In this paper, we propose an efficient 3D face recognition method based on statistics of range image differences. Each pixel value of range image represents normalized depth value of corresponding point on facial surf...
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ISBN:
(纸本)9783540763895
In this paper, we propose an efficient 3D face recognition method based on statistics of range image differences. Each pixel value of range image represents normalized depth value of corresponding point on facial surface, and so depth differences between two range images' pixels of the same position on face can straightforwardly describe the differences between two faces' structures. Here, we propose to use histogram proportion of depth differences to discriminate intra and inter personal differences for 3D face recognition. Depth differences are computed from a neighbor district instead of direct subtraction to avoid the impact of non-precise registration. Furthermore, three schemes are proposed to combine the local rigid region(nose) and holistic face to overcome expression variation for robust recognition. Promising experimental results are achieved on the 3D dataset of FRGC2.0, which is the most challenging 3D database so far.
This survey paper addresses some issues related to the application of computervision techniques to improve the welfare of people with special needs. The main problems and current work on topics like sign language pro...
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ISBN:
(纸本)9780415433495
This survey paper addresses some issues related to the application of computervision techniques to improve the welfare of people with special needs. The main problems and current work on topics like sign language processing and wheelchair control will be presented. The paper also introduces an ongoing project that aims at creating a free software environment that will include implementations of a large amount of computervision, patternrecognition and machine learning techniques, tuned to the problems related to the digital inclusion of people with special needs. The software will also serve as an experimental environment, where new techniques will be implemented, tested and compared.
Characters connectivity is a problem in automated printed Farsi/Arabic script recognition. This paper introduces a novel scheme based on wavelet transform to solve segmentation of printed Farsi/Arabic words into chara...
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ISBN:
(纸本)9781424410309
Characters connectivity is a problem in automated printed Farsi/Arabic script recognition. This paper introduces a novel scheme based on wavelet transform to solve segmentation of printed Farsi/Arabic words into characters. Our novel algorithm employs a new wavelet transform by which the extracted wavelet coefficients are exploited, in detecting, underlying horizontal edges and base line. Projection of horizontal edges and their location on base line provide the segmentation points. A classification method distinguishes true segmenting points. New algorithm is robust against noise, gray level, font and size of characters. Simulation results provide a comparison between new algorithm and three schemes, closed contour, structural and holistic, in terms Of precision, speed and robustness against Gaussian noise. Experimental Results indicate superiority of our scheme in terms of precision and show that new algorithm improves recognition speed by a factor of at least 2.5 times.
The Machine Learning and patternrecognition communities are facing two challenges: solving the normalization problem, and solving the deep learning problem. The normalization problem is related to the difficulty of t...
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ISBN:
(纸本)9780769528229
The Machine Learning and patternrecognition communities are facing two challenges: solving the normalization problem, and solving the deep learning problem. The normalization problem is related to the difficulty of training probabilistic models over large spaces while keeping them properly normalized. In recent years, the ML and Natural Language communities have devoted considerable efforts to circumventing this problem by developing "unnormalized" learning models for tasks in which the output is highly structured (e.g. English sentences). This class of models was in fact originally developed during the 90's in the handwriting recognition community, and includes Graph Tran former Networks, Conditional Random Fields, Hidden Markov SVMs, and Maximum Margin Markov Networks. We describe these models within the unifying framework, of "Energy-Based Models" (EBM). The Deep Learning Problem is related to the issue of training all the levels of a recognition system (e.g. segmentation, feature extraction, recognition, etc) in an integrated fashion. We first consider "traditional" methods for deep learning, such as convolutional networks and back-propagation, and show that, although they produce very low error rates for handwriting and object recognition, they require many training samples. We show that using unsupervised learning to initialize the layers of a deep network dramatically reduces the required number of training samples, particularly for such tasks as the recognition of everyday objects at the category level.
This paper deals with a compact catadioptric omnidirectional stereovision system based on a single camera and multi-mirrors (at least two mirrors). Many configurations were empirically designed in previous works with ...
