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Wyszukujesz frazę "Image quality" wg kryterium: Temat


Tytuł:
Image Quality Assessment Using Edge Correlation
Autorzy:
Ruikar, J.
Sinha, A.
Chaudhury, S.
Powiązania:
https://bibliotekanauki.pl/articles/226152.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
image quality assessment
image quality metrics
steerable Gaussian filter
subjective assessment
Opis:
In literature, oriented filters are used for low-level vision tasks. In this paper, we propose use of steerable Gaussian filter in image quality assessment. Human visual system is more sensitive to multidirectional edges present in natural images. The most degradation in image quality is caused due to its edges. In this work, an edge based metric termed as steerable Gaussian filtering (SGF) quality index is proposed as objective measure for image quality assessment. The performance of the proposed technique is evaluated over multiple databases. The experimental result shows that proposed method is more reliable and outperform the conventional image quality assessment method.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 1; 99-107
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quality Assessment of Resampled Digital Images by Statistical Metrics
Autorzy:
KORNETA, WOJCIECH
Powiązania:
https://bibliotekanauki.pl/articles/457632.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Rzeszowski
Tematy:
image quality
image resampling
similarity index
Opis:
The visual degradation of resampled (downsampled and then upsampled to the original size) greyscale digital images is quantified by local luminance, contrast and structure statistical comparison indexes. Spatial distributions of these indexes are shown. The global quality of resampled image is quantifiedby the similarity index defined by median values of local indexes. Parameters of this index consistent with the median opinion score are determined. The dependence of global indexes on the size of downsampled image is presented.
Źródło:
Edukacja-Technika-Informatyka; 2017, 8, 3; 282-287
2080-9069
Pojawia się w:
Edukacja-Technika-Informatyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prior Image Jpeg-Compression Detection
Autorzy:
Koziel, G.
Powiązania:
https://bibliotekanauki.pl/articles/117800.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
compression detection
image quality
JPEG
Opis:
The paper presents two methods of prior JPEG-compression detection. In the first method the histogram of chrominance is analysed. In JPEG-compressed images the histogram contains significantly more local maxima than in uncompressed files. The second method is based on neighbouring pixel Ø value difference. In JPEG-compressed image the distribution of these values is different than the distribution counted on the edges of compression 8x8 blocks. These differences are summed up to create a classifier that allows to assess if the image was compressed.
Źródło:
Applied Computer Science; 2016, 12, 3; 17-28
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Xception-based Architecture with Cross-sampled Training for Image Quality Assessment on KonIQ-10ĸ
Autorzy:
Tomasz, M. Lehmann
Przemyslaw, Rokita
Powiązania:
https://bibliotekanauki.pl/articles/31339412.pdf
Data publikacji:
2023
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Instytut Informatyki Technicznej
Tematy:
image quality assessment
computer vision
Xception
Opis:
Image quality assessment is a crucial task in various fields such as digital photography, online content creation, and automated quality control, as it ensures an optimal visual experience and aids in maintaining consistent standards. In this paper, we propose an efficient method for training image quality assessment models on the KonIQ-10ĸ dataset. Our novel approach utilizes a dual-Xception architecture that analyzes both the image content and additional image parameters, outperforming traditional single convolutional models. We introduce cross-sampling methods with random draw sampling of instances from majority classes, effectively enhancing prediction quality in the Mean Opinion Score(MOS) ranges that are underrepresented in the database. This methodology allows us to achieve near state-of-the-art results with limited computing costs and resources. Most importantly, our predictions across the entire spectrum of MOS values maintain consistent quality. Because of using a novel and highly effective method for image sampling, we achieved these results with much lower computational cost, making our approach the most effective way of MOS estimation on the KonIQ-10ĸ database.
