Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065719
Songnan Li, Lin Ma, K. Ngan
In this paper, a review on existing methods of extending image quality metric to video quality metric is given. It is found that three processing steps are usually involved which include the temporal channel decomposition, temporal masking and error pooling. They are utilized to extend our previously proposed image quality metric, which separately evaluates additive impairments and detail losses, to video quality metric. The resultant algorithm is tested on subjective video database LIVE and shows a good performance in matching subjective ratings.
{"title":"Video quality assessment by decoupling additive impairments and detail losses","authors":"Songnan Li, Lin Ma, K. Ngan","doi":"10.1109/QoMEX.2011.6065719","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065719","url":null,"abstract":"In this paper, a review on existing methods of extending image quality metric to video quality metric is given. It is found that three processing steps are usually involved which include the temporal channel decomposition, temporal masking and error pooling. They are utilized to extend our previously proposed image quality metric, which separately evaluates additive impairments and detail losses, to video quality metric. The resultant algorithm is tested on subjective video database LIVE and shows a good performance in matching subjective ratings.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"145 1","pages":"90-95"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90679695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065692
Julie Lassalle, Lætitia Gros, G. Coppin
The competitive context in which the number of new audiovisual services increases requires taking user preferences into account to maintain the best possible quality of experience. The aim of the experiment presented in this paper is to study how standardized ITU subjective measures may be supplemented by physiological measurements. Subjective assessments (ITU-T P.920, P.911) and physiological measurements (Blood Volume Pulse, Temperature, Skin Conductance and Eye Tracking) are collected from 34 subjects viewing three different 2D audiovisual contents. Each content was presented under three different quality conditions: a reference one (without degradation) and two degraded ones (audio/video asynchrony or bitrates variations on audio and/or video). Results show an impact of quality variations on the subjective data but not on physiological measures. It might be explained by this first exploratory protocol (degradation, thresholds, content presentation layout, etc.) proposed to study audiovisual quality impact on physiological activity.
{"title":"Combination of physiological and subjective measures to assess quality of experience for audiovisual technologies","authors":"Julie Lassalle, Lætitia Gros, G. Coppin","doi":"10.1109/QoMEX.2011.6065692","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065692","url":null,"abstract":"The competitive context in which the number of new audiovisual services increases requires taking user preferences into account to maintain the best possible quality of experience. The aim of the experiment presented in this paper is to study how standardized ITU subjective measures may be supplemented by physiological measurements. Subjective assessments (ITU-T P.920, P.911) and physiological measurements (Blood Volume Pulse, Temperature, Skin Conductance and Eye Tracking) are collected from 34 subjects viewing three different 2D audiovisual contents. Each content was presented under three different quality conditions: a reference one (without degradation) and two degraded ones (audio/video asynchrony or bitrates variations on audio and/or video). Results show an impact of quality variations on the subjective data but not on physiological measures. It might be explained by this first exploratory protocol (degradation, thresholds, content presentation layout, etc.) proposed to study audiovisual quality impact on physiological activity.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"32 1","pages":"13-18"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75261575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065705
J. Redi, I. Heynderickx
Understanding bottom-up and top-down visual attention mechanisms related to visual quality perception can be greatly beneficial for the design of effective objective quality metrics. Subjective studies based on eye-movement tracking have been recently published that try to get more insight in these interactions. However, it is still not easy to find coherence across their results, also due to the different methodologies adopted to analyze eye-tracking data. In this paper we propose a robust methodology to measure differences between eye-tracking data collected under different experimental conditions. The proposed method takes into account inter-observer variability and content effects, producing results that give an accurate insight in attention variations.
