Texture as pixel feature for video object segmentation
- Authors: Ahmed, Rakib , Karmakar, Gour , Dooley, Laurence
- Date: 2008
- Type: Text , Journal article
- Relation: Electronics Letters Vol. 44, no. 19 (2008), p. 1126-1127
- Full Text: false
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Bezier curve-based generic shape encoder
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence , Bennamoun, M.
- Date: 2010
- Type: Text , Journal article
- Relation: IET Image Processing Vol. 4, no. 2 (2010), p. 92-102
- Full Text: false
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- Description: Existing Bezier curve-based shape description techniques primarily focus upon determining a set of pertinent control points (CP) to represent a particular shape contour. While many different approaches have been proposed, none adequately consider domain-specific information about the shape contour like its gradualness and sharpness, in the CP generation process which can potentially result in large distortions in the object's shape representation. This study introduces a novel Bezier curve-based generic shape encoder (BCGSE) that partitions an object contour into contiguous segments based upon its cornerity, before generating the CP for each segment using relevant shape curvature information. In addition, although CP encoding has generally been ignored, BCGSE embeds an efficient vertex-based encoding strategy exploiting the latent equidistance between consecutive CP. A non-linear optimisation technique is also presented to enable the encoder is automatically adapt to bit-rate constraints. The performance of the BCGSE framework has been rigorously tested on a variety of diverse arbitrary shapes from both a distortion and requisite bit-rate perspective, with qualitative and quantitative results corroborating its superiority over existing shape descriptors.
Image-dependent spatial shape-error concealment
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence
- Date: 2008
- Type: Text , Conference paper
- Relation: Signal Processing, 2008. ICSP 2008. 9th International Conference
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- Description: Existing spatial shape-error concealment techniques are broadly based upon either parametric curves that exploit geometric information concerning a shapepsilas contour or object shape statistics using a combination of Markov random fields and maximum a posteriori estimation. Both categories are to some extent, able to mask errors caused by information loss, provided the shape is considered independently of the image/video. They palpably however, do not afford the best solution in applications where shape is used as metadata to describe image and video content. This paper presents a novel image-dependent spatial shape-error concealment (ISEC) algorithm that uses both image and shape information by employing the established rubber-band contour detecting function, with the novel enhancement of automatically determining the optimal width of the band to achieve superior error concealment. Experimental results qualitatively and numerically corroborate the enhanced performance of the new ISEC strategy compared with established shape-based concealment techniques.
Detection and separation of generic-shaped objects by fuzzy clustering
- Authors: Ali, Mohammad , Karmakar, Gour , Dooley, Laurence
- Date: 2010
- Type: Text , Journal article
- Relation: International Journal of Intelligent Computing and Cybernetics Vol. 3, no. 3 (2010 2010), p. 365-390
- Full Text: false
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- Description: Image segmentation involves the separation of mutually exclusive regions/objects of interest (Gonzalez and Woods, 2002), and is integral to the image processing, coding and interpretation domains, with examples of some of the eclectic range of applications including: image analysis, robot vision, automatic car assembly, security surveillance systems, object recognition and medical imaging (Gonzalez and Woods, 2002; Hoppner et al., 1999; Pham and Prince, 1999; Gath and Geva, 1989; Pal and Pal, 1993). As there are potentially a very large number of perceptual objects in an image, with subtle variations between them, this makes generalised object-based segmentation an especially challenging task.
Heuristic non parametric collateral missing value imputation : A step towards robust post-genomic knowledge discovery
- Authors: Sehgal, Muhammad Shoaib B , Gondal, Iqbal , Dooley, Laurence , Coppel, Ross
- Date: 2008
- Type: Text , Conference paper
- Relation: Third IAPR International Conference on Pattern Recognition in Bioinformatics (PRIB 2008) Vol. 5625
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- Description: Microarrays are able to measure the patterns of expression of thousands of genes in a genometo give profiles that faciliate much faster analysis of biological process for diagnosis, prognosis and tailored drug discovery. Microarrays, however commonly have missing values, various algorithms have been proposed including Collateral Missing Value Estimation (CMVE), Bayesian Principal Component Analysis (BPCA), Least Square Impute (LSImpute). Local Least Square Impute (LLSImpute) and K-Nearest Neighbour (KNN).
