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Torres Vega, Maria, Vittorio Sguazzo, Decebal Constantin Mocanu et Antonio Liotta. « An experimental survey of no-reference video quality assessment methods ». International Journal of Pervasive Computing and Communications 12, no 1 (4 avril 2016) : 66–86. http://dx.doi.org/10.1108/ijpcc-01-2016-0008.
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Purpose The Video Quality Metric (VQM) is one of the most used objective methods to assess video quality, because of its high correlation with the human visual system (HVS). VQM is, however, not viable in real-time deployments such as mobile streaming, not only due to its high computational demands but also because, as a Full Reference (FR) metric, it requires both the original video and its impaired counterpart. In contrast, No Reference (NR) objective algorithms operate directly on the impaired video and are considerably faster but loose out in accuracy. The purpose of this paper is to study how differently NR metrics perform in the presence of network impairments. Design/methodology/approach The authors assess eight NR metrics, alongside a lightweight FR metric, using VQM as benchmark in a self-developed network-impaired video data set. This paper covers a range of methods, a diverse set of video types and encoding conditions and a variety of network impairment test-cases. Findings The authors show the extent by which packet loss affects different video types, correlating the accuracy of NR metrics to the FR benchmark. This paper helps identifying the conditions under which simple metrics may be used effectively and indicates an avenue to control the quality of streaming systems. Originality/value Most studies in literature have focused on assessing streams that are either unaffected by the network (e.g. looking at the effects of video compression algorithms) or are affected by synthetic network impairments (i.e. via simulated network conditions). The authors show that when streams are affected by real network conditions, assessing Quality of Experience becomes even harder, as the existing metrics perform poorly.
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Pinson, Margaret H., Philip J. Corriveau, Mikołaj Leszczuk et Michael Colligan. « Open Software Framework for Collaborative Development of No Reference Image and Video Quality Metrics ». Electronic Imaging 2020, no 11 (26 janvier 2020) : 92–1. http://dx.doi.org/10.2352/issn.2470-1173.2020.11.hvei-092.
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This paper describes ongoing work within the video quality experts group (VQEG) to develop no-reference (NR) audiovisual video quality analysis (VQA) metrics. VQEG provides an open forum that encourages knowledge sharing and collaboration. The VQEG no-reference Metric (NORM) group’s goal is to develop open-source NR-VQA metrics that meet industry requirements for scope, accuracy, and capability. This paper presents industry specifications from discussions at VQEG face-to-face meetings among industry, academic, and government participants. This paper also announces an open software framework for collaborative development of NR image quality Analysis (IQA) and VQA metrics <ext-link ext-link-type="url" xlink:href="https://github.com/NTIA/NRMetricFramework"><https://github.com/NTIA/NRMetricFramework></ext-link>. This framework includes the support tools necessary to begin research and avoid common mistakes. VQEG’s goal is to produce a series of NR-VQA metrics with progressively improving scope and accuracy. This work draws upon and enables IQA metric research, as both use the human visual system to analyze the quality of audiovisual media on modern displays. Readers are invited to participate.
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Woodard, Jeffrey P., et Monica P. Carley-Spencer. « No-Reference Image Quality Metrics for Structural MRI ». Neuroinformatics 4, no 3 (2006) : 243–62. http://dx.doi.org/10.1385/ni:4:3:243.
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Cao, Zhipeng, Zhenzhong Wei et Guangjun Zhang. « A No-Reference Sharpness Metric Based on Structured Ringing for JPEG2000 Images ». Advances in Optical Technologies 2014 (24 juin 2014) : 1–13. http://dx.doi.org/10.1155/2014/295615.
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This work presents a no-reference image sharpness metric based on human blur perception for JPEG2000 compressed image. The metric mainly uses a ringing measure. And a blurring measure is used for compensation when the blur is so severe that ringing artifacts are concealed. We used the anisotropic diffusion for the preliminary ringing map and refined it by considering the property of ringing structure. The ringing detection of the proposed metric does not depend on edge detection, which is suitable for high degraded images. The characteristics of the ringing and blurring measures are analyzed and validated theoretically and experimentally. The performance of the proposed metric is tested and compared with that of some existing JPEG2000 sharpness metrics on three widely used databases. The experimental results show that the proposed metric is accurate and reliable in predicting the sharpness of JPEG2000 images.
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LE CALLET, P. « No Reference and Reduced Reference Video Quality Metrics for End to End QoS Monitoring ». IEICE Transactions on Communications E89-B, no 2 (1 février 2006) : 289–96. http://dx.doi.org/10.1093/ietcom/e89-b.2.289.
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Rubel, Andrii, Oleg Ieremeiev, Vladimir Lukin, Jarosław Fastowicz et Krzysztof Okarma. « Combined No-Reference Image Quality Metrics for Visual Quality Assessment Optimized for Remote Sensing Images ». Applied Sciences 12, no 4 (14 février 2022) : 1986. http://dx.doi.org/10.3390/app12041986.
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No-reference image quality assessment is one of the most demanding areas of image analysis for many applications where the results of the analysis should be strongly correlated with the quality of an input image and the corresponding reference image is unavailable. One of the examples might be remote sensing since the transmission of such obtained images often requires the use of lossy compression and they are often distorted, e.g., by the presence of noise and blur. Since the practical usefulness of acquired and/or preprocessed images is directly related to their quality, there is a need for the development of reliable and adequate no-reference metrics that do not need any reference images. As the performance and universality of many existing metrics are quite limited, one of the possible solutions is the design and application of combined metrics. Several possible approaches to their composition have been previously proposed and successfully used for full-reference metrics. In the paper, three possible approaches to the development and optimization of no-reference combined metrics are investigated and verified for the dataset of images containing distortions typical for remote sensing. The proposed approach leads to good results, significantly improving the correlation of the obtained results with subjective quality scores.
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Wang, Hui, Xiaojuan Hu, Hui Xu, Shiyin Li et Zhaolin Lu. « No-Reference Quality Assessment Method for Blurriness of SEM Micrographs with Multiple Texture ». Scanning 2019 (2 juin 2019) : 1–15. http://dx.doi.org/10.1155/2019/4271761.
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Scanning electron microscopy (SEM) plays an important role in the intuitive understanding of microstructures because it can provide ultrahigh magnification. Tens or hundreds of images are regularly generated and saved during a typical microscopy imaging process. Given the subjectivity of a microscopist’s focusing operation, blurriness is an important distortion that debases the quality of micrographs. The selection of high-quality micrographs using subjective methods is expensive and time-consuming. This study proposes a new no-reference quality assessment method for evaluating the blurriness of SEM micrographs. The human visual system is more sensitive to the distortions of cartoon components than to those of redundant textured components according to the Gestalt perception psychology and the entropy masking property. Micrographs are initially decomposed into cartoon and textured components. Then, the spectral and spatial sharpness maps of the cartoon components are extracted. One metric is calculated by combining the spatial and spectral sharpness maps of the cartoon components. The other metric is calculated on the basis of the edge of the maximum local variation map of the cartoon components. Finally, the two metrics are combined as the final metric. The objective scores generated using this method exhibit high correlation and consistency with the subjective scores.
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Liu, Xinwei, Marius Pedersen et Christophe Charrier. « Performance evaluation of no-reference image quality metrics for face biometric images ». Journal of Electronic Imaging 27, no 02 (2 mars 2018) : 1. http://dx.doi.org/10.1117/1.jei.27.2.023001.
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Gu, Ke, Guangtao Zhai, Xiaokang Yang et Wenjun Zhang. « No-Reference Stereoscopic IQA Approach : From Nonlinear Effect to Parallax Compensation ». Journal of Electrical and Computer Engineering 2012 (2012) : 1–12. http://dx.doi.org/10.1155/2012/436031.
