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1.
王振 《电脑与信息技术》2010,18(5):11-12,37
表现人脸的皱纹特征是提高人脸动画真实感的重要因素之一,文章提出了一种基于关键帧的皱纹动画方法,使用高度图、法线图和MPEG-4人脸运动参数描述皱纹动画关键帧,通过对高度图、法线图插值生成皱纹动画中间帧。所提方法对人脸模型网格复杂度要求不高,且合成的皱纹动画具有真实感强和实时性高的特点。  相似文献   

2.
Despite the fact that progress in face recognition algorithms over the last decades has been made, changing lighting conditions and different face orientation still remain as a challenging problem. A standard face recognition system identifies the person by comparing the input picture against pictures of all faces in a database and finding the best match. Usually face matching is carried out in two steps: during the first step detection of a face is done by finding exact position of it in a complex background (various lightning condition), and in the second step face identification is performed using gathered databases. In reality detected faces can appear in different position and they can be rotated, so these disturbances reduce quality of the recognition algorithms dramatically. In this paper to increase the identification accuracy we propose original geometric normalization of the face, based on extracted facial feature position such as eyes. For the eyes localization lbllowing methods has been used: color based method, mean eye template and SVM (Support Vector Machine) technique. Experimental investigation has shown that the best results for eye center detection can be achieved using SVM technique. The recognition rate increases statistically by 28% using face orientation normalization based on the eyes position.  相似文献   

3.
Phase extraction, phase unwrapping and phase to height conversion are consecutive steps within the fringe projection method for reconstruction of 3D objects. The procedure of determining discontinuities on the wrapped phase, resolving them and achieving the unwrapped phase is called phase unwrapping. A software system was developed that provides the ability to create many kinds of patterns with a verity of desirable properties suitable for different demands in fringe projection systems. In our previous work, an experimental study was reported based on a multi-wavelength unwrapping approach. In the following work, we implemented a new method called binary code pattern unwrapping that is based on time analysis. A comparison of the two unwrapping approaches in terms of resolution, quality, noise, depth accuracy, and computational cost is provided.  相似文献   

4.
We present a lightweight non-parametric method to generate wrinkles for 3D facial modeling and animation. The key lightweight feature of the method is that it can generate plausible wrinkles using a single low-cost Kinect camera and one high quality 3D face model with details as the example. Our method works in two stages: (1) offline personalized wrinkled blendshape construction. User-specific expressions are recorded using the RGB-Depth camera, and the wrinkles are generated through example-based synthesis of geometric details. (2) Online 3D facial performance capturing. These reconstructed expressions are used as blendshapes to capture facial animations in real-time. Experiments on a variety of facial performance videos show that our method can produce plausible results, approximating the wrinkles in an accurate way. Furthermore, our technique is low-cost and convenient for common users.  相似文献   

5.
MoCap(motion capture)-based animation is a hot issue in computer animation research currently.Based on the optical MoCap system,this paper proposes a novel cross-mapping based facial expression simulating method.To overcome the problem of the false upper and lower jaw correlation derived from the facial global RBFbased cross-mapping method,we construct a functional partition based RBF cross-mapping method.During model animating,enhanced markers are added and animated by our proposed skin motion mechanism.In addition,based on the enhanced markers,an improved RBF-based animating approach is raised to derive realistic facial animation.Further more,a pre-computing algorithm is presented to reduce computational cost for real-time simulation.The experiments proved that the method can not only map the MoCap data of one subject to diferent personalized faces but generate realistic facial animation.  相似文献   

6.
In order to increase the localization coverage while keeping the localization error small in a unique network architecture in which there are not evenly distributed anchor nodes with great ability of communication or additional infrastructure,a Top-down Positioning Scheme(TPS)for underwater acoustic sensor networks is proposed.By defining node’s confidence reasonably,TPS insures the quality of the new reference nodes.TPS also refines the nodes which have just been positioned via the gradient method and helps non-localized nodes search for more reference nodes via the new scheme for 3D Euclidean distance estimation.By comparing the new scheme for 3D Euclidean distance estimation with the existing scheme,the new scheme is shown to have greater ability to estimate two-hop Euclidean distance in 3D space.Simulation results show that TPS which integrates node’s confidence defined reasonably,the gradient method,and the new scheme for 3D Euclidean distance estimation can increase the localization coverage ratio,while keeping the localization error small.  相似文献   

7.
SDN (Software-Defined Networking) and NFV (Network Functions Virtualization) are technologies for enabling innovative network architectures. Nevertheless, a fundamental problem in instantiation of VNs (Virtual Networks), performed by NFV, is an optimal allocation of resources offered by one or more SDN domain networks. The process of instantiation of VNs is performed in several phases, including splitting and mapping algorithms. For each one of these phases, researchers have developed algorithms, being possible to obtain different results combining them. This paper introduces a modular and flexible graphical discrete event simulation tool for solving the complete virtual resource allocation in SDN domain networks problem. A Java-based tool has been developed to integrate existing and future algorithms related researchers can select the appropriate algorithm in each phase performance evaluation of the selected and proposed algorithms. to each phase of the process. The simulator is a test-bed in which and display the results in a graphical form, while obtaining a  相似文献   

