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Banaszewski Jacek Pabiszczak Maciej Pastusiak Tomasz Buczkowska Agata Kuczko Wiesław Wichniarek Radosław Górski Filip 《Journal of materials science. Materials in medicine》2018,29(2):23
The aim of the study was to compare two types of mandible reconstructive operations with scapula and fibula free flaps: procedures with 3-D models from thermoplastic materials and conventional planning surgeries. 8 patients were treated due to an advanced oral cavity squamous cell carcinoma. In four patients with a mandibular defect, a physical 3-D model consisting of the reconstructed and unaffected sites was prepared for a reconstruction protocol. The 3-D models were designed based to high resolution CT scans. Assessment of comparative functionality (stability of junction, mobility, mastication ability) and cosmetics was examined in both groups, following a 8 weeks healing period with better results in group with 3D model. 3-D models for mandible and donor bones allow to obtain better functionality of restored mandible in comparison to the traditional method also significantly decreases time of the operation and allows to achieve the desired shape and esthetic effect within the 1/3 of the lower face. 相似文献
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As the use of facial attributes continues to expand, research into facial age estimation is also developing. Because face images are easily affected by factors including illumination and occlusion, the age estimation of faces is a challenging process. This paper proposes a face age estimation algorithm based on lightweight convolutional neural network in view of the complexity of the environment and the limitations of device computing ability. Improving face age estimation based on Soft Stagewise Regression Network (SSR-Net) and facial images, this paper employs the Center Symmetric Local Binary Pattern (CSLBP) method to obtain the feature image and then combines the face image and the feature image as network input data. Adding feature images to the convolutional neural network can improve the accuracy as well as increase the network model robustness. The experimental results on IMDB-WIKI and MORPH 2 datasets show that the lightweight convolutional neural network method proposed in this paper reduces model complexity and increases the accuracy of face age estimations. 相似文献
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《中国工程学刊》2012,35(5):529-534
Faces are highly deformable objects which may easily change their appearance over time. Not all face areas are subject to the same variability. Therefore, decoupling of the information from independent areas of the face is of paramount importance to improve the robustness of any face recognition technique. The aim of this article is to present a robust face recognition technique based on the extraction and matching of probabilistic graphs drawn on scale invariant feature transform (SIFT) features related to independent face areas. The face matching strategy is based on matching individual salient facial graphs characterized by SIFT features as connected to facial landmarks such as the eyes and the mouth. In order to reduce the face matching errors, the Dempster–Shafer decision theory is applied to fuse the individual matching scores obtained from each pair of salient facial features. The proposed algorithm is evaluated with the Olivetti Research Lab (ORL) and the Indian Institute of Technology Kanpur (IITK) face databases. The experimental results demonstrate the effectiveness and potential of the proposed face recognition technique, even in the case of partially occluded faces. 相似文献
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B Li R Chellappa 《Journal of the Optical Society of America. A, Optics, image science, and vision》2001,18(12):2969-2981
We propose an algorithm for face verification through tracking facial features by using sequential importance sampling. Specifically, we first formulate tracking as a Bayesian inference problem and propose to use Markov chain Monte Carlo techniques for obtaining an empirical solution. A reparameterization is introduced under parametric motion assumption, which facilitates the empirical estimation and also allows verification to be addressed along with tracking. The facial features to be tracked are defined on a grid with Gabor attributes (jets). The motion of facial feature points is modeled as a global two-dimensional (2-D) affine transformation (accounting for head motion) plus a local deformation (accounting for residual motion that is due to inaccuracies in 2-D affine modeling and other factors such as facial expression). Motion of both types is processed simultaneously by the tracker: The global motion is estimated by importance sampling, and the residual motion is handled by incorporating local deformation into the measurement likelihood in computing the weight of a sample. Experiments with a real database of face image sequences are presented. 相似文献
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Yi‐Chih Liu Sheng‐De Wang 《International journal of imaging systems and technology》2010,20(4):323-332
In this article, we proposed a novel teleconferencing system that combines a facial muscle model and the techniques of face detection and facial feature extraction to synthesize a sequence of life‐like face animation. The proposed system can animate realistic 3D face images in a low‐bandwidth environment to support virtual videoconferencing. Based on the technique of feature extraction, a face detection algorithm for the virtual conferencing system is proposed in this article. In the proposed face detection algorithm, the YCbCr skin color model is used to detect the possible face area of the image; the feature points of the face is determined by using the symmetry property of the face and the gray level characteristics of the eyes and the mouth. According to the positions of the feature points on a facial image, we can compute the transformation values of the feature points. These values will then be sent via a network from the sender's side to the receiver's side frame by frame. We can synthesize the realistic facial animations on the receiver's side based on these. Experimental results show that the proposed system can achieve a practical animated face‐to‐face virtual conference with good facial expressions and a low‐bandwidth requirement. © 2010 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 20, 323–332, 2010 相似文献