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The last decade has seen a booming of the applications of stereoscopic images/videos and the corresponding technologies, such as 3D modeling, reconstruction, and disparity estimation. However, only a very limited number of stereoscopic image quality assessment metrics was proposed through the years. In this paper, we propose a new no-reference stereoscopic image quality assessment algorithm based on the nonlinear additive model, ocular dominance model, and saliency based parallax compensation. Our studies using the Toyama database result in three valuable findings. First, quality of the stereoscopic image has a nonlinear relationship with a direct summation of two monoscopic image qualities. Second, it is a rational assumption that the right-eye response has the higher impact on the stereoscopic image quality, which is based on a sampling survey in the ocular dominance research. Third, the saliency based parallax compensation, resulted from different stereoscopic image contents, is considerably valid to improve the prediction performance of image quality metrics. Experimental results confirm that our proposed stereoscopic image quality assessment paradigm has superior prediction accuracy as compared to state-of-the-art competitors.
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Ye, Zhongchang, Xin Ye et Zhonghua Zhao. « Hybrid No-Reference Quality Assessment for Surveillance Images ». Information 13, no 12 (16 décembre 2022) : 588. http://dx.doi.org/10.3390/info13120588.
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Intelligent video surveillance (IVS) technology is widely used in various security systems. However, quality degradation in surveillance images (SIs) may affect its performance on vision-based tasks, leading to the difficulties in the IVS system extracting valid information from SIs. In this paper, we propose a hybrid no-reference image quality assessment (NR IQA) model for SIs that can help to identify undesired distortions and provide useful guidelines for IVS technology. Specifically, we first extract two main types of quality-aware features: the low-level visual features related to various distortions, and the high-level semantic information, which is extracted by a state-of-the-art (SOTA) vision transformer backbone. Then, we fuse these two kinds of features into the final quality-aware feature vector, which is mapped into the quality index through the feature regression module. Our experimental results on two surveillance content quality databases demonstrate that the proposed model achieves the best performance compared to the SOTA on NR IQA metrics.
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Li, Shuang, Zewei Yang et Hongsheng Li. « Statistical Evaluation of No-Reference Image Quality Assessment Metrics for Remote Sensing Images ». ISPRS International Journal of Geo-Information 6, no 5 (28 avril 2017) : 133. http://dx.doi.org/10.3390/ijgi6050133.
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Mykola, Ponomarenko, Ghanbaralizadeh Bahnemiri Sheyda et Egiazarian Karen. « Transfer learning for no-reference image quality metrics using large temporary image sets ». Electronic Imaging 34, no 14 (16 janvier 2022) : 219–1. http://dx.doi.org/10.2352/ei.2022.34.14.coimg-219.
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Gawande, Pravin G., et Ashok M. Sapkal. « Quality-dependent fusion system using no-reference image quality metrics for multimodal biometrics ». Periodicals of Engineering and Natural Sciences (PEN) 6, no 1 (5 juin 2018) : 260. http://dx.doi.org/10.21533/pen.v6i1.282.
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Nawała, Jakub, Lucjan Janowski et Mikołaj Leszczuk. « Modeling of Quality of Experience in No-Reference Model ». Journal of Telecommunications and Information Technology, no 2 (30 juin 2017) : 11–17. http://dx.doi.org/10.26636/jtit.2017.114517.
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The key objective of no-reference (NR) visual metrics is to predict the end-user experience concerning remotely delivered video content. Rapidly increasing demand for easily accessible, high quality video material makes it crucial for service providers to test the user experience without the need for comparison with reference material. Nevertheless, the QoE measurement is not enough. The information about the source or error is very important as well. Therefore, the described system is based on calculating numerous different NR indicators, which are combined to provide the overall quality score. In this paper, more quality indicators than are used in the QoE calculation are described, since some of them detect specific errors. Such specific errors are dificult to include in a global QoE model but are important from the operation point of view.
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Irshad, Muhammad, Camilo Sanchez-Ferreira, Sana Alamgeer, Carlos H. Llanos et Mylène C. Q. Farias. « No-reference Image Quality Assessment of Underwater Images Using Multi-Scale Salient Local Binary Patterns ». Electronic Imaging 2021, no 9 (18 janvier 2021) : 265–1. http://dx.doi.org/10.2352/issn.2470-1173.2021.9.iqsp-265.
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Images acquired in underwater scenarios may contain severe distortions due to light absorption and scattering, color distortion, poor visibility, and contrast reduction. Because of these degradations, researchers have proposed several algorithms to restore or enhance underwater images. One way to assess these algorithms’ performance is to measure the quality of the restored/enhanced underwater images. Unfortunately, since reference (pristine) images are often not available, designing no-reference (blind) image quality metrics for this type of scenario is still a challenge. In fact, although the area of image quality has evolved a lot in the last decades, estimating the quality of enhanced and restored images is still an open problem. In this work, we present a no-reference image quality evaluation metric for enhanced underwater images (NR-UWIQA) that uses an adapted version of the multi-scale salient local binary pattern operator to extract image features and a machine learning approach to predict quality. The proposed metric was tested on the UID-LEIA database and presented good accuracy performance when compared to other state-of-the-art methods. In summary, the proposed NR-UWQIA method can be used to evaluate the results of restoration techniques quickly and efficiently, opening a new perspective in the area of underwater image restoration and quality assessment.
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Lee, Wonkyeong, Eunbyeol Cho, Wonjin Kim, Hyebin Choi, Kyongmin Sarah Beck, Hyun Jung Yoon, Jongduk Baek et Jang-Hwan Choi. « No-reference perceptual CT image quality assessment based on a self-supervised learning framework ». Machine Learning : Science and Technology 3, no 4 (1 décembre 2022) : 045033. http://dx.doi.org/10.1088/2632-2153/aca87d.
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Abstract Accurate image quality assessment (IQA) is crucial to optimize computed tomography (CT) image protocols while keeping the radiation dose as low as reasonably achievable. In the medical domain, IQA is based on how well an image provides a useful and efficient presentation necessary for physicians to make a diagnosis. Moreover, IQA results should be consistent with radiologists’ opinions on image quality, which is accepted as the gold standard for medical IQA. As such, the goals of medical IQA are greatly different from those of natural IQA. In addition, the lack of pristine reference images or radiologists’ opinions in a real-time clinical environment makes IQA challenging. Thus, no-reference IQA (NR-IQA) is more desirable in clinical settings than full-reference IQA (FR-IQA). Leveraging an innovative self-supervised training strategy for object detection models by detecting virtually inserted objects with geometrically simple forms, we propose a novel NR-IQA method, named deep detector IQA (D2IQA), that can automatically calculate the quantitative quality of CT images. Extensive experimental evaluations on clinical and anthropomorphic phantom CT images demonstrate that our D2IQA is capable of robustly computing perceptual image quality as it varies according to relative dose levels. Moreover, when considering the correlation between the evaluation results of IQA metrics and radiologists’ quality scores, our D2IQA is marginally superior to other NR-IQA metrics and even shows performance competitive with FR-IQA metrics.
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Рубель, Андрей Сергеевич, et Владимир Васильевич Лукин. « АНАЛИЗ И ПРОГНОЗИРОВАНИЕ ЭФФЕКТИВНОСТИ ФИЛЬТРАЦИИ С ИСПОЛЬЗОВАНИЕМ БЕЗЭТАЛОННЫХ МЕР ВИЗУАЛЬНОГО КАЧЕСТВА ИЗОБРАЖЕНИЙ ». RADIOELECTRONIC AND COMPUTER SYSTEMS, no 1 (23 février 2018) : 4–14. http://dx.doi.org/10.32620/reks.2018.1.01.
