The combination of Medical image based computer Aided Diagnosis (MICAD) and Medical image has become a new hotspot gradually. The development of MICAD is a complex procedure, and it's a cross-disciplinary. It need...
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The combination of Medical image based computer Aided Diagnosis (MICAD) and Medical image has become a new hotspot gradually. The development of MICAD is a complex procedure, and it's a cross-disciplinary. It needs not only the rich Medical knowledge but also the other branches such as computer artificial intelligence, graphics, imageprocessing. imageprocessing module in aided diagnosis system is most important. A computer-Aided imaging system to deal with a good part of their success is a very important factor. Based on the full investigation of medical diagnose method, this article brings up a new perspective based on CBR to research and implement Medical Diagnosis Expert System against the shortcomings of RBR System. Analyzed the content and method of image cases representation Uses frame to represent image cases, puts case ID, case Category, case features, diagnosis result, treatment, auxiliary property into cases. Made a detailed analysis and design of case-base' structure and organization. Used two-level-structure to organize case-base:typical case-base and specific *** maximum-similarity-method to classify the original case-base to construct each specific sub-case-base;used calculating "max sum among cases" to search the typical case in each *** a method to calculate case symptom weight. The key technologies of the system have been discussed comprehensively, which contains: case retrieving, modifying, learning and case-base maintaining. Among those key technologies, case retrieving is the core *** system used phasic-nearest-neighbor strategy to retrieve cases in *** strategy combining with two-level-structure highly reduced retrieving times,so that improved the efficiency of search.
We present our recent efforts in the digital preservation of a set of baroque sculptures made by Antonio Francisco Lisboa, known as O. Aleijadinho, which is an important American baroque artist. The set was made in th...
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We present our recent efforts in the digital preservation of a set of baroque sculptures made by Antonio Francisco Lisboa, known as O. Aleijadinho, which is an important American baroque artist. The set was made in the beginning of the XIX century and is composed of 12 near real sized sculptures, hand-carved in soapstone. These sculptures represent 12 of the 16 prophets from the Holy Bible and are part of a UNESCO World Heritage Site. Our group has been collaborating with UNESCO in a project that aims to preserve all these statues. We hereby present our initial efforts, consisting of the 3D digital preservation of the Prophet Joel sculpture. We developed a complete 3D digital preservation pipeline composed of four main stages: data acquisition, 3D reconstruction, texture generation and 3D model visualization. By evaluating our results in this first sculpture, we discuss the improvements we conceived before applying our pipeline in the remaining ones. Finally, we present the 3D model of the Prophet which registers the sculpture's current state and will be used in restoration, research and educational activities. We believe this contribution may be useful to guide further research on similar scenarios, showing how to avoid some practical mistakes and achieve good results. (C) 2011 Elsevier Masson SAS. All rights reserved.
Most small-animal X-ray computed tomography (CT) scanners are based on cone-beam geometry with a flat-panel detector orbiting in a circular trajectory. image reconstruction in these systems is usually performed by app...
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Direct volume rendering (DVR) has become a widely used technique for visualizing anatomical structures in medical 3D datasets The aim of this study was to locally adapt the opacity transfer function (OTF) in order to ...
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ISBN:
(纸本)9781467345620;9781467345613
Direct volume rendering (DVR) has become a widely used technique for visualizing anatomical structures in medical 3D datasets The aim of this study was to locally adapt the opacity transfer function (OTF) in order to improve the results achieved when rendering 3D echocardiographic datasets using DVR. A novel approach for defining locally adaptive OTFs has been tested and adapted to echo data and implemented on the GPU. The local OTF is modeled as a truncated second order polynomial. The algorithm locates significant transitions along the ray profile (feature detection along the ray) in order to estimate an opacity threshold (below which all values are considered transparent) and the steepness of the polynomial for each ray. A reference global OTF and the locally adaptive algorithm have been implemented on a GPU using OpenCL and tested on a dataset of nine 3D echo recordings. The rendering resolution is 512x512x300, while average timing is 28ms, 104ms for the reference and the new method respectively. The locally adaptive OTFs were able to compensate for high variations in tissue (and such reducing wall drop-outs) and blood pool signal (reducing spurious structures inside the cavity). The method depends on a number of user defined parameters, determining these values robustly is subject of ongoing research.
In this paper, the "3D mesh model plus texture" strategy is adopted to implement a 3D video system. First, the acquired multi-view videos are processed to construct dynamic 3D mesh models about the foregroun...
