• Reference based holoscopic 3D camera aperture stitching for widening the overall viewing angle

      Swash, M.R.; Fernandez, Juan C. J.; Aggoun, Amar; Fatah, O. Abdul; Tsekleves, Emmanuel; Brunel University; University of Bedfordshire (IEEE, 2014-07)
      Holoscopic 3D imaging also known as Integral imaging is a promising technique for creating full color 3D optical models that exist in space independently of the viewer. The images exhibit continuous parallax throughout the viewing zone. In order to achieve depth control, robust and real-time, a single aperture holoscopic 3D imaging camera is used for recording holoscopic 3D image using a regularly spaced array of small lenslets, which view the scene at a slightly different angle to its neighbour. However, the main problem the holoscopic 3D camera aperture faces is that it is not big enough for recording larger scene with existing 2D camera sensors. This paper proposes a novel reference based holoscopic 3D camera aperture stitching method that enlarges overall viewing angle of the holoscopic 3D camera in post-production after the capture.
    • The refocusing distance of a standard plenoptic photograph

      Hahne, Christopher; Aggoun, Amar; Velisavljević, Vladan; University of Bedfordshire (IEEE, 2015-06-12)
      In the past years, the plenoptic camera aroused an increasing interest in the field of computer vision. Its capability of capturing three-dimensional image data is achieved by an array of micro lenses placed in front of a traditional image sensor. The acquired light field data allows for the reconstruction of photographs focused at different depths. Given the plenoptic camera parameters, the metric distance of refocused objects may be retrieved with the aid of geometric ray tracing. Until now there was a lack of experimental results using real image data to prove this conceptual solution. With this paper, the very first experimental work is presented on the basis of a new ray tracing model approach, which considers more accurate micro image centre positions. To evaluate the developed method, the blur metric of objects in a refocused image stack is measured and compared with proposed predictions. The results suggest quite an accurate approximation for distant objects and deviations for objects closer to the camera device.
    • Rendering of novel views from photographs using inference in Markov random field

      Dong, Feng; Clapworthy, Gordon J.; Lin, Hai (IET, 2009-12-03)
    • RESTful web service composition: extracting a process model from Linear Logic theorem proving

      Zhao, Xia; Liu, Enjie; Clapworthy, Gordon J.; Ye, Na; Lu, Yueming (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2011-10)
    • A scalable data repository for recording self-managed longitudinal health data of digital patients

      Zhao, Xia; Zhao, Youbing; Ersotelos, Nikolaos; Fan, Dina; Liu, Enjie; Clapworthy, Gordon J.; Dong, Feng; University of Bedfordshire (2013-11)
      This paper presents the proof-of-concept design of the data repository for 4D digital avatars in the MyHealthAvatar project. Taking account of the privacy and legal issues of patient health information, the research generates a set of synthetic data based on publicly available survey data. At the prototype stage, these synthetic data are used in the scenarios of data storage and management. The paper discusses the early proof-of-concept design of the technical stack which enables the storage and query of large scale patients' health data and empowers the future data mining and analysis for health care support. It provides the first stage implementation and the use of it for data analytics.
    • Scene depth extraction from Holoscopic Imaging technology

      Alazawi, E.; Aggoun, Amar; Abbod, M.; Swash, M.R.; Abdul Fatah, O.; Fernandez, Juan C. J.; University of Bedfordshire; Brunel University (IEEE, 2013-10)
      3D Holoscopic Imaging (3DHI) is a promising technique for viewing natural continuous parallax 3D objects within a wide viewing zone using the principle of “Fly's eye”. The 3D content is captured using a single aperture camera in real-time and represents a true volume spatial optical model of the object scene. The 3D content viewed by multiple viewers independently of their position, without 3D eyewear glasses. The 3DHI technique merely requires a single recording that the acquisition of the 3D information and the compactness of depth measurement that is used has been attracting attention as a novel depth extraction technique. This paper presents a new corresponding and matching technique based on a novel automatic Feature-Match Selection (FMS) algorithm. The aim of this algorithm is to estimate and extract an accurate full parallax 3D model form from a 3D Omni-directional Holoscopic Imaging (3DOHI) system. The basis for the novelty of the paper is on two contributions: feature blocks selection and corresponding automatic optimization process. There are solutions for three main problems related to the depth map estimation from 3DHI: uncertainty and region homogeneity at image location, dissimilar displacements within the matching block around object borders, and computational complexity.
    • Scheduling and optimisation of batch plants: model development and comparison of approaches

