576 research outputs found
Pose-invariant, model-based object recognition, using linear combination of views and Bayesian statistics
This thesis presents an in-depth study on the problem of object recognition, and in particular the detection
of 3-D objects in 2-D intensity images which may be viewed from a variety of angles. A solution to this
problem remains elusive to this day, since it involves dealing with variations in geometry, photometry
and viewing angle, noise, occlusions and incomplete data. This work restricts its scope to a particular
kind of extrinsic variation; variation of the image due to changes in the viewpoint from which the object
is seen.
A technique is proposed and developed to address this problem, which falls into the category of
view-based approaches, that is, a method in which an object is represented as a collection of a small
number of 2-D views, as opposed to a generation of a full 3-D model. This technique is based on the
theoretical observation that the geometry of the set of possible images of an object undergoing 3-D rigid
transformations and scaling may, under most imaging conditions, be represented by a linear combination
of a small number of 2-D views of that object. It is therefore possible to synthesise a novel image of an
object given at least two existing and dissimilar views of the object, and a set of linear coefficients that
determine how these views are to be combined in order to synthesise the new image.
The method works in conjunction with a powerful optimization algorithm, to search and recover the
optimal linear combination coefficients that will synthesize a novel image, which is as similar as possible
to the target, scene view. If the similarity between the synthesized and the target images is above some
threshold, then an object is determined to be present in the scene and its location and pose are defined,
in part, by the coefficients. The key benefits of using this technique is that because it works directly
with pixel values, it avoids the need for problematic, low-level feature extraction and solution of the
correspondence problem. As a result, a linear combination of views (LCV) model is easy to construct
and use, since it only requires a small number of stored, 2-D views of the object in question, and the
selection of a few landmark points on the object, the process which is easily carried out during the offline,
model building stage. In addition, this method is general enough to be applied across a variety of
recognition problems and different types of objects.
The development and application of this method is initially explored looking at two-dimensional
problems, and then extending the same principles to 3-D. Additionally, the method is evaluated across
synthetic and real-image datasets, containing variations in the objects’ identity and pose. Future work on
possible extensions to incorporate a foreground/background model and lighting variations of the pixels
are examined
Computational intelligence approaches to robotics, automation, and control [Volume guest editors]
No abstract available
Affective Computing
This book provides an overview of state of the art research in Affective Computing. It presents new ideas, original results and practical experiences in this increasingly important research field. The book consists of 23 chapters categorized into four sections. Since one of the most important means of human communication is facial expression, the first section of this book (Chapters 1 to 7) presents a research on synthesis and recognition of facial expressions. Given that we not only use the face but also body movements to express ourselves, in the second section (Chapters 8 to 11) we present a research on perception and generation of emotional expressions by using full-body motions. The third section of the book (Chapters 12 to 16) presents computational models on emotion, as well as findings from neuroscience research. In the last section of the book (Chapters 17 to 22) we present applications related to affective computing
Bioinformatics Applications Based On Machine Learning
The great advances in information technology (IT) have implications for many sectors, such as bioinformatics, and has considerably increased their possibilities. This book presents a collection of 11 original research papers, all of them related to the application of IT-related techniques within the bioinformatics sector: from new applications created from the adaptation and application of existing techniques to the creation of new methodologies to solve existing problems
Advanced Information Systems and Technologies
This book comprises the proceedings of the V International Scientific Conference "Advanced Information Systems and Technologies, AIST-2017". The proceeding papers cover issues related to system analysis and modeling, project management, information system engineering, intelligent data processing computer networking and telecomunications. They will be useful for students, graduate students, researchers who interested in computer science
Advanced Information Systems and Technologies
This book comprises the proceedings of the V International Scientific Conference "Advanced Information Systems and Technologies, AIST-2017". The proceeding papers cover issues related to system analysis and modeling, project management, information system engineering, intelligent data processing computer networking and telecomunications. They will be useful for students, graduate students, researchers who interested in computer science
Study on the Method of Constructing a Statistical Shape Model and Its Application to the Segmentation of Internal Organs in Medical Images