Źródło:
Machine Graphics & Vision; 2023, 32, 2; 109-127
1230-0535
2720-250X
Pojawia się w:
Machine Graphics & Vision
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measuring the effective coverage of the image databases
Autorzy:
Buczkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/114262.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
image quality assessment
coverage analysis
image characteristic analysis
Opis:
The paper presents new methods for estimating effective coverage of the image databases in spatial information (SI) vs. colorfulness (CF) space. Existing and commonly used metrics are vulnerable to databases containing very different images in terms of SI and CF, which can maximize the relative ranges, while preserving, in specific cases, high uniformity. The area covered by convex hull created on SI × CF space can be large, but the interior of the convex envelope might be poorly filled. To overcome this flaw, a fill factor is proposed, which determines how well the convex hull area is utilized. In the paper the method is described in details and presented on a few existing databases, as well as on artificial, non-existing databases to prove its robustness in different scenarios. Provided results show that new metric is closer to the actual coverage than existing methods.
Źródło:
Measurement Automation Monitoring; 2017, 63, 5; 183-185
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of the spatio-temporal vector median filtering algorithms using colour video quality metrics
Autorzy:
Okarma, K.
Powiązania:
https://bibliotekanauki.pl/articles/97449.pdf
Data publikacji:
2011
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
Vector Median Filter
VMF
video quality
image quality
Opis:
In this paper the application of the combined video quality assessment method as well as some other recently developed objective metrics for the analysis of the results of the nonlinear colour video filtering is discussed. The spatio-temporal versions of colour image filtering methods, including the Vector Median Filter, can be obtained using frame-by-frame approach but the proper choice of the spatio-temporal kernel weights and the colour space used during filtration should be based on a reliable video quality assessment. In some earlier papers the combined video quality assessment method has been proposed, which has a highly linear correlation with subjective quality scores and can be extended into the colour version. As the illustration of the problem, some results of the colour video denoising using the spatio-temporal VMF, also in a weighted version, together with the quality assessment results have been presented in the paper.
Źródło:
Computer Applications in Electrical Engineering; 2011, 9; 200-212
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the optimisation of nonlinear mapping functions towards high correlation of full-reference image quality metrics and their combinations with subjective evaluations
Autorzy:
Okarma, K.
Powiązania:
https://bibliotekanauki.pl/articles/97539.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
image quality
VQEG
state of the art
Opis:
One of the most relevant problems related to most of the objective full-reference image and video quality assessment methods is their correlation with subjective perception of various types of distortions. Since the relation between the subjective scores, typically expressed as Mean Opinion Scores (MOS) or Differential MOS, and most of the metrics is nonlinear, various mapping functions are used in order to linearize this relation e.g. logistic function recommended by the Video Quality Experts Group (VQEG). Such compensation can also be conducted using some other function e.g. polynomial or exponential ones. Nevertheless, the results obtained for each of available datasets differ and such approach cannot be considered as universal. One of possible solutions, proposed in some earlier papers, is the use of combined metrics, which have significantly higher linear correlation with MOS or DMOS values without the necessity of nonlinear mapping. The comparative analysis of the optimisation results for some “state-of-the-art” metrics and proposed combined ones is also provided in the paper.
Źródło:
Computer Applications in Electrical Engineering; 2012, 10; 416-430
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Irreversible medical image compression: conditions of acceptability
Autorzy:
Przelaskowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1965779.pdf
Data publikacji:
2004
Wydawca:
Politechnika Gdańska
Tematy:
irreversible compression
medical image compression
diagnostic accuracy
diagnostic image quality
Opis:
Acceptance of irreversible image compression applicable to medical imagery is controversial in the medical community. The influence of this irreversible process on degradation of diagnostic image features is considered and how to preserve diagnostic accuracy. Fears, doubts, the disadvantages of the data distortion process and the advantages of safe and efficient irreversible compression for image information storage and interchange are discussed. The effects of compression on various image exams are analysed. The conclusion is that irreversible compression is not to be afraid of, but its characteristics should be well understood before implementing it in current practice.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2004, 8, 2; 303-316
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Filters’ Influence on Digital Image Quality in High Temperature Measurements of Surface Properties
Autorzy:
Fabijanska, A
Sankowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/108736.pdf
Data publikacji:
2009
Wydawca:
Społeczna Akademia Nauk w Łodzi
Tematy:
digital image processing
image quality
optical filters
image quantitative analysis
image noise
Opis:
This paper is concerned with high temperature image quantitative analysis systems. Particular attention is paid to computerised system for surface properties (wetting angle and surface tension) determination. A brief description of the system is given. The specificity of the performed measurements based on images presenting heat-emitting objects is considered. Moreover, the significance of optical filters’ usage is explained. Infrared and neutral density filters are regarded. Influence of these filters on digital image quality is deliberated. Especially image noise presence is considered. The detailed analysis of noise properties change due filters usage is carried out. Finally, results of the analysis are presented and discussed.
