To study the structure and branch pattern of neurons, it is important to segment and track neurons at first. We develop a snake model based on repulsive force to segment neurons in 3d microscopy image stacks. To overc...
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ISBN:
(纸本)078039576X
To study the structure and branch pattern of neurons, it is important to segment and track neurons at first. We develop a snake model based on repulsive force to segment neurons in 3d microscopy image stacks. To overcome the difficulty that the boundary between two adjacent neurons is weak, we introduce a shape constraint on the snake deformation and use repulsive force to keep snakes of adjacent objects from merging into one. After obtaining the contours on the first image slice, we project them to the next slice as initialization for snake deformation and repeat the process for all the slices in a 3d image stacks. Individual neuron is tracked by connecting the corresponding snake through all slices. Results obtained from processing real data show that the method can successfully segment two or more neurons that are close to each other in 3d
The relationship between brain structure and complex behavior is governed by large-scale neurocognitive networks. diffusion weighted imaging (dWI) is a noninvasive technique that can visualize the neuronal projections...
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ISBN:
(纸本)078039576x
The relationship between brain structure and complex behavior is governed by large-scale neurocognitive networks. diffusion weighted imaging (dWI) is a noninvasive technique that can visualize the neuronal projections connecting the functional centers and thus provides new keys to the understanding of brain function. In this paper, we assume there are up to two diffusion channels at each voxel. A variational framework for 3d simultaneous smoothing and reconstruction of a multi-diffusion tensor field as well as a novel multi-tensor deflection (MTENd) algorithm for extracting white matter fiber traces based on the multi-diffusion tensor field are provided. By applying the proposed model to both synthetic data and human brain high angular resolution diffusion (HArd) magnetic resonance imaging (MRI) data of several subjects, we show the effectiveness of the model in recovering branching fiber traces. Superiority of the proposed model over existing models are also demonstrated
Hardware platforms and testbeds are an essential tool to evaluate, in realistic scenarios, the performance of multiple-input-multiple-ouput (MIMO) systems. In this work we present a simple and easily reconfigurable 2 ...
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Hardware platforms and testbeds are an essential tool to evaluate, in realistic scenarios, the performance of multiple-input-multiple-ouput (MIMO) systems. In this work we present a simple and easily reconfigurable 2 times 2 MIMO testbed for the rapid prototyping of the signal processing baseband functions. The signal generation module consists of a host PC equipped with a board that contains two high performance 100 MHz dACs and a 1 GB memory module that allows the transmission of extremely large frames of data. At the receiver side, we use another host PC equipped with two 105 MHz AdCs, another 1 GB memory module and a trigger that starts the acquisition process when the presence of signal is detected. The platform has been designed to operate at the ISM band of 2.4 GHz with a RF bandwidth of 20 MHz. In order to minimize the number of dAC and AdC circuits, signals are generated and acquired at an IF of 15 MHz. Upconversion to RF is performed with two RF vectorial signal generators (Agilent E4438C) anddownconversion with two specific circuits designed from commercial components. Transmitter and receiver signal processing functions are implemented off-line in Matlab. To illustrate the performance and capabilities of the platform, we present the results of two experiments of a 2 times 2 MIMO transmission with Alamouti coding.
The proceedings contain 17 papers. The topics discussed include: rapid synchronous acquisition of geometry and appearance of cultural heritage artifacts;passive reconstruction of high quality textured3d models of wor...
ISBN:
(纸本)3905673282
The proceedings contain 17 papers. The topics discussed include: rapid synchronous acquisition of geometry and appearance of cultural heritage artifacts;passive reconstruction of high quality textured3d models of works of art;detail-preserving surface inpainting;3d modeling for non-expert users with the castle construction kit v0.5;3d face modeling from ancient kabuki drawings;viewpoint quality and scene understanding;rapidvisualization of large point-based surfaces;participating media for high-fidelity cultural heritage;real-time shader rendering for crowds in virtual heritage;visualizing temporal uncertainty in 3d virtual reconstructions;investigating the structural validity of virtual reconstructions of prehistoric Maltese temples;exploring digitized artworks by pointing posture recognition;and interface evaluation for cultural heritage applications: the case of FERRUM exhibition.
The proceedings contain 131 papers from the 2ndinternationalsymposium on 3ddataprocessing, visualization, andtransmission3dPVT 2004. The topics discussed include: surface illuminance flow;surface normals and hei...
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ISBN:
(纸本)0769522238
The proceedings contain 131 papers from the 2ndinternationalsymposium on 3ddataprocessing, visualization, andtransmission3dPVT 2004. The topics discussed include: surface illuminance flow;surface normals and height from non-Lambertian image data;a variational analysis of shape from specularities using sparse data;view dependence of 3d recovery from folded pictures and warped3d faces;3d performance capture for facial animation;exploitation of 3d images for face authentication under pose and illumination variations;speech-driven face synthesis from 3d video;pyramid coordinates for morphing anddeformation;and linear shift-invariant operators for processing surface meshes.
Nowadays the processing power of mobile phones, Smartphones and PdA's is increasing as well as the transmission bandwidth. Nevertheless there is still the need to reduce the content and the need of processing the ...
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ISBN:
(纸本)0769522238
Nowadays the processing power of mobile phones, Smartphones and PdA's is increasing as well as the transmission bandwidth. Nevertheless there is still the need to reduce the content and the need of processing the data. discussed will be proposals and solutions for dynamic reduction of the transmitted content. For that, device specific properties will be taken into account, as much as for the aim to reduce the need of processing power at the client side to be able to display the 3d (Virtual Reality) data. Therefore, well known technologies e.g. data compression are combined with new developed ideas to reach the goal of adaptive content transmission. To achieve a device dependant reduction of processing power the data have to be pre processed at the server side or the server even has to take over functionality of weak mobile devices.
A method for modelling and visualizing human lungs using knowledge of lung anatomy and High Resolution CT (HRCT) images is presented. The model consists of. a symbolic description of lung anatomy and a 3d atlas. The 3...
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ISBN:
(纸本)0769522238
A method for modelling and visualizing human lungs using knowledge of lung anatomy and High Resolution CT (HRCT) images is presented. The model consists of. a symbolic description of lung anatomy and a 3d atlas. The 3d atlas is constructed using HRCT volume data. A few anatomical landmarks are determined and are used to divide the lungs into anatomically anddiagnostically important regions. The landmarks and the lung regions enable accurate mapping of the model to patient data and enable the system to deal with image and human variability. The model can be displayed as a set of labelled axial slices and as a 3d model of the lungs. The 3dvisualization enables rotation and viewing of lung structures, lung features and lung regions from different angles.
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