8.
We present two O(1)-time algorithms for solving the 2D all nearest neighbor (2D/spl I.bar/ANN) problem, the 2D closest pair (2D/spl I.bar/CP) problem, the 3D all nearest neighbor (3D/spl I.bar/ANN) problem and the 3D-closest pair (3D/spl I.bar/CP) problem of n points on the linear array with a reconfigurable pipelined bus system (LARPBS) from the computational geometry perspective. The first O(1) time algorithm, which invokes the ANN properties (introduced in this paper) only once, can solve the 2D/spl I.bar/ANN and 2D/spl I.bar/CP problems of n points on an LARPBS of size 1/2n/sup 5/3+c/, and the 3D/spl I.bar/ANN and 3D/spl I.bar/CP problems pf n points on an LARPBS of size 1/2n/sup 7/4+c/, where 0 < /spl epsi/ = 1/2/sup c+1/-1 /spl Lt/ 1, c is a constant and positive integer. The second O(1) time algorithm, which recursively invokes the ANN properties k times, can solve the kD/spl I.bar/ANN, and kD/spl I.bar/CP problems of n points on an LARPBS of size 1/2n/sup 3/2+c/, where k = 2 or 3, 0 < /spl epsi/ = 1/2/sup n+1/-1 /spl Lt/ 1, and c is a constant and positive integer. To the best of our knowledge, all results derived above are the best O(1) time ANN algorithms known.  相似文献   

9.
为了提取较为精细的图像信息,引入了多尺度2维小波分析织物的表面折皱。织物图像首先经过高斯滤波,再利用小波变换分解并从中提取高频信息,然后结合4种表征织物折皱的特征参数,计算不同折皱等级模板的特征值,通过分析特征值与折皱等级的相关系数,表明这4种特征参数可以作为模式识别的输入量;最后采用Kohonen自组织神经网络客观评定织物的折皱等级,自组织神经网络将不同等级的织物折皱模板进行分类,并以此为依据,确定26种不同织物类型的折皱等级。为了定量描述评定结果,通过计算客观评定与主观评定结果的相关系数,验证该方法的可行性。  相似文献   

10.
Abstract: Open collaboration-based R&D (research and development) has become an important issue recently. Researchers' performance is necessary to be understood by analyzing researchers' paper outcome. To drive successful outcomes and co-research, researchers' paper outcome should be autonomously established. Therefore we propose an approach to manage and update easily paper outcome of researchers. The proposed approach makes researchers search their paper using the Google Scholar's opened API (application program interface) and update their outcome. Since researchers autonomously can establish the list of their own papers in our service using open service, researchers' personal outcome can be efficiently managed.  相似文献   

11.
12.
提出了一个人脸动画与语音同步的系统,重点解决协同发音、表现人脸细微表情特征的问题。输入带有情绪标志的文本,就能够产生对应表情的、与语音同步的人脸动画;本系统能够生成各种不同性别、年龄、表情特征的高度真实感3D人脸模型,人脸细微表情特征(如额头皱纹)可以随人脸表情的变化而动态改变。基于语言学理论,本系统提出了解决协同发音问题的一套规则。  相似文献   

13.
Realistic wrinkles are extremely important for enhancing the realism of three-dimensional (3D) virtual face models. This paper proposes an approach for generating realistic wrinkle on a 3D face model based on a face image. It includes image preprocessing, automatically extracting wrinkle curves and generating wrinkles on a 3D surface. For image preprocessing, we use a linear transform method to conduct a grayscale conversion. We then use a transfinite-pixel neighborhood averaging method to reduce the noise, and a high pass filter to sharpen the image. For the automatic extraction of wrinkle curves, an improved Canny edge detector is employed. For wrinkle generation on a 3D surface, a number of novel techniques are employed. Some feature points are firstly defined both on the face image and on the 3D face model. By aligning these feature points, the extracted wrinkle curves are then projected onto the 3D face model. Finally, three shape control functions are used to produce more realistic properties of the 3D wrinkles. They are the proposed cross-section shape control function (CSCF) to determine the cross-section shape and size, the depth attenuation function (DAF) and the width attenuation function (WAF) to control the depth and width amplitude variations of the wrinkles, respectively. For better results, an adaptive subdivision is applied to the predefined influence region to adjust the resolution around the wrinkle mesh. The experiment results of applying this method to individualized 3D human models demonstrate the ability of our method to generate more natural wrinkles.  相似文献   