      Tan, Yaqing; Huang, Wei; Sun, Yanming; Yue, Yong; University of Bedfordshire (Inderscience Publishers, 2014-06)
      The application of parallel machines and storage facilities provides flexibility but raises challenges for batch plants. This research proposes a scheduling model in batch plants, considering complex real-world constraints that were seldom addressed together. Two optimisation approaches, genetic algorithm (GA) and constraint programming (CP), are applied to solve the complex batch plant scheduling problem. A case study and scalability tests are conducted to investigate different performance of GA and CP in the problem to prepare for further research application. It is found that the CP approach has a better performance in solving batch plant scheduling problems with complex constraints although it needs longer time. The ‘restart’ search strategy is better than two other search strategies for the CP approach.
    • Semi-supervised tissue segmentation of 3D brain MR images

      Zhang, Xiangrong; Dong, Feng; Clapworthy, Gordon J.; Zhao, Youbing; Jiao, Licheng (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2010)
    • Shape-enhanced maximum intensity projection

      Zhou, Zhiguang; Tao, Yubo; Lin, Hai; Dong, Feng; Clapworthy, Gordon J. (SpringerLink, 2011)
      Maximum intensity projection (MIP) displays the voxel with the maximum intensity along the viewing ray, and this offers simplicity in usage, as it does not require a complex transfer function, the specification of which is a highly challenging and time-consuming process in direct volume rendering (DVR). However, MIP also has its inherent limitation, the loss of spatial context and shape information. This paper proposes a novel technique, shape-enhanced maximum intensity projection (SEMIP), to resolve this limitation. Inspired by lighting in DVR to emphasize surface structures, SEMIP searches a valid gradient for the maximum intensity of each viewing ray, and applies gradient-based shading to improve shape and depth perception of structures. As SEMIP may result in the pixel values over the maximum intensity of the display device, a tone reduction technique is introduced to compress the intensity range of the rendered image while preserving the original local contrast. In addition, depth-based color cues are employed to enhance the visual perception of internal structures, and a focus and context interaction is used to highlight structures of interest. We demonstrate the effectiveness of the proposed SEMIP with several volume data sets, especially from the medical field.
    • Single feed stacked patch circular polarized antenna for triple band GPS receivers

      Falade, Oluyemi Peter; Ur-Rehman, Masood; Gao, Yue; Chen, Xiaodong; Parini, Clive G.; Queen Mary University, London (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2012-10)
      A novel design of a circular polarized antenna for multiband GPS receivers is presented. The design employs the concept of multistacked patches fed through a single coaxial probe. Three patches being stacked together with a slit and symmetry I-slot are used to achieve triple operating frequency bands for GPS including L1 (1.575 GHz), L2 (1.227 GHz) and L5 (1.176 GHz). The proposed antenna has achieved a bandwidth of 2.0%, 1.5%, and 1.7% at GPS L1, L2, and L5 bands, respectively. It exhibits a minimum axial ratio of 0.51 dB with broad beamwidth in the upper hemisphere required for the GPS applications. The design of the proposed antenna is verified in the experiment. In addition, a detailed analysis has been carried out to study the effects of different geometrical parameters on the performance of the antenna.
    • SOA-based digital library services and composition in biomedical applications

