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Lövström, Benny
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Publications (10 of 25) Show all publications
Usman, M. A., Young Shin, S., Shahid, M. & Lövström, B. (2017). A No Reference Video Quality Metric Based on Jerkiness Estimation Focusing on Multiple Frame Freezing in Video Streaming. IETE Technical Review, 34(3), 309-320
Open this publication in new window or tab >>A No Reference Video Quality Metric Based on Jerkiness Estimation Focusing on Multiple Frame Freezing in Video Streaming
2017 (English)In: IETE Technical Review, ISSN 0256-4602, E-ISSN 0974-5971, Vol. 34, no 3, p. 309-320Article in journal (Refereed) Published
Abstract [en]

In wireless networks, due to limited bandwidth and packet losses, seamless and ubiquitous delivery of high-quality video streaming services is a big challenge for the operators. In order to improve the process of online video quality monitoring, the presence of no reference (NR) objective video quality assessment (VQA) methods is required. In some networks, the video decoder on the reception side adopts a mechanism in which last correctly received frame is frozen and displayed on video display terminal until the next correct frame is received. This phenomenon, employed as an error concealment technique, can cause a perceptual jerkiness on the video display terminal. In this paper, we have proposed an enhanced model of objective VQA based on the estimation of jerkiness. A study of three contemporary NR methods, used for objective VQA and online monitoring of videos, has been included along with subjective VQA tests. The subjective tests were performed for a set of video sequences with specific spatial and temporal information. The proposed NR method is based on our careful observations from the subjective test results and our main focus is to cater the effect of multiple frame freeze impairments in video steaming. Comparison with other NR methods shows that the proposed method performs better, in terms of estimating the impact of multiple frame freezing impairments, and has more affinity with the subjective test results.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
Keywords
No reference, Temporal artefacts, Video quality assessment
National Category
Telecommunications
Identifiers
urn:nbn:se:bth-13257 (URN)10.1080/02564602.2016.1185975 (DOI)000402715400009 ()
Note

open access

Available from: 2016-10-14 Created: 2016-10-14 Last updated: 2018-05-22Bibliographically approved
Rossholm, A. & Lövström, B. (2016). A robust method for estimating synchronization and delay of audio and video for communication services. Multimedia tools and applications, 75(1), 527-545
Open this publication in new window or tab >>A robust method for estimating synchronization and delay of audio and video for communication services
2016 (English)In: Multimedia tools and applications, ISSN 1380-7501, E-ISSN 1573-7721, Vol. 75, no 1, p. 527-545Article in journal (Refereed) Published
Abstract [en]

One of the main contributions to the quality of experience in streaming services or in two-way communication of audio and video applications is synchronization. This has been shown in several studies and experiments but methods to measure synchronization are less frequent, especially for situations without internal access to the application and independent of platform and device. In this paper we present a method for measuring synchronization skewness as well as delay for audio and video. The solution incorporates audio and video reference streams, where audio and video frames are marked with frame numbers which are decoded on the receiver side to enable calculation of synchronization and delay. The method has been verified in a two-way communication application in a transparent network with and without inserting known delays, as well as in a network with 5 and 10 % packet loss levels. The method can be used for both streaming and two-way communication services, both with and without access to the internal structures, and enables measurements of applications running on e.g. smartphones, tablets, and laptops under various conditions.

Place, publisher, year, edition, pages
Springer US, 2016
Keywords
Lip sync · Synchronization, Delay, QoE, Video streaming, Video conferencing
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-6407 (URN)10.1007/s11042-014-2306-6 (DOI)000367856500024 ()
Available from: 2015-02-27 Created: 2015-02-26 Last updated: 2017-12-04Bibliographically approved
Shahid, M., Pandremmenou,, K., Lisimachos P., K., Andreas, R. & Lövström, B. (2016). Perceptual quality estimation of H.264/AVC videos using reduced-reference and no-reference models. Journal of Electronic Imaging (JEI), 25(5)
Open this publication in new window or tab >>Perceptual quality estimation of H.264/AVC videos using reduced-reference and no-reference models
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2016 (English)In: Journal of Electronic Imaging (JEI), ISSN 1017-9909, E-ISSN 1560-229X, Vol. 25, no 5Article in journal (Refereed) Published
Abstract [en]

