Bibliografie tematiche / Segmentation

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Segmentation"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 23 novembre 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Segmentation".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Segmentation"

Saker, Halima, Rainer Machné, Jörg Fallmann, Douglas B. Murray, Ahmad M. Shahin e Peter F. Stadler. "Weighted Consensus Segmentations". Computation 9, n. 2 (5 febbraio 2021): 17. http://dx.doi.org/10.3390/computation9020017.

Testo completo

Abstract (sommario):

The problem of segmenting linearly ordered data is frequently encountered in time-series analysis, computational biology, and natural language processing. Segmentations obtained independently from replicate data sets or from the same data with different methods or parameter settings pose the problem of computing an aggregate or consensus segmentation. This Segmentation Aggregation problem amounts to finding a segmentation that minimizes the sum of distances to the input segmentations. It is again a segmentation problem and can be solved by dynamic programming. The aim of this contribution is (1) to gain a better mathematical understanding of the Segmentation Aggregation problem and its solutions and (2) to demonstrate that consensus segmentations have useful applications. Extending previously known results we show that for a large class of distance functions only breakpoints present in at least one input segmentation appear in the consensus segmentation. Furthermore, we derive a bound on the size of consensus segments. As show-case applications, we investigate a yeast transcriptome and show that consensus segments provide a robust means of identifying transcriptomic units. This approach is particularly suited for dense transcriptomes with polycistronic transcripts, operons, or a lack of separation between transcripts. As a second application, we demonstrate that consensus segmentations can be used to robustly identify growth regimes from sets of replicate growth curves.

Gli stili APA, Harvard, Vancouver, ISO e altri

Buser, Myrthe A. D., Alida F. W. van der Steeg, Marc H. W. A. Wijnen, Matthijs Fitski, Harm van Tinteren, Marry M. van den Heuvel-Eibrink, Annemieke S. Littooij e Bas H. M. van der Velden. "Radiologic versus Segmentation Measurements to Quantify Wilms Tumor Volume on MRI in Pediatric Patients". Cancers 15, n. 7 (1 aprile 2023): 2115. http://dx.doi.org/10.3390/cancers15072115.

Testo completo

Abstract (sommario):

Wilms tumor is a common pediatric solid tumor. To evaluate tumor response to chemotherapy and decide whether nephron-sparing surgery is possible, tumor volume measurements based on magnetic resonance imaging (MRI) are important. Currently, radiological volume measurements are based on measuring tumor dimensions in three directions. Manual segmentation-based volume measurements might be more accurate, but this process is time-consuming and user-dependent. The aim of this study was to investigate whether manual segmentation-based volume measurements are more accurate and to explore whether these segmentations can be automated using deep learning. We included the MRI images of 45 Wilms tumor patients (age 0–18 years). First, we compared radiological tumor volumes with manual segmentation-based tumor volume measurements. Next, we created an automated segmentation method by training a nnU-Net in a five-fold cross-validation. Segmentation quality was validated by comparing the automated segmentation with the manually created ground truth segmentations, using Dice scores and the 95th percentile of the Hausdorff distances (HD95). On average, manual tumor segmentations result in larger tumor volumes. For automated segmentation, the median dice was 0.90. The median HD95 was 7.2 mm. We showed that radiological volume measurements underestimated tumor volume by about 10% when compared to manual segmentation-based volume measurements. Deep learning can potentially be used to replace manual segmentation to benefit from accurate volume measurements without time and observer constraints.

Gli stili APA, Harvard, Vancouver, ISO e altri

Nanni, Loris, Daniel Fusaro, Carlo Fantozzi e Alberto Pretto. "Improving Existing Segmentators Performance with Zero-Shot Segmentators". Entropy 25, n. 11 (30 ottobre 2023): 1502. http://dx.doi.org/10.3390/e25111502.

Testo completo

Abstract (sommario):

This paper explores the potential of using the SAM (Segment-Anything Model) segmentator to enhance the segmentation capability of known methods. SAM is a promptable segmentation system that offers zero-shot generalization to unfamiliar objects and images, eliminating the need for additional training. The open-source nature of SAM allows for easy access and implementation. In our experiments, we aim to improve the segmentation performance by providing SAM with checkpoints extracted from the masks produced by mainstream segmentators, and then merging the segmentation masks provided by these two networks. We examine the “oracle” method (as upper bound baseline performance), where segmentation masks are inferred only by SAM with checkpoints extracted from the ground truth. One of the main contributions of this work is the combination (fusion) of the logit segmentation masks produced by the SAM model with the ones provided by specialized segmentation models such as DeepLabv3+ and PVTv2. This combination allows for a consistent improvement in segmentation performance in most of the tested datasets. We exhaustively tested our approach on seven heterogeneous public datasets, obtaining state-of-the-art results in two of them (CAMO and Butterfly) with respect to the current best-performing method with a combination of an ensemble of mainstream segmentator transformers and the SAM segmentator. The results of our study provide valuable insights into the potential of incorporating the SAM segmentator into existing segmentation techniques. We release with this paper the open-source implementation of our method.