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The authors describe a method to re-map animation parameters between multiple types of facial model for performance-driven animation. A facial performance can be analysed in terms of a set of facial action parameter trajectories using a modified appearance model with modes of variation encoding specific facial actions which can be pre-defined. These parameters can then be used to animate other modified appearance models or 3D morph-target-based facial models. Thus, the animation parameters analysed from the video performance may be re-used to animate multiple types of facial model. The authors demonstrate the effectiveness of the proposed approach by measuring its ability to successfully extract action parameters from performances and by displaying frames from example animations. The authors also demonstrate its potential use in fully automatic performance-driven animation applications. 相似文献
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Khalil Khan Rehan Ullah Khan Jehad Ali Irfan Uddin Sahib Khan Byeong-hee Roh 《计算机、材料和连续体(英文)》2021,68(3):3483-3498
Race classification is a long-standing challenge in the field of face image analysis. The investigation of salient facial features is an important task to avoid processing all face parts. Face segmentation strongly benefits several face analysis tasks, including ethnicity and race classification. We propose a race-classification algorithm using a prior face segmentation framework. A deep convolutional neural network (DCNN) was used to construct a face segmentation model. For training the DCNN, we label face images according to seven different classes, that is, nose, skin, hair, eyes, brows, back, and mouth. The DCNN model developed in the first phase was used to create segmentation results. The probabilistic classification method is used, and probability maps (PMs) are created for each semantic class. We investigated five salient facial features from among seven that help in race classification. Features are extracted from the PMs of five classes, and a new model is trained based on the DCNN. We assessed the performance of the proposed race classification method on four standard face datasets, reporting superior results compared with previous studies. 相似文献
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Yu Zhang Norman I. Badler 《International journal of imaging systems and technology》2007,17(6):341-358
This article presents a novel method based on statistical facial feature control models for generating realistic controllable face models. The local feature control models are constructed based on the exemplar 3D face scans. We use a three‐step model fitting approach for the 3D registration problem. Once we have a common surface representation for examples, we form feature shape spaces by applying a principal component analysis (PCA) to the data sets of facial feature shapes. We compute a set of anthropometric measurements to parameterize the exemplar shapes of each facial feature in a measurement space. Using PCA coefficients as a compact shape representation, we approach the shape synthesis problem by forming scattered data interpolation functions that are devoted to the generation of desired shape by taking the anthropometric parameters as input. The correspondence among all exemplar face textures is obtained by parameterizing a 3D generic mesh over a 2D image domain. The new feature texture with desired attributes is synthesized by interpolating the exemplar textures. With the exception of an initial tuning of feature point positions and assignment of texture attribute values, our method is fully automated. In the resulting system, users are assisted in automatically generating or editing a face model by controlling the high‐level parameters. © 2008 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 341–358, 2007 相似文献
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This paper proposes variable kinematic, mixed theories for laminated plates built via the asymptotic/axiomatic method (AAM). This method has been recently developed and successfully applied to develop refined theories for multilayered plates and shells. The AAM evaluates the accuracy of each unknown variables of a structural model. The present paper extends the AAM to mixed theories based on the Reissner Mixed Variational Theorem (RMVT). The displacement and transverse stress fields are modeled by means of the Carrera Unified Formulation (CUF), and expansions up to the fourth-order are employed. Equivalent Single Layer (ESL) and Layer Wise (LW) schemes are adopted, and closed-form Navier-type solutions are considered.The AAM is exploited to determine the set of active terms of a refined plate model. The inactive terms are then discarded. The effectiveness of each variable is evaluated with respect to an LW, fourth-order mixed model. Reduced models are built for different thickness ratios, stacking sequences and displacement/stress variables.The results suggest that reduced models with significantly less unknown variables than full models can be built with no accuracies penalties. Such models are problem dependent, and full models should be preferred in the case of thick, asymmetric plates. 相似文献
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With job-shop scheduling (JSS) it is usually difficult to achieve the optimal solution with classical methods due to a high computational complexity (NP-hard). According to the nature of JSS, an improved definition of the JSS problem is presented and a JSS model based on a novel algorithm is established through the analysis of working procedure, working data, precedence constraints, processing performance index, JSS algorithm and so on. A decode select string (DSS) decoding genetic algorithm based on operation coding modes, which includes assembly problems, is proposed. The designed DSS decoding genetic algorithm (GA) can avoid the appearance of infeasible solutions through comparing current genes with DSS in the decoding procedure to obtain working procedure which can be decoded. Finally, the effectiveness and superiority of the proposed method is clarified compared to the classical JSS methods through the simulation experiments and the benchmark problem. 相似文献