Reduced-reference (RR) and no-reference (NR) models for video quality estimation, using featuresthat account for the impact of coding artifacts, spatio-temporal complexity, and packet losses, are proposed. Thepurpose of this study is to analyze a number of potentially quality-relevant features in order to select the mostsuitable set of features for building the desired models. The proposed sets of features have not been used in theliterature and some of the features are used for the first time in this study. The features are employed by the leastabsolute shrinkage and selection operator (LASSO), which selects only the most influential of them toward per-ceptual quality. For comparison, we apply feature selection in the complete feature sets and ridge regression onthe reduced sets. The models are validated using a database of H.264/AVC encoded videos that were subjec-tively assessed for quality in an ITU-T compliant laboratory. We infer that just two features selected by RRLASSO and two bitstream-based features selected by NR LASSO are able to estimate perceptual qualitywith high accuracy, higher than that of ridge, which uses more features. The comparisons with competingworks and two full-reference metrics also verify the superiority of our models.

Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2016
Keywords
no-reference; packet loss; perceptual quality estimation; reduced-reference; video q
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-13256 (URN)10.1117/1.JEI.25.5.053012 (DOI)000388216900023 ()
Available from: 2016-10-14 Created: 2016-10-14 Last updated: 2018-05-23Bibliographically approved
Minhas, T. N., Shahid, M., Lövström, B., Rossholm, A., Zepernick, H.-J. & Fiedler, M. (2016). QoE rating performance evaluation of ITU-T recommended video quality metrics in the context of video freezes. Australian Journal of Electrical and Electronics Engineering, 13(2), 122-131
Open this publication in new window or tab >>QoE rating performance evaluation of ITU-T recommended video quality metrics in the context of video freezes
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2016 (English)In: Australian Journal of Electrical and Electronics Engineering, ISSN 1448-837X, Vol. 13, no 2, p. 122-131Article in journal (Refereed) Published
Abstract [en]

In real-time video streaming, video quality can be degraded due to network performance issues. Among other artefacts, video freezing and video jumping are factors that influence user experience. Service providers, operators and manufacturers are interested in evaluating the quality of experience (QoE) objectively because subjective assessment of QoE is expensive and, in many user cases, subjective assessment is not possible to perform. Different algorithms have been proposed and implemented in this regard. Some of them are in the recommendation list of the ITU Telecommunication Standardization Sector (ITU-T). In this paper, we study the effect of the freezing artefact on user experience and compare the mean opinion score of these videos with the results of two algorithms, the perceptual evaluation of video quality (PEVQ) and temporal quality metric (TQM). Both metrics are part of the ITU-T Recommendation J.247 Annex B and C. PEVQ is a full-reference video quality metric, whereas TQM is a no-reference quality metric. Another contribution of this paper is the study of the impact of different resolutions and frame rates on user experience and how accurately PEVQ and TQM measure varying frame rates.

Place, publisher, year, edition, pages
Taylor & Francis, 2016
Keywords
Freezing; Image quality; Quality of service; Video signal processing; Video streaming, Objective video quality; Quality of experience (QoE); Subjective video quality; Temporal quality; Video quality, Quality control
National Category
Signal Processing Communication Systems
Identifiers
urn:nbn:se:bth-13135 (URN)10.1080/1448837X.2015.1094855 (DOI)2-s2.0-84965031048 (Scopus ID)
Available from: 2016-10-04 Created: 2016-10-03 Last updated: 2016-12-19Bibliographically approved
Pandremmenou, K., Shahid, M., Kondi, L. & Lövström, B. (2015). A No-Reference Bitstream-based Perceptual Model for Video Quality Estimation of Videos Affected by Coding Artifacts and Packet Losses. In: Proceedings of SPIE - The International Society for Optical Engineering: . Paper presented at Human Vision and Electronic Imaging XX; San Francisco (pp. Article number 93941F). San Francisco: SPIE Press, 9394
Open this publication in new window or tab >>A No-Reference Bitstream-based Perceptual Model for Video Quality Estimation of Videos Affected by Coding Artifacts and Packet Losses
2015 (English)In: Proceedings of SPIE - The International Society for Optical Engineering, San Francisco: SPIE Press , 2015, Vol. 9394, p. Article number 93941F-Conference paper, Published paper (Refereed)
Abstract [en]