Źródło:
Journal of Applied Computer Science Methods; 2009, 1 No. 2; 53-63
1689-9636
Pojawia się w:
Journal of Applied Computer Science Methods
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Ingenious Application-Specific Quality Assessment Methods for Compressed Wireless Capsule Endoscopy Images
Autorzy:
Fante, Kinde Anlay
Abdurahman, Fetulhak
Gemeda, Mulugeta Tegegn
Powiązania:
https://bibliotekanauki.pl/articles/136180.pdf
Data publikacji:
2020
Wydawca:
EEEIC International Barbara Leonowicz Szabłowska
Tematy:
image quality assessment
wireless capsule endoscopy
compressed images
image compression
Opis:
Image quality assessment methods are used in different image processing applications. Among them, image compression and image super-resolution can be mentioned in wireless capsule endoscopy (WCE) applications. The existing image compression algorithms for WCE employ the generalpurpose image quality assessment (IQA) methods to evaluate the quality of the compressed image. Due to the specific nature of the images captured by WCE, the general-purpose IQA methods are not optimal and give less correlated results to that of subjective IQA (visual perception). This paper presents improved image quality assessment techniques for wireless capsule endoscopy applications. The proposed objective IQA methods are obtained by modifying the existing full-reference image quality assessment techniques. The modification is done by excluding the noninformative regions, in endoscopic images, in the computation of IQA metrics. The experimental results demonstrate that the proposed IQA method gives an improved peak signal-tonoise ratio (PSNR) and structural similarity index (SSIM). The proposed image quality assessment methods are more reliable for compressed endoscopic capsule images.
Źródło:
Transactions on Environment and Electrical Engineering; 2020, 4, 1; 18-24
2450-5730
Pojawia się w:
Transactions on Environment and Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Effective Coverage Calculation Methods for Image Quality Assessment Databases
Autorzy:
Buczkowski, M.
Stasiński, R.
Powiązania:
https://bibliotekanauki.pl/articles/225967.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Image Quality Assessment
IQA database analysis
effective coverage
Opis:
This article provides a comparison of a three methods that can be used for calculating effective coverage of image quality assessment database. The aim of this metric is to show how well the database is filled with variety of images. For each image in the database the Spatial Information (SI) and Colorfulness (CF) metric is calculated. The area of convex hull containing all the points on SI x CF plane is indication of total coverage of the database, but it does not show how efficiently this area is utilized. For this purpose an effective coverage was introduced. An analysis is performed for 16 databases - 13 publicaly available and 3 artificial created for the purpose of showing advantages of the effective coverage.
Źródło:
International Journal of Electronics and Telecommunications; 2018, 64, 3; 307-313
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of noise in the Monte Carlo point sampling method
Autorzy:
Guzek, K.
Napieralski, P.
Powiązania:
https://bibliotekanauki.pl/articles/202392.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photorealism
image evaluation methods
image quality metrics
visual perception
global illumination
Opis:
This paper gives a concise overview of the techniques we have used to find out the degree of measuring the quality of rendered images and a level of noise in particular. First part of the paper presents designed and conducted psychophysical experiment involving human subjective judgment. Then, two of the existing numerical image comparison methods are considered in the context of assessing the level of noise produced by global illuminations algorithms. The results of the participants’ subjective responses are correlated with the data obtained from objective mathematical metrics. The main goal of research was to determine the objective and perceptual measure of quality for images with fixed sampling strategy. The results will help to establish the measures of identifying the human perception in the assessment of images generated with global illumination algorithms.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 1; 15-19
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Poszukiwanie miar oceny straty jakości obrazów po kompresji JPEG
An automatic identification of linear objects on digital images
Autorzy:
Mikrut, S.
Pyka, K.
