The Experts below are selected from a list of 3915 Experts worldwide ranked by ideXlab platform
Aliihsan Sekertekin - One of the best experts on this subject based on the ideXlab platform.
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a survey on Global Thresholding methods for mapping open water body using sentinel 2 satellite imagery and normalized difference water index
Archives of Computational Methods in Engineering, 2021Co-Authors: Aliihsan SekertekinAbstract:The aim of this study is to investigate the performance of fifteen automatic Thresholding methods, namely Huang and Wang’s fuzzy Thresholding method, inter-mode Thresholding method, isodata Thresholding method, Li and Tam’s Thresholding method, maximum entropy Thresholding method, mean Thresholding method, minimum error Thresholding method, minimum Thresholding method, moment-preserving Thresholding method, Otsu’s Thresholding method, percentile (p-tile) Thresholding method, Renyi’s entropy Thresholding method, Shanbhag’s Thresholding method, triangle Thresholding method and Yen’s Thresholding method, for mapping open water body using Sentinel-2 data based on Normalized Difference Water Index (NDWI). Sentinel-2 data was acquired on 22 September 2018 and Lake Salda from Turkey was selected as a test site. Due to the lack of digital reference data of the test site, Support Vector Machine (SVM) classification was implemented to Sentinel-2 data and the classified image was utilized as reference data since previous studies proved that SVM classification provided better results than the Thresholding methods. SVM classification results were evaluated using 1000 random points and the Overall Accuracy (OA) and Kappa coefficient were obtained 96.2% and 0.90, respectively. The Thresholding methods were assessed using the statistical measures, namely OA, Kappa and Misclassification Error (ME). Considering the remote sensing perspective, all Thresholding methods presented satisfying results having at least 92% OA for open water body extraction. The obtained accuracy results showed that minimum Thresholding method was the best method among these fifteen algorithms with 0.000264 ME, 99.9355% OA and 0.9987 Kappa. On the other hand, p-tile and Shanbhag’s Thresholding method provided the worst accuracy results for open water body delineation.
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potential of Global Thresholding methods for the identification of surface water resources using sentinel 2 satellite imagery and normalized difference water index
Journal of Applied Remote Sensing, 2019Co-Authors: Aliihsan SekertekinAbstract:The aim of this study is to investigate the performance of 15 automatic Thresholding methods, namely Huang and Wang’s fuzzy Thresholding method, intermode Thresholding method, isodata Thresholding method, Li and Tam’s Thresholding method, maximum entropy Thresholding method, mean Thresholding method, minimum error Thresholding method, minimum Thresholding method, moment-preserving Thresholding method, Otsu’s Thresholding method, percentile (p-tile) Thresholding method, Renyi’s entropy Thresholding method, Shanbhag’s Thresholding method, triangle Thresholding method, and Yen’s Thresholding method, for mapping water body using Sentinel-2 data based on normalized difference water index. Three different types of surface water bodies, such as a natural lake (Lake Burdur), a dam reservoir (Aslantas Dam Reservoir), and a part of a river (Aras River), are chosen to reveal the potential of 15 Thresholding methods. The reference water body maps of each test site were generated by manual digitization of high-resolution Google Earth images. The Thresholding methods were assessed using the statistical measures, namely overall accuracy (OA), Kappa coefficient, producer’s accuracy, user’s accuracy, and misclassification error (ME). The accuracy analyses of 15 Thresholding methods were carried out separately for each test site, and then the overall accuracies were calculated to determine the best method. The obtained OA results showed that minimum Thresholding method was the best method among these 15 algorithms with 0.0008 ME, 99.92% OA, and 0.9758 Kappa coefficient. On the other hand, Shanbhag’s method provided the lowest overall accuracies as 0.3133 ME, 68.67% OA, and 0.3190 Kappa coefficient.