In this work, we propose a No-Reference (NR) bitstream-based model for predicting the quality of H.264/AVC video sequences, a effected by both compression artifacts and transmission impairments. The concept of the article is based on a feature extraction procedure, where a large number of features are calculated from the impaired bitstream. Many of the features are mostly proposed in this work, while the specific c set of the features as a whole is applied for the first time for making NR video quality predictions. All feature observations are taken as input to the Least Absolute Shrinkage and Selection Operator (LASSO) regression method. LASSO indicates the most important features, and using only them, it is able to estimate the Mean Opinion Score (MOS) with high accuracy. Indicatively, we point out that only 13 features are able to produce a Pearson Correlation Coefficient of 0:92 with the MOS. Interestingly, the performance statistics we computed in order to assess our method for predicting the Structural Similarity Index and the Video Quality Metric are equally good. Thus, the obtained experimental results verifi ed the suitability of the features selected by LASSO as well as the ability of LASSO in making accurate predictions through sparse modeling.

Place, publisher, year, edition, pages
San Francisco: SPIE Press, 2015
Keywords
LASSO, MOS, No-Reference, packet loss, quality estimation.
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-6401 (URN)10.1117/12.2077709 (DOI)000354081600044 ()978-1628414844 (ISBN)
Conference
Human Vision and Electronic Imaging XX; San Francisco
Available from: 2015-03-05 Created: 2015-03-04 Last updated: 2016-01-18Bibliographically approved
Pandremmenou, K., Shahid, M., Kondi, L. P. & Lövström, B. (2015). ON THE IMPROVEMENT OF NO-REFERENCE MEAN OPINION SCORE ESTIMATION ACCURACY BY FOLLOWING A FRAME-LEVEL REGRESSION APPROACH. In: 2015 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP): . Paper presented at IEEE International Conference on Image Processing (ICIP), SEP 27-30, 2015, Quebec City, CANADA (pp. 1850-1854).
Open this publication in new window or tab >>ON THE IMPROVEMENT OF NO-REFERENCE MEAN OPINION SCORE ESTIMATION ACCURACY BY FOLLOWING A FRAME-LEVEL REGRESSION APPROACH
2015 (English)In: 2015 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP), 2015, p. 1850-1854Conference paper, Published paper (Refereed)
Abstract [en]

In order to estimate subjective video quality, we usually deal with a large number of features and a small sample set. Applying regression on complex datasets may lead to imprecise solutions due to possibly irrelevant or noisy features as well as the effect of overfitting. In this work, we propose a No-Reference (NR) method for the estimation of the quality of videos that are impaired by both compression artifacts and packet losses. Particularly, in an effort to establish a robust regression model that generalizes well to unknown data and to increase Mean Opinion Score (MOS) estimation accuracy, we propose a frame-level MOS estimation approach, where the MOS estimate of a sequence is obtained by averaging the perframe MOS estimates, instead of performing regression directly at the sequence-level. Since it is impractical to obtain the actual perframe MOS values through subjective experiments, we propose an objective metric able to do this task. Thus, our proposed NR method has the dual benefit of offering improved sequence-level MOS estimation accuracy, while giving an indication of the relative quality of each individual video frame.