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ISBN:
(纸本)9783540728481
This paper deals with a compact catadioptric omnidirectional stereovision system based on a single camera and multi-mirrors (at least two mirrors). Many configurations were empirically designed in previous works with the aim to obtain a good 3D reconstruction accuracy. In this paper, we propose to use optimization techniques for omnidirectional catadioptric stereovision design, by using a stochastic local search method in order to find a good sensor (number, relative positions and sizes of mirrors). We explain principles of our approach and provide automatically designed sensors with a number of mirrors from two to nine. We finally simulate the 3D-reconstruction of a real environment modeled under a ray-tracing software with some of these sensors.
Recent developments in computervision provide powerful tools for the examination and classification of data of our cultural heritage. it is generally recognized that the cultural heritage we are preserving for future...
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Recent developments in computervision provide powerful tools for the examination and classification of data of our cultural heritage. it is generally recognized that the cultural heritage we are preserving for future generations will profit considerably from passing over to state of the art technologies. New camera hardware allows new insights into cultural heritage, especially if infrared cameras are concerned, since they allow the study of structures that are visually hidden. In this paper a strategy for the analysis of underdrawing strokes in infrared reflectograms is presented. Underdrawings are the basic concept or "primal sketch" of the artist before the complete painting is created. We focus on infrared reflectograms of medieval panel paintings, since their underdrawings are common and help art historians to study the school of the old masters. The purpose of the stroke analysis is the determination of the drawing tool used to draft the painting. This information allows significant support for a systematic stylistic approach in the analysis of paintings. Stroke segmentation in paintings is related to the extraction and recognition of handwriting, therefore similar techniques to segment the strokes from the background incorporating boundary information are used. Following the segmentation of single strokes, a classification of strokes with respect to the drawing tool used to create the strokes is performed. Two different classification methods, one texture-based and one based on active contour models are combined in order to improve the classification results, which are presented and discussed for strokes on selected test panels. (c) 2006 Elsevier B.V. All rights reserved.
Object tracking using active contours has attracted increasing interest in recent years due to acquisition of effective shape descriptions. In this paper, an object tracking method based on level sets using moving cam...
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ISBN:
(纸本)9783540763857
Object tracking using active contours has attracted increasing interest in recent years due to acquisition of effective shape descriptions. In this paper, an object tracking method based on level sets using moving cameras is proposed. We develop an automatic contour initialization method based on optical flow detection. A Markov Random Field (MRF)-like model measuring the correlations between neighboring pixels is added to improve the general region-based level sets speed model. The experimental results on several real video sequences show that our method successfully tracks objects despite object scale changes, motion blur, background disturbance, and gets smoother and more accurate results than the current region-based method.
Template matching is one of the key problems in computervision and has been widely used in tracking, recognition and many other applications. Traditional methods are usually slow because the template needs to be matc...
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In this paper, we present a new solution to the problem of multi-camera tracking with non-overlapping fields of view. The identities of moving objects are maintained when they are traveling from one camera to another....
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ISBN:
(纸本)9783540763857
In this paper, we present a new solution to the problem of multi-camera tracking with non-overlapping fields of view. The identities of moving objects are maintained when they are traveling from one camera to another. Appearance information and spatio-temporal information are explored and combined in a maximum a posteriori (MAP) framework. In computing appearance probability, a two-layered histogram representation is proposed to incorporate spatial information of objects. Diffusion distance is employed to histogram matching to compensate for illumination changes and camera distortions. In deriving spatio-temporal probability, transition time distribution between each pair of entry zone and exit zone is modeled as a mixture of Gaussian distributions. Experimental results demonstrate the effectiveness of the proposed method.
In this paper a coarse region segmentation of liver cancer in ultrasound Images is introduced. The reason employing coarse region segmentation is to reflect the inhomogeneous distribution of the image gray levels and ...
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ISBN:
(纸本)9780819469533
In this paper a coarse region segmentation of liver cancer in ultrasound Images is introduced. The reason employing coarse region segmentation is to reflect the inhomogeneous distribution of the image gray levels and provide the features such as the distribution, shape and size of the suspect region of liver cancer. Then combine with the prior knowledge we can divide the image into three different classes, which the results of the analysis of the region's location can be used by a classifier in a multilayer classifier. Furthermore, the result of the coarse region segmentation will support the texture analysis for further classification. The segmentation is based on watershed algorithm in order to receive an integrated region and two processing techniques are adopted to avoid the over segmentation of watershed algorithm.
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