Gli stili APA, Harvard, Vancouver, ISO e altri

Liu, Qiming, Qifan Lu, Yezi Chai, Zhengyu Tao, Qizhen Wu, Meng Jiang e Jun Pu. "Radiomics-Based Quality Control System for Automatic Cardiac Segmentation: A Feasibility Study". Bioengineering 10, n. 7 (1 luglio 2023): 791. http://dx.doi.org/10.3390/bioengineering10070791.

Testo completo

Abstract (sommario):

Purpose: In the past decade, there has been a rapid increase in the development of automatic cardiac segmentation methods. However, the automatic quality control (QC) of these segmentation methods has received less attention. This study aims to address this gap by developing an automatic pipeline that incorporates DL-based cardiac segmentation and radiomics-based quality control. Methods: In the DL-based localization and segmentation part, the entire heart was first located and cropped. Then, the cropped images were further utilized for the segmentation of the right ventricle cavity (RVC), myocardium (MYO), and left ventricle cavity (LVC). As for the radiomics-based QC part, a training radiomics dataset was created with segmentation tasks of various quality. This dataset was used for feature extraction, selection, and QC model development. The model performance was then evaluated using both internal and external testing datasets. Results: In the internal testing dataset, the segmentation model demonstrated a great performance with a dice similarity coefficient (DSC) of 0.954 for whole heart segmentations. Images were then appropriately cropped to 160 × 160 pixels. The models also performed well for cardiac substructure segmentations. The DSC values were 0.863, 0.872, and 0.940 for RVC, MYO, and LVC for 2D masks and 0.928, 0.886, and 0.962 for RVC, MYO, and LVC for 3D masks with an attention-UNet. After feature selection with the radiomics dataset, we developed a series of models to predict the automatic segmentation quality and its DSC value for the RVC, MYO, and LVC structures. The mean absolute values for our best prediction models were 0.060, 0.032, and 0.021 for 2D segmentations and 0.027, 0.017, and 0.011 for 3D segmentations, respectively. Additionally, the radiomics-based classification models demonstrated a high negative detection rate of >0.85 in all 2D groups. In the external dataset, models showed similar results. Conclusions: We developed a pipeline including cardiac substructure segmentation and QC at both the slice (2D) and subject (3D) levels. Our results demonstrate that the radiomics method possesses great potential for the automatic QC of cardiac segmentation.

Gli stili APA, Harvard, Vancouver, ISO e altri

Sithole, G., e L. Majola. "FRAMEWORK FOR COMPARING SEGMENTATION ALGORITHMS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-4/W5 (11 maggio 2015): 131–36. http://dx.doi.org/10.5194/isprsarchives-xl-4-w5-131-2015.

Testo completo

Abstract (sommario):

The notion of a ‘Best’ segmentation does not exist. A segmentation algorithm is chosen based on the features it yields, the properties of the segments (point sets) it generates, and the complexity of its algorithm. The segmentation is then assessed based on a variety of metrics such as homogeneity, heterogeneity, fragmentation, etc. Even after an algorithm is chosen its performance is still uncertain because the landscape/scenarios represented in a point cloud have a strong influence on the eventual segmentation. Thus selecting an appropriate segmentation algorithm is a process of trial and error. <br><br> Automating the selection of segmentation algorithms and their parameters first requires methods to evaluate segmentations. Three common approaches for evaluating segmentation algorithms are ‘goodness methods’, ‘discrepancy methods’ and ‘benchmarks’. Benchmarks are considered the most comprehensive method of evaluation. This paper shortcomings in current benchmark methods are identified and a framework is proposed that permits both a visual and numerical evaluation of segmentations for different algorithms, algorithm parameters and evaluation metrics. The concept of the framework is demonstrated on a real point cloud. Current results are promising and suggest that it can be used to predict the performance of segmentation algorithms.

Gli stili APA, Harvard, Vancouver, ISO e altri

Stevens, Michiel, Afroditi Nanou, Leon W. M. M. Terstappen, Christiane Driemel, Nikolas H. Stoecklein e Frank A. W. Coumans. "StarDist Image Segmentation Improves Circulating Tumor Cell Detection". Cancers 14, n. 12 (13 giugno 2022): 2916. http://dx.doi.org/10.3390/cancers14122916.