Powiązania:
https://bibliotekanauki.pl/articles/129819.pdf
Data publikacji:
2000
Wydawca:
Stowarzyszenie Geodetów Polskich
Tematy:
JPEG
jakość obrazu
kompresja
obraz cyfrowy
image quality
compression
digital image
Źródło:
Archiwum Fotogrametrii, Kartografii i Teledetekcji; 2000, 10; 53-1-53-9
2083-2214
2391-9477
Pojawia się w:
Archiwum Fotogrametrii, Kartografii i Teledetekcji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Visual attention pooling and understanding the structural similarity index in multi-scale analysis
Autorzy:
Bondzulic, B. P.
Petrovic, V. S.
Mitrovic, S. T.
Pavlovic, B. Z.
Andric, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/173580.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image quality assessment
structural similarity index
visual attention pooling
Opis:
We present a novel spatial pooling strategy and the results of an extensive multi-scale analysis of the well-known structural similarity index metric (SSIM) for objective image quality evaluation. We show, in contrast with some previous studies, that even relatively simple perceptual importance pooling strategies can significantly improve objective metric performance evaluated as the correlation with subjective quality assessment. In particular, we define an attention and quality driven pooling mechanism that focuses structural comparisons within the SSIM model to only those pixels exhibiting significant structural degradations. We show that optimal objective metric performance is achieved over very sparse spatial domains indeed that ignore most of the signal data. We also investigate an explicit breakdown of the structural models within SSIM and show that in combination with the proposed attention and quality driven pooling some of these models represent well performing metrics in their own right, when applied at appropriate scale for which there may not be a single optimal value. Our experiments demonstrate that the augmented SSIM metric using the proposed pooling model provides performance advantage on an extensive LIVE dataset covering hundreds of degraded images and 5 different distortion types compared to both conventional SSIM and state-of-the-art objective quality metrics.
Źródło:
Optica Applicata; 2014, 44, 2; 267-283
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Benchmarking image codecs by assessment of coded test images: the development of test images and new objective quality metrics
Autorzy:
Punchihewa, A.
Bailey, D. G.
Hodgson, R. M.
Powiązania:
https://bibliotekanauki.pl/articles/309074.pdf
Data publikacji:
2006
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
image quality
artefacts
subjective
objective
coding
metric
blockiness
blur
ringing
Opis:
Objective quality measures are required for benchmarking codec performance. Our aim was to develop a simple, accurate method capable of rapidly measuring the degree of blockiness, edge-blur and ringing due to image compression. Two test images were designed to emphasise these artefacts. The efficacy of the new metrics is demonstrated using a JPEG codec at a range of compression levels.
Źródło:
Journal of Telecommunications and Information Technology; 2006, 1; 11-16
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie nowoczesnych metod oceny jakości obrazów do weryfikacji algorytmów splattingu w subpikselowej metodzie Image Based Rendering
Application of modern image quality assessment methods to verification of splatting algorithms in the sub-pixel Image Based Rendering
Autorzy:
Okarma, K.
Tecław, M.
Powiązania:
https://bibliotekanauki.pl/articles/153441.pdf
Data publikacji:
2012
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
metoda IBR
splatting
ocena jakości obrazów
IBR
image quality assessment
Opis:
W artykule przedstawiono możliwości wykorzystania nowoczesnych wskaźników jakości obrazów do wyboru i weryfikacji algorytmu splattingu służącego do wypełniania brakujących pikseli w metodzie IBR, a także do wyboru obrazu wyjściowego dla algorytmu splattingu. Dzięki zastosowaniu metod automatycznej oceny jakości obrazów możliwy jest wybór właściwego algorytmu splattingu wykorzystującego współrzędne uzyskiwanych punktów z dokładnością subpikselową, co zapewnia dużo wyższą jakość obrazu wynikowego.