{"title":"Image quality and visual attention interactions: Towards a more reliable analysis in the saliency space","authors":"J. Redi, I. Heynderickx","doi":"10.1109/QoMEX.2011.6065705","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065705","url":null,"abstract":"Understanding bottom-up and top-down visual attention mechanisms related to visual quality perception can be greatly beneficial for the design of effective objective quality metrics. Subjective studies based on eye-movement tracking have been recently published that try to get more insight in these interactions. However, it is still not easy to find coherence across their results, also due to the different methodologies adopted to analyze eye-tracking data. In this paper we propose a robust methodology to measure differences between eye-tracking data collected under different experimental conditions. The proposed method takes into account inter-observer variability and content effects, producing results that give an accurate insight in attention variations.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"213 1","pages":"201-206"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73138582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065694
Luís Pinto, J. Carreira, S. Faria, Nuno M. M. Rodrigues, P. Assunção
This paper presents an experimental study on subjective quality of 3D video under packet loss conditions. A priority network is assumed, such that the base view of a stereoscopic video stream is delivered through a guaranteed channel and the auxiliary view is subject to packet losses over a low priority channel. Due to the packetisation scheme, one frame is lost whenever a packet is lost. Three frame concealment methods are proposed to deal with frame losses and seven different 3DTV sequences are used. The subjective evaluation study was carried out for different packet loss ratios and concealment methods, using shutter glasses with synchronized display. The experimental results show that sequence disparity, type of loss concealment and packet loss pattern should be jointly considered as relevant quality factors in 3D video over packet networks.
{"title":"Subjective quality factors in packet 3D video","authors":"Luís Pinto, J. Carreira, S. Faria, Nuno M. M. Rodrigues, P. Assunção","doi":"10.1109/QoMEX.2011.6065694","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065694","url":null,"abstract":"This paper presents an experimental study on subjective quality of 3D video under packet loss conditions. A priority network is assumed, such that the base view of a stereoscopic video stream is delivered through a guaranteed channel and the auxiliary view is subject to packet losses over a low priority channel. Due to the packetisation scheme, one frame is lost whenever a packet is lost. Three frame concealment methods are proposed to deal with frame losses and seven different 3DTV sequences are used. The subjective evaluation study was carried out for different packet loss ratios and concealment methods, using shutter glasses with synchronized display. The experimental results show that sequence disparity, type of loss concealment and packet loss pattern should be jointly considered as relevant quality factors in 3D video over packet networks.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"10 1","pages":"149-154"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84177144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065707
Jong-Seok Lee, F. D. Simone, T. Ebrahimi
Scalable video coding is a promising solution for efficient video content distribution to users having heterogeneous network and terminal capabilities. Thanks to its inherent multidimensional adaptability, a scalable bit stream can be used to simultaneously transmit multiple video sequences having different bit rates to corresponding target users, without necessity of re-encoding or transcoding. In order to exploit such an advantage effectively, it is crucial to understand the effects of multidimensional scalability options on the perceived quality and the trade-off between the scalability dimensions through subjective quality assessment. This paper reviews existing studies aiming at achieving this goal in order to summarize their results and common findings.
{"title":"Subjective quality assessment of scalable video coding: A survey","authors":"Jong-Seok Lee, F. D. Simone, T. Ebrahimi","doi":"10.1109/QoMEX.2011.6065707","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065707","url":null,"abstract":"Scalable video coding is a promising solution for efficient video content distribution to users having heterogeneous network and terminal capabilities. Thanks to its inherent multidimensional adaptability, a scalable bit stream can be used to simultaneously transmit multiple video sequences having different bit rates to corresponding target users, without necessity of re-encoding or transcoding. In order to exploit such an advantage effectively, it is crucial to understand the effects of multidimensional scalability options on the perceived quality and the trade-off between the scalability dimensions through subjective quality assessment. This paper reviews existing studies aiming at achieving this goal in order to summarize their results and common findings.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"270 1","pages":"25-30"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86593641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065706
Seyed Navid Haji Mirza, E. Izquierdo
This report tries to measure users' interest in images that appear on the screen by monitoring their attention via eye-tracking. Our Gaze Inference System analyzes the gaze-movement features to assign a user interest level (UIL) from 0 to 1 to every image that appears on the screen. Because the properties of the gaze features for every user are different from others, the framework is designed to be user adaptive. This framework is capable of building a new processing system for every new user that starts experiencing it. The generated UILs can be used in different scenarios that use the users' interest as an input. The developed framework produces promising and reliable results where 10% of the target images that the users were searching for received UILs over 0.8 with precision of 100%.
