Attributions aim to identify input pixels that are relevant to the decision-making process. A popular approach involves using modified backpropagation (BP) rules to reverse decisions, which improves interpretability c...
The basic idea of calibrating a camera system in previous approaches is to determine camera parameters by using a set of known 3D points as calibration *** this paper,we present a method of camera calibration in which...
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The basic idea of calibrating a camera system in previous approaches is to determine camera parameters by using a set of known 3D points as calibration *** this paper,we present a method of camera calibration in which camera parameters are determined by a set of 3D lines.A set of constraints is derived on camera parameters in terms of perspective line *** these con- straints,the same perspective transformation matrix as that for point mapping can be computed *** minimum number of calibration lines is *** result generalizes that of Lin,Huang and Faugeras for camera location determination in which at least 8 line correspondences are re- quired for linear computation of camera *** line segments in an image can be located easi- ly and more accurately than points,the use of lines as calibration reference tends to ease the compu- tation in image preprocessing and to improve calibration *** results on the calibration along with stereo reconstruction are reported.
In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo *** the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr)to comput...
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In this paper,a new method is presented for 3D motion estimation by image region correspon- dences using stereo *** the weak perspectivity assumption,we first employ the moment tensor theory(Cyganski and Orr)to compute the monocular affine transformations relating images taken by the same camera at different time instants and the binocular affine transformations relating images taken by different cameras at the same time *** then show that 3D motion can he recovered from these 2D transformations.A space-time fusion strategy is proposed to aim at robust *** knowledge of point correspondences is required in the above processes and the computa- lions involved are *** find corresponding image regions,new affine invariants,which show stronger invariance,are derived in term of tensor contraction *** on real motion images are conducted to verify the proposed method.
Projective reconstruction is a key step for 3D metric reconstruction from a sequence of images captured by an uncalibrated camera. Due to its inherent robustness, the factorization method is widely used in literatures...
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Projective reconstruction is a key step for 3D metric reconstruction from a sequence of images captured by an uncalibrated camera. Due to its inherent robustness, the factorization method is widely used in literatures. However, the main shortcoming of the standard factorization method is that it requires the corresponding points to appear across ALL the images. When large changes of view angles occur in the image sequence, or the scene is easy to be self-occluded, nearly it will be very difficult to have some corresponding points visible across all the images. But it is much easier for only several images to have enough correspondences required by factorization method. These images are called as a subsequence in the whole image set. In this paper,a sub-sequence factorization method is proposed to cope with the problem. The basic principle of the sub-sequence factorization method is to divide a long image sequence into several short subsequences according to its spatial continuity, and the standard factorization method is employed for each ***, a novel alignment process is invoked to transform different reconstructions under different subsequences into one reference coordinates system. It is more practical as it only demands that there are enough correspondences in each subsequence, not the whole sequence. The proposed sub-sequence factorization method preserves the robustness aspect embedded in the standard factorization method. The experiments on synthetic and real images validate our proposed new method.
Linear subspace analysis methods have been successfully applied to extract features for face recognition. But they are inadequate to represent the complex and nonlinear variations of real face images, such as illumina...
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Linear subspace analysis methods have been successfully applied to extract features for face recognition. But they are inadequate to represent the complex and nonlinear variations of real face images, such as illumination, facial expression and pose variations, because of their linear properties. In this paper, a nonlinear subspace analysis method, Kernel-based Nonlinear Discriminant Analysis (KNDA), is presented for face recognition, which combines the nonlinear kernel trick with the linear subspace analysis method - Fisher Linear Discriminant Analysis (FLDA).First, the kernel trick is used to project the input data into an implicit feature space, then FLDA is performed in this feature space. Thus nonlinear discriminant features of the input data are yielded. In addition, in order to reduce the computational complexity, a geometry-based feature vectors selection scheme is adopted. Another similar nonlinear subspace analysis is Kernel-based Principal Component Analysis (KPCA), which combines the kernel trick with linear Principal Component Analysis (PCA). Experiments are performed with the polynomial kernel, and KNDA is compared with KPCA and FLDA. Extensive experimental results show that KNDA can give a higher recognition rate than KPCA and FLDA.
In this paper, we introduce the HMM-state sequence confusion characteristics as prior knowledge into the framework of MLLR to relax the transformation and reduce the risks of over-training when adaptation data size is...
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ISBN:
(纸本)7801501144
In this paper, we introduce the HMM-state sequence confusion characteristics as prior knowledge into the framework of MLLR to relax the transformation and reduce the risks of over-training when adaptation data size is small. There are two issues to be addressed as follows: first, how to estimate such confusion information reliably;second how to use the information in refining the estimation of MLLR adaptation. The pronunciation modeling technology was utilized to build the state sequence confusion table. Then the correlation of states is calculated according to the confusion table. Following proposed algorithm made a relaxation in the process of MLLR adaptation when the adaptation data is very small. Our experiment on a Mandarin state-tying triphone toneless LVCSR system showed that error rate reduction is 9.5% over standard MLLR with about 10 utterances (less than 30 seconds) of adaptation data.
Fingerprint matching is one of the most important stages in automatic fingerprint identification systems (AFIS). Traditional methods treat this problem as point pattern matching, which is essentially an intractable pr...
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Fingerprint matching is one of the most important stages in automatic fingerprint identification systems (AFIS). Traditional methods treat this problem as point pattern matching, which is essentially an intractable problem due to the various nonlinear deformations commonly observed in fingerprint images. In this article, we propose an effective fingerprint matching algorithm based on error propagation. Firstly, ridge information and Hough transformation are adopted to find several pairs of matching minutiae, the initial correspondences, which are used to estimate the common region of two fingerprints and the alignment, parameters. Then a MatchedSet which includes the correspondence and its surrounding matched minutiae pairs is established. The subsequent matching process is guided by the concept of error propagation: the matching errors of each unmatched minutiae are estimated according to those of its most relevant neighbor minutiae. In order to prevent the process from being misguided by mismatched minutiae pairs, we adopt a flexible propagation scheme. Experimental results demonstrate the robustness of our algorithm to non-linear deformation.
In this paper we present a novel method for online text-independent writer identification. Most of the existing writer identification techniques require the data to be from a specific text which is not applicable to c...
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This paper presents a system of data decomposition and spatial mixture modeling for part based models. Recently, many enhanced part based models (with e.g., multiple features, more components or parts) have been propo...
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In social media, many existing websites (e.g., Flickr, YouTube, and Facebook) are for users to share their own interests and opinions of many popular events, and success-fully facilitate the event generation, sharing ...
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ISBN:
(纸本)9781450328104
In social media, many existing websites (e.g., Flickr, YouTube, and Facebook) are for users to share their own interests and opinions of many popular events, and success-fully facilitate the event generation, sharing and propagation. As a result, there are substantial amounts of user-contributed media data (e.g., images, videos, and textual content) for a wide variety of real-world events of different types and scales. The aim of this paper is to automatically identify the interesting events from massive social media data, which are useful to browse, search and monitor social events by users or governments. To achieve this goal, we propose a novel multi-modal supervised latent dirichlet allocation (mm-SLDA) for social event classification. Our proposed mm-SLDA has a number of advantages. (1) It can effectively exploit the multi-modality and the multi-class property of social events jointly. (2) It makes use of the supervised social event category label information and is able to classify multi-class social event directly. We evaluate our proposed mm-SLDA on a real world dataset and show extensive experimental results, which demonstrate that our model outperforms state-of-the-art methods. Copyright 2014 ACM.
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