| 1. |
- Allison, Robert S., et al.
(author)
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Perspectives on the definition of visually lossless quality for mobile and large format displays
- 2018
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In: Journal of Electronic Imaging (JEI). - 1017-9909 .- 1560-229X. ; 27:5, s. 1-23
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Journal article (peer-reviewed)abstract
- Advances in imaging and display engineering have given rise to new and improved image and videoapplications that aim to maximize visual quality under given resource constraints (e.g., power, bandwidth).Because the human visual system is an imperfect sensor, the images/videos can be represented in a mathematicallylossy fashion but with enough fidelity that the losses are visually imperceptible—commonly termed“visually lossless.” Although a great deal of research has focused on gaining a better understanding ofthe limits of human vision when viewing natural images/video, a universally or even largely accepted definitionof visually lossless remains elusive. Differences in testing methodologies, research objectives, and targetapplications have led to multiple ad-hoc definitions that are often difficult to compare to or otherwise employ inother settings. We present a compendium of technical experiments relating to both vision science and visualquality testing that together explore the research and business perspectives of visually lossless image quality,as well as review recent scientific advances. Together, the studies presented in this paper suggest that a singledefinition of visually lossless quality might not be appropriate; rather, a better goal would be to establish varyinglevels of visually lossless quality that can be quantified in terms of the testing paradigm.
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| 2. |
- An, Siwen, et al.
(author)
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Geometrical influence on Hg determination in wet sediment using K-shell fluorescence analysis
- 2023
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In: X-Ray Spectrometry. - : John Wiley and Sons Ltd. - 0049-8246 .- 1097-4539. ; 52:4, s. 82-196
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Journal article (peer-reviewed)abstract
- To quickly identify maritime sites polluted by heavy metal contaminants, reductions in the size of instrumentation have made it possible to bring an X-ray fluorescence (XRF) analyzer into the field and in direct contact with various samples. The choice of source-sample-detector geometry plays an important role in minimizing the Compton scattering noise and achieving a better signal-to-noise ratio (SNR) in XRF measurement conditions, especially for analysis of wet sediments. This paper presents the influence of geometrical factors on a prototype, designed for in situ XRF analysis of mercury (Hg) in wet sediments using a 57Co excitation source and an X-ray spectrometer. The unique XRF penetrometer prototype has been constructed and tested for maritime wet sediment. The influence on detection efficiency and SNR of various geometrical arrangements have been investigated using the combination of Monte Carlo simulations and laboratory experiments. Instrument calibration was performed for Hg analysis by means of prepared wet sediments with the XRF prototype. The presented results show that it is possible to detect Hg by K-shell emission, thus enabling XRF analysis for underwater sediments. Consequently, the XRF prototype has the potential to be applied as an environmental screening tool for analysis of polluted sediments with relatively high concentrations (e.g., >2880 ppm for Hg), which would benefit in situ monitoring of maritime pollution caused by heavy metals. © 2022 The Authors
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| 3. |
- Andersson, Henrik, et al.
(author)
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Assembling surface mounted components on ink-jet printed double sided paper circuit board
- 2014
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In: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 25:9
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Journal article (peer-reviewed)abstract
- Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed.
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| 4. |
- Andrén, Börje, et al.
(author)
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Characterizations of 3D TV : Active vs passive
- 2012
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In: SID Symposium Digest of Technical Papers 2012. - : Blackwell Publishing Ltd. - 0097-966X. ; , s. 137-140
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Conference paper (peer-reviewed)abstract
- Two different techniques are dominating the 3D TV market today i.e. active shutter glasses and passive film patterned retarder. Both the techniques have their pros and cons. In this paper we compare these two types of 3D TV3D TV by evaluating them with respect to some important visual ergonomic parameters such as angle dependent cross talk, luminance levels, flicker and resolution.
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| 5. |
- Arndt, Sebastian, et al.
(author)
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Review on using physiology in quality of experience
- 2016
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In: Electronic Imaging. - : The Society for Imaging Science and Technology. - 9781510827943 ; , s. 197-205
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Conference paper (peer-reviewed)abstract
- In the area of Quality of Experience (QoE), one challenge is to design test methodologies in order to evaluate the perceived quality of multimedia content delivered through technical sys-tems. Traditionally, this evaluation is done using subjective opinion tests. However, sometimes it is difficult for observers to communicate the experienced quality through the given scale. Fur-thermore. those tests do not give insights into how the user is reacting on an internal physiological level. To overcome these issues, one approach is to use physiological measures, in order to derive a direct non-verbal response of the recipient. In this paper, we review studies that have been performed in the domain of QoE using physiological measures and we look into current activities in standardization bodies. We present challenges this research faces. and give an overview on what researchers should be aware of when they want to start working in this research area.
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| 6. |
- Barkowsky, Marcus, et al.