Video coding for mobile communications
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence
- Date: 2008
- Type: Text , Book chapter
- Relation: Mobile Multimedia Communications: Concepts, Applications, and Challenges p. 109-150
- Full Text: false
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Fuzzy clustering for image segmentation using generic shape information
- Authors: Ali, Mohammad , Karmakar, Gour , Dooley, Laurence
- Date: 2008
- Type: Text , Journal article
- Relation: Malaysian Journal of Computer Science Vol. 21, no. 2 (2008), p. 122-138
- Full Text: false
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- Description: The performance of clustering algorithms for image segmentation are highly sensitive to the features used and types of objects in the image, which ultimately limits their generalization capability. This provides strong motivation to investigate integrating shape information into the clustering framework to improve the generality of these algorithms. Existing shape-based clustering techniques mainly focus on circular and elliptical clusters and so are unable to segment arbitrarily-shaped objects. To address this limitation, this paper presents a new shape-based algorithm called fuzzy clustering for image segmentation using generic shape information (FCGS), which exploits the B-spline representation of an object’s shape in combination with the Gustafson-Kessel clustering algorithm. Qualitative and quantitative results for FCGS confirm its superior segmentation performance consistently compared to well-established shape-based clustering techniques, for a wide range of test images comprising various regular and arbitrary-shaped objects
Computational modelling strategies for gene regulatory network reconstruction
- Authors: Sehgal, Muhammad Shoaib B , Gondal, Iqbal , Dooley, Laurence
- Date: 2008
- Type: Text , Book chapter
- Relation: Studies in Computational Intelligence p. 207-220
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- Description: Gene Regulatory Network (GRN) modelling infers genetic interactions between different genes and other cellular components to elucidate the cellular functionality. This GRN modelling has overwhelming applications in biology starting from diagnosis through to drug target identification. Several GRN modelling methods have been proposed in the literature, and it is important to study the relative merits and demerits of each method. This chapter provides a comprehensive comparative study on GRN reconstruction algorithms. The methods discussed in this chapter are diverse and vary from simple similarity based methods to state of the art hybrid and probabilistic methods. In addition, the chapter also underpins the need of strategies which should be able to model the stochastic behavior of gene regulation in the presence of limited number of samples, noisy data, multi-collinearity for high number of genes.
Geometric distortion measurement for shape coding: a contemporary review
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence , Bennamoun, M.
- Date: 2011
- Type: Text , Journal article
- Relation: ACM Computing Surveys Vol. 43, no. 4 (2011), p. 1-22
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- Description: Geometric distortion measurement and the associated metrics involved are integral to the Rate Distortion (RD) shape coding framework, with importantly the efficacy of the metrics being strongly influenced by the underlying measurement strategy. This has been the catalyst for many different techniques with this article presenting a comprehensive review of geometric distortion measurement, the diverse metrics applied, and their impact on shape coding. The respective performance of these measuring strategies is analyzed from both a RD and complexity perspective, with a recent distortion measurement technique based on arc-length-parameterization being comparatively evaluated. Some contemporary research challenges are also investigated, including schemes to effectively quantify shape deformation.
Gene expression imputation techniques for robust post genomic knowledge discovery
- Authors: Sehgal, Muhammad Shoaib B , Gondal, Iqbal , Dooley, Laurence
- Date: 2008
- Type: Text , Book chapter
- Relation: Studies in Computational Intelligence p. 185-206
- Full Text: false
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- Description: Microarrays measure expression patterns of thousands of genes at a time, under same or diverse conditions, to facilitate faster analysis of biological processes. This gene expression data is being widely used for diagnosis, prognosis and tailored drug discovery. Microarray data, however, commonly contains missing values, which can have high impact on subsequent biological knowledge discovery methods. This has been catalyst for the manifest of different imputation algorithms, including Collateral Missing Value Estimation (CMVE), Bayesian Principal Component Analysis (BPCA), Least Square Impute (LSImpute), Local Least Square Impute (LLSImpute) and K-Nearest Neighbour (KNN). This Chapter investigates the impact of missing values on post genomic knowledge discovery methods like, Gene Selection and Gene Regulatory Network (GRN) reconstruction. A framework for robust subsequent biological knowledge inference has been proposed which has shown significant improvements in the outcomes of Gene Selection and GRN reconstruction methods.
