with full reference image and video quality metrics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.11C
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• pp.655-661
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• 2011

The transmission issues for the scalable video coding extension of H.264/AVC (H.264 SVC) video has been widely studied. In this paper, we propose an objective video-quality assessment metric based on no-reference for H.264 SVC using scalability information. The proposed metric estimate the perceptual video-quality reflecting error conditions with the consideration of the motion vectors, error propagation patterns with the hierarchical prediction structure, quantization parameters, and number of frame which damaged by packet loss. The proposed metric reflects the human perceptual quality of video and we evaluate the performance of proposed metric by using correlation relationship between differential mean opinion score (DMOS) as a subjective quality and proposed one.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.102-111
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• 2007

Currently, the efficient adaptive video streaming services and coding techniques are required to ensure quality of service (QoS) in diverse multimedia environments. To maintain optimal video quality in these environments, it is required to support scalable video coding (SVC) technique and proper QoS metric methods. In this paper, we propose a new quality metric that takes in to the temporal, the SNR, the spatial scalability on SVC. Experimental results shows that proposed method has a higher correlation with the subjective quality. We expect that the proposed metric plays an important role in deciding the coding parameter to optimize the quality of the SVC based video.

• Journal of Communications and Networks
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• v.7 no.3
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• pp.235-242
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• 2005

Multimedia applications and especially encoded video services, are expected to playa major role in the 3rd generation (3G) and beyond mobile communication systems. Given that future service providers are expected to provide video applications at various price and quality levels, quick and economically affordable methods for preparing/encoding the offering media at various qualities are necessary to be developed. This paper presents a method for objective evaluation of the perceived quality of MPEG­4 video content, based on a quantification of subjective assessments. Showing that subjectively derived perceived quality of service (PQoS) vs. bit rate curves can be successfully approximated by a group of exponential functions, the proposed method exploits a simple objective metric, which is obtained from the mean frame rate vs. bit rate curves of an encoded clip. The validity of this metric is assessed by comparing subjectively derived PQoS results to the corresponding ones, which come from the proposed objective method, showing that the proposed technique provides satisfactory PQoS estimation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.5
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• pp.1388-1399
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• 2012

This paper proposes a quality metric based on a No-Reference Bitstream (NR-B) having least computational complexity for the assessment of the human-perceptual quality of H.264 encoded video. The proposed NR-B method performs a modeling of encoding distortion with three bit-stream information (i.e. frame-rate, motion-vector, and quantization-parameter) that can be directly extractable from the encoded bitstream and does not require additional complex processing of final pictures. From performance evaluation using 165 compressed video sequences, the experiment results show that the proposed metric has a higher correlation with subjective quality than is achieved with other comparable methods.

• Journal of Broadcast Engineering
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• v.13 no.2
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• pp.179-187
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• 2008

In this paper, we proposed the qualify metric based on SVC and the subjective quality. The proposed quality metric is for a general purpose. It means we can use it for any video sequences regardless of its temporal and spatial characteristics. The Quality of Service(QoS) is one of the important issues in heterogeneous environment which has diverse restrictions such as limited network bandwidth and limited display resolution. Scalable Video Coding(SVC) is the efficient video coding skill in heterogeneous environment. Because SVC can be adapted to various quality bitstreams using three scalabilities(spatial, temporal, and SNR) from one bitstream which has full scalability. To maximize the QoS in this environment, we should consider the subjective quality which is the viewer response. And also we should consider temporal and spatial characteristics of video sequence because the subjective quality is affected by temporal and spatial characteristics of video sequence. To verify the efficiency of the proposed method, we perform subjective assessments. The experimental results show that the proposed method has high correlation with subjective quality. The proposed method can be a decision tool of SVC birstream extraction.

• Journal of Korea Society of Digital Industry and Information Management
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• v.18 no.4
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• pp.13-21
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• 2022

Recently, in wireless video sensor networks(WVSN), various schemes for efficient video data transmission have been studied. In this paper, a layer based cooperative relaying(LCR) algorithm is proposed for minimizing scalable video transmission distortion from packet loss in WVSN. The proposed LCR algorithm consists of two modules. In the first step, a parameter based error propagation metric is proposed to predict the effect of each scalable layer on video quality degradation at low complexity. In the second step, a layer-based cooperative relay algorithm is proposed to minimize distortion due to packet loss using the proposed error propagation metric and channel information of the video sensor node and relay node. In the experiment, the proposed algorithm showed that the improvement of peak signal-to-noise ratio (PSNR) in various channel environments, compared to the previous algorithm(Energy based Cooperative Relaying, ECR) without considering the metric of error propagation.The proposed LCR algorithm minimizes video quality degradation from packet loss using both the channel information of relaying node and the amount of layer based error propagation in scalable video.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.5
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• pp.255-265
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• 2013

3DTV is expected to be a promising next-generation broadcasting service. On the other hand, the visual discomfort/fatigue problems caused by viewing 3D videos have become an important issue. This paper proposes a perceptual quality assessment metric for a stereoscopic video (SV-PQAM). To model the SV-PQAM, this paper presents the following features: temporal variance, disparity variation in intra-frames, disparity variation in inter-frames and disparity distribution of frame boundary areas, which affect the human perception of depth and visual discomfort for stereoscopic views. The four features were combined into the SV-PQAM, which then becomes a no-reference stereoscopic video quality perception model, as an objective quality assessment metric. The proposed SV-PQAM does not require a depth map but instead uses the disparity information by a simple estimation. The model parameters were estimated based on linear regression from the mean score opinion values obtained from the subjective perception quality assessments. The experimental results showed that the proposed SV-PQAM exhibits high consistency with subjective perception quality assessment results in terms of the Pearson correlation coefficient value of 0.808, and the prediction performance exhibited good consistency with a zero outlier ratio value.