14581660
An Improved Physically-Based Method for Geometric Restoration of Distorted Document Images
In document digitization through camera-based systems, simple imaging setups often produce geometric distortions in the resultant 2D images because of the nonplanar geometric shapes of certain documents such as thick bound books, rolled, folded, or crumpled materials, etc. Previous work [1], [2], [3], [4] has demonstrated that arbitrary warped documents can be successfully restored by flattening a 3D scan of the document. These approaches use physically-based or relaxation-based techniques in their flattening process. While this has been demonstrated to be effective in rectifying the image content and improving OCR, these previous approaches have several limitations in terms of speed and stability. In this paper, we propose a distance-based penalty metric to replace the mass- spring model and introduce additional bending resistance and drag forces to improve the efficiency of the existing approaches. The use of Verlet integration and special plane collision handling schemes also help to achieve better stability without sacrificing efficiency. Experiments on various document images captured from books, brochures, and historical documents with arbitrary warpings have demonstrated large improvements over the existing approaches in terms of stability and efficiency.
31519303
Data-Driven Facial Feature Morphing for 3D Face Synthesis
59703933
Anatomy-based 3D facial modeling for expression animation
In this paper we propose a new hierarchical 3D facial model that conforms to the human facial anatomy for realistic facial expression animation. The facial model has a hierarchical biomechanical structure, incorporating a physically-based approximation to facial skin tissue, a set of anatomically-motivated facial muscle actuators and underlying skull structure. The deformable skin model has multi-layer structure to approximate different types of soft tissue. It takes into account the nonlinear stress-strain relationship of the skin and the fact that soft tissue is almost incompressible. Different kinds of muscle models have been developed to simulate the distribution of the muscle force on the skin due to muscle contraction. By the presence of the skull model, our facial model takes advantage of both more accurate facial deformation and the consideration of facial anatomy during the interactive definition of facial muscles. Under the muscular force, the deformation of the facial skin is evaluated by solving the governing dynamic equation numerically. To improve computational efficiency, we use a localized, semi-implicit integration method which allows a larger time step to be taken in the simulation while retaining stability. The dynamic facial animation algorithm runs at an interactive rate with flexible and realistic facial expressions to be generated.
43457446
Synthesis of facial expressions using a 3D anatomical model
In this paper we propose an individualized 3D facial model constructed from the anatomical perspective for realistic facial expression synthesis. Our model incorporates a physically-based approximation to facial skin tissue, a set of anatomically-motivated facial muscle actuators and underlying skull structure. The skin is modeled as a multi-layer mass-spring lattice by taking into account the nonlinear stress-strain relationship of the real skin. The 3D face model incorporates a skull structure which extends the scope of facial motion and facilitates facial muscle definition. The automatic facial muscle construction is achieved by using an efficient muscle mapping approach that ensures different muscles to be located at the anatomically correct positions between the skin and skull layers. For computational efficiency, we devise a semi-implicit integration method to numerically solve the governing dynamics. The dynamic facial animation algorithm runs at an interactive rate with realistic facial expressions to be synthesized.
45254253
A physically-based model for real-time facial expression animation
In this paper we propose a physically-based 3D dynamic facial model based on anatomical knowledge for facial expression animation. The facial model incorporates a physically-based approximation to facial skin and a set of anatomically-motivated facial muscles. The skin model is established through the use of a mass-spring system with nonlinear springs which simulate the elastic dynamics of a real facial skin. Facial muscle models are developed to emulate facial muscle contraction. Lagrangian mechanics governs the dynamics, dictating the deformation of facial surface in response to muscle forces. The dynamic facial modeling algorithm runs at interactive rate with continuous 3D display on a graphics workstation. Using our system, we can effectively synthesize realistic facial expressions and analyze tile relationship between facial surface deformation and the activation of underlying facial muscles.