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Images are subject to noise during acquisition, transmission and processing. Image denoising is highly desirable, not only to provide better visual quality, but also to improve performance of the subsequent operations such as compression, segmentation, classification, object detection and recognition. In the past decades, a large number of image denoising algorithms has been developed, ranging from simple linear methods to complex methods based on similar blocks search and deep convolutional neural networks. However, most of existing denoising techniques have a tendency to oversmooth image edges, fine details and textures. Thus, there are cases when noise reduction leads to loss of image features and filtering does not produce better visual quality. According to this, it is very important to evaluate denoising result and hence to undertake a decision whether denoising is expedient. Despite the fact that image denoising has been one of the most active research areas, only a little work has been dedicated to visual quality evaluation for denoised images. There are many approaches and metrics to characterize image quality, but adequateness of these metrics is of question. Existing image quality metrics, especially no-reference ones, have not been thoroughly studies for image denoising. In terms of using visual quality metrics, it is usually supposed that the higher the improvement for a given metric, the better visual quality for denoised image. However, there are situations when denoising does not result in visual quality enhancement, especially for texture images. Thus, it would be desirable to predict human subjective evaluation for denoised image. Then, this information will clarify when denoising can be expedient. The purpose of this paper is to give analysis of denoising expedience using no-reference (NR) image quality metrics. In addition, this work considers possible ways to predict human subjective evaluation of denoised images based on several input parameters. More in details, two denoising techniques, namely the standard sliding window DCT filter and the BM3D filter have been considered. Using a specialized database of test images SubjectiveIQA, performance evaluation of existing state-of-the-art objective no-reference quality metrics for denoised images is carried out
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Leclaire, Arthur, et Lionel Moisan. « No-Reference Image Quality Assessment and Blind Deblurring with Sharpness Metrics Exploiting Fourier Phase Information ». Journal of Mathematical Imaging and Vision 52, no 1 (12 mars 2015) : 145–72. http://dx.doi.org/10.1007/s10851-015-0560-5.
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Smyth, Christine, Masumi Yamada et Jim Mori. « Earthquake forecast enrichment scores ». Research in Geophysics 2, no 1 (5 mars 2012) : 2. http://dx.doi.org/10.4081/rg.2012.e2.
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The Collaboratory for the Study of Earthquake Predictability (CSEP) is a global project aimed at testing earthquake forecast models in a fair environment. Various metrics are currently used to evaluate the submitted forecasts. However, the CSEP still lacks easily understandable metrics with which to rank the universal performance of the forecast models. In this research, we modify a well-known and respected metric from another statistical field, bioinformatics, to make it suitable for evaluating earthquake forecasts, such as those submitted to the CSEP initiative. The metric, originally called a <em>gene-set enrichment score</em>, is based on a Kolmogorov-Smirnov statistic. Our modified metric assesses if, over a certain time period, the forecast values at locations where earthquakes have occurred are significantly increased compared to the values for all locations where earthquakes did not occur. Permutation testing allows for a significance value to be placed upon the score. Unlike the metrics currently employed by the CSEP, the score places no assumption on the distribution of earthquake occurrence nor requires an arbitrary reference forecast. In this research, we apply the modified metric to simulated data and real forecast data to show it is a powerful and robust technique, capable of ranking competing earthquake forecasts.
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Nieniewski, Mariusz, et Paweł Zajączkowski. « COMPARISON OF ULTRASOUND IMAGE FILTERING METHODS BY MEANS OF MULTIVARIABLE KURTOSIS ». Image Analysis & ; Stereology 36, no 2 (23 juin 2017) : 79. http://dx.doi.org/10.5566/ias.1639.
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Comparison of the quality of despeckled US medical images is complicated because there is no image of a human body that would be free of speckles and could serve as a reference. A number of various image metrics are currently used for comparison of filtering methods; however, they do not satisfactorily represent the visual quality of images and medical expert’s satisfaction with images. This paper proposes an innovative use of relative multivariate kurtosis for the evaluation of the most important edges in an image. Multivariate kurtosis allows one to introduce an order among the filtered images and can be used as one of the metrics for image quality evaluation. At present there is no method which would jointly consider individual metrics. Furthermore, these metrics are typically defined by comparing the noisy original and filtered images, which is incorrect since the noisy original cannot serve as a golden standard. In contrast to this, the proposed kurtosis is the absolute measure, which is calculated independently of any reference image and it agrees with the medical expert’s satisfaction to a large extent. The paper presents a numerical procedure for calculating kurtosis and describes results of such calculations for a computer-generated noisy image, images of a general purpose phantom and a cyst phantom, as well as real-life images of thyroid and carotid artery obtained with SonixTouch ultrasound machine. 16 different methods of image despeckling are compared via kurtosis. The paper shows that visually more satisfactory despeckling results are associated with higher kurtosis, and to a certain degree kurtosis can be used as a single metric for evaluation of image quality.
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Finazzi, Guilherme Antonio, et Vivianni Marques Leite Santos. « Proposal of a holistic environmental metric based on environmental indicators ». Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental 25 (8 avril 2021) : e13. http://dx.doi.org/10.5902/2236117064032.
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There is no doubt Sustainability reaching is essential. Natural resources rational use is extremely important to human development. Beyond the years, this preoccupation led various institutions to elaborate legislation and international guides, as Kyoto protocol, to satisfy sustainability conditions. Agenda 2030 is the most recent instrument, whose proposals attempt to these conditions. Within this context, human activity related to Chemistry is noteworthy: to guarantee all sustainable aspects in a procedure is a great challenge. The assessment of Sustainability in Chemistry is performed by green metrics calculations, whose utility is most appropriate in comparison of procedures than in a single procedure assessment. Due to problematics with the utilization of metrics, related to: simplifications leading to pseudo-results, need of various misunderstanding calculations and incorrect adoption of metrics, an environmental metric that attempts to current necessities related to materials and energetics consumption and to assessment of sustainability in individual chemistry procedures is proposed. The metric was elaborated aiming to attempt all environmental requirements of chemical sustainability in a simplified and reliable manner, basing on bibliographic search and expertise. The metric elaboration has a combined approach, in which reference values are established to the main indicators of sustainability, using a Soft System Methodology (SSM).
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Taylor, Timothy Ryan, Chun-Tang Chao et Juing-Shian Chiou. « Novel Deep Level Image State Ensemble Enhancement Method for M87 Imaging ». Applied Sciences 10, no 11 (6 juin 2020) : 3952. http://dx.doi.org/10.3390/app10113952.
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Standard spatial domain filters fail to adequately denoise and enhance the contrast of an image. These filters have drawbacks like oversmoothing, diminished texture, and lack of generative capabilities. This paper proposes a new method of image reconstruction, Image State Ensemble Enhancement (ISEE), based on our previous work, Image State Ensemble Decomposition (ISED). Deep level ISEE and ISED have been developed to produce a class of filters that can address these issues. Full-reference and no-reference quality metrics are used to assess the image, and the full reference metrics showed a marked improvement, while the no-reference metrics were often better than the test image. The test image was taken from the Spitzer Space Telescope (SST), and ISEE reconstruction yielded improved structural detail over that of ISED and the original test image. Glare and noise were reduced in a narrow bandwidth, which led to the discovery of a vortex-shaped structure and an outburst in M87′s dusty infrared core. The vortex is located over M87′s visible core and black hole. This is verified with an SST and Hubble Space Telescope (HST) overlay, ISEE processed image. A counter-jet channel was also discovered, and it appears to be the path of the unobservable superluminal counter-jet.