{"title":"Examining visual attention: A method for revealing users' interest for images on screen","authors":"Seyed Navid Haji Mirza, E. Izquierdo","doi":"10.1109/QoMEX.2011.6065706","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065706","url":null,"abstract":"This report tries to measure users' interest in images that appear on the screen by monitoring their attention via eye-tracking. Our Gaze Inference System analyzes the gaze-movement features to assign a user interest level (UIL) from 0 to 1 to every image that appears on the screen. Because the properties of the gaze features for every user are different from others, the framework is designed to be user adaptive. This framework is capable of building a new processing system for every new user that starts experiencing it. The generated UILs can be used in different scenarios that use the users' interest as an input. The developed framework produces promising and reliable results where 10% of the target images that the users were searching for received UILs over 0.8 with precision of 100%.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"1 1","pages":"207-212"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85644110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065715
Tsung-Jung Liu, Weisi Lin, C.-C. Jay Kuo
This paper presents a new methodology for objective visual quality assessment with multi-metric fusion (MMF). The current research is motivated by the observation that there is no single metric that gives the best performance scores in all situations. To achieve MMF, we adopt a regression approach. First, we collect a large number of image samples, each of which has a score labeled by human observers and scores associated with different metrics. The new MMF score is set to be the nonlinear combination of multiple metrics with suitable weights obtained by a training process. Furthermore, we divide image distortions into groups and perform regression within each group, which is called “context-dependent MMF” (CD-MMF). One task in CD-MMF is to determine the context automatically, which is achieved by a machine learning approach. It is shown by experimental results that the proposed MMF metric outperforms all existing metrics by a significant margin.
{"title":"A multi-metric fusion approach to visual quality assessment","authors":"Tsung-Jung Liu, Weisi Lin, C.-C. Jay Kuo","doi":"10.1109/QoMEX.2011.6065715","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065715","url":null,"abstract":"This paper presents a new methodology for objective visual quality assessment with multi-metric fusion (MMF). The current research is motivated by the observation that there is no single metric that gives the best performance scores in all situations. To achieve MMF, we adopt a regression approach. First, we collect a large number of image samples, each of which has a score labeled by human observers and scores associated with different metrics. The new MMF score is set to be the nonlinear combination of multiple metrics with suitable weights obtained by a training process. Furthermore, we divide image distortions into groups and perform regression within each group, which is called “context-dependent MMF” (CD-MMF). One task in CD-MMF is to determine the context automatically, which is achieved by a machine learning approach. It is shown by experimental results that the proposed MMF metric outperforms all existing metrics by a significant margin.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"29 1","pages":"72-77"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87334412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065712
Pengpeng Ni, Ragnhild Eg, Alexander Eichhorn, C. Griwodz, P. Halvorsen
Scalable video streaming may result in flicker effects — visual artifacts in video presentation due to adaptive layer switching. In our work, we have identified three types of flicker, noise, blur and motion flicker. Here, we investigate the blur and noise flicker, which are both related to the spatial domain. The perceptual impact of blur and noise flicker is explored through subjective assessments, focusing on acceptance of variations in the amplitudes and frequencies of the quality changes, across four content types. Our results indicate that the perception and acceptance of different layer variations are jointly influenced by multiple factors. When video scaling is required, frequency can be adjusted to relieve the annoyance of flicker artifacts, while amplitude still plays the dominant role in delivering satisfactory video quality. In addition, contents with complex details are more affected by blur flicker than other contents. This difference is not observed for noise flicker.