The paper presents possibilities of using some modern image quality assessment methods for choice and verification of the splatting algorithm used to fill some missing pixels in the IBR method, as well as for selection of the basic output image for the splatting algorithm. By using automatic image quality assessment methods, it is possible to choose the accurate splatting algorithm which utilizes the coordinates of points with sub-pixel accuracy and provides much higher quality of the output image. The first discussed approach is the idea of Vector Median Splatting based on the vector median filters used mainly for multichannel nonlinear filtering purposes. Since the main goal of splatting is filling the missing pixels by the most similar colour to its nearest neighbourhood, preventing the sharpness of the obtained image, such algorithm allows achieving satisfactory results. Nevertheless, even better results can be achieved by some sub-pixel based methods preventing the loss of information caused by the rounding of the pixels coordinates after the warping operation. The results of the application of some modified algorithms have been verified using some modern image quality assessment methods, mainly based on the similarity of images, such as e.g. Structural Similarity or recently proposed Feature Similarity index. The advantages of the sub-pixel splatting algorithms have been confirmed by higher values of all image quality metrics calculated for the achieved destination images.
Źródło:
Pomiary Automatyka Kontrola; 2012, R. 58, nr 6, 6; 493-497
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Open access resources on motion artifact in adult dentomaxillofacial CBCT: illustrated pictorial review of medical literature
Autorzy:
Olszewski, Raphael
Powiązania:
https://bibliotekanauki.pl/articles/2129251.pdf
Data publikacji:
2021-02-05
Wydawca:
Presses Universitaires de Louvain
Tematy:
CBCT
motion artifact
patient movement
image quality
open access medical images
Opis:
Objective: to know how much open access/open knowledge reference figures were available on motion artifacts in CBCT dentomaxillofacial imaging, and to describe and to categorize clinical variation of motion artifacts related to diverse types of head motion retrospectively observed during CBCT scanning time. Material and methods: a search equation was performed on Pubmed database. We found 56 articles. The 45 articles were out of scope, and 7 articles were excluded after applying exclusion and inclusion criteria. Only 4 articles were finally freely accessible and selected for this review. Moreover, we retrospectively used our department CBCT database to search examinations with motion artifacts. We also checked retrospectively for radiological protocols as the type of motion artifact was described when occurred during the CBCT scanning time by the main observer. We had obtained the approval from the Ethical committee for this study. Results: The accessibility of free figures on motion artifact in dentomaxillofacial CBCT is limited to 13 figures not annotated, and to one annotated figure presenting a double contour around cortex of bony orbits. We proposed to categorize the motion artifacts into three levels: low, intermediary, and major. Each level was related to: 1) progressive image quality degradation, 2) distortion of anatomy, and 3) potential possibility of performing clinical diagnosis. All 45 figures were annotated. Conclusions: There exists a scarce open access literature on motion artifacts in CBCT. In our pictorial review we found that low level motion artifacts were more related to head rotation in axial plane (rolling). Rolling and lateral translation were responsible of intermediary level motion artifacts. Major level motion artifacts were created by complex motion with multiple rotation axes, multiple translation directions, and by anteroposterior translation. The main limitation of this study is related to retrospectively report empirical observation of patient motion during CBCT scanning and to compare these observations with motion artifacts found on clinical images. More robust methodology should be further developed using a virtual simulation of various types of head movements and associated parameters to consolidate the open knowledge on motion artifacts in dentomaxillofacial CBCT.  
Źródło:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery; 2021, 15, 1; 1-37
2593-3604
Pojawia się w:
Nemesis. Negative Effects in Medical Sciences Oral and Maxillofacial Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stereoscopic image visual perception
Autorzy:
Fornalczyk, K.
Napieralski, P.
Szajerman, D.
Wojciechowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/397815.pdf
Data publikacji:
2015
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
stereoscopic image
image quality factors
perception convenience
visual fatigue
obrazy stereoskopowe
jakość obrazu
wygoda percepcji
zmęczenie wzroku
Opis:
Stereoscopic films and interactive presentations are extensively popularized whereas their perceived quality still dissatisfies viewers. The reasons are shared between hardware inconsistencies and stereo image producers unawareness concerning factors influencing depth perception quality. This paper reviews aspects influencing 3D image perception visual comfort, presents visual comfort estimation methods and suggests how to measure image perception quality. It also comprises results of researches conducted on dedicated CinemaVision Movie Diagnostics work stand.