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Kaur, Rupinder. « A Medical Image Watermarking Technique for Embedding EPR and Its Quality Assessment Using No-Reference Metrics ». International Journal of Information Technology and Computer Science 5, no 2 (3 janvier 2013) : 73–79. http://dx.doi.org/10.5815/ijitcs.2013.02.08.
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Hossain, Kabir, Claire Mantel et Søren Forchhammer. « No Reference Prediction of Quality Metrics for H.264 Compressed Infrared Image Sequences for UAV Applications ». Electronic Imaging 2018, no 12 (28 janvier 2018) : 108–1. http://dx.doi.org/10.2352/issn.2470-1173.2018.12.iqsp-108.
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Han, Aaron L. F., Derek F. Wong, Lidia S. Chao, Liangye He et Yi Lu. « Unsupervised Quality Estimation Model for English to German Translation and Its Application in Extensive Supervised Evaluation ». Scientific World Journal 2014 (2014) : 1–12. http://dx.doi.org/10.1155/2014/760301.
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With the rapid development of machine translation (MT), the MT evaluation becomes very important to timely tell us whether the MT system makes any progress. The conventional MT evaluation methods tend to calculate the similarity between hypothesis translations offered by automatic translation systems and reference translations offered by professional translators. There are several weaknesses in existing evaluation metrics. Firstly, the designed incomprehensive factors result in language-bias problem, which means they perform well on some special language pairs but weak on other language pairs. Secondly, they tend to use no linguistic features or too many linguistic features, of which no usage of linguistic feature draws a lot of criticism from the linguists and too many linguistic features make the model weak in repeatability. Thirdly, the employed reference translations are very expensive and sometimes not available in the practice. In this paper, the authors propose an unsupervised MT evaluation metric using universal part-of-speech tagset without relying on reference translations. The authors also explore the performances of the designed metric on traditional supervised evaluation tasks. Both the supervised and unsupervised experiments show that the designed methods yield higher correlation scores with human judgments.
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Messai, Oussama, Aladine Chetouani, Fella Hachouf et Zianou Ahmed Seghir. « No-reference Stereoscopic Image Quality Predictor using Deep Features from Cyclopean Image ». Electronic Imaging 2021, no 9 (18 janvier 2021) : 297–1. http://dx.doi.org/10.2352/issn.2470-1173.2021.9.iqsp-297.
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With the expanding use of stereoscopic imaging for 3D applications, no-reference perceptual quality evaluation has become important to provide good viewing experience. The effect of the quality distortion is related to the scene’s spatial details. Taking this into account, this paper introduces a blind stereoscopic image quality measurement using synthesized cyclopean image and deep feature extraction. The proposed method is based on Human Visual System (HVS) modeling and quality-aware indicators. First, the cyclopean image is formed, taking on the existence of binocular rivalry / suppression that includes the asymmetric distortion case. Second, the cyclopean image is decomposed into four equivalent parts. Then, four Convolutional Neural Network (CNN) models are deployed to automatically extract quality feature sets. Finally, a feature bank is then created from the four patches and mapped to quality score using a Support Vector Regression (SVR) model. The best known 3D LIVE phase I and phase II databases were used to evaluate the efficiency of our technique. Compared with the state-of-the-art stereoscopic image quality measurement metrics, the proposed method has shown competitive outcomes and achieved good performance.
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Seybold, Tamara, Marion Knopp, Christian Keimel et Walter Stechele. « Beyond Standard Noise Models : Evaluating Denoising Algorithms with Respect to Realistic Camera Noise ». International Journal of Semantic Computing 08, no 02 (juin 2014) : 145–67. http://dx.doi.org/10.1142/s1793351x14400029.
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The development and tuning of denoising algorithms is usually based on readily processed test images that are artificially degraded with additive white Gaussian noise (AWGN). While AWGN allows us to easily generate test data in a repeatable manner, it does not reflect the noise characteristics in a real digital camera. Realistic camera noise is signal-dependent and spatially correlated due to the demosaicking step required to obtain full-color images. Hence, the noise characteristic is fundamentally different from AWGN. Using such unrealistic data to test, optimize and compare denoising algorithms may lead to incorrect parameter tuning or suboptimal choices in research on denoising algorithms. In this paper, we therefore propose an approach to evaluate denoising algorithms with respect to realistic camera noise: we describe a new camera noise model that includes the full processing chain of a single sensor camera. We determine the visual quality of noisy and denoised test sequences using a subjective test with 18 participants. We show that the noise characteristics have a significant effect on visual quality. Quality metrics, which are required to compare denoising results, are applied, and we first evaluate the performance of 12 full-reference metrics. As no-reference metrics are especially useful for parameter tuning, we additionally evaluate five no-reference metrics with our realistic test data. We conclude that a more realistic noise model should be used in future research to improve the quality estimation of digital images and videos and to improve the research on denoising algorithms.
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Hasanah, Nur, Vita Sarasi et Ina Primiana. « Aplikasi Supply Chain Operation Reference (SCOR) pada Produk Chocodot PT Tama Cokelat Garut Indonesia ». Operations Excellence : Journal of Applied Industrial Engineering 14, no 2 (1 septembre 2022) : 153. http://dx.doi.org/10.22441/oe.2022.v14.i2.052.
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This study applies the SCOR (Supply Chain Operations Reference) method at one of the companies engaged in the Food and Beverage (F&B) sector, namely PT. Chocolate Tama. The goal is to determine the level of importance of the company's five main activities, namely Plan, Source, Make, Deliver and Return so as to measure and improve the company's total supply chain performance. The research begins with determining KPIs and Supply Chain Management Metrics and weighting supply chain management metrics Level I, II and III using AHP. The results of the validation process there are 44 metrics that represent the performance of supply chain activities, namely 11 plan metrics, 10 source metrics, 7 make metrics, 10 deliver metrics and 6 return metrics. The plan activity has the highest weight value of 0.3188, after that successively source is 0.2254, deliver is 0.1560, make is 0.1511 and return is 0.1487. There are 21 sequences of supply chain performance metrics that must be improved so that there are no more delays in the supply of raw materials as well as recommendations for improvement for increasing the company's revenue in the future. The first three sequences that have the highest values that need to be improved are plan source (planning the source of raw materials), forecast accuracy (forecasting accuracy) and purchase order cycle time (determination of purchase order cycle time).
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Dogvanich, A., N. Mamaev, A. Krylov et N. Makhneva. « DERMATOLOGICAL IMAGE DENOISING USING ADAPTIVE HENLM METHOD ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W12 (9 mai 2019) : 47–52. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w12-47-2019.
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<p><strong>Abstract.</strong> In this paper we propose automatic image denoising method based on Hermite functions (HeNLM). It is an extension of non-local means (NLM) algorithm. Differences between small image blocks (patches) are replaced by differences between feature vectors thus reducing computational complexity. The features are calculated in coordinate system connected with image gradient and are invariant to patch rotation. HeNLM method depends on the parameter that controls filtering strength. To chose automatically this parameter we use a no-reference denoising quality assessment method. It is based on Hessian matrix analysis. We compare the proposed method with full-reference methods using PSNR metrics, SSIM metrics, and its modifications MSSIM and CMSC. Image databases TID, DRIVE, BSD, and a set of dermatological immunofluorescence microscopy images were used for the tests. It was found that more perceptual CMSC and MSSIM metrics give worse correspondence than SSIM and PSNR to the results of information preservation by the non-reference image denoising.</p>
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Hossain, Kabir, Claire Mantel et Søren Forchhammer. « No-reference prediction of quality metrics for H.264-compressed infrared sequences for unmanned aerial vehicle applications ». Journal of Electronic Imaging 28, no 04 (16 juillet 2019) : 1. http://dx.doi.org/10.1117/1.jei.28.4.043012.