Testo completo

Abstract (sommario):

After a CellSearch-processed circulating tumor cell (CTC) sample is imaged, a segmentation algorithm selects nucleic acid positive (DAPI+), cytokeratin-phycoerythrin expressing (CK-PE+) events for further review by an operator. Failures in this segmentation can result in missed CTCs. The CellSearch segmentation algorithm was not designed to handle samples with high cell density, such as diagnostic leukapheresis (DLA) samples. Here, we evaluate deep-learning-based segmentation method StarDist as an alternative to the CellSearch segmentation. CellSearch image archives from 533 whole blood samples and 601 DLA samples were segmented using CellSearch and StarDist and inspected visually. In 442 blood samples from cancer patients, StarDist segmented 99.95% of CTC segmented by CellSearch, produced good outlines for 98.3% of these CTC, and segmented 10% more CTC than CellSearch. Visual inspection of the segmentations of DLA images showed that StarDist continues to perform well when the cell density is very high, whereas CellSearch failed and generated extremely large segmentations (up to 52% of the sample surface). Moreover, in a detailed examination of seven DLA samples, StarDist segmented 20% more CTC than CellSearch. Segmentation is a critical first step for CTC enumeration in dense samples and StarDist segmentation convincingly outperformed CellSearch segmentation.

Gli stili APA, Harvard, Vancouver, ISO e altri

Harkey, Matthew S., Nicholas Michel, Christopher Kuenze, Ryan Fajardo, Matt Salzler, Jeffrey B. Driban e Ilker Hacihaliloglu. "Validating a Semi-Automated Technique for Segmenting Femoral Articular Cartilage on Ultrasound Images". CARTILAGE 13, n. 2 (aprile 2022): 194760352210930. http://dx.doi.org/10.1177/19476035221093069.

Testo completo

Abstract (sommario):

Objective To validate a semi-automated technique to segment ultrasound-assessed femoral cartilage without compromising segmentation accuracy to a traditional manual segmentation technique in participants with an anterior cruciate ligament injury (ACL). Design We recruited 27 participants with a primary unilateral ACL injury at a pre-operative clinic visit. One investigator performed a transverse suprapatellar ultrasound scan with the participant’s ACL injured knee in maximum flexion. Three femoral cartilage ultrasound images were recorded. A single expert reader manually segmented the femoral cartilage cross-sectional area in each image. In addition, we created a semi-automatic program to segment the cartilage using a random walker-based method. We quantified the average cartilage thickness and echo-intensity for the manual and semi-automated segmentations. Intraclass correlation coefficients (ICC2,k) and Bland-Altman plots were used to validate the semi-automated technique to the manual segmentation for assessing average cartilage thickness and echo-intensity. A dice correlation coefficient was used to quantify the overlap between the segmentations created with the semi-automated and manual techniques. Results For average cartilage thickness, there was excellent reliability (ICC2,k = 0.99) and a small mean difference (+0.8%) between the manual and semi-automated segmentations. For average echo-intensity, there was excellent reliability (ICC2,k = 0.97) and a small mean difference (−2.5%) between the manual and semi-automated segmentations. The average dice correlation coefficient between the manual segmentation and semi-automated segmentation was 0.90, indicating high overlap between techniques. Conclusions Our novel semi-automated segmentation technique is a valid method that requires less technical expertise and time than manual segmentation in patients after ACL injury.

Gli stili APA, Harvard, Vancouver, ISO e altri

Mendoza Garay, Juan Ignacio. "Segmentation boundaries in accelerometer data of arm motion induced by music: Online computation and perceptual assessment". Human Technology 18, n. 3 (28 dicembre 2022): 250–66. http://dx.doi.org/10.14254/1795-6889.2022.18-3.4.

Testo completo

Abstract (sommario):

Segmentation is a cognitive process involved in the understanding of information perceived through the senses. Likewise, the automatic segmentation of data captured by sensors may be used for the identification of patterns. This study is concerned with the segmentation of dancing motion captured by accelerometry and its possible applications, such as pattern learning and recognition, or gestural control of devices. To that effect, an automatic segmentation system was formulated and tested. Two participants were asked to ‘dance with one arm’ while their motion was measured by an accelerometer. The performances were recorded on video, and manually segmented by six annotators later. The annotations were used to optimize the automatic segmentation system, maximizing a novel similarity score between computed and annotated segmentations. The computed segmentations with highest similarity to each annotation were then manually assessed by the annotators, resulting in Precision between 0.71 and 0.89, and Recall between 0.82 to 1.

Gli stili APA, Harvard, Vancouver, ISO e altri

Schmidt-Richberg, A., J. Fiehler, T. Illies, D. Möller, H. Handels, D. Säring e N. D. Forkert. "Automatic Correction of Gaps in Cerebrovascular Segmentations Extracted from 3D Time-of-Flight MRA Datasets". Methods of Information in Medicine 51, n. 05 (2012): 415–22. http://dx.doi.org/10.3414/me11-02-0037.