Źródło:
International Journal of Microelectronics and Computer Science; 2015, 6, 1; 15-22
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A semi-analytic approach to calculating the Strehl ratio for a circularly symmetric system. Part 1: static wavefront
Autorzy:
Castaño-Fernandez, A. B.
Martínez-Finkelshtein, A.
Iskander, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/174316.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image quality assessment
optical transfer function
mathematical methods in physics
finite analogs of Fourier transforms
Opis:
Close-form expression for the Strehl ratio calculated in the spatial frequency domain of the optical transfer function (SOTF) is considered for the case of an optical system that has circular symmetry. First, it is proved that the SOTF for the aberration-free diffraction limited optical system is equal to one. Further, a semi-analytic solution for the SOTF for a system described by the second (defocus) and the fourth (spherical) order aberrations is provided. It is shown that the proposed semi-analytical solution is of an order of a magnitude computationally more efficient than the commonly used approach based on the discrete Fourier transformation.
Źródło:
Optica Applicata; 2018, 48, 2; 201-210
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image classification for jpeg compression
Autorzy:
Tichonov, Jevgenij
Kurasova, Olga
Filatovas, Ernestas
Powiązania:
https://bibliotekanauki.pl/articles/103336.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
Image quality
image classification
JPEG algorithm
storage of images
quality prediction
SSIM
PSNR
jakość obrazu
klasyfikacja obrazu
algorytm JPEG
przechowywanie obrazów
prognozowanie jakości
Opis:
We analyse storage problems of digital images in accordance with image quality and image compression efficiency. Storage problems are relevant for Cloud storage and file hosting services, online file storage providers, social networks, etc. In this paper, an approach is proposed to process a group of images with a JPEG algorithm that all the processed images satisfy the minimum threshold of quality with the automatic selection of the quality factor (QF). The experimental investigation reveals advantages of the compression efficiency of the proposed approach over the traditional JPEG algorithm. The proposed approach enables saving storage spaces while maintaining the desirable image quality.
Źródło:
Advances in Science and Technology. Research Journal; 2018, 12, 2; 29-34
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An efficient estimation of the Structural Similarity index using the GPGPU programming techniques
Wydajna estymacja wskaźnika podobieństwa strukturalnego z wykorzystaniem technik programowania układów GPGPU
Autorzy:
Mazurek, P.
Okarma, K.
Powiązania:
https://bibliotekanauki.pl/articles/154554.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ocena jakości obrazów cyfrowych
programowanie układów GPGPU
podobieństwo strukturalne
image quality assessment
GPGPU programming
structural similarity
Opis:
In the paper a fast implementation of the SSIM index is presented. Because of specific features of the CUDA architecture, the 8×8 pixel sliding window is used. In order to speed up the computations, the vertical passes are limited to the 32-pixels wide fragments, so four pixels margins should be left for each fragment. The verification of the proposed estimation is performed for the LIVE database with images corrupted by five common types of distortions and their subjective evaluations.
W artykule zaprezentowano wydajną technikę implementacji nowoczesnej metody oceny jakości obrazu znanej jako podobieństwo strukturalne (SSIM). Uwzględniając specyficzne uwarunkowania architektury CUDA, obliczenia wykonano przy użyciu okna przesuwnego o rozmiarze 8×8 pikseli, podobnie jak we wcześniejszym wariancie tego wskaźnika określanym jako uniwersalny wskaźnik jakości obrazu (UIQI). W celu przyspieszenia obliczeń, przebiegi pionowe zostały ograniczone do fragmentów obrazu o szerokości 32 pikseli, co przy tym rozmiarze okna wymaga pozostawienia czteropikselowych marginesów z obu stron. Estymowana wartość globalna wskaźnika SSIM jest obliczana jako średnia z wartości lokalnych obliczanych dla każdego fragmentu obrazu. Praktyczna weryfikacja dokładności proponowanej metody została przeprowadzona z wykorzystaniem obrazów ze znanej bazy LIVE Image Quality Assessment Database Release 2 zawierającej obrazy poddane pięciu typowym rodzajom zniekształceń wraz z ich ocenami subiektywnymi (wartościami DMOS).
