20 research outputs found
Machine learning methods for discriminating natural targets in seabed imagery
The research in this thesis concerns feature-based machine learning processes and methods for discriminating qualitative natural targets in seabed imagery. The applications considered, typically involve time-consuming manual processing stages in an industrial setting. An aim of the research is to facilitate a means of assisting human analysts by expediting the tedious interpretative tasks, using machine methods. Some novel approaches are devised and investigated for solving the application problems.
These investigations are compartmentalised in four coherent case studies linked by common underlying technical themes and methods. The first study addresses pockmark discrimination in a digital bathymetry model. Manual identification and mapping of even a relatively small number of these landform objects is an expensive process. A novel, supervised machine learning approach to automating the task is presented. The process maps the boundaries of ≈ 2000 pockmarks in seconds - a task that would take days for a human analyst to complete. The second case study investigates different feature creation methods for automatically discriminating sidescan sonar image textures characteristic of Sabellaria spinulosa colonisation.
Results from a comparison of several textural feature creation methods on sonar waterfall imagery show that Gabor filter banks yield some of the best results. A further empirical investigation into the filter bank features created on sonar mosaic imagery leads to the identification of a useful configuration and filter parameter ranges for discriminating the target textures in the imagery. Feature saliency estimation is a vital stage in the machine process. Case study three concerns distance measures for the evaluation and ranking of features on sonar imagery. Two novel consensus methods for creating a more robust ranking are proposed. Experimental results show that the consensus methods can improve robustness over a range of feature parameterisations and various seabed texture
classification tasks. The final case study is more qualitative in nature and brings together a number of ideas, applied to the classification of target regions in real-world
sonar mosaic imagery.
A number of technical challenges arose and these were
surmounted by devising a novel, hybrid unsupervised method. This fully automated machine approach was compared with a supervised approach in an application to the problem of image-based sediment type discrimination. The hybrid unsupervised method produces a plausible class map in a few minutes of processing time. It is concluded that the versatile, novel process should be generalisable to the discrimination of other subjective natural targets in real-world seabed imagery, such as Sabellaria textures and pockmarks (with appropriate features and feature tuning.) Further, the full automation
of pockmark and Sabellaria discrimination is feasible within this framework
Recommended from our members
Development of computer-based algorithms for unsupervised assessment of radiotherapy contouring
INTRODUCTION: Despite the advances in radiotherapy treatment delivery, target volume
delineation remains one of the greatest sources of error in the radiotherapy delivery process,
which can lead to poor tumour control probability and impact clinical outcome. Contouring
assessments are performed to ensure high quality of target volume definition in clinical trials
but this can be subjective and labour-intensive.
This project addresses the hypothesis that computational segmentation techniques, with a given
prior, can be used to develop an image-based tumour delineation process for contour
assessments. This thesis focuses on the exploration of the segmentation techniques to develop
an automated method for generating reference delineations in the setting of advanced lung
cancer. The novelty of this project is in the use of the initial clinician outline as a prior for
image segmentation.
METHODS: Automated segmentation processes were developed for stage II and III non-small
cell lung cancer using the IDEAL-CRT clinical trial dataset. Marker-controlled watershed
segmentation, two active contour approaches (edge- and region-based) and graph-cut applied
on superpixels were explored. k-nearest neighbour (k-NN) classification of tumour from
normal tissues based on texture features was also investigated.
RESULTS: 63 cases were used for development and training. Segmentation and classification
performance were evaluated on an independent test set of 16 cases. Edge-based active contour
segmentation achieved highest Dice similarity coefficient of 0.80 ± 0.06, followed by graphcut
at 0.76 ± 0.06, watershed at 0.72 ± 0.08 and region-based active contour at 0.71 ± 0.07,
with mean computational times of 192 ± 102 sec, 834 ± 438 sec, 21 ± 5 sec and 45 ± 18 sec
per case respectively. Errors in accuracy of irregularly shaped lesions and segmentation
leakages at the mediastinum were observed.
In the distinction of tumour and non-tumour regions, misclassification errors of 14.5% and
15.5% were achieved using 16- and 8-pixel regions of interest (ROIs) respectively. Higher
misclassification errors of 24.7% and 26.9% for 16- and 8-pixel ROIs were obtained in the
analysis of the tumour boundary.
CONCLUSIONS: Conventional image-based segmentation techniques with the application of
priors are useful in automatic segmentation of tumours, although further developments are
required to improve their performance. Texture classification can be useful in distinguishing
tumour from non-tumour tissue, but the segmentation task at the tumour boundary is more
difficult. Future work with deep-learning segmentation approaches need to be explored.Funded by National Radiotherapy Trials Quality Assurance (RTTQA) grou
Fundamentals
Volume 1 establishes the foundations of this new field. It goes through all the steps from data collection, their summary and clustering, to different aspects of resource-aware learning, i.e., hardware, memory, energy, and communication awareness. Machine learning methods are inspected with respect to resource requirements and how to enhance scalability on diverse computing architectures ranging from embedded systems to large computing clusters
Fundamentals
Volume 1 establishes the foundations of this new field. It goes through all the steps from data collection, their summary and clustering, to different aspects of resource-aware learning, i.e., hardware, memory, energy, and communication awareness. Machine learning methods are inspected with respect to resource requirements and how to enhance scalability on diverse computing architectures ranging from embedded systems to large computing clusters
EUSN 2021 Book of Abstracts, Fifth European Conference on Social Networks
Book of abstract of the fifth European conference on Social Networks EUSN 202
Very High Resolution (VHR) Satellite Imagery: Processing and Applications
Recently, growing interest in the use of remote sensing imagery has appeared to provide synoptic maps of water quality parameters in coastal and inner water ecosystems;, monitoring of complex land ecosystems for biodiversity conservation; precision agriculture for the management of soils, crops, and pests; urban planning; disaster monitoring, etc. However, for these maps to achieve their full potential, it is important to engage in periodic monitoring and analysis of multi-temporal changes. In this context, very high resolution (VHR) satellite-based optical, infrared, and radar imaging instruments provide reliable information to implement spatially-based conservation actions. Moreover, they enable observations of parameters of our environment at greater broader spatial and finer temporal scales than those allowed through field observation alone. In this sense, recent very high resolution satellite technologies and image processing algorithms present the opportunity to develop quantitative techniques that have the potential to improve upon traditional techniques in terms of cost, mapping fidelity, and objectivity. Typical applications include multi-temporal classification, recognition and tracking of specific patterns, multisensor data fusion, analysis of land/marine ecosystem processes and environment monitoring, etc. This book aims to collect new developments, methodologies, and applications of very high resolution satellite data for remote sensing. The works selected provide to the research community the most recent advances on all aspects of VHR satellite remote sensing
Advances in knowledge discovery and data mining Part II
19th Pacific-Asia Conference, PAKDD 2015, Ho Chi Minh City, Vietnam, May 19-22, 2015, Proceedings, Part II</p
NOTIFICATION !!!
All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition
NOTIFICATION !!!
All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition
NOTIFICATION !!!
All the content of this special edition is retrieved from the conference proceedings published by the European Scientific Institute, ESI. http://eujournal.org/index.php/esj/pages/view/books The European Scientific Journal, ESJ, after approval from the publisher re publishes the papers in a Special edition