Testo completo

Abstract (sommario):

Summary Objectives: Exact cerebrovascular segmentations are required for several applications in today’s clinical routine. A major drawback of typical automatic segmentation methods is the occurrence of gaps within the segmentation. These gaps are typically located at small vessel structures exhibiting low intensities. Manual correction is very time-consuming and not suitable in clinical practice. This work presents a post-processing method for the automatic detection and closing of gaps in cerebrovascular segmentations. Methods: In this approach, the 3D centerline is calculated from an available vessel segmentation, which enables the detection of corresponding vessel endpoints. These endpoints are then used to detect possible connections to other 3D centerline voxels with a graph-based approach. After consistency check, reasonable detected paths are expanded to the vessel boundaries using a level set approach and combined with the initial segmentation. Results: For evaluation purposes, 100 gaps were artificially inserted at non-branching vessels and bifurcations in manual cerebrovascular segmentations derived from ten Time-of-Flight magnetic resonance angiography datasets. The results show that the presented method is capable of detecting 82% of the non-branching vessel gaps and 84% of the bifurcation gaps. The level set segmentation expands the detected connections with 0.42 mm accuracy compared to the initial segmentations. A further evaluation based on 10 real automatic segmentations from the same datasets shows that the proposed method detects 35 additional connections in average per dataset, whereas 92.7% were rated as correct by a medical expert. Conclusion: The presented approach can considerably improve the accuracy of cerebrovascular segmentations and of following analysis outcomes.

Gli stili APA, Harvard, Vancouver, ISO e altri

van der Putten, Joost, Fons van der Sommen, Jeroen de Groof, Maarten Struyvenberg, Svitlana Zinger, Wouter Curvers, Erik Schoon, Jacques Bergman e Peter H. N. de With. "Modeling clinical assessor intervariability using deep hypersphere encoder–decoder networks". Neural Computing and Applications 32, n. 14 (21 novembre 2019): 10705–17. http://dx.doi.org/10.1007/s00521-019-04607-w.

Testo completo

Abstract (sommario):

AbstractIn medical imaging, a proper gold-standard ground truth as, e.g., annotated segmentations by assessors or experts is lacking or only scarcely available and suffers from large intervariability in those segmentations. Most state-of-the-art segmentation models do not take inter-observer variability into account and are fully deterministic in nature. In this work, we propose hypersphere encoder–decoder networks in combination with dynamic leaky ReLUs, as a new method to explicitly incorporate inter-observer variability into a segmentation model. With this model, we can then generate multiple proposals based on the inter-observer agreement. As a result, the output segmentations of the proposed model can be tuned to typical margins inherent to the ambiguity in the data. For experimental validation, we provide a proof of concept on a toy data set as well as show improved segmentation results on two medical data sets. The proposed method has several advantages over current state-of-the-art segmentation models such as interpretability in the uncertainty of segmentation borders. Experiments with a medical localization problem show that it offers improved biopsy localizations, which are on average 12% closer to the optimal biopsy location.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Segmentation"

Ross, Michael G. (Michael Gregory) 1975. "Learning static object segmentation from motion segmentation". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/34470.

Testo completo

Abstract (sommario):

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.
Includes bibliographical references (p. 105-110).
This thesis describes the SANE (Segmentation According to Natural Examples) algorithm for learning to segment objects in static images from video data. SANE uses background subtraction to find the segmentation of moving objects in videos. This provides object segmentation information for each video frame. The collection of frames and segmentations forms a training set that SANE uses to learn the image and shape properties that correspond to the observed motion boundaries. Then, when presented with new static images, the model infers segmentations similar to the observed motion segmentations. SANE is a general method for learning environment-specific segmentation models. Because it is self-supervised, it can adapt to a new environment and new objects with relative ease. Comparisons of its output to a leading image segmentation algorithm demonstrate that motion-defined object segmentation is a distinct problem from traditional image segmentation. The model outperforms a trained local boundary detector because it leverages the shape information it learned from the training data.
by Michael Gregory Ross.
Ph.D.

Gli stili APA, Harvard, Vancouver, ISO e altri

Vyas, Aseem. "Medical Image Segmentation by Transferring Ground Truth Segmentation". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32431.