Series
IEEE International Conference on Image Processing ICIP, ISSN 1522-4880
Keywords
Estimation accuracy, frame-level quality estimation, MOS, objective metric, sequence-level quality estimation
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-11930 (URN)000371977801194 ()978-1-4799-8339-1 (ISBN)
Conference
IEEE International Conference on Image Processing (ICIP), SEP 27-30, 2015, Quebec City, CANADA
Available from: 2016-05-30 Created: 2016-05-30 Last updated: 2016-06-03Bibliographically approved
Shahid, M., Panasiuk, J., Van Wallendael, G., Barkowsky, M. & Lövström, B. (2015). Predicting full-reference video quality measures using HEVC bitstream-based no-reference features. In: International Workshop on Quality of Multimedia Experience: . Paper presented at 7th International Workshop on Quality of Multimedia Experience, QoMEX 2015; Costa Navarino, Messinia; Greece. IEEE Communications Society, Article number 7148118
Open this publication in new window or tab >>Predicting full-reference video quality measures using HEVC bitstream-based no-reference features
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2015 (English)In: International Workshop on Quality of Multimedia Experience, IEEE Communications Society, 2015, Vol. Article number 7148118Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents bitstream-based features for perceptual quality estimation of HEVC coded videos. Various factors including the impact of different sizes of block-partitions, use of reference-frames, the relative amount of various prediction modes, statistics of motion vectors and quantization parameters are taken into consideration for producing 52 features relevant for perceptual quality prediction. The used test stimuli constitutes 560 bitstreams that have been carefully extracted for this analysis from the 59, 520 bistreams of the large-scale database generated by the Joint Effort Group (JEG) of the Video Quality Experts Group (VQEG). The obtained results show the significance of the considered features through reasonably accurate and monotonic prediction of a number of objective quality metrics. © 2015 IEEE.

Place, publisher, year, edition, pages
IEEE Communications Society, 2015
Series
International Workshop on Quality of Multimedia Experience, ISSN 2372-7179
Keywords
Binary sequences; Multimedia systems, Bit stream; HEVC; Large-scale database; No reference methods; Objective qualities; Quantization parameters; Video quality assessment; Video quality experts groups, Forecasting
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-10630 (URN)10.1109/QoMEX.2015.7148118 (DOI)000375091800039 ()2-s2.0-84939503927 (Scopus ID)978-147998958-4 (ISBN)
External cooperation:
Conference
7th International Workshop on Quality of Multimedia Experience, QoMEX 2015; Costa Navarino, Messinia; Greece
Available from: 2015-09-17 Created: 2015-09-15 Last updated: 2016-09-08Bibliographically approved
Rossholm, A., Shahid, M. & Lövström, B. (2014). Analysis of the impact of temporal, spatial, and quantization variations on perceptual video quality. In: : . Paper presented at IEEE/IFIP Network Operations and Management Symposium: Management in a Software Defined World, Krakow. IEEE
Open this publication in new window or tab >>Analysis of the impact of temporal, spatial, and quantization variations on perceptual video quality
2014 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The growing consumer interest in video communication has increased the users' awareness in the visual quality of the delivered media. This in turn increases, at the service provider end, the need for intelligent methodologies of optimal techniques for adapting to varying network conditions. Recent studies show that constraints on the bandwidth of transmission media should not always be translated to an increase in compression ratio to lower the bitrate of the video. Instead, a suitable option for adaptive streaming is to scale down the video temporally or spatially before encoding to maintain a desirable level of perceptual quality, while the viewing resolution is constant. Most of the existing studies to examine these scenarios are either limited to low resolution videos or lack in provisioning of subjective assessment of quality. We present here the results of our campaign of subjective quality assessment experiments done on a range of spatial and temporal resolutions, up to VGA and 30 frames per second respectively, under a number of bitrate conditions. The analysis shows, among other things, that keeping the spatial resolution is perceptually preferred among the three parameters that have impact on the video quality, even in the case with high temporal activity.

