980 research outputs found

    Robust tracking for augmented reality

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    In this paper a method for improving a tracking algorithm in an augmented reality application is presented. This method addresses several issues to this particular application, like marker-less tracking and color constancy with low quality cameras, or precise tracking with real-time constraints. Due to size restrictions some of the objects are tracked using color information. To improve the quality of the detection, a color selection scheme is proposed to increase color distance between different objects in the scene. Moreover, a new color constancy method based in a diagonal-offset model and k-means is presented. Finally, some real images are used to show the improvement with this new method.Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech. Ministry of Education of Spain (TIN2013-42253P), Junta de Andalucía of Spain (TIC-1692

    Detection of elliptical shapes via cross-entropy clustering

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    The problem of finding elliptical shapes in an image will be considered. We discuss the solution which uses cross-entropy clustering. The proposed method allows the search for ellipses with predefined sizes and position in the space. Moreover, it works well for search of ellipsoids in higher dimensions

    Application of the Fisher-Rao metric to ellipse detection

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    The parameter space for the ellipses in a two dimensional image is a five dimensional manifold, where each point of the manifold corresponds to an ellipse in the image. The parameter space becomes a Riemannian manifold under a Fisher-Rao metric, which is derived from a Gaussian model for the blurring of ellipses in the image. Two points in the parameter space are close together under the Fisher-Rao metric if the corresponding ellipses are close together in the image. The Fisher-Rao metric is accurately approximated by a simpler metric under the assumption that the blurring is small compared with the sizes of the ellipses under consideration. It is shown that the parameter space for the ellipses in the image has a finite volume under the approximation to the Fisher-Rao metric. As a consequence the parameter space can be replaced, for the purpose of ellipse detection, by a finite set of points sampled from it. An efficient algorithm for sampling the parameter space is described. The algorithm uses the fact that the approximating metric is flat, and therefore locally Euclidean, on each three dimensional family of ellipses with a fixed orientation and a fixed eccentricity. Once the sample points have been obtained, ellipses are detected in a given image by checking each sample point in turn to see if the corresponding ellipse is supported by the nearby image pixel values. The resulting algorithm for ellipse detection is implemented. A multiresolution version of the algorithm is also implemented. The experimental results suggest that ellipses can be reliably detected in a given low resolution image and that the number of false detections can be reduced using the multiresolution algorithm

    Self-calibration and motion recovery from silhouettes with two mirrors

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    LNCS v. 7724-7727 (pts. 1-4) entitled: Computer vision - ACCV 2012: 11th Asian Conference on Computer Vision ... 2012: revised selected papersThis paper addresses the problem of self-calibration and motion recovery from a single snapshot obtained under a setting of two mirrors. The mirrors are able to show five views of an object in one image. In this paper, the epipoles of the real and virtual cameras are firstly estimated from the intersection of the bitangent lines between corresponding images, from which we can easily derive the horizon of the camera plane. The imaged circular points and the angle between the mirrors can then be obtained from equal angles between the bitangent lines, by planar rectification. The silhouettes produced by reflections can be treated as a special circular motion sequence. With this observation, technique developed for calibrating a circular motion sequence can be exploited to simplify the calibration of a single-view two-mirror system. Different from the state-of-the-art approaches, only one snapshot is required in this work for self-calibrating a natural camera and recovering the poses of the two mirrors. This is more flexible than previous approaches which require at least two images. When more than a single image is available, each image can be calibrated independently and the problem of varying focal length does not complicate the calibration problem. After the calibration, the visual hull of the objects can be obtained from the silhouettes. Experimental results show the feasibility and the preciseness of the proposed approach. © 2013 Springer-Verlag.postprin

    Kinesiology taping for breast lymphoedema after breast cancer treatment: A feasibility randomised controlled tria

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    PURPOSE: The primary aim of this study was to determine the feasibility of conducting a randomised controlled trial (RCT) to evaluate the effectiveness of kinesiology tape (KT) and usual care versus usual care alone in the treatment of breast lymphoedema (BLE). METHODS: Fourteen participants with BLE were randomly assigned to either the KT and usual care group or usual care alone group. Both groups received three sessions of manual lymphatic drainage (MLD) once per week for three weeks, with the KT group additionally wearing the KT for two seven-day periods in between MLD sessions. Safety and acceptability of the KT were assessed by recording adverse events, skin changes and compliance with KT. Outcomes included were: ease of recruitment, attrition and acceptability of KT, percentage breast tissue water, patient-reported breast heaviness/fullness, breast discomfort and breast redness. RESULTS: Recruitment for this study was an average of 2.8 participants per month. There were no dropouts from either group. No adverse events or major skin side effects were recorded in either group. Minor skin redness was the most common dermal change (n  = 5). Compliance with KT was excellent. Percentage tissue water in the worst affected breast quadrant reduced, on average, by 15.14% and 10.43% in both the KT group and the usual care group respectively. CONCLUSION: This feasibility RCT into the use of KT in BLE has shown that recruitment to a larger scale RCT is feasible. It has been demonstrated that KT is a safe and acceptable intervention with no adverse events and minor dermal changes. A large, multi-centred RCT is now necessary to accurately assess the effect of KT in BLE

    A 6-year update of the health policy and advocacy priorities of the Society of Behavioral Medicine

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    Government policy affects virtually every topic of interest to health behavior researchers, from research funding to reimbursement for clinical services to application of evidence to impact health outcomes. This paper provides a 6-year update on the expansion of Society of Behavioral Medicine's (SBM) public policy and advocacy agenda and proposed future directions. SBM's Health Policy Council is responsible for ensuring coordination of the policy-related activities of the Health Policy Committee (HPC), the Civic and Public Engagement Committee (CPEC), and the Scientific and Professional Liaison Council (SPLC). These committees and councils have written letters to Congress, signed onto advocacy letters with hundreds of organizations, and developed and disseminated 15 health policy briefs, the majority of which have been presented to legislative staffers on Capitol Hill. With the assistance of the SPLC, SBM has collaborated on policy efforts with like-minded organizations to increase the impact of the Society's policy work. Moving forward, SBM plans to continue to increase efforts to disseminate policy work more broadly and develop long-term relationships with Congressional staffers. SBM leadership realizes that to remain relevant, demonstrate impact, and advance the role of behavioral medicine, we must advance a policy agenda that reflects our mission of better health through behavior change
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