Źródło:
Pomiary Automatyka Kontrola; 2010, R. 56, nr 7, 7; 668-670
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie przetwarzania równoległego w procesorach graficznych do szybkiej estymacji wskaźnika wielorozdzielczego podobieństwa strukturalnego dla celów oceny jakości obrazów cyfrowych
Application of parallel processing to GPGPUs for fast estimation of the Multi-Scale Structural Similarity index for digital image quality assessment purposes
Autorzy:
Mazurek, P.
Okarma, K.
Powiązania:
https://bibliotekanauki.pl/articles/155062.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ocena jakości obrazów cyfrowych
programowanie układów GPGPU
podobieństwo strukturalne
image quality assessment
GPGPU programming
structural similarity
Opis:
W artykule zaprezentowano technikę estymacji jakości obrazów opartą na implementacji zmodyfikowanego wskaźnika MS-SSIM z wykorzystaniem technik programowania procesorów graficznych. Ze względu na specyfikę technologii CUDA nie obliczano wszystkich lokalnych wartości wskaźników, jednak te same dane w znacznej części są wykorzystane dla kolejnych poziomów analizy. Weryfikację wyników przeprowadzono dla powszechnie używanej bazy LIVE zawierającej obrazy z pięcioma typowymi rodzajami zniekształceń.
In the paper an efficient method for fast estimation of the image quality is presented. It is based on implementation of the modified Multi-Scale Structural Similarity Index using the CUDA technology and the GPGPU architecture. Considering the architecture specific character, some of the local SSIM index values have not been calculated. Nevertheless, the most part of this information is used at next levels in the multi-scale analysis. The calculation procedure of the local SSIM index for each level is similar to the previously published estimation method of the single scale SSIM index, which uses 32 pixels wide blocks with the 8×8 pixels sliding window. Nevertheless, all the operations are performed using float numbers instead of the unsigned chars. Verification of the results has been performed using the LIVE Image Quality Assessment Database Release 2 containing the images corrupted by five common types of distortions together with their subjective quality evaluations expressed as the Differential Mean Opinion Score (DMOS) values. The obtained estimation results are much better correlated with the subjective quality evaluations than the original MS-SSIM values without using any nonlinear mapping. The average calculation time for a single image from the LIVE database is about 10 ms and is about 30 times shorter than the full MS-SSIM calculation using the typical Matlab implementation.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 8, 8; 908-910
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of the weighted Distance Directional Filter for various colour spaces in the aspect of modern image quality metrics
Zastosowanie ważonego filtru odległościowo-kierunkowego w różnych przestrzeniach barw w aspekcie nowoczesnych wskaźników jakości obrazów
Autorzy:
Okarma, K.
Miętus, A.
Tecław, M.
Powiązania:
https://bibliotekanauki.pl/articles/158266.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ważony filtr odległościowo-kierunkowy
filtracja obrazów kolorowych
ocena jakości obrazów
weighted Distance Directional Filter
colour image filtering
image quality assessment
Opis:
Some promising results obtained by the application of the weighted Distance Directional Filter (DDF) for the filtration of an impulse noise are presented in the paper. An interesting fact to emerge is that the trade-off between the Vector Median Filter and the Basic Vector Directional Filter, which is the essence of the DDF, not only depends on the colour space used during calculations but also on the weighting coefficients within the filter mask. These results may form the basis for further research to identify a closer relationship among the filter parameters in order to develop the fast adaptive version of the nonlinear weighted filter.
W artykule zaprezentowane zostały rezultaty filtracji obrazów kolorowych uzyskane w wyniku zastosowania ważonego filtru odległościowo-kierunkowego w celu zredukowania szumu impulsowego. Interesujący jest fakt silnej zależności wyników zastosowania tego filtru, będącego połączeniem wektorowego filtru medianowego z wektorowym filtrem kierunkowym, zarówno od przestrzeni barw, jak również współczynników wagowych maski filtru. Wynikowe obrazy uzyskane po zastosowaniu filtracji w rożnych przestrzeniach barw zostały ocenione za pomocą kilku nowoczesnych porównawczych wskaźników jakości omówionych w rozdziale 3. W publikacji zamieszczono reprezentatywne wyniki oceny jakości z użyciem wskaźnika podobieństwa strukturalnego (SSIM). Ich analiza pozwala na określenie zależności pozwalających na modyfikację algorytmu filtracji w kierunku maksymalizacji wartości nowoczesnych wskaźników jakości obrazu o wysokim stopniu korelacji z ocenami subiektywnymi. Uzyskane wyniki mogą stanowić podstawę dalszych badań w celu dokładniejszego zbadania właściwości filtracji DDF oraz opracowania opartego na niej szybkiego adaptacyjnego algorytmu nieliniowej filtracji obrazów kolorowych.