A. Carmona-poyato - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of Global Thresholding techniques in non-contextual edge detection
Pattern Recognition Letters, 2005Co-Authors: Rafael Medina-carnicer, F. J. Madrid-cuevas, N. L. Fernández-garcía, A. Carmona-poyatoAbstract:The performance of Global Thresholding techniques in edge detection is a problem that has yet to be studied in depth. Basically, an edge detection process consists of applying an edge intensity detector sequence and a Thresholding technique to a given image. In this paper, we demonstrate that applying this sequence to an image and comparing it with a reference image does not constitute a valid process for the evaluation of Global Thresholding techniques in edge detection. Instead we propose a method that allows the performance of a Global Thresholding technique to be jointly or independently evaluated using a detector. Our methodology is applied to assess the performance of seven Global Thresholding techniques, which have been widely cited in the literature and evaluated in other contexts, using five color image edge intensity detectors. We show how the results may differ depending on the criterion selected. A new criterion is proposed that brings together different aspects, permitting a more valid evaluation of the performance of Thresholding techniques both alone or in conjunction with a determined detector.
C.g. Leedham - One of the best experts on this subject based on the ideXlab platform.
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Integral ratio: a new class of Global Thresholding techniques for handwriting images
IEEE Transactions on Pattern Analysis and Machine Intelligence, 1999Co-Authors: Yan Solihin, C.g. LeedhamAbstract:We propose a class of histogram based Global Thresholding techniques called integral ratio. They are designed to threshold gray-scale handwriting images and separate the handwriting from the background. The following tight requirements must be met: 1) all the details of the handwriting are to be retained, 2) the writing paper used may contain strong colored and/or patterned background which must be removed, and 3) the handwriting may be written using a wide variety of pens such as a fountain pen, ballpoint pen, or pencil. A specific application area which requires these tight requirements is forensic document examination, where a handwritten document is often considered as legal evidence and the handwriting must not be tampered with or modified in any way. The proposed class of techniques is based on a two stage Thresholding approach requiring each pixel of a handwritten image to be placed into one of three classes: foreground, background, and a fuzzy area between them where it is hard to determine whether a pixel belongs to the foreground or the background. Two techniques, native integral ratio (NIR) and quadratic integral ratio (QIR), were created based on this class and tested against two well-known Thresholding techniques: Otsu's (1979) technique and the entropy Thresholding technique. We found that QIR has superior performance compared to all the other techniques tested.
Jozef Kaiser - One of the best experts on this subject based on the ideXlab platform.
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computed tomography based procedure for reproducible porosity measurement of additive manufactured samples
Ndt & E International, 2019Co-Authors: Tomas Zikmund, Jakub Salplachta, Aneta Zatocilova, Adam Břinek, Libor Pantělejev, Roman Stěpanek, Daniel Koutný, David Palousek, Jozef KaiserAbstract:Abstract Metallic parts made by selective laser melting technology are evaluated for internal porosity. The non-standardized pores segmentation is one of the key aspects to apply in order to achieve a precise porosity measurement using X-ray computed micro tomography. In this work, we present a new porosity analysis procedure which is based on the Global Thresholding and the correlation with metallographic image data. The procedure is independent on the obtained voxel resolution and makes an analysis reproducible. The novelty of this work is that the computed tomography is used for a comparative porosity analysis of samples from separate measurements. The functionality of proposed procedure is demonstrated on a test sample of aluminium alloy and is compared to standardly used procedures.
A K Pilkey - One of the best experts on this subject based on the ideXlab platform.
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an evaluation of Global Thresholding techniques for the automatic image segmentation of automotive aluminum sheet alloys
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: W B Lievers, A K PilkeyAbstract:Digital image analysis is a valuable tool for the quantification of microstructural morphology, such as the size and clustering distributions of second-phase particles. However, the first step to such analysis is the segmentation of digital micrographs to identify the features of interest. Since the outcome of this step will have a significant influence on all subsequent processing, accurate segmentation is of the utmost importance. Grayscale images of the microstructures of three automotive aluminum alloys are used (AA5182, AA5754, and AA6111) to compare the abilities of several automatic Global image Thresholding techniques. The minimum cross-entropy method of Li and Lee [Pattern Recognit. 30 (1993) 617] was found to work well for all alloys when combined with the cost function of Yen et al. [IEEE T. Image Process. 4 (1995) 370].