The number of 3d models that are available from the Web is increasingly growing, motivating the research on content-based retrieval from shape information. In this paper we propose to extend the approach to colored3d...
详细信息
Three-dimensional (3d) urban models, come with huge data size, mainly consisting of the information of geometry and the texture, and the simplification of both is often needed for efficient streaming, rendering and vi...
详细信息
ISBN:
(纸本)9780780397323
Three-dimensional (3d) urban models, come with huge data size, mainly consisting of the information of geometry and the texture, and the simplification of both is often needed for efficient streaming, rendering andvisualization. In this paper, we present different techniques for simplification of different types of the texture images in 3d urban maps, aiming at their visualization on low resolution screens, such as those of the cell phones. We sort the images into two different classes based on their certain features, anddevelop suitable simplification techniques for each class. The simplified images preserve the main features and have significantly smaller size as compared to the originals.
We present an algorithm for automatic locating of anthropometric landmarks on 3d human scans. Our method is based on learning landmark characteristics and the spatial relationships between them from a set of human sca...
详细信息
In this paper, we develop a new hybrid active vision/geometric modeling approach dedicated to 3d human face recovery. Initially, a 3d coarse reconstruction is obtained via a structured-light assisted stereo sensor. He...
详细信息
in this article, we put forth the contribution of cartographic map projection in image analysis for 2d and3d spheric-shapeddata. In the 2d case, map projection of the underlying hemispherical surface has the merit t...
详细信息
ISBN:
(纸本)9780780395763
in this article, we put forth the contribution of cartographic map projection in image analysis for 2d and3d spheric-shapeddata. In the 2d case, map projection of the underlying hemispherical surface has the merit to overcome deformations generated by perspective sights. In the 3d case, processing cartographic references of the original spheroid surfaces presents mainly two advantages. On one hand, it decreases significantly the amount of processeddata. On the other hand, we avoid extension of exhaustive processes to a higher dimension. We make use of this geographical transformation in several classical image processing applications such as temporal tracking, information visualization, and feature extraction, such as segmentation. These applications are described and results of cell wall simulations are displayed.
In general the ultrasonic testing is used for flaw detection and localization in tested materials. The flaws in materials are commonly characterized in measured ultrasonic signals by faults echoes. In the case of mate...
详细信息
ISBN:
(纸本)9780780397538
In general the ultrasonic testing is used for flaw detection and localization in tested materials. The flaws in materials are commonly characterized in measured ultrasonic signals by faults echoes. In the case of materials with coarse - grained structure the ultrasonic signal contains undesirable echoes caused by the scattering from these grains considered as noise. Another source of noise is caused by the electronic circuitry which is called electronic noise. These sources of noise make the flaw detection more difficult. The efficient methods for noise reduction have to be used. This paper evaluates different filtering methods used for noise reduction. Methods based on Wiener filtering, stationary wavelet transform, neural networks in 2d space are compared with conventional mathematical filtering methods based on median filter and mean value. The goal of this paper is to determine efficient method for noise reduction in B-scan for the exact flaw shape characterization. Filtered B-scans are used for the construction of 3d - volume visualization of flaws in the tested materials. Final 3d - volume visualization represents the flaw shape and is useful in the case of characterization of the flaw visualization.
With the advances in medical imaging devices, large volumes of high-resolution 3d medical image data have been produced. These high-resolution 3ddata are very large in size, and severely stress storage systems and ne...
详细信息
ISBN:
(纸本)0769525172
With the advances in medical imaging devices, large volumes of high-resolution 3d medical image data have been produced. These high-resolution 3ddata are very large in size, and severely stress storage systems and networks. Most existing Web-based3d medical image interactive applications therefore deal with only low- or medium-resolution image data. While it is possible to download the whole 3d high-resolution image data from the server and perform the image visualization and analysis at the client site, such an alternative is infeasible when the high-resolution data are very huge, and many users concurrently access the server. In this paper, we propose a novel framework for Web-based interactive applications of high-resolution 3d medical image data. Specifically, we first partition the whole 3ddata into buckets, and then compress each bucket separately. We also propose an indexing structure for these buckets to efficiently support typical queries such as 3d slicer and region of interest (ROI), and only the relevant buckets are transmitted instead of the whole high-resolution 3d medical image data. Furthermore, in order to better support concurrent accesses and to improve the average response time, we also propose some techniques for bucket group access on the server side and incremental transmission. Our experimental study based on a human brain MRI data set indicates that the proposed framework can significantly reduce storage and communication requirements, and can enable real-time interaction with remote high-resolution 3d medical image data for many concurrent users.
Real-time display of dynamic three-dimensional (3d) cardiac images has important applications in minimally invasive image-guided cardiac surgery and therapy. However, in practice, the high computational cost usually p...
详细信息
ISBN:
(纸本)9780780395763
Real-time display of dynamic three-dimensional (3d) cardiac images has important applications in minimally invasive image-guided cardiac surgery and therapy. However, in practice, the high computational cost usually prohibits its application in a real-time medical environment, or else the low image quality does not satisfy the clinical requirements. Surface based organ models or orthogonal image planes are often employed instead, but in the process important intra cardiac data are lost, and intuitive spatial anatomical relationships are eliminated. In this paper, we take advantage of the programmability, parallelism and increased computational precision of modem graphics processing units (GPUs) to build a ray casting based real-time 3d rendering engine, directly running on the graphics vertex and fragment processors. This approach provides enhanced image quality similar to software-based implementations, but its rendering speed is competitive with the traditional but inferior quality slice based volume rendering approaches. In addition, we propose a new dynamic volume texture binding technique, and embedded it into our 3d rendering engine to permit visualize the 4d MR cardiac dataset in real-time.
In this paper we discuss a framework for modeling the 3d lung dynamics of normal anddiseased human subjects and visualizing them using an Augmented Reality (AR) based environment. The framework is based on the result...
详细信息
ISBN:
(纸本)0769525172
In this paper we discuss a framework for modeling the 3d lung dynamics of normal anddiseased human subjects and visualizing them using an Augmented Reality (AR) based environment. The framework is based on the results obtained from pulmonary function tests and lung image-data of human subjects obtained from 4d High-Resolution Computed Tomography (HRCT). The components of the framework include a parameterized pressure-volume (P V) relation estimated from normal human subjects, and a physics and physiology-based3ddeformable lung model extracted from the 4d HRCT data of normal and tumor-influenced human subjects. The parameterized PV relation allows modeling different breathing conditions of a human subject. The 3ddeformable lung model allows visualizing the 3d shape changes of the lung for the breathing condition simulated by the PV relation. Additionally, the 3d lung model is deformed using a graphics processing unit (GPU) and its vertex shaders, which satisfies the real-time frame-rate requirements of the AR environment.
Three-dimensional data generated from range scanners is usually composed of a huge amount of information. Simplification and compression techniques must be adopted in order to reduce transmission or processing time an...
详细信息
ISBN:
(纸本)9781424403660
Three-dimensional data generated from range scanners is usually composed of a huge amount of information. Simplification and compression techniques must be adopted in order to reduce transmission or processing time and to allow real-time visualization. In this paper we propose an approach to semantic simplification of triangular meshes representing faces. The algorithm is aimed to preserve facial features and can be used especially for face recognition systems purposes. In a first phase we detect salient regions using a 3d face detector based on curvature analysis and holistic classification. In a second phase, vertex decimation is applied to the mesh with different decimation parameters for salient and non salient-regions. We have tested our algorithm on a set of 150 acquisitions obtaining good visual quality meshes with approximately 90% or more of decimated vertexes.
暂无评论