Źródło:
Pomiary Automatyka Kontrola; 2010, R. 56, nr 10, 10; 1150-1153
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A semi-analytic approach to calculating the Strehl ratio for a circularly symmetric system.Part 2: dynamic wavefront
Autorzy:
Castaño-Fernandez, A. B.
Martínez-Finkelshtein, A.
Iskander, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/173593.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image quality assessment
optical transfer function
longitudinal vibrations
mathematical methods in physics
finite analogs of Fourier transforms
Opis:
Close-form expression for the Strehl ratio calculated in the spatial frequency domain of the optical transfer function (SOTF) is considered for the case of time-varying dynamic optical system that has circular symmetry. Specifically, closed-form expressions for the temporally averaged SOTF are considered, which can be easily evaluated numerically (what we call a semi-analytic solution). As for the case of a static wavefront, described in Part 1 of this work, it is shown that the proposed methods are computationally more efficient than the commonly used approach based on the discrete Fourier transform.
Źródło:
Optica Applicata; 2018, 48, 2; 211-223
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optymalizacja korelacji szybkiej metody estymacji jakości obrazów opartej na podobieństwie strukturalnym z oceną subiektywną
Optimisation of the correlation of the fast image quality estimation based on the Structural Similarity with the subjective evaluation
Autorzy:
Okarma, K.
Powiązania:
https://bibliotekanauki.pl/articles/154290.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
ocena jakości obrazów cyfrowych
podobieństwo strukturalne
metoda Monte Carlo
digital image quality assessment
structural similarity
Monte Carlo method
Opis:
W pracy przedstawiono analizę wyników estymacji jakości obrazów przy użyciu metody Monte Carlo w połączeniu z podobieństwem strukturalnym (SSIM) pod kątem korelacji z oceną subiektywną. Jako platformy testowej użyto bazy obrazów poddanych pięciu typowym rodzajom zniekształceń wraz z ich ocenami subiektywnymi udostępnianej przez Laboratorium Inżynierii Obrazu i Wideo (LIVE) Uniwersytetu w Teksasie. Uzyskane wyniki korelacji liniowej oraz z zastosowaniem funkcji logistycznej potwierdzają wysoką przydatność zaproponowanej szybkiej metody estymacji jakości obrazu.
The paper presents the analysis of the results of the image quality estimation when using the Monte Carlo method applied to the Structural Similarity index [5] in the aspect of correlation with the subjective evaluation. As a test platform, the LIVE database (available at the Laboratory for Image & Video Engineering of the University of Texas at Austin) [7] containing the Differential Mean Opinion Score (DMOS) values for almost 1000 images corrupted by five common types of distortions has been used. After the short introduction containing the analysis of some modern image quality assessment techniques, the idea of the image quality fast estimation with use of the Monte Carlo Structural Similarity Index [6] is described. The results of the Pearson's correlation of the DMOS values and MC-SSIM for the individual types of distortions and for the whole database, excluding the original images, are presented in Tables 1-2. Tables 3-4 illustrate the optimised results obtained after the nonlinear mapping with use of the logistic function (6). The obtained results of the linear correlation, as well as those obtained when using the nonlinear mapping by the optimised logistic function, confirm the usefulness of the proposed fast image quality estimation technique. An interesting fact is not only the preservation of the high correlation coefficients even for the small number of pixels used for the quality estimation but also a slight increase in them which may be an interesting stimulus for further research.
Źródło:
Pomiary Automatyka Kontrola; 2009, R. 55, nr 7, 7; 444-446
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł

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