      Zhao, Xia; Liu, Enjie; Clapworthy, Gordon J.; Viceconti, Marco; Testi, Debora (Elsevier, 2012-06)
    • Strategic team AI path plans: probabilistic pathfinding

      John, Tng C. H.; Prakash, Edmond C.; Chaudhari, Narendra S. (Hindawi, 2008)
      This paper proposes a novel method to generate strategic team AI pathfinding plans for computer games and simulations using probabilistic pathfinding. This method is inspired by genetic algorithms (Russell and Norvig, 2002), in that, a fitness function is used to test the quality of the path plans. The method generates high-quality path plans by eliminating the low-quality ones. The path plans are generated by probabilistic pathfinding, and the elimination is done by a fitness test of the path plans. This path plan generation method has the ability to generate variation or different high-quality paths, which is desired for games to increase replay values. This work is an extension of our earlier work on team AI: probabilistic pathfinding (John et al., 2006). We explore ways to combine probabilistic pathfinding and genetic algorithm to create a new method to generate strategic team AI pathfinding plans.
    • Structure-aware lighting design for volume visualization

      Tao, Yubo; Lin, Hai; Dong, Feng; Wang, Chao; Clapworthy, Gordon J.; Bao, Hujun (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2012-12)
      Lighting design is a complex, but fundamental, problem in many fields. In volume visualization, direct volume rendering generates an informative image without external lighting, as each voxel itself emits radiance. However, external lighting further improves the shape and detail perception of features, and it also determines the effectiveness of the communication of feature information. The human visual system is highly effective in extracting structural information from images, and to assist it further, this paper presents an approach to structure-aware automatic lighting design by measuring the structural changes between the images with and without external lighting. Given a transfer function and a viewpoint, the optimal lighting parameters are those that provide the greatest enhancement to structural information - the shape and detail information of features are conveyed most clearly by the optimal lighting parameters. Besides lighting goodness, the proposed metric can also be used to evaluate lighting similarity and stability between two sets of lighting parameters. Lighting similarity can be used to optimize the selection of multiple light sources so that different light sources can reveal distinct structural information. Our experiments with several volume data sets demonstrate the effectiveness of the structure-aware lighting design approach. It is well suited to use by novices as it requires little technical understanding of the rendering parameters associated with direct volume rendering.
    • Subspace-based SNR estimator for OFDM system under different channel conditions

      Li, Wei; Zhang, Yue; Zhang, Yuan; Huang, Li-Ke; Cosmas, John; Maple, Carsten; University of Bedfordshire (IEEE, 2013-06)
      Signal-to-noise ratio (SNR) estimation plays an important role to adaptive modulation in Evolved Multimedia Broadcast Multicast Services (eMBMS). Based on the knowledge that the received signal space consists of signal subspace and noise subspace, we propose a subspace-based SNR estimation solution to cope with the time-varying channel with frequency selective effect and different OFDM pilot structure situations in eMBMS. The simulation is carried out on both PC and Aeroflex PXI platform. Simulation results show this proposed method gives good performance with different eMBMS pilot length and time-varying channels.
    • Super depth-map rendering by converting holoscopic viewpoint to perspective projection

      Alazawi, E.; Abbod, M.; Aggoun, Amar; Swash, M.R.; Fatah, O. Abdul; Fernandez, Juan C. J.; University of Bedfordshire; Brunel University (IEEE, 2014-07)
      The expansion of 3D technology will enable observers to perceive 3D without any eye-wear devices. Holoscopic 3D imaging technology offers natural 3D visualisation of real 3D scenes that can be viewed by multiple viewers independently of their position. However, the creation of a super depth-map and reconstruction of the 3D object from a holoscopic 3D image is still in its infancy. The aim of this work is to build a high-quality depth map of a real 3D scene from a holoscopic 3D image through extraction of multi-view high resolution Viewpoint Images (VPIs) to compensate for the poor features of VPIs. To manage this, we propose a reconstruction method based on the perspective formula to convert sets of directional orthographic low resolution VPIs into perspective projection geometry. Following that, we implement an Auto-Feature point algorithm for synthesizing VPIs to distinctive Feature-Edge (FE) blocks to localize and provide an individual feature detector that is responsible for integration of 3D information. Detailed experiments proved the reliability and efficiency of the proposed method, which outperforms state-of-the-art methods for depth map creation.
    • Support for the calculation of stent fatigue fracture in peripheral arteries