39711298
Data-Driven Feature Control Models for Creating Virtual Faces
This paper presents a novel data-driven method for creating realistic face models based on estimated high-level feature control models. Our method takes as examples 3D face scans. By bringing scanned models into full correspondence with a model fitting approach, we apply principal component analysis (PCA) to the exemplar shapes of each facial feature to build a shape space. We compute a set of face anthropometric measurements to parameterize example feature shapes in the measurement spaces. Using the 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 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 example textures.
39739560
Optimal Motion Generation of Flexible Macro-micro Manipulator Systems Using Estimation of Distribution Algorithm
In this paper, a new approach for motion generation and optimization of the flexible macro-micro manipulator system is proposed based on Estimation of Distribution Algorithm (EDA). The macro-micro manipulator system is a redundant system, of which inverse kinematics remains challenging, with no generic solution to date. Here, the manipulator system configurations, or the optimal joint motions, are generated using the EDA algorithm base on Gaussian probability model. Compared with simple genetic algorithms (SGA), this approach uses fewer parameters and the time for motion optimization is remarkably reduced. The proposed approach shows excellent performance on motion generation and optimization of a flexible macro-micro manipulator system, as demonstrated by the simulation results.
36214906
New routing algorithms in trustworthy Internet
Since the lack of source IP address checking in today's Internet makes it easy for the attackers to spoof the source address, the mechanism of Source Address Validation Architecture (SAVA) is proposed for building effective source-address validation to ensure that packets forwarded hold authentic source addresses. In this paper, we study the routing selection in partial deployment of SAVA nodes in the trustworthy Internet. We propose and compare three routing algorithms, i.e., Shortest-Path Algorithm (SPA), SAVA based Shortest-Path Algorithm (SSPA), and SAVA based Shortest-Path Algorithm with Load Balancing (SSPALB). Beside analytical results, we run simulations which met our expectations.
197131
Multi-hop Cross-Layer Design in Wireless Sensor Networks: A Case Study
Cross-layer design has been proposed as a promising paradigm to tackle various problems of wireless communication systems. Recent research has led to a variety of protocols that rely on intensive interaction between different layers of the classical layered OSI protocol architecture. These protocols involve different layers and introduce new ideas how layers shall communicate and interact. In existing cross-layer approaches, the violation of the OSI architecture typically consists in passing information between different adjacent or non-adjacent layers of one single station's protocol stack to solve an optimization problem and exploiting the dependencies between the layers. This paper proposes to go a step further and to consider cross-layer information exchange across different layers of multiple stations involved in multi-hop communication systems. It outlines possible application scenarios of this approach, and trades off between advantages and disadvantages of the proposed \emph {multi-hop cross-layer design}. It examines an application scheme in a scenario of a wireless sensor network environment operating with a recent energy-efficient power saving protocol.
5444016
Arbitrary warped document image restoration based on segmentation and Thin-Plate Splines
Warping is a common appearance in camera captured document images. It is the primary factor that makes such kind of document images hard to be recognized. Therefore it is necessary to restore warped document image before recognition. In this paper, a novel restore method is presented. The method takes a rough line segmentation and character segmentation firstly in order to estimate the warping direction. Then several pairs of key points mapping between the original image and the restored image are determined and thin-plate splines (TPS), which is an interpolation algorithm, is introduced to restore the image. Such process can effectively describe the warping direction of the document and successfully restore the image. Some experimental results show the effect of the image restoration and compare the recognition rate before and after the restoration based on a same OCR application.
481284
A Novel Method for Image Spam Filtering
As spamming morphs from text-only to multi-media in content, the existing text-based spam filters are no longer effective for the task. Image analysis technology will provide an effective tool to solve the above problem. This paper proposes a novel filter approach that focuses on the spam which change the content text to image files, or embed the spam message into attached images. Spam images are analyzed and specific features are selected for inspection based on components-based method. Then the network junk-mail-filter system can use these features to identify whether to filter the mail or not by feature matching. Experiments show that our method is efficient in inspecting document images with different geometric structure. The proposed method has potential applications in document image information extraction and filtering.