(author)
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Hybrid video quality prediction : Re-viewing video quality measurement for widening application scope
- 2015
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In: Multimedia tools and applications. - : Springer Science and Business Media LLC. - 1380-7501 .- 1573-7721. ; 74:2, s. 323-343
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Journal article (peer-reviewed)abstract
- A tremendous number of objective video quality measurement algorithms have been developed during the last two decades. Most of them either measure a very limited aspect of the perceived video quality or they measure broad ranges of quality with limited prediction accuracy. This paper lists several perceptual artifacts that may be computationally measured in an isolated algorithm and some of the modeling approaches that have been proposed to predict the resulting quality from those algorithms. These algorithms usually have a very limited application scope but have been verified carefully. The paper continues with a review of some standardized and well-known video quality measurement algorithms that are meant for a wide range of applications, thus have a larger scope. Their individual artifacts prediction accuracy is usually lower but some of them were validated to perform sufficiently well for standardization. Several difficulties and shortcomings in developing a general purpose model with high prediction performance are identified such as a common objective quality scale or the behavior of individual indicators when confronted with stimuli that are out of their prediction scope. The paper concludes with a systematic framework approach to tackle the development of a hybrid video quality measurement in a joint research collaboration.
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| 7. |
- Barkowsky, Marcus, et al.
(author)
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Objective Video Quality Assessment - Towards large scale video database enhanced model development
- 2015
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In: IEICE transactions on communications. - 0916-8516 .- 1745-1345. ; E98.B:1, s. 2-11
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Journal article (peer-reviewed)abstract
- The current development of video quality assessment algorithms suffers from the lack of available video sequences for training, verification and validation to determine and enhance the algorithm’s application scope. The Joint Effort Group of the Video Quality Experts Group (VQEG-JEG) is currently driving efforts towards the creation of large scale, reproducible, and easy to use databases. These databases will contain bitstreams of recent video encoders (H.264, H.265), packet loss impairment patterns and impaired bitstreams, pre-parsed bitstream information into files in XML syntax, and well-known objective video quality measurement outputs. The database is continuously updated and enlarged using reproducible processing chains. Currently, more than 70,000 sequences are available for statistical analysis of video quality measurement algorithms. New research questions are posed as the database is designed to verify and validate models on a very large scale, testing and validating various scopes of applications, while subjective assessment has to be limited to a comparably small subset of the database. Special focus is given on the principles guiding the database development, and some results are given to illustrate the practical usefulness of such a database with respect to the detailed new research questions.
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| 8. |
- Barkowsky, Marcus, et al.
(author)
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Subjective and objective visual quality assessment in the context of stereoscopic 3D-TV
- 2013
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In: 3D-TV System with Depth-Image-Based Rendering: Architectures, Techniques and Challenges. - New York, NY : Springer New York. - 9781441999641 - 1441999639 - 9781441999634 ; , s. 413-437
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Book chapter (other academic/artistic)abstract
- Subjective and objective visual quality assessment in the context of stereoscopic three-dimensional TV (3D-TV) is still in the nascent stage and needs to consider the effect of the added depth dimension. As a matter of fact, quality assessment of 3D-TV cannot be considered as a trivial extension of two-dimensional (2D) cases. Furthermore, it may also introduce negative effects not experienced in 2D, e.g., discomfort or nausea. Based on efforts initiated within the cost action ICT 1003 QUALINET, this chapter discusses current challenges in relation to subjective and objective visual quality assessment for stereo-based 3D-TV. Two case studies are presented to illustrate the current state of the art and some of the remaining challenges.
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| 9. |
- Barkowsky, Marcus, et al.
(author)
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Towards standardized 3DTV QoE assessment : Cross-lab study on display technology and viewing environment parameters
- 2013
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819494214
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Conference paper (peer-reviewed)abstract
- Subjective assessment of Quality of Experience in stereoscopic 3D requires new guidelines for the environmental setup as existing standards such as ITU-R BT.500 may no longer be appropriate. A first step is to perform cross-lab experiments in different viewing conditions on the same video sequences. Three international labs performed Absolute Category Rating studies on a freely available video database containing degradations that are mainly related to video quality degradations. Different conditions have been used in the labs: Passive polarized displays, active shutter displays, differences in viewing distance, the number of parallel viewers, and the voting device. Implicit variations were introduced due to the three different languages in Sweden, South Korea, and France. Although the obtained Mean Opinion Scores are comparable, slight differences occur in function of the video degradations and the viewing distance. An analysis on the statistical differences obtained between the MOS of the video sequences revealed that obtaining an equivalent number of differences may require more observers in some viewing conditions. It was also seen that the alignment of the meaning of the attributes used in Absolute Category Rating in different languages may be beneficial. Statistical analysis was performed showing influence of the viewing distance on votes and MOS results.
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| 10. |
- Björk, Elisabeth, et al.
(author)
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Fines-enriched pulp as a strength agent in a CTMP middle ply
- 2018
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In: PaperCon 2018. - : TAPPI. - 9781595102683 ; , s. 741-760
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Conference paper (peer-reviewed)abstract
- The objective of this pilot scale trial, was to evaluate fines-enriched pulp (FE-pulp) as a strength agent in amiddle ply of a board product.A typical CTMP-based middle ply was produced on the FEX pilot paper machine. The stock consisted of CTMP,refined hardwood and softwood pulp, and filler. FE-pulp as strength agent was compared with glue pulp, ahighly refined chemical pulp. FEX sheets and hand sheets made of pulp mixtures were evaluated. Also, thedewatering and pressing conditions on the paper machine were compared.The results confirmed the results of earlier experiments with handsheets; FE-pulp used as strength agent showedto be twice as efficient as glue pulp regarding strength properties without impairing the bulk. Further, thedewatering conditions and press dryness's on the paper machine was comparable at these additions. Thus, allthese results imply that addition of FE-pulp can replace the double amount of glue pulp as a strength agent.
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