Quasi-Bezier curves integrating localised information
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence , Arkinstall, John
- Date: 2008
- Type: Text , Journal article
- Relation: Pattern Recognition Vol. 41, no. 2 (2008), p. 531-542
- Full Text: false
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- Description: Bezier curves (BC) have become fundamental tools in many challenging and varied applications, ranging from computer-aided geometric design to generic object shape descriptors. A major limitation of the classical Bezier curve, however, is that only global information about its control points (CP) is considered, so there can often be a large gap between the curve and its control polygon, leading to large distortion in shape representation. While strategies such as degree elevation, composite BC, refinement and subdivision reduce this gap, they also increase the number of CP and hence bit-rate, and computational complexity. This paper presents novel contributions to BC theory, with the introduction of quasi-Bezier curves (QBC), which seamlessly integrate localised CP information into the inherent global Bezier framework, with no increase in either the number of CP or order of computational complexity. QBC crucially retains the core properties of the classical BC, such as geometric continuity and affine invariance, and can be embedded into the vertex-based shape coding and shape descriptor framework to enhance rate-distortion performance. The performance of QBC has been empirically tested upon a number of natural and synthetically shaped objects, with both qualitative and quantitative results confirming its consistently superior approximation performance in comparison with both the classical BC and other established BC-based shape descriptor methods.
Introduction to mobile multimedia communications
- Authors: Karmakar, Gour , Dooley, Laurence , Mathew, Michael
- Date: 2008
- Type: Text , Book chapter
- Relation: Mobile Multimedia Communications: Concepts, Applications, and Challenge p. 1-23
- Full Text: false
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Sliding-window designs for vertex-based shape coding
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence , Bennamoun, M.
- Date: 2012
- Type: Text , Journal article
- Relation: IEEE Transactions on Multimedia Vol. 14, no. 3 (June 2012), p. 683-692
- Full Text: false
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- Description: Traditionally the sliding window (SW) has been employed in vertex-based operational rate distortion (ORD) optimal shape coding algorithms to ensure consistent distortion (quality) measurement and improve computational efficiency. It also regulates the memory requirements for an encoder design enabling regular, symmetrical hardware implementations. This paper presents a series of new enhancements to existing techniques for determining the best SW-length within a rate-distortion (RD) framework, and analyses the nexus between SW-length and storage for ORD hardware realizations. In addition, it presents an efficient bit-allocation strategy for managing multiple shapes together with a generalized adaptive SW scheme which integrates localized curvature information (cornerity) on contour points with a bi-directional spatial distance, to afford a superior and more pragmatic SW design compared with existing adaptive SW solutions which are based on only cornerity values. Experimental results consistently corroborate the effectiveness of these new strategies.
Dynamic Bezier curves for variable rate-distortion
- Authors: Sohel, Ferdous , Karmakar, Gour , Dooley, Laurence
- Date: 2008
- Type: Text , Journal article
- Relation: Pattern Recognition Vol. 41, no. 10 (2008), p. 3153-3165
- Full Text: false
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- Description: Bezier curves (BC) are important tools in a wide range of diverse and challenging applications, from computer-aided design to generic object shape descriptors. A major constraint of the classical BC is that only global information concerning control points (CP) is considered, consequently there may be a sizeable gap between the BC and its control polygon (CtrlPoly), leading to a large distortion in shape representation. While BC variants like degree elevation, composite BC and refinement and subdivision narrow this gap, they increase the number of CP and thereby both the required bit-rate and computational complexity. In addition, while quasi-Bezier curves (QBC) close the gap without increasing the number of CP, they reduce the underlying distortion by only a fixed amount. This paper presents a novel contribution to BC theory, with the introduction of a dynamic Bezier curve (DBC) model, which embeds variable localised CP information into the inherently global Bezier framework, by strategically moving BC points towards the CtrlPoly. A shifting parameter (SP) is defined that enables curves lying within the region between the BC and CtrlPoly to be generated, with no commensurate increase in CP. DBC provides a flexible rate-distortion (RD) criterion for shape coding applications, with a theoretical model for determining the optimal SP value for any admissible distortion being formulated. Crucially DBC retains core properties of the classical BC, including the convex hull and affine invariance, and can be seamlessly integrated into both the vertex-based shape coding and shape descriptor frameworks to improve their RD performance. DBC has been empirically tested upon a number of natural and synthetically shaped objects, with qualitative and quantitative results confirming its consistently superior shape approximation performance, compared with the classical BC, QBC and other established BC-based shape descriptor techniques.