{"title":"Spatial flicker effect in video scaling","authors":"Pengpeng Ni, Ragnhild Eg, Alexander Eichhorn, C. Griwodz, P. Halvorsen","doi":"10.1109/QoMEX.2011.6065712","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065712","url":null,"abstract":"Scalable video streaming may result in flicker effects — visual artifacts in video presentation due to adaptive layer switching. In our work, we have identified three types of flicker, noise, blur and motion flicker. Here, we investigate the blur and noise flicker, which are both related to the spatial domain. The perceptual impact of blur and noise flicker is explored through subjective assessments, focusing on acceptance of variations in the amplitudes and frequencies of the quality changes, across four content types. Our results indicate that the perception and acceptance of different layer variations are jointly influenced by multiple factors. When video scaling is required, frequency can be adjusted to relieve the annoyance of flicker artifacts, while amplitude still plays the dominant role in delivering satisfactory video quality. In addition, contents with complex details are more affected by blur flicker than other contents. This difference is not observed for noise flicker.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"42 1","pages":"55-60"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81058331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065696
J. Korhonen, U. Reiter, Junyong You
In video streaming applications, it is necessary to choose the rate of the encoded stream to match the available transmission channel capacity. To provide flexible means for rate adaptation, different scalable video coding schemes have been proposed. For example, if necessary the bitrate can be reduced either by downscaling the frame rate (temporal scalability) or the image quality (quality scalability). However, the user preferences between different scalability types are not well known in different scenarios. In this paper, we present a methodology for subjective comparison between temporal and quality scalability. The practical experiments with low resolution video sequences show that in general, distortion is a more crucial factor for the perceived subjective quality than frame rate. However, the results also depend on the content. Moreover, we discuss the role of other different influence factors on perception.
{"title":"Subjective comparison of temporal and quality scalability","authors":"J. Korhonen, U. Reiter, Junyong You","doi":"10.1109/QoMEX.2011.6065696","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065696","url":null,"abstract":"In video streaming applications, it is necessary to choose the rate of the encoded stream to match the available transmission channel capacity. To provide flexible means for rate adaptation, different scalable video coding schemes have been proposed. For example, if necessary the bitrate can be reduced either by downscaling the frame rate (temporal scalability) or the image quality (quality scalability). However, the user preferences between different scalability types are not well known in different scenarios. In this paper, we present a methodology for subjective comparison between temporal and quality scalability. The practical experiments with low resolution video sequences show that in general, distortion is a more crucial factor for the perceived subjective quality than frame rate. However, the results also depend on the content. Moreover, we discuss the role of other different influence factors on perception.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"28 1","pages":"161-166"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78765422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2011-11-03DOI: 10.1109/QoMEX.2011.6065701
T. Richter
While traditional image quality metrics like MSE are mathematically well understood and tractable, they are known to correlate weakly to image distortion as observed by human observers. To address this situation, many full reference quality indices have been suggested over the years that correlate better to human perception, one of them being the well-known Structural Similarity Index by Wang and Bovik. However, while these expressions show higher correlations, they are often not very tractable mathematically, and — in specific — are rarely metrics in the strict mathematical sense. Specifically, the triangle inequality is often not satisfied, which could either be seen as an effect of the human visual system being unable to compare images that are visually too different, or as a defect of the index capturing the global situation correctly. In this article, the latter position is taken, and it is shown how the SSIM can be understood as a local approximation of a global metric, namely the geodesic distance on a manifold. While the metric cannot be computed explicitly in most cases, it is nevertheless shown that in specific cases its expression is identical to Weber's Law of luminance sensitivity of the human eye.
{"title":"SSIM as global quality metric: A differential geometry view","authors":"T. Richter","doi":"10.1109/QoMEX.2011.6065701","DOIUrl":"https://doi.org/10.1109/QoMEX.2011.6065701","url":null,"abstract":"While traditional image quality metrics like MSE are mathematically well understood and tractable, they are known to correlate weakly to image distortion as observed by human observers. To address this situation, many full reference quality indices have been suggested over the years that correlate better to human perception, one of them being the well-known Structural Similarity Index by Wang and Bovik. However, while these expressions show higher correlations, they are often not very tractable mathematically, and — in specific — are rarely metrics in the strict mathematical sense. Specifically, the triangle inequality is often not satisfied, which could either be seen as an effect of the human visual system being unable to compare images that are visually too different, or as a defect of the index capturing the global situation correctly. In this article, the latter position is taken, and it is shown how the SSIM can be understood as a local approximation of a global metric, namely the geodesic distance on a manifold. While the metric cannot be computed explicitly in most cases, it is nevertheless shown that in specific cases its expression is identical to Weber's Law of luminance sensitivity of the human eye.","PeriodicalId":6441,"journal":{"name":"2011 Third International Workshop on Quality of Multimedia Experience","volume":"22 1","pages":"189-194"},"PeriodicalIF":0.0,"publicationDate":"2011-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82375910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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