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Costa, André H. M., Helard Becerra Martinez, Daniel G. Silva et Mylène C. Q. Farias. « Analyzing the effect of adding temporal features to an autoencoder-based video quality model ». Electronic Imaging 2021, no 9 (18 janvier 2021) : 261–1. http://dx.doi.org/10.2352/issn.2470-1173.2021.9.iqsp-261.
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According to Cisco, most Internet traffic is currently comprised of videos. Therefore, developing a quality assessment method for assuring that those videos are received and displayed with quality at the user side is an important and challenging task. As a consequence, over the last decades, several no-reference video quality metrics have been proposed with the goal of blindly predicting (with no access to the original signal) the quality of videos in streaming applications. One of such metrics is NAVE, whose architecture includes an auto-encoder module that produces a compact set of visual features with a higher descriptive capacity. Nevertheless, the visual features in NAVE do not include descriptive temporal features that are sensitive to temporal degradation. In this work, we analyze the effect on accuracy performance of using a new type of temporal features, based on natural scene statistics. This approach has the goal of making the tested video quality metric more generic, i.e. sensitive to both spatial and temporal distortions and therefore adequate for video streaming applications.
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Mehmood, Imran, Muhammad Usman Khan, Ming Ronnier Luo et Muhammad Farhan Mughal. « Tone Mapping Operators Evaluation Based on High Quality Reference Images ». Color and Imaging Conference 2019, no 1 (21 octobre 2019) : 268–72. http://dx.doi.org/10.2352/issn.2169-2629.2019.27.48.
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High Dynamic Range (HDR) imaging applications have been commonly placed recently. Several tone mapping operators (TMOs) have been developed which project the HDR radiance range to that of a display. Currently, there is no agreement on a technique for evaluation of tone mapping operators. The goal of this study is to establish a method based on reference images to evaluate the TMOs. Two psychophysical experiments were carried out for the evaluation of tone mapping operators. In the first experiment, a set of high quality images were generated to possess right extents of image features including contrast, colourfulness and sharpness. These images were further used in the second experiment as reference images to evaluate different TMOs. It was found Reinhard's photographic reproduction based on local TMO gave an overall better performance. CIELAB(2:1) and S- CIELAB metrics were also used to judge colour image quality of the same TMOs. It was found that both metrics agreed well with the visual results.
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Finžgar, Miha, et Primož Podržaj. « Feasibility of assessing ultra-short-term pulse rate variability from video recordings ». PeerJ 8 (7 janvier 2020) : e8342. http://dx.doi.org/10.7717/peerj.8342.
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Objectives Remote photoplethysmography (rPPG) is a promising non-contact measurement technique for assessing numerous physiological parameters: pulse rate, pulse rate variability (PRV), respiratory rate, pulse wave velocity, blood saturation, blood pressure, etc. To justify its use in ultra-short-term (UST) PRV analysis, which is of great benefit for several healthcare applications, the agreement between rPPG- and PPG-derived UST-PRV metrics was studied. Approach Three time-domain metrics—standard deviation of normal-to-normal (NN) intervals (SDNN), root mean square of successive NN interval differences (RMSSD), and the percentage of adjacent NN intervals that differ from each other by more than 50 ms (pNN50)—were extracted from 56 video recordings in a publicly available data set. The selected metrics were calculated on the basis of three groups of 10 s recordings and their average, two groups of 30 s recordings and their average, and a group of 60 s recordings taken from the full-length recordings and then compared with metrics derived from the corresponding reference (PPG) pulse waveform signals by using correlation and effect size parameters, and Bland–Altman plots. Main results The results show there is stronger agreement as the recording length increases for SDNN and RMSSD, yet there is no significant change for pNN50. The agreement parameters reach r = 0.841 (p < 0.001), r = 0.529 (p < 0.001), and r = 0.657 (p < 0.001), estimated median bias −1.52, −2.28 ms and −1.95% and a small effect size for SDNN, RMSSD, and pNN50 derived from the 60 s recordings, respectively. Significance Remote photoplethysmography-derived UST-PRV metrics manage to capture UST-PRV metrics derived from reference (PPG) recordings well. This feature is highly desirable in numerous applications for the assessment of one’s health and well-being. In future research, the validity of rPPG-derived UST-PRV metrics compared to the gold standard electrocardiography recordings is to be assessed.
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Sun, Shanlei, Jiazhi Wang, Wanrong Shi, Rongfan Chai et Guojie Wang. « Capacity of the PERSIANN-CDR Product in Detecting Extreme Precipitation over Huai River Basin, China ». Remote Sensing 13, no 9 (30 avril 2021) : 1747. http://dx.doi.org/10.3390/rs13091747.
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Assessing satellite-based precipitation product capacity for detecting precipitation and linear trends is fundamental for accurately knowing precipitation characteristics and changes, especially for regions with scarce and even no observations. In this study, we used daily gauge observations across the Huai River Basin (HRB) during 1983–2012 and four validation metrics to evaluate the Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR) capacity for detecting extreme precipitation and linear trends. The PERSIANN-CDR well captured climatologic characteristics of the precipitation amount- (PRCPTOT, R85p, R95p, and R99p), duration- (CDD and CWD), and frequency-based indices (R10mm, R20mm, and Rnnmm), followed by moderate performance for the intensity-based indices (Rx1day, R5xday, and SDII). Based on different validation metrics, the PERSIANN-CDR capacity to detect extreme precipitation varied spatially, and meanwhile the validation metric-based performance differed among these indices. Furthermore, evaluation of the PERSIANN-CDR linear trends indicated that this product had a much limited and even no capacity to represent extreme precipitation changes across the HRB. Briefly, this study provides a significant reference for PERSIANN-CDR developers to use to improve product accuracy from the perspective of extreme precipitation, and for potential users in the HRB.
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Taylor, Timothy Ryan, Chun-Tang Chao et Juing-Shian Chiou. « Novel Image State Ensemble Decomposition Method for M87 Imaging ». Applied Sciences 10, no 4 (24 février 2020) : 1535. http://dx.doi.org/10.3390/app10041535.
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This paper proposes a new method of image decomposition with a filtering capability. The image state ensemble decomposition (ISED) method has generative capabilities that work by removing a discrete ensemble of quanta from an image to provide a range of filters and images for a single red, green, and blue (RGB) input image. This method provides an image enhancement because ISED is a spatial domain filter that transforms or eliminates image regions that may have detrimental effects, such as noise, glare, and image artifacts, and it also improves the aesthetics of the image. ISED was used to generate 126 images from two tagged image file (TIF) images of M87 taken by the Spitzer Space Telescope. Analysis of the images used various full and no-reference quality metrics as well as histograms and color clouds. In most instances, the no-reference quality metrics of the generated images were shown to be superior to those of the two original images. Select ISED images yielded previously unknown galactic structures, reduced glare, and enhanced contrast, with good overall performance.
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Osadebey, Michael, Marius Pedersen, Douglas Arnold et Katrina Wendel-Mitoraj. « Local Indicators of Spatial Autocorrelation (LISA) : Application to Blind Noise-Based Perceptual Quality Metric Index for Magnetic Resonance Images ». Journal of Imaging 5, no 1 (15 janvier 2019) : 20. http://dx.doi.org/10.3390/jimaging5010020.