In image processing, segmentation is one of the critical tasks for diagnostic analysis and image interpretation. In the following thesis, we describe the investigation of three problems related to the segmentation algorithms for medical images: Active shape model algorithm, 3-dimensional (3-D) statistical shape model building and organic segmentation experiments. For the development of Active shape models, the constraints of statistical model reduced this algorithm to be difficult for various biological shapes. To overcome the coupling of parameters in the original algorithm, in this thesis, the genetic algorithm is introduced to relax the shape limitation. How to construct a robust and effective 3-D point model is still a key step in statistical shape models. Generally the shape information is obtained from manually segmented voxel data. In this thesis, a two-step procedure for generating these models was designed. After transformed the voxel data to triangular polygonal data, in the first step, attitudes of these interesting objects are aligned according their surface features. We propose to reflect the surface orientations by means of their Gauss maps. As well the Gauss maps are mapped to a complex plane using stereographic projection approach. The experiment was run to align a set of left lung models. The second step is identifying the positions of landmarks on polygonal surfaces. This is solved by surface parameterization method. We proposed two simplex methods to correspond the landmarks. A semi-automatic method attempts to “copy” the phasic positions of pre-placed landmarks to all the surfaces, which have been mapped to the same parameterization domain. Another automatic corresponding method attempts to place the landmarks equidistantly. Finally, the goodness experiments were performed to measure the difference to manually corresponded results. And we also compared the affection to correspondence when using different surface mapping methods. The third part of this thesis is applying the segmentation algorithms to solve clinical problems. We did not stick to the model-based methods but choose the suitable one or their complex according to the objects. In the experiment of lung regions segmentation which includes pulmonary nodules, we propose a complementary region growing method to deal with the unpredictable variation of image densities of lesion regions. In the experiments of liver regions, instead of using region growing method in 3-D style, we turn into a slice-by-slice style in order to reduce the overflows. The image intensity of cardiac regions is distinguishable from lung regions in CT image. But as to the adjacent zone of heart and liver boundary are generally blurry. We utilized a shape model guided method to refine the segmentation results.3-D segmentation techniques have been applied widely not only in medical imaging fields, but also in machine vision, computer graphic. At the last part of this thesis, we resume some interesting topics such as 3-D visualization for medical interpretation, human face recognition and object grasping robot etc.九州工業大学博士学位論文 学位記番号:工博甲第353号 学位授与年月日:平成25年9月27日Chapter 1: Introduction|Chapter 2: Framework of Medical Image Segmentation|Chapter 3: 2-D Organic Regions Using Active Shape Model and Genetic Algorithm|Chapter 4: Alignment of 3-D Models|Chapter 5: Corespondence of 3-D Models|Chapter 6:Experiments of Organic Segmentation|Chapter 7: Visualization Technology and Its Applications|Chapter 8: Conclusions and Future Works九州工業大学平成25年
Adaptive threshold optimisation for colour-based lip segmentation in automatic lip-reading systems
A thesis submitted to the Faculty of Engineering and the Built Environment,
University of the Witwatersrand, Johannesburg, in ful lment of the requirements for
the degree of Doctor of Philosophy.
Johannesburg, September 2016Having survived the ordeal of a laryngectomy, the patient must come to terms with
the resulting loss of speech. With recent advances in portable computing power,
automatic lip-reading (ALR) may become a viable approach to voice restoration. This
thesis addresses the image processing aspect of ALR, and focuses three contributions
to colour-based lip segmentation.
The rst contribution concerns the colour transform to enhance the contrast
between the lips and skin. This thesis presents the most comprehensive study to
date by measuring the overlap between lip and skin histograms for 33 di erent
colour transforms. The hue component of HSV obtains the lowest overlap of 6:15%,
and results show that selecting the correct transform can increase the segmentation
accuracy by up to three times.
The second contribution is the development of a new lip segmentation algorithm
that utilises the best colour transforms from the comparative study. The algorithm
is tested on 895 images and achieves percentage overlap (OL) of 92:23% and segmentation
error (SE) of 7:39 %.
The third contribution focuses on the impact of the histogram threshold on the
segmentation accuracy, and introduces a novel technique called Adaptive Threshold
Optimisation (ATO) to select a better threshold value. The rst stage of ATO
incorporates -SVR to train the lip shape model. ATO then uses feedback of shape
information to validate and optimise the threshold. After applying ATO, the SE
decreases from 7:65% to 6:50%, corresponding to an absolute improvement of 1:15 pp
or relative improvement of 15:1%. While this thesis concerns lip segmentation in
particular, ATO is a threshold selection technique that can be used in various
segmentation applications.MT201
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