Object analysis with visual sensors and RFID
- Authors: Karmakar, Gour , Karmakar, Nemai , Dooley, Laurence , Kamruzzaman, Joarder
- Date: 2013
- Type: Text , Book chapter
- Relation: Image Processing: Concepts, Methodologies, Tools, and Applications p. 1492-1507
- Full Text: false
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- Description: Object analysis using visual sensors is one of the most important and challenging issues in computer vision research due principally to difficulties in object representation, segmentation, and recognition within a general framework. This has motivated researchers to investigate exploiting the potential identification capability of RFID (radio frequency identification) technology for object analysis. RFID however, has a number of fundamental limitations including a short sensing range, missing tag detection, not working for all objects, and some items being just too small to be tagged. This has meant applying RFID alone has not been entirely effective in computer vision applications. To address these restrictions, object analysis approaches based on a combination of visual sensors and RFID have recently been successfully introduced. This chapter presents a contemporary review on these object analysis techniques for localisation, tracking, and object and activity recognition, together with some future research directions in this burgeoning field. © 2013, IGI Global.
Object analysis with visual sensors and RFID
- Authors: Karmakar, Gour , Dooley, Laurence , Karmakar, Nemai , Kamruzzaman, Joarder
- Date: 2012
- Type: Text , Book chapter
- Relation: Chipless and conventional radio frequency identification : Systems for ubiquitous tagging Chapter 12 p. 234-250
- Full Text: false
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- Description: Object analysis using visual sensors is one of the most important and challenging issues in computer vision research due principally to difficulties in object representation, segmentation, and recognition within a general framework. This has motivated researchers to investigate exploiting the potential identification capability of RFID (radio frequency identification) technology for object analysis. RFID however, has a number of fundamental limitations including a short sensing range, missing tag detection, not working for all objects, and some items being just too small to be tagged. This has meant applying RFID alone has not been entirely effective in computer vision applications. To address these restrictions, object analysis approaches based on a combination of visual sensors and RFID have recently been successfully introduced. This chapter presents a contemporary review on these object analysis techniques for localisation, tracking, and object and activity recognition, together with some future research directions in this burgeoning field.
How to improve postgenomic knowledge discovery using imputation
- Authors: Sehgal, Muhammad Shoaib B , Gondal, Iqbal , Dooley, Laurence , Coppel, Ross
- Date: 2009
- Type: Text , Journal article
- Relation: Eurasip Journal on Bioinformatics and Systems Biology Vol. 2009, no. 1 (2009), p. 1-14
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- Description: While microarrays make it feasible to rapidly investigate many complex biological problems, their multistep fabrication has the proclivity for error at every stage. The standard tactic has been to either ignore or regard erroneous gene readings as missing values, though this assumption can exert a major influence upon postgenomic knowledge discovery methods like gene selection and gene regulatory network (GRN) reconstruction. This has been the catalyst for a raft of new flexible imputation algorithms including local least square impute and the recent heuristic collateral missing value imputation, which exploit the biological transactional behaviour of functionally correlated genes to afford accurate missing value estimation. This paper examines the influence of missing value imputation techniques upon postgenomic knowledge inference methods with results for various algorithms consistently corroborating that instead of ignoring missing values, recycling microarray data by flexible and robust imputation can provide substantial performance benefits for subsequent downstream procedures