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Noise-based quality evaluation of MRI images is highly desired in noise-dominant environments. Current noise-based MRI quality evaluation methods have drawbacks which limit their effective performance. Traditional full-reference methods such as SNR and most of the model-based techniques cannot provide perceptual quality metrics required for accurate diagnosis, treatment and monitoring of diseases. Although techniques based on the Moran coefficients are perceptual quality metrics, they are full-reference methods and will be ineffective in applications where the reference image is not available. Furthermore, the predicted quality scores are difficult to interpret because their quality indices are not standardized. In this paper, we propose a new no-reference perceptual quality evaluation method for grayscale images such as MRI images. Our approach is formulated to mimic how humans perceive an image. It transforms noise level into a standardized perceptual quality score. Global Moran statistics is combined with local indicators of spatial autocorrelation in the form of local Moran statistics. Quality score is predicted from perceptually weighted combination of clustered and random pixels. Performance evaluation, comparative performance evaluation and validation by human observers, shows that the proposed method will be a useful tool in the evaluation of retrospectively acquired MRI images and the evaluation of noise reduction algorithms.
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Davidson, Patricia M., Phillip J. Newton, Caleb Ferguson, John Daly, Doug Elliott, Caroline Homer, Christine Duffield et Debra Jackson. « Rating and Ranking the Role of Bibliometrics and Webometrics in Nursing and Midwifery ». Scientific World Journal 2014 (2014) : 1–6. http://dx.doi.org/10.1155/2014/135812.
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Background. Bibliometrics are an essential aspect of measuring academic and organizational performance.Aim. This review seeks to describe methods for measuring bibliometrics, identify the strengths and limitations of methodologies, outline strategies for interpretation, summarise evaluation of nursing and midwifery performance, identify implications for metric of evaluation, and specify the implications for nursing and midwifery and implications of social networking for bibliometrics and measures of individual performance.Method. A review of electronic databases CINAHL, Medline, and Scopus was undertaken using search terms such as bibliometrics, nursing, and midwifery. The reference lists of retrieved articles and Internet sources and social media platforms were also examined.Results. A number of well-established, formal ways of assessment have been identified, includingh- andc-indices. Changes in publication practices and the use of the Internet have challenged traditional metrics of influence. Moreover, measuring impact beyond citation metrics is an increasing focus, with social media representing newer ways of establishing performance and impact.Conclusions. Even though a number of measures exist, no single bibliometric measure is perfect. Therefore, multiple approaches to evaluation are recommended. However, bibliometric approaches should not be the only measures upon which academic and scholarly performance are evaluated.
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Mangkuto, Rizki A., Atthaillah, Mochamad Donny Koerniawan et Brian Yuliarto. « Theoretical Impact of Building Façade Thickness on Daylight Metrics and Lighting Energy Demand in Buildings : A Case Study of the Tropics ». Buildings 11, no 12 (17 décembre 2021) : 656. http://dx.doi.org/10.3390/buildings11120656.
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In daylighting design, variation of building façade thickness (f) will result in variation of the daylight opening areas, which in turn will modify the values of daylight metrics within the space. However, studies dedicated to investigating the impact of varying f on indoor daylight metrics are relatively scarce. This study, therefore, aims to assess the theoretical impact of various façade thicknesses on various daylight metrics and lighting energy demands in a reference office space. Analytical calculations are performed using an outdoor diffuse illuminance profile of a tropical city. The building façade thickness values are varied within 0–0.50 m, at window-to-wall ratios (WWR) of 25%, 50%, and 75%. Based on sensitivity analysis, it is found that variation of f yields different impacts on the observed metrics, with sDA300/50% being the least influenced. Among all metrics in the central calculation point, DA300, UDI-a, and UDI-a′ yield relatively small coefficients of variation, and thus, have the lowest uncertainty with respect to f. Among all metrics for the entire room, sDA300/50% and sUDI-a50% have the lowest uncertainty, with interquartile ranges of no more than 0.4%. Overall, the contribution of this study is providing insight into the impact of façade thickness on various daylight metrics in indoor spaces, particularly in the worst-case scenario under the standard CIE overcast sky.
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Borgogno-Mondino, Enrico, et Vanina Fissore. « Reading Greenness in Urban Areas : Possible Roles of Phenological Metrics from the Copernicus HR-VPP Dataset ». Remote Sensing 14, no 18 (9 septembre 2022) : 4517. http://dx.doi.org/10.3390/rs14184517.
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Vegetation phenology is that branch of science that describes periodic plant life cycle events across the growing seasons. Remote sensing typically monitors these significant events by means of time series of vegetation indices, permitting to characterize vegetation dynamics. It is well known that vegetation in urban areas, i.e., green spaces in general, may benefit human health mainly by mitigating noise and air pollution, promoting physical or social activities, and improving mental health. Based on the influence that green space exposure seems to exert on Public Health and using a multidisciplinary approach, we mapped phenological behavior of urban green areas to explore yearly persistence of their potential favorable effect, such as heat reduction, air purification, noise mitigation, and promotion of physical/social activities and improvement of mental health. The study area corresponds to the municipality of Torino (about 800,000 inhabitants, NW, Italy). Renouncing to a rigorous at-species level phenological description, this work investigated macro-phenology of vegetated areas for the 2018, 2019 and 2020 years with reference to the new free and open Copernicus HR-VPP dataset. Vegetation type, deduced with reference to the 2019 BDTRE official technical map of the Piemonte Region, was considered and related to the correspondent macro-phenology using a limited number of metrics from the HR-VPP dataset. Investigation was aimed at exploring their capability of providing synthetic and easy-to-use information for urban planners. No validation was achieved about phenological metrics values (assuming their accuracy correspondent to the nominal one reported in the associated manuals). Nevertheless, a spatial validation was operated to investigate the capability of the dataset to properly recognize vegetated areas, thus providing correspondent metrics. Preliminary results showed a spatial inconsistency related to the HR-VPP dataset, that greatly overestimates (about 50%) vegetated areas in the city, assigning metric values to pixels that, if compared with technical maps, do not fall within vegetated areas. The work found out that, among HR-VPP metrics, LOS (Length Of Season) and SPROD (Seasonal Productivity) well characterized vegetation patches, making it possible to clearly read vegetation behavior, which can be effectively exploited to zone the city and make management of green areas and real estate considerations more effective.
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Idígoras Chaumel, Almudena L., David G. Armanini, John A. Schwindt et Adam G. Yates. « Interannual Variation of Benthic Macroinvertebrate Communities at Long-Term Monitoring Sites Impacted by Human Activities : Implications for Bioassessment ». Diversity 11, no 9 (16 septembre 2019) : 167. http://dx.doi.org/10.3390/d11090167.
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Bioassessment assumes that ecological conditions remain stable in the absence of environmental changes. Evidence suggests this assumption may hold for reference streams, but knowledge gaps remain for impacted streams. Our study quantified interannual variation of benthic macroinvertebrate communities, monitored for at least 14 years in eight impacted streams in the Upper Thames River watershed in Ontario, Canada. Benthic communities exhibited moderate interannual variation in relative abundance of EPT (Ephemeroptera, Plecoptera and Trichoptera) and Chironomidae taxa. Year-to-year changes were reflected in lower community persistence than that observed in studies of reference streams. In contrast, tolerance-based metrics showed minimal interannual variation, suggesting compositional changes were because of taxonomic substitutions, in which one tolerant taxon replaced another. Analyses indicated limited directionality in temporal variation for most bioassessment metrics. An exception was taxa richness, which increased at most sites, possibly because of changes in subsampling. However, no associations between calculated bioassessment metrics and measured environmental factors (stream flow and water chemistry) or sampling procedures were observed. We conclude interannual variation in ecological conditions can be substantial and may not be associated with deterministic factors routinely measured in stream assessments. We recommend increased sampling frequency and traits-based assessment as options for limiting effects of interannual variation on assessment results.
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Shoshin, A. V., et E. A. Shvets. « Veiling glare removal : synthetic dataset generation, metrics and neural network architecture ». Computer Optics 45, no 4 (juillet 2021) : 615–26. http://dx.doi.org/10.18287/2412-6179-co-883.