      McFarlane, Nigel J.B.; Wei, Hui; Zhao, Youbing; Clapworthy, Gordon J.; Testi, Debora; Chiarini, Alessandro; University of Bedfordshire (European Association for Computer Graphics, 2013)
      Vascular stenting is a medical intervention in which a wire mesh tube is inserted into an artery or vein to provide internal support. This is a safe and common procedure, but stents are now increasingly being deployed in peripheral locations, such as the femoral artery, as part of a procedure called Peripheral Vascular Angioplasty (PVA). Stents in such locations are subject to cyclic bending, and are therefore at risk of fatigue fracture. This paper describes the work of the RT3S project, which brings together stent modelling, surgical simulation and risk calculation for surgical planning. This will allow the clinical user to interactively assess different stent models and deployment options for breakage risk. In the RT3S system, models of several commercial models of self-expanding stent are available for simulation. The placement of the stent in the vessel and the withdrawal of the catheter sheath to expand the stent are visualised. A simplex control mesh is used to guide the deformation of the stent from its compressed start configuration to its expanded final position. The fracture risk for the given model and its patient-specific final position is precomputed using the response surfaces methodology.
    • A survey and classification of visualisation in multiscale biomedical applications

      McFarlane, Nigel J.B.; Ma, Xiangyin; Clapworthy, Gordon J.; Bessis, Nik; Testi, Debora (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2012)
    • Synopsis of an engineering solution for a painful problem - phantom limb pain

      Mousavi, A.; Cole, J.; Kalganova, T.; Stone, R.; Zhang, J.; Pettifer, S.; Walker, R.; Nikopoulou-Smyrni, P.; Henderson Slater, D.; Aggoun, Amar; et al. (Scitepress, 2014)
      This paper is synopsis of a recently proposed solution for treating patients who suffer from Phantom Limb Pain (PLP). The underpinning approach of this research and development project is based on an extension of "mirror box" therapy which has had some promising results in pain reduction. An outline of an immersive individually tailored environment giving the patient a virtually realised limb presence, as a means to pain reduction is provided. The virtual 3D holographic environment is meant to produce immersive, engaging and creative environments and tasks to encourage and maintain patients' interest, an important aspect in two of the more challenging populations under consideration (over-60s and war veterans). The system is hoped to reduce PLP by more than 3 points on an 11 point Visual Analog Scale (VAS), when a score less than 3 could be attributed to distraction alone.
    • Taxonomy of optimisation techniques and applications

      Maple, Carsten; Prakash, Edmond C.; Huang, Wei; Qureshi, Adnan Nabeel Abid; University of Bedfordshire (Inderscience Publishers, 2014-06)
      This paper presents a review of recent advances in optimisation techniques. Optimisation is a complex task and it is nearly impossible to identify a single technique which can act as a silver bullet in all contexts where scarcity and limitation of resources and constraints exist. The list of individual optimisation methods, their combinations and hybridisations is endless and, hence, it is imperative to classify them based on common attributes and highlight some of the salient industrial and research domains where they have been implemented. This paper concentrates on application areas of the different optimisation techniques in particular, with the objective to establish a practical taxonomy based on the combination of heuristic or non-heuristic nature of algorithms, nature of design variables and nature of equations. A précis of research at the University of Bedfordshire is also given to highlight the contributions made towards optimising different industrial and engineering problems exemplifying the latest trends and research arenas.