Testo completo

Abstract (sommario):

The segmentation of medical images is a difficult task due to the inhomogeneous intensity variations that occurs during digital image acquisition, the complicated shape of the object, and the medical expert’s lack of semantic knowledge. Automated segmentation algorithms work well for some medical images, but no algorithm has been general enough to work for all medical images. In practice, most of the time the segmentation results are corrected by the experts before the actual use. In this work, we are motivated to determine how to make use of manually segmented data in automatic segmentation. The key idea is to transfer the ground truth segmentation from the database of train images to a given test image. The ground truth segmentation of MR images is done by experts. The process includes a hierarchical image decomposition approach that performs the shape matching of test images at several levels, starting with the image as a whole (i.e. level 0) and then going through a pyramid decomposition (i.e. level 1, level 2, etc.) with the database of the train images and the given test image. The goal of pyramid decomposition is to find the section of the training image that best matches a section of the test image of a different level. After that, a re-composition approach is taken to place the best matched sections of the training image to the original test image space. Finally, the ground truth segmentation is transferred from the best training images to their corresponding location in the test image. We have tested our method on a hip joint MR image database and the experiment shows successful results on level 0, level 1 and level 2 re-compositions. Results improve with deeper level decompositions, which supports our hypotheses.

Gli stili APA, Harvard, Vancouver, ISO e altri

Jomaa, Diala. "Fingerprint Segmentation". Thesis, Högskolan Dalarna, Datateknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:du-4264.

Testo completo

Abstract (sommario):

In this thesis, a new algorithm has been proposed to segment the foreground of the fingerprint from the image under consideration. The algorithm uses three features, mean, variance and coherence. Based on these features, a rule system is built to help the algorithm to efficiently segment the image. In addition, the proposed algorithm combine split and merge with modified Otsu. Both enhancements techniques such as Gaussian filter and histogram equalization are applied to enhance and improve the quality of the image. Finally, a post processing technique is implemented to counter the undesirable effect in the segmented image. Fingerprint recognition system is one of the oldest recognition systems in biometrics techniques. Everyone have a unique and unchangeable fingerprint. Based on this uniqueness and distinctness, fingerprint identification has been used in many applications for a long period. A fingerprint image is a pattern which consists of two regions, foreground and background. The foreground contains all important information needed in the automatic fingerprint recognition systems. However, the background is a noisy region that contributes to the extraction of false minutiae in the system. To avoid the extraction of false minutiae, there are many steps which should be followed such as preprocessing and enhancement. One of these steps is the transformation of the fingerprint image from gray-scale image to black and white image. This transformation is called segmentation or binarization. The aim for fingerprint segmentation is to separate the foreground from the background. Due to the nature of fingerprint image, the segmentation becomes an important and challenging task. The proposed algorithm is applied on FVC2000 database. Manual examinations from human experts show that the proposed algorithm provides an efficient segmentation results. These improved results are demonstrating in diverse experiments.

Gli stili APA, Harvard, Vancouver, ISO e altri

Scholte, Huibert Steven. "Scene segmentation". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2003. http://dare.uva.nl/document/70449.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Horne, Caspar. "Unsupervised image segmentation /". Lausanne : EPFL, 1991. http://library.epfl.ch/theses/?nr=905.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Sundøy, Kristoffer Johan. "Audiovisual Contents Segmentation". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-11264.

Testo completo

Abstract (sommario):

The objective of this thesis is to detect high level semantic ideas to help to impose a structure on television talk shows. Indexing TV-shows is a subject that, to our knowledge, is rarely talked about in the scientific community.There is no common understanding of what this imposed structure should look like. We can say that the purpose is to organise the audiovisual content into sections that convey a specific information. It thus encompasses issues as diverse as scene segmentation, speech noise detection, speaker identification, etc. The basic problem of structuring is the gap between the information extracted from visual data flow and human interpretation made by the user of these data. Numerous studies have examined the organisation of highly structured video content. Thus, the state of the art has many studies on sport or newscast transmissions. Our goal is to detect key audiovisual events using a variety of descriptors and generic classifiers. We propose a generic approach that is able to assess all TV-show indexing problems. This enables an operator to use one single tool to infer a logical structure. Our approach can be considered as ``semi-automatic'' in the sense that the training data is collected on the fly by the operator who is asked to arbitrarily select one video excerpt of each concept involved. We have assessed a wide selection of audio and video features, used MKL as a feature selection algorithm and then built various content detectors and segmentors useful for imposing broad semantic classes on television data.This master's thesis was set forth by TELECOM ParisTech and was begun there March 1, 2010. This final report was submitted to TELECOM ParisTech, NTNU and Institute EURECOM August 29, 2010.

Gli stili APA, Harvard, Vancouver, ISO e altri

Camilleri, Kenneth P. "Multiresolution texture segmentation". Thesis, University of Surrey, 1999. http://epubs.surrey.ac.uk/843549/.