14.
Synthesizing facial wrinkles has been tackled either by a long process of manual sculpting on 3D models, or using automatic methods that do not allow for user interaction or artistic expression. In this paper, we propose a method that accepts interactive sketchy drawings depicting wrinkle patterns, and synthesizes realistic looking wrinkles on faces. The method inherits the simplicity of sketching, making it possible for artists as well as novice users to generate realistic facial detail very efficiently, allowing fast preview for physical makeup, or aging simulations for fun and professional applications. All strokes are used to infer the wrinkles, retaining the expressiveness of the sketches and realism of the final result at the same time. This is achieved by designing novel multi‐scale statistics tailored to the wrinkle geometry and coupled to the sketch interpretation method. The statistics capture the cross‐sectional profiles of wrinkles at different scales and parts of a face. The strokes are augmented with the statistics extracted from given example face models, and applied to an input face model interactively. The interface gives the user control over the shapes and scales of wrinkles via sketching while adding extra details required for realism automatically.  相似文献   

15.
This paper extends a physically-based approach to the realistic modelling and animation of human heads using scanned data. A three-step procedure is proposed which begins with geometry and colour data acquired from a subject's head using a radial laser scanner, continues with the construction of a 3D model of the head with complete colour texture mapping, and culminates in real-time, interactive facial animation. First, an adaptive meshing technique is described that creates non-uniform facial meshes from the densely sampled data. These geometrically accurate facial meshes adapt to features of interest in the data, increasing polygon density over articulate face regions and areas of high curvature. Secondly, the mesh is transformed into a physically-based head model of the subject. This incorporates a physical approximation to facial tissue and a set of anatomically-motivated facial muscle actuators. Finally, these components are integrated in a facial modelling and animation system.  相似文献   

16.
为了提高三维人脸建模的精确度,在双目立体视觉理论的基础上,提出了一种基于多台摄像机拍摄的人脸三维建模方法。该方法利用两组摄像机分别在不同的角度拍摄人脸,并采用双目立体视觉理论计算三维人脸信息,最后结合两组摄像机分别得到的三维人脸信息,进行坐标变换并重构三维人脸。该方法有效弥补了原来由两台摄像机拍摄人脸所得的三维信息的精确度较差的缺点,并具有一定的实用性。  相似文献   

17.
Multi-scale local feature detection enables downstream registration and recognition tasks in med- ical image analysis. This paper articulates a novel robust method for multi-scale local feature extraction on volumetric data. The central idea is the elegant unification of local/global eigen-structures within the powerful framework of anisotropic heat diffusion. First, the local vector field is constructed by way of Hessian matrix and its eigenvectors/eigenvalues. Second, anisotropic heat kernels are computed using the vector field's global graph Laplacian. Robust local features are manifested as extrema across multiple time scales, serving as volumetric heat kernel signature. To tackle the computational challenge for massive volumetric data, we propose a multi- resolution strategy for hierarchical feature extraction based on our feature-preserving down-sampling approach. As a result, heat kernels and local feature identification can be approximated at a coarser level first, and then are pinpointed in a localized region at a finer resolution. Another novelty of this work lies at the initial heat design directly using local eigenvalue for anisotropic heat diffusion across the volumetric domain. We conduct experiments on various medical datasets, and draw comparisons with 3D SIFT method. The diffusion property of our local features, which can be interpreted as random walks in statistics, makes our method robust to noise, and gives rise to intrinsic multi-scale characteristics.  相似文献   

18.
E-commerce (business-to-consumer electronic commerce), one form of which is Web-based shopping, is defined as electronic-based economic transactions conducted between individual consumers and organizations. While this form of ecommerce is forecasted to grow rapidly for the foreseeable future, it still represents only a small fraction of total consumer spending. To better take advantage and be prepared for this economic phenomenon, organizations need to identify and understand factors that may impact consumers' decisions to engage in Web-based e-commerce. Recently, the importance of security has been discussed in both the academic and practitioner press. The impact of security on the use of e-commerce has been established empirically.  相似文献   

19.
Autonomous navigation is a complex challenge that involves the interpretation and analysis of information about the scenario to facilitate the cognitive processes of a robot to perform free trajectories in dynamic environments. To solve this, the paper introduces a Case-Based Reasoning methodology to endow robots with an efficient decision structure aiming of selecting the best maneuver to avoid collisions. In particular, Manhattan Distance was implemented to perform the retrieval process in CBR method. Four scenarios were depicted to run a set of experiments in order to validate the functionality of the implemented work. Finally, conclusions emphasize the advantages of CBR methodology to perform autonomous navigation in unknown and uncertain environments.  相似文献   

20.
Automatic facial expression recognition constitutes an active research field due to the latest advances in computing technology that make the user's experience a clear priority. The majority of work conducted in this area involves 2D imagery, despite the problems this presents due to inherent pose and illumination variations. In order to deal with these problems, 3D and 4D (dynamic 3D) recordings are increasingly used in expression analysis research. In this paper we survey the recent advances in 3D and 4D facial expression recognition. We discuss developments in 3D facial data acquisition and tracking, and present currently available 3D/4D face databases suitable for 3D/4D facial expressions analysis as well as the existing facial expression recognition systems that exploit either 3D or 4D data in detail. Finally, challenges that have to be addressed if 3D facial expression recognition systems are to become a part of future applications are extensively discussed.  相似文献   

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