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In photography, the presence of a bright light source often reduces the quality and readability of the resulting image. Light rays reflect and bounce off camera elements, sensor or diaphragm causing unwanted artifacts. These artifacts are generally known as "lens flare" and may have different influences on the photo: reduce contrast of the image (veiling glare), add circular or circular-like effects (ghosting flare), appear as bright rays spreading from light source (starburst pattern), or cause aberrations. All these effects are generally undesirable, as they reduce legibility and aesthetics of the image. In this paper we address the problem of removing or reducing the effect of veiling glare on the image. There are no available large-scale datasets for this problem and no established metrics, so we start by (i) proposing a simple and fast algorithm of generating synthetic veiling glare images necessary for training and (ii) studying metrics used in related image enhancement tasks (dehazing and underwater image enhancement). We select three such no-reference metrics (UCIQE, UIQM and CCF) and show that their improvement indicates better veil removal. Finally, we experiment on neural network architectures and propose a two-branched architecture and a training procedure utilizing structural similarity measure.
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van Borsel, John, et Lien D’haeseleer. « The Process Density Index as a Measure of Phonological Development : Data From Dutch ». Communication Disorders Quarterly 40, no 4 (17 août 2018) : 220–27. http://dx.doi.org/10.1177/1525740118790532.
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The Process Density Index (PDI), originally developed by Edwards, is a potentially useful metric for assessing phonological development that is based on the average number of phonological process applications per word in a speech sample. The purpose of the present study was to gather PDI reference data for Dutch-speaking children. Speech samples were collected and the PDI values were determined in 120 Dutch-speaking children aged between 2;6 and 5;6 years of both genders. Boys showed a higher PDI than girls, and there was a strong negative relationship between age and PDI. The presence of a history of otitis media, socioeconomic status, and sibling status, however, were of no influence. The results confirm trends seen in previous studies on phonological development of typically developing children using other metrics. This suggests that the PDI is a valid measure to assess phonological acquisition.
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Ozcinar, Cagri, et Aakanksha Rana. « Quality Assessment of Super-Resolved Omnidirectional Image Quality Using Tangential Views ». Electronic Imaging 2021, no 9 (18 janvier 2021) : 295–1. http://dx.doi.org/10.2352/issn.2470-1173.2021.9.iqsp-295.
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Omnidirectional images (ODIs), also known as 360-degree images, enable viewers to explore all directions of a given 360-degree scene from a fixed point. Designing an immersive imaging system with ODI is challenging as such systems require very large resolution coverage of the entire 360 viewing space to provide an enhanced quality of experience (QoE). Despite remarkable progress on single image super-resolution (SISR) methods with deep-learning techniques, no study for quality assessments of super-resolved ODIs exists to analyze the quality of such SISR techniques. This paper proposes an objective, full-reference quality assessment framework which studies quality measurement for ODIs generated by GAN-based and CNN-based SISR methods. The quality assessment framework offers to utilize tangential views to cope with the spherical nature of a given ODIs. The generated tangential views are distortion-free and can be efficiently scaled to high-resolution spherical data for SISR quality measurement. We extensively evaluate two state-of-the-art SISR methods using widely used full-reference SISR quality metrics adapted to our designed framework. In addition, our study reveals that most objective metric show high performance over CNN based SISR, while subjective tests favors GAN-based architectures.
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Kanani, Fatima Zehra, Adnan Haider Kazmi et Bushra Kaleem. « Sigma metrics of Alinity ci system – a study on thirty-nine clinical chemistry and immunoassay parameters ». Advances in Laboratory Medicine / Avances en Medicina de Laboratorio 2, no 2 (1 avril 2021) : 267–75. http://dx.doi.org/10.1515/almed-2021-0001.
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Abstract Objectives Sigma metrics in an invaluable and inexpensive tool used in laboratories to monitor analytical quality of the assays. Alinity ci platform is a relatively recent analytical system launched by Abbott Diagnostics, and as such performance studies on it are few. We have calculated sigma metrics of 39 clinical chemistry and immunoassay analytes on two Alinity ci systems. Methods Sigma metrics were calculated using results of method validation studies. Coefficient of variation (CV) was calculated according to CLSI EP 15 guidelines. Bias was calculated using three different methods i.e., proficiency testing material, alternate method comparison with existent analyzers and linearity experiment. Total allowable error limits were kept similar to or less than the ones used in reference studies. Results All analytes except blood urea nitrogen (BUN) demonstrated greater than six sigma value across one or more levels and methods. No analyte amongst clinical chemistry and immunoassays was at below three sigma class. Amongst electrolytes, sodium was below three sigma class at two levels by proficiency testing method, although it was above four sigma class by other two methods. Sigma levels obtained were comparable to those reported in previously published studies. Conclusions Acceptable sigma metrics were achieved for all clinical chemistry, immunoassays and electrolytes on Alinity ci. Sigma metrics is an objective and well established cost effective tool to tailor internal quality control practices. This study determines sigma metrics for a wide range of high throughput assays. Long term assay performance needs to be monitored.
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Furlan, Raffaello, Mauro Gatti, Roberto Mene, Dana Shiffer, Chiara Marchiori, Alessandro Giaj Levra, Vincenzo Saturnino, Enrico Brunetta et Franca Dipaola. « Learning Analytics Applied to Clinical Diagnostic Reasoning Using a Natural Language Processing–Based Virtual Patient Simulator : Case Study ». JMIR Medical Education 8, no 1 (3 mars 2022) : e24372. http://dx.doi.org/10.2196/24372.
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Background Virtual patient simulators (VPSs) log all users’ actions, thereby enabling the creation of a multidimensional representation of students’ medical knowledge. This representation can be used to create metrics providing teachers with valuable learning information. Objective The aim of this study is to describe the metrics we developed to analyze the clinical diagnostic reasoning of medical students, provide examples of their application, and preliminarily validate these metrics on a class of undergraduate medical students. The metrics are computed from the data obtained through a novel VPS embedding natural language processing techniques. Methods A total of 2 clinical case simulations (tests) were created to test our metrics. During each simulation, the students’ step-by-step actions were logged into the program database for offline analysis. The students’ performance was divided into seven dimensions: the identification of relevant information in the given clinical scenario, history taking, physical examination, medical test ordering, diagnostic hypothesis setting, binary analysis fulfillment, and final diagnosis setting. Sensitivity (percentage of relevant information found) and precision (percentage of correct actions performed) metrics were computed for each issue and combined into a harmonic mean (F1), thereby obtaining a single score evaluating the students’ performance. The 7 metrics were further grouped to reflect the students’ capability to collect and to analyze information to obtain an overall performance score. A methodological score was computed based on the discordance between the diagnostic pathway followed by students and the reference one previously defined by the teacher. In total, 25 students attending the fifth year of the School of Medicine at Humanitas University underwent test 1, which simulated a patient with dyspnea. Test 2 dealt with abdominal pain and was attended by 36 students on a different day. For validation, we assessed the Spearman rank correlation between the performance on these scores and the score obtained by each student in the hematology curricular examination. Results The mean overall scores were consistent between test 1 (mean 0.59, SD 0.05) and test 2 (mean 0.54, SD 0.12). For each student, the overall performance was achieved through a different contribution in collecting and analyzing information. Methodological scores highlighted discordances between the reference diagnostic pattern previously set by the teacher and the one pursued by the student. No significant correlation was found between the VPS scores and hematology examination scores. Conclusions Different components of the students’ diagnostic process may be disentangled and quantified by appropriate metrics applied to students’ actions recorded while addressing a virtual case. Such an approach may help teachers provide students with individualized feedback aimed at filling competence drawbacks and methodological inconsistencies. There was no correlation between the hematology curricular examination score and any of the proposed scores as these scores address different aspects of students’ medical knowledge.