Testo completo

Abstract (sommario):

The problem of unsupervised texture segmentation was studied and a texture segmentation algorithm was developed making use of the minimum number of prior assumptions. In particular, no prior information about the type of textures, the number of textures and the appropriate scale of analysis for each texture was required. The texture image was analysed by the multiresolution Gabor expansion. The Gabor expansion generates a large number of features for each image and the most suitable feature space for segmentation needs to be determined automatically. The two-point correlation function was used to test the separability of the distributions in each feature space. A measure was developed to evaluate evidence of multiple clusters from the two-point correlation function, making it possible to determine the most suitable feature space for clustering. Thus, at a given resolution level, the most appropriate feature space was selected and used to segment the image. Due to inherent ambiguities and limitations of the two-point correlation function, this feature space exploration and segmentation was performed several times at the same resolution level until no further evidence of multiple clusters was found, at which point, the process was repeated at the next finer resolution level. In this way, the image was progressively segmented, proceeding from coarse to fine Gabor resolution levels without any knowledge of the actual number of textures present. In order to refine the region-labelled image obtained at the end of the segmentation process, two postprocessing pixel-level algorithms were developed and implemented. The first was the mixed pixel classification algorithm which is based on the analysis of the effect of the averaging window at the boundary between two regions and re-assigns the pixel labels to improve the boundary localisation. Multiresolution probabilistic relaxation is the second postprocessing algorithm which we developed. This algorithm incorporates contextual evidence to relabel pixels close to the boundary in order to smooth it and improve its localisation. The results obtained were quantified by known error measures, as well as by new error measures which we developed. The quantified results were compared to similar results by other authors and show that our unsupervised algorithm performs as well as other methods which assume prior information.

Gli stili APA, Harvard, Vancouver, ISO e altri

Debeir, Olivier. "Segmentation supervisée d'images". Doctoral thesis, Universite Libre de Bruxelles, 2001. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211474.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Bhalerao, Abhir. "Multiresolution image segmentation". Thesis, University of Warwick, 1991. http://wrap.warwick.ac.uk/60866/.

Testo completo

Abstract (sommario):

Image segmentation is an important area in the general field of image processing and computer vision. It is a fundamental part of the 'low level' aspects of computer vision and has many practical applications such as in medical imaging, industrial automation and satellite imagery. Traditional methods for image segmentation have approached the problem either from localisation in class space using region information, or from localisation in position, using edge or boundary information. More recently, however, attempts have been made to combine both region and boundary information in order to overcome the inherent limitations of using either approach alone. In this thesis, a new approach to image segmentation is presented that integrates region and boundary information within a multiresolution framework. The role of uncertainty is described, which imposes a limit on the simultaneous localisation in both class and position space. It is shown how a multiresolution approach allows the trade-off between position and class resolution and ensures both robustness in noise and efficiency of computation. The segmentation is based on an image model derived from a general class of multiresolution signal models, which incorporates both region and boundary features. A four stage algorithm is described consisting of: generation of a low-pass pyramid, separate region and boundary estimation processes and an integration strategy. Both the region and boundary processes consist of scale-selection, creation of adjacency graphs, and iterative estimation within a general framework of maximum a posteriori (MAP) estimation and decision theory. Parameter estimation is performed in situ, and the decision processes are both flexible and spatially local, thus avoiding assumptions about global homogeneity or size and number of regions which characterise some of the earlier algorithms. A method for robust estimation of edge orientation and position is described which addresses the problem in the form of a multiresolution minimum mean square error (MMSE) estimation. The method effectively uses the spatial consistency of output of small kernel gradient operators from different scales to produce more reliable edge position and orientation and is effective at extracting boundary orientations from data with low signal-to-noise ratios. Segmentation results are presented for a number of synthetic and natural images which show the cooperative method to give accurate segmentations at low signal-to-noise ratios (0 dB) and to be more effective than previous methods at capturing complex region shapes.

Gli stili APA, Harvard, Vancouver, ISO e altri

Fournier, Christopher. "Evaluating Text Segmentation". Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24064.

Testo completo

Abstract (sommario):