Place, publisher, year, edition, pages
IEEE, 2014
Series
IEEE IFIP Network Operations and Management Symposium, ISSN 1542-1201
Keywords
Compression ratio (machinery), Consumer interests, Low resolution video, Perceptual quality, Perceptual video quality, Spatial and temporal resolutions, Subjective assessments, Subjective quality assessments, Video communications
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-6406 (URN)10.1109/NOMS.2014.6838397 (DOI)000356862300166 ()9781479909131 (ISBN)
Conference
IEEE/IFIP Network Operations and Management Symposium: Management in a Software Defined World, Krakow
Available from: 2015-02-27 Created: 2014-11-24 Last updated: 2017-03-17Bibliographically approved
Tavakoli, S., Shahid, M., Brunnström, K., Lövström, B. & Narciso, G. (2014). Effect of content characteristics on quality of experience of adaptive streaming. Paper presented at Sixth International Workshop on Quality of Multimedia Experience (QoMEX). Paper presented at Sixth International Workshop on Quality of Multimedia Experience (QoMEX). Singapore: IEEE
Open this publication in new window or tab >>Effect of content characteristics on quality of experience of adaptive streaming
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2014 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

The growing popularity of adaptive streaming-based video delivery nowadays has raised the interest about the user's perception when experiencing quality adaptation. The impact of the video content characteristics on user's perceptual quality has already become evident. The aim of this study is to investigate the influence of this factor on the quality of experience of adaptive streaming scenarios. Our results show that the perceptual quality of adaptation strategies applied on videos with high spatial and low temporal amount of activity is significantly lower compared to the other content types.

Place, publisher, year, edition, pages
Singapore: IEEE, 2014
Keywords
Adaptive Streaming Content Characteristics Quality of Experience
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-6403 (URN)10.1109/QoMEX.2014.6982294 (DOI)oai:bth.se:forskinfo9C78137E417110FEC1257DFE0038AD67 (Local ID)oai:bth.se:forskinfo9C78137E417110FEC1257DFE0038AD67 (Archive number)oai:bth.se:forskinfo9C78137E417110FEC1257DFE0038AD67 (OAI)
Conference
Sixth International Workshop on Quality of Multimedia Experience (QoMEX)
Available from: 2015-03-05 Created: 2015-03-04 Last updated: 2015-06-30Bibliographically approved
Shahid, M., Rossholm, A., Lövström, B. & Zepernick, H.-J. (2014). No-reference image and video quality assessment: a classification and review of recent approaches. EURASIP Journal on Image and Video Processing, 2014(40)
Open this publication in new window or tab >>No-reference image and video quality assessment: a classification and review of recent approaches
2014 (English)In: EURASIP Journal on Image and Video Processing, ISSN 1687-5176, E-ISSN 1687-5281, Vol. 2014, no 40Article, review/survey (Refereed) Published
Abstract [en]

The field of perceptual quality assessment has gone through a wide range of developments and it is still growing. In particular, the area of no-reference (NR) image and video quality assessment has progressed rapidly during the last decade. In this article, we present a classification and review of latest published research work in the area of NR image and video quality assessment. The NR methods of visual quality assessment considered for review are structured into categories and subcategories based on the types of methodologies used for the underlying processing employed for quality estimation. Overall, the classification has been done into three categories, namely, pixel-based methods, bitstream-based methods, and hybrid methods of the aforementioned two categories. We believe that the review presented in this article will be helpful for practitioners as well as for researchers to keep abreast of the recent developments in the area of NR image and video quality assessment. This article can be used for various purposes such as gaining a structured overview of the field and to carry out performance comparisons for the state-of-the-art methods.

Place, publisher, year, edition, pages
Springer, 2014
Keywords
No-reference, Image quality assessment, Video quality assessment, Perceptual quality
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-6339 (URN)10.1186/1687-5281-2014-40 (DOI)000347551600001 ()oai:bth.se:forskinfoD7B57209B4F14304C1257D49004E907F (Local ID)oai:bth.se:forskinfoD7B57209B4F14304C1257D49004E907F (Archive number)oai:bth.se:forskinfoD7B57209B4F14304C1257D49004E907F (OAI)
Note

Open access journal

Available from: 2015-05-26 Created: 2014-09-04 Last updated: 2017-12-04Bibliographically approved
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