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在无约束的开放空间中,由于面部姿态变化、背景环境复杂、运动模糊等,人脸检测仍是一个具有挑战性的任务。本文针对视频流中人脸检测存在的平面内旋转问题,将人脸关键点与金字塔光流相结合,提出了基于级联网络和金字塔光流的旋转不变人脸检测算法。首先利用级联渐进卷积神经网络对视频流中前一帧进行人脸位置和关键点的定位;其次为获取关键点与人脸候选框间光流映射,使用独立的关键点检测网络对当前帧进行再次定位;之后计算前后两帧之间关键点光流位移;最后通过关键点光流位移与人脸候选框的映射关系,对视频中检测到的人脸进行校正,从而完成平面内旋转人脸不变性检测。实验经FDDB公开数据集上测试,证明该方法精确度较高。并且,在Boston面部跟踪数据集上进行动态测试,证明该人脸检测算法能有效解决平面内旋转人脸检测问题。对比其它检测算法,该算法检测速度有较大优势,同时视频中窗口抖动问题得到了很好解决。 相似文献
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人脸图像中人眼的检测与定位 总被引:6,自引:0,他引:6
利用人脸几何特征和图像分割原理,提出了一种在有背景的灰度和彩色人脸图像中自动检测与定位人眼的新算法。首先,基于人脸器官几何分布先验知识建立人眼位置判定准则;其次对人眼的分割阈值范围进行粗估计;然后采用分割阈值递增法,并结合人眼位置判定准则判定分割图像中双眼黑块是否出现;最后利用二雏相关系数作为对称相似性测度,检验检测到的双眼的真实性。为了避免图像背景对人眼检测的干扰,还运用了肤色分割原理来缩小检测人眼的搜索区域,从而进一步提高人眼定位的准确性。实验验证表明,所提出的人眼检测与定位方法在速度和准确性方面具有良好的性能。 相似文献
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《IEEE transactions on instrumentation and measurement》2009,58(7):2087-2093
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Abdulsamad A. AL-Marghilani 《计算机、材料和连续体(英文)》2022,71(1):809-824
Presently, suspect prediction of crime scenes can be considered as a classification task, which predicts the suspects based on the time, space, and type of crime. Performing digital forensic investigation in a big data environment poses several challenges to the investigational officer. Besides, the facial sketches are widely employed by the law enforcement agencies for assisting the suspect identification of suspects involved in crime scenes. The sketches utilized in the forensic investigations are either drawn by forensic artists or generated through the computer program (composite sketches) based on the verbal explanation given by the eyewitness or victim. Since this suspect identification process is slow and difficult, it is required to design a technique for a quick and automated facial sketch generation. Machine Learning (ML) and deep learning (DL) models find it useful to automatically support the decision of forensics experts. The challenge is the incorporation of the domain expert knowledge with DL models for developing efficient techniques to make better decisions. In this view, this study develops a new artificial intelligence (AI) based DL model with face sketch synthesis (FSS) for suspect identification (DLFSS-SI) in a big data environment. The proposed method performs preprocessing at the primary stage to improvise the image quality. In addition, the proposed model uses a DL based MobileNet (MN) model for feature extractor, and the hyper parameters of the MobileNet are tuned by quasi oppositional firefly optimization (QOFFO) algorithm. The proposed model automatically draws the sketches of the input facial images. Moreover, a qualitative similarity assessment takes place with the sketch drawn by a professional artist by the eyewitness. If there is a higher resemblance between the two sketches, the suspect will be determined. To validate the effective performance of the DLFSS-SI method, a detailed qualitative and quantitative examination takes place. The experimental outcome stated that the DLFSS-SI model has outperformed the compared methods in terms of mean square error (MSE), peak signal to noise ratio (PSNR), average actuary, and average computation time. 相似文献
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Although a foil three-dimensional (3-D) reconstruction with both 3-D forward and inverse models provide, the optimal solution for diffuse optical tomography (DOT), because of the 3-D nature of photon diffusion in tissue, it is computationally costly for both memory requirement and execution time in a conventional computing environment. Thus in practice there is motivation to develop an image reconstruction algorithm with dimensional reduction based on some modeling approximations. Here we have implemented a semi-3-D modified generalized pulse spectrum technique for time-resolved DOT, where a two-dimensional (2-D) distribution of optical properties is approximately assumed, while we retain 3-D distribution of photon migration in tissue. We have validated the proposed algorithm by reconstructing 3-D structural test objects from both numerically simulated and experimental date. We demonstrate our algorithm by comparing it with the calibrated 2-D reconstruction that is in widespread use as a shortcut to 3-D imaging and proving that the semi-3-D algorithm outperforms the calibrated 2-D algorithm. 相似文献
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This work focuses on the formulation of an asymptotically correct theory for symmetric composite honeycomb sandwich plate structures. In these panels, transverse stresses tremendously influence design. The conventional 2-D finite elements cannot predict the thickness-wise distributions of transverse shear or normal stresses and 3-D displacements. Unfortunately, the use of the more accurate three-dimensional finite elements is computationally prohibitive. The development of the present theory is based on the Variational Asymptotic Method (VAM). Its unique features are the identification and utilization of additional small parameters associated with the anisotropy and non-homogeneity of composite sandwich plate structures. These parameters are ratios of smallness of the thickness of both facial layers to that of the core and smallness of 3-D stiffness coefficients of the core to that of the face sheets. Finally, anisotropy in the core and face sheets is addressed by the small parameters within the 3-D stiffness matrices. Numerical results are illustrated for several sample problems. The 3-D responses recovered using VAM-based model are obtained in a much more computationally efficient manner than, and are in agreement with, those of available 3-D elasticity solutions and 3-D FE solutions of MSC NASTRAN. 相似文献