This thesis investigates the evaluation of automatic and manual text segmentation. Text segmentation is the process of placing boundaries within text to create segments according to some task-dependent criterion. An example of text segmentation is topical segmentation, which aims to segment a text according to the subjective definition of what constitutes a topic. A number of automatic segmenters have been created to perform this task, and the question that this thesis answers is how to select the best automatic segmenter for such a task. This requires choosing an appropriate segmentation evaluation metric, confirming the reliability of a manual solution, and then finally employing an evaluation methodology that can select the automatic segmenter that best approximates human performance. A variety of comparison methods and metrics exist for comparing segmentations (e.g., WindowDiff, Pk), and all save a few are able to award partial credit for nearly missing a boundary. Those comparison methods that can award partial credit unfortunately lack consistency, symmetricity, intuition, and a host of other desirable qualities. This work proposes a new comparison method named boundary similarity (B) which is based upon a new minimal boundary edit distance to compare two segmentations. Near misses are frequent, even among manual segmenters (as is exemplified by the low inter-coder agreement reported by many segmentation studies). This work adapts some inter-coder agreement coefficients to award partial credit for near misses using the new metric proposed herein, B. The methodologies employed by many works introducing automatic segmenters evaluate them simply in terms of a comparison of their output to one manual segmentation of a text, and often only by presenting nothing other than a series of mean performance values (along with no standard deviation, standard error, or little if any statistical hypothesis testing). This work asserts that one segmentation of a text cannot constitute a “true” segmentation; specifically, one manual segmentation is simply one sample of the population of all possible segmentations of a text and of that subset of desirable segmentations. This work further asserts that an adapted inter-coder agreement statistics proposed herein should be used to determine the reproducibility and reliability of a coding scheme and set of manual codings, and then statistical hypothesis testing using the specific comparison methods and methodologies demonstrated herein should be used to select the best automatic segmenter. This work proposes new segmentation evaluation metrics, adapted inter-coder agreement coefficients, and methodologies. Most important, this work experimentally compares the state-or-the-art comparison methods to those proposed herein upon artificial data that simulates a variety of scenarios and chooses the best one (B). The ability of adapted inter-coder agreement coefficients, based upon B, to discern between various levels of agreement in artificial and natural data sets is then demonstrated. Finally, a contextual evaluation of three automatic segmenters is performed using the state-of-the art comparison methods and B using the methodology proposed herein to demonstrate the benefits and versatility of B as opposed to its counterparts.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Segmentation"

McDonald, Malcolm, e Ian Dunbar. Market Segmentation. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar, a cura di. Market Segmentation. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781119207863.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Wedel, Michel, e Wagner A. Kamakura. Market Segmentation. Boston, MA: Springer US, 2000. http://dx.doi.org/10.1007/978-1-4615-4651-1.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Malcolm, McDonald. Market Segmentation. San Diego: Elsevier Science & Technology, 2010.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

El-Baz, Ayman, Xiaoyi Jiang e Suri Jasjit, a cura di. Biomedical Image Segmentation. Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2016. http://dx.doi.org/10.4324/9781315372273.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Bhalerao, Abhir H. Multiresolution image segmentation. [s.l.]: typescript, 1991.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Dolnicar, Sara, Bettina Grün e Friedrich Leisch. Market Segmentation Analysis. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-8818-6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Protopappa-Sieke, Margarita, e Ulrich W. Thonemann, a cura di. Supply Chain Segmentation. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-54133-4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

He, Jia, Chang-Su Kim e C. C. Jay Kuo. Interactive Segmentation Techniques. Singapore: Springer Singapore, 2014. http://dx.doi.org/10.1007/978-981-4451-60-4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Hati, Avik, Rajbabu Velmurugan, Sayan Banerjee e Subhasis Chaudhuri. Image Co-segmentation. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-8570-6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Capitoli di libri sul tema "Segmentation"

McDonald, Malcolm, e Ian Dunbar. "Preparing for Segmentation". In Market Segmentation, 1–33. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_1.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Company Competitiveness and the Portfolio Matrix (Step 12)". In Market Segmentation, 223–32. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_10.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Setting Marketing Objectives and Strategies for Identified Segments". In Market Segmentation, 235–59. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_11.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Organisational Issues in Market Segmentation". In Market Segmentation, 263–76. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_12.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "The Contribution of Segmentation to Business Planning: A Case Study of the Rise, Fall and Recovery of ICI Fertilizers". In Market Segmentation, 279–316. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_13.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Market Mapping (Step 1)". In Market Segmentation, 37–67. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_2.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Who Buys (Step 2)". In Market Segmentation, 68–94. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_3.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "What, Where, When and How (Step 3)". In Market Segmentation, 95–117. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Who Buys What, Where, When and How (Step 4)". In Market Segmentation, 118–41. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McDonald, Malcolm, e Ian Dunbar. "Why it is Bought (Step 5)". In Market Segmentation, 142–71. London: Palgrave Macmillan UK, 1998. http://dx.doi.org/10.1007/978-1-349-26591-6_6.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Segmentation"