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Rotaru, Kristian, Carla Wilkin et Andrzej Ceglowski. « Analysis of SCOR’s approach to supply chain risk management ». International Journal of Operations & ; Production Management 34, no 10 (30 septembre 2014) : 1246–68. http://dx.doi.org/10.1108/ijopm-09-2012-0385.
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Purpose – SCOR 10.0, released in late 2010, is the second version of the supply chain operations reference model (SCOR) to incorporate risk management processes, metrics and best practices. Given the paucity of studies that have explored the coverage and integration of supply chain risk management (SCRM) within SCOR, the analysis and suggested improvements for SCRM are designed to enhance SCOR’s collaborative and coordinated management of supply chain (SC) risks. The paper aims to dicsuss these issues. Design/methodology/approach – Critical analysis was used to analyse the coverage and integration of SCRM within SCOR 10.0. Findings – Discrepancies were identified in how SCRM has been incorporated into SCOR, including issues with the hierarchical representation of SCRM processes, metrics, best practices and skills. These may potentially propagate into difficulties in embedding risk management processes within other SC processes, visualizing risk metrics in a SC’s value hierarchy and reconciling SCOR’s SCRM with organizational enterprise risk management. Research limitations/implications – This paper is limited to theoretical analysis of the coverage and integration of risk in SCOR 10.0. Once the issues identified are remedied, the subsequent suggested improvements require validation through empirical testing. Originality/value – Despite SCOR’s wide acceptance as a reference model in managing SC operations, there has been no investigation of its approach to SCRM. The analysis addresses this lack of prior investigation by analysing SCRM in the latest version, SCOR 10.0. The paper identifies deficiencies and suggests amendments regarding SCRM’s coverage and integration of SCRM.
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Boyce, PR, et JR Stampfli. « LRT Digest 3 : New colour metrics and their use ». Lighting Research & ; Technology 51, no 5 (27 mai 2019) : 657–81. http://dx.doi.org/10.1177/1477153519850006.
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Executive summary The two metrics traditionally used to quantify the colour properties of light sources are the correlated colour temperature and the CIE General Colour Rendering Index. With the arrival of LEDs as a major light source questions began to be asked about the merits of both of these metrics. The question asked about correlated colour temperature was how far should the chromaticity of a light source be allowed to depart from the Planckian locus before the light emitted could no longer be said to be white? A tolerance to such a departure ( Duv) already existed but now gathered much more attention. The questions asked about the CIE General Colour Rendering Index were more searching. The limitations of the CIE General Colour Rendering Index were explored and, as a result, several alternative approaches to quantifying the colour rendition properties of light sources were proposed. The most comprehensive approach was produced by the Illuminating Engineering Society of North America, first in its Technical Memorandum IES TM-30-15 and more recently in its revision, Technical Memorandum ANSI/IES TM-30-18, which has been accepted as an American Standard. Both these documents describe a system that contains two high-level summary metrics: One for the average fidelity, i.e. how accurately a test light source renders 99 colour samples relative to how they are rendered under a reference illuminant, and the other for the average colourfulness, i.e. the overall increase or decrease in colourfulness of the same colour samples under the same test light source compared to the same reference illuminant. Associated with these overall average metrics are a number of more detailed metrics and graphical presentations. These aim to quantify and illustrate the variations in fidelity and the direction and magnitude of the shifts in chroma and hue around the hue circle. Compared to the CIE General Colour Rendering Index or the CIE Fidelity Index, a metric published by the CIE in 2017, ANSI/IES TM-30-18 provides a more comprehensive approach to quantifying and understanding the effects of light source spectrum on the perception of colour. Unfortunately, the new colour metrics described in IES TM-30-15 and ANSI/IES TM-30-18 have not yet been accepted by the CIE. Despite this, some light source manufacturers have started to provide information on their products expressed in terms of the ANSI/IES TM-30-18 colour metrics and designers are beginning to request them. The expectation is that, eventually, the ANSI/IES TM-30-18 metrics will be adopted by many countries and authorities, because they provide a much more comprehensive description of the colour properties of a light source than the CIE General Colour Rendering Index. This will be of value to light source manufacturers and lighting designers as well as those who prepare lighting codes and guides. It is expected that in the future the minimum set of data considered acceptable for describing the colour properties of a light source are likely to be the correlated colour temperature and the associated Duv value, the CIE Fidelity Index or the matching ANSI/IES TM-30-18 Fidelity Index, together with the ANSI/IES TM-30-18 Gamut Index and the ANSI/IES TM-30-18 Colour Vector Graphic.
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Uziębło, Aldona. « Kryzys wartości czy wartość kryzysu ? Implikacje pandemii COVID-19 w jednostce non profit ». Optimum Economic Studies, no 1(107) (2022) : 84–96. http://dx.doi.org/10.15290/oes.2022.01.107.06.
Texte intégralRésumé :
Purpose – A presentation of the pandemic implications in a non-profit organisation on the example of the Hospice Foundation in Gdańsk. Research method – An individual in-depth interview, the analysis of financial statements, financial metrics, a description. Results – The Hospice Foundation survived the crisis by strengthening and developing social relations and communication with the environment, and despite the deterioration of revenues, it retained correct business metrics and is able to continue its activity. Originality / value / implications / recommendations – So far in Poland, there have been no studies on the effects of the pandemic on non-profit organisations. Proprietary measures of effectiveness in achieving the Foundation’s goals in 2019–2020 were proposed. The results of the author’s own research for the period of 2009–2010 were used as a reference.
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Karim, Sajida, Hui He, A. R. Junejo et Mariyam Sattar. « Measurement of Objective Video Quality in Social Cloud Based on Reference Metric ». Wireless Communications and Mobile Computing 2020 (13 janvier 2020) : 1–13. http://dx.doi.org/10.1155/2020/5028132.
Texte intégralRésumé :
This paper explores the objective of the present video quality analysis (VQA) and measures the full reference metrics keeping in view the quality degradation. During the research work, we conduct experiments on different social clouds (SCs) and low-quality videos. Selected videos are uploaded to SC to assess differences in video service and quality. WeChat shows that the average of all videos (Avg = 100), peak signal-to-noise ratio (PSNR), has no impact on other indicators. Therefore, we believe that WeChat provides the best video quality and multimedia services to their users to meet Quality of Service (QoS)/Quality of Experience (QoE).
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Specziár, András, et Tibor Erős. « Development of a fish-based index for the assessment of the ecological status of Lake Balaton in the absence of present day reference condition ». Knowledge & ; Management of Aquatic Ecosystems, no 421 (2020) : 11. http://dx.doi.org/10.1051/kmae/2020002.
Texte intégralRésumé :
A fish-based index is proposed to indicate the ecological status of Lake Balaton, Hungary in accordance with the standard of the European Water Framework Directive (WFD). The Balaton fish index (BFI) synthetises information of 13 lake-specific fish metrics including gillnetting and electric fishing data of species richness of native assemblages, relative abundance, biomass and age structure of native key species, representation of non-native species and general health status. The main anthropogenic pressures considered were the degradation of littoral habitats, invasion of non-native fish species, eutrophication and fishing/angling including stocking. Ecological quality ratio (EQR) is assessed by relating actual fish assemblage metrics to the supposed undisturbed reference status of Lake Balaton reconstructed by expert judgement based on recent and historic information on the fish fauna and its changes. Values of BFI were consistent and indicated good ecological status of Lake Balaton in the period of 2005–2018. This study provides an example on how an EQR assessment methodology might be established in unique habitats with no possibilities for statistical evaluation of pressure-respond relationships and exact determination of the reference status.