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ISBN:
(纸本)9781467302197
In this paper, the "3D mesh model plus texture" strategy is adopted to implement a 3D video system. First, the acquired multi-view videos are processed to construct dynamic 3D mesh models about the foreground subject. These 3D mesh models, together with the acquired texture information, are then compressed and transmitted via networks to receivers. Main contributions of our work lies on the proposals of data reduction and pre-processing of multi-view texture information before H.264/AVC encoding at transmitter and a robust occlusion test on synthesizing novel views at receiver. Our proposed data reduction and pre-processing schemes are capable of removing redundant texture information, while maintaining inter-frame correlation, to result in high coding efficiency. Experiment results show that the proposed occlusion test is capable of eliminating texture-rendering artifacts due to 3D model reconstruction errors, thus improving the viewing quality of 3D video at receiver. Besides, our texture encoder achieves a saving of 40% similar to 57% in transmission bit rate, compared with the traditional approach.
Visually coherent rendering for augmented reality is concerned with seamlessly blending the virtual world and the real world in real-time. One challenge in achieving this is the correct handling of lighting. We are in...
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ISBN:
(纸本)9781467346627
Visually coherent rendering for augmented reality is concerned with seamlessly blending the virtual world and the real world in real-time. One challenge in achieving this is the correct handling of lighting. We are interested in applying real-world light to virtual objects, and compute the interaction of light between virtual and real. This implies the measurement of the real-world lighting, also known as photometric registration. So far, photometric registration has mainly been done through capturing images with artificial light probes, such as mirror balls or planar markers, or by using high dynamic range cameras with fish-eye lenses. In this paper, we present a novel non-invasive system, using arbitrary scene geometry as a light probe for photometric registration, and a general AR rendering pipeline supporting real-time global illumination techniques. Based on state of the art real-time geometric reconstruction, we show how to robustly extract data for photometric registration to compute a realistic representation of the real-world diffuse lighting. Our approach estimates the light from observations of the reconstructed model and is based on spherical harmonics, enabling plausible illumination such as soft shadows, in a mixed virtual-real rendering pipeline.
In this paper, we propose a method to model the Copacabana beach sidewalk pavement, and Portuguese pavements in general. Given a black and white source image, the proposed method outputs the geometry of all individual...
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In this paper, we propose a method to model the Copacabana beach sidewalk pavement, and Portuguese pavements in general. Given a black and white source image, the proposed method outputs the geometry of all individual stones that compose the pavement. Different from previous mosaic techniques, we focus on capturing the particularities of such pavements: the stones (tiles) must completely follow the edges, being mostly represented by irregular quadrilaterals with no particular orientation. A set of experiments demonstrates the effectiveness and stability of our proposal.
This paper describes the use of GPU-specific optimization techniques applied to the problem of simulation of scale free gene regulatory networks based on threshold function on GPU. We made attempts to optimize memory ...
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Transparency and anti-aliasing are crucial to enhance realism in computer-generated images, which have a high demand for such effects. Transparency is largely used to denote relationships among objects in a scene, and...
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Transparency and anti-aliasing are crucial to enhance realism in computer-generated images, which have a high demand for such effects. Transparency is largely used to denote relationships among objects in a scene, and to render several structures, such as particles and foliage. Anti-aliasing (AA) is also important, since jagged edges can be easily spotted and create disruptive distractions during a scene walkthrough, which are unacceptable in real-time applications. Figure 1 illustrates both effects. In common, they have the fact that they rely on processing discrete samples from a given function, but using the samples for different purposes. In this tutorial we review state-of the-art techniques for transparency and anti-aliasing effects, their initial ideas and subsequent GPU accelerations. We support our presentation with a discussion on their strengths and limitations.
In this paper we present a method to simulate fluids on smooth surfaces of arbitrary topology using a graphicsprocessing unit (GPU). To do this we use the parametrization of Cat mull-Clark subdivision surfaces and ob...
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In this paper we present a method to simulate fluids on smooth surfaces of arbitrary topology using a graphicsprocessing unit (GPU). To do this we use the parametrization of Cat mull-Clark subdivision surfaces and obtain the metric information of the distortion caused by this parametrization, so we can calculate differential operators of functions defined on this surface. Then the Navier-Stokes equations on surfaces are solved in the domain of parametrization of each patch. This process can be done in parallel for each point in the discretization of the surface, so the GPU implementation can heavily increase the velocity of computation.
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