Tsai, Yi-Chin, e Yung-Nien Sun. "KiTS19 Challenge Segmentation". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.021.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Sirazitdinov, Ilyas, e Bulat Ibragimov. "Kits19 segmentation challenge". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.062.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Sharma, Rochan. "Kidney Tumour Segmentation". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.080.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Dahiya, Navdeep, e Alok Sharma. "Segmentation of Kidney Tumor". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.060.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Chen, Tung-I., Min-Sheng Wu, Yu-Cheng Chang e Jhih-Yuan Lin. "2019 Kidney Tumor Segmentation Challenge: Medical Image Segmentation with Two-Stage Process". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.065.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Cui, Zhiying. "3D Segmentation For Kidney Data". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.081.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Adão, Milena Menezes, Silvio Jamil F. Guimarães e Zenilton K. G. Patrocı́nio Jr. "Evaluation of machine learning applied to the realignment of hierarchies for image segmentation". In XXXII Conference on Graphics, Patterns and Images. Sociedade Brasileira de Computação - SBC, 2019. http://dx.doi.org/10.5753/sibgrapi.est.2019.8311.

Testo completo

Abstract (sommario):

A hierarchical image segmentation is a set of image segmentations at different detail levels. However, objects can be located at different scales due to their size differences or to their distinct distances from the camera. In literature, many works have been developed to improve hierarchical image segmentation results. One possible solution is to realign the hierarchy such that every region containing an object (or its parts) is at the same level. In this work, we have explored the use of random forest and artificial neural network as regressors models to predict score values for regions belonging to a hierarchy of partitions, which are used to realign it. We have also proposed a new score calculation witch considering all user-defined segmentations that exist in the ground-truth. Experimental results are presented for two different hierarchical segmentation methods. Moreover, an analysis of the adoption of different combination of mid-level features to describe regions and different architectures from random forest and artificial neural network to train regressors models. Experimental results have point out that the use of new proposed score was able to improve final segmentation results.

Gli stili APA, Harvard, Vancouver, ISO e altri

Meng, Zhe. "Kidney Segmentation Framework using 3D CNN". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.040.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Hou, Xiaoshuai, Chunmei Xie, Fengyi Li e Yang Nan. "Cascaded Semantic Segmentation for Kidney and Tumor". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.002.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Yiwen, Zhang. "Two stages kidney and tumor segmentation(kits2019)". In 2019 Kidney Tumor Segmentation Challenge: KiTS19. University of Minnesota Libraries Publishing, 2019. http://dx.doi.org/10.24926/548719.028.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Segmentation"

Kobla, Vikrant, David Doermann e Azriel Rosenfeld. Compressed Video Segmentation. Fort Belvoir, VA: Defense Technical Information Center, settembre 1996. http://dx.doi.org/10.21236/ada458852.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

King, Lucy. FSA Consumer segmentation. Food Standards Agency, settembre 2021. http://dx.doi.org/10.46756/sci.fsa.bmo506.

Testo completo

Abstract (sommario):

For our audiences, it is important to find out how their attitudes and behaviours relating to food safety differ, in order to understand who is more likely to take food safety risks and in what context. This is essential for effective communications and helps us to shape food safety policy. The audiences in these documents have been created using attitudinal and behavioural segmentation that categorises people based on their attitudes to food and their reported hygiene and food safety behaviours.

Gli stili APA, Harvard, Vancouver, ISO e altri

Pool, Tristen. Segmentation Model Distillation. Office of Scientific and Technical Information (OSTI), agosto 2024. http://dx.doi.org/10.2172/2429880.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Bonney, Bradford L. Non-Orthogonal Iris Segmentation. Fort Belvoir, VA: Defense Technical Information Center, maggio 2005. http://dx.doi.org/10.21236/ada437155.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Brown, S. Kathi. Retirement Attitudes Segmentation Survey. AARP Research, ottobre 2013. http://dx.doi.org/10.26419/res.00069.001.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kim, A., I. Pollak, H. Krim e A. S. Willsky. Scale-Based Robust Image Segmentation. Fort Belvoir, VA: Defense Technical Information Center, marzo 1997. http://dx.doi.org/10.21236/ada457838.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Shah, Jayant. Object Oriented Segmentation of Images. Fort Belvoir, VA: Defense Technical Information Center, dicembre 1994. http://dx.doi.org/10.21236/ada290792.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Snyder, Wesley E. Segmentation Using Multispectral Adaptive Contours. Fort Belvoir, VA: Defense Technical Information Center, febbraio 2004. http://dx.doi.org/10.21236/ada424462.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Fosgate, C. H., H. Krim, A. S. Willsky, W. W. Irving e R. D. Chaney. Multiscale Segmentation of SAR Imagery. Fort Belvoir, VA: Defense Technical Information Center, aprile 1996. http://dx.doi.org/10.21236/ada458575.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Franaszek, Marek. Gauging Difficulty of Image Segmentation. Gaithersburg, MD: National Institute of Standards and Technology, 2022. http://dx.doi.org/10.6028/nist.tn.2207.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!