We present a method for computing dense visual correspondence based on general assumptions about scene geometry. Our algorithm does not rely on cor relation, and uses a variable region of support. We assume that image...
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ISBN:
(纸本)0780342364
We present a method for computing dense visual correspondence based on general assumptions about scene geometry. Our algorithm does not rely on cor relation, and uses a variable region of support. We assume that images consist of a number of connected sets of pixels with the same disparity, which we call disparity components. Using maximum likelihood arguments, at each pixel we compute a small set of plausible disparities. A pixel is assigned a disparity d based on connected components of pixels, where each pixel in a component considers d to be plausible. Our implementation chooses the largest plausible disparity component;however;global contextual constraints can also be applied. While the algorithm was originally designed for visual correspondence, it can also be used for other early vision problems such as image restoration. It runs in a few seconds on traditional benchmark images with standard parameter settings, and gives quite promising results.
We develop a method for recognizing color texture independent of rotation, scale, and illumination. Color texture is modeled using spatial correlation functions defined within and between sensor bands. Using a linear ...
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ISBN:
(纸本)0818672587
We develop a method for recognizing color texture independent of rotation, scale, and illumination. Color texture is modeled using spatial correlation functions defined within and between sensor bands. Using a linear model for surface spectral reflectance with the same number of parameters as the number of sensor classes, we show that illumination and geometry changes in the scene correspond to a linear transformation of the correlation functions and a linear transformation of their coordinates. A several step algorithm which includes scale estimation and correlation moment computation is used to achieve the invariance. The key to the method is the new result that illumination and geometry changes in the scene correspond to a specific transformation of correlation function Zernike moment matrices. These matrices can be estimated from a color image. This relationship is used to derive an efficient algorithm for recognition. The algorithm is substantiated using classification results on over 200 images of color textures obtained under various illumination conditions and geometric configurations.
The detection of smooth curves in images and their completion over gaps are two important problems in perceptual grouping. lit this paper we examine the nation of completion energy and introduce a fast method to compu...
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ISBN:
(纸本)0780342364
The detection of smooth curves in images and their completion over gaps are two important problems in perceptual grouping. lit this paper we examine the nation of completion energy and introduce a fast method to compute the most likely completions in images. Specifically, we develop two novel analytic approximations to the curve of least energy. In addition, we introduce a fast numerical method to compute the curve of least energy and show that our approximations are obtained at early stages of this numerical computation. We then use our newly developed energies to find the most likely completions in images through a generalized summation of induction fields. Since in practice edge elements are obtained by applying filters of certain widths and lengths to the image, we adjust our computation to take these parameters into account. Finally, we show that, due to the smoothness of the kernel of summation the process of summing induction fields can be run in time that is linear in the number of different edge elements in the image, or in O(N log N) where N is the number of pixels in the image, using multigrid methods.
For the analysis of images, a deeper understanding of their intrinsic structure is required. This has been obtained for 2D images by means of statistical analysis [15, 18]. Here, we analyze the relation between local ...
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In this paper, efforts have been made to analyze the impact of training strategies, transfer learning and domain knowledge on two biometric-based problems namely: three class oculus classification and fingerprint sens...
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ISBN:
(数字)9781538661000
ISBN:
(纸本)9781538661000
In this paper, efforts have been made to analyze the impact of training strategies, transfer learning and domain knowledge on two biometric-based problems namely: three class oculus classification and fingerprint sensor classification. For analyzing these problems we have considered deep-learning based architecture and evaluated our results on benchmark contact-lens datasets like IIIT-D, ND, IIT-K ( our model is publicly available) and on fingerprint datasets like FVC-2002, FVC-2004, FVC-2006, IIITD-MOLF, IIT-K. In-depth feature analysis of various proposed deep-learning models has been done in order to infer that indeed training in different ways along with transfer learning and domain knowledge plays a vital role in deciding the learning ability of any network.
Automatic target recognition (ATR) applications require simultaneously a wide field of view (FOV) for better detection and situation awareness, high resolution for target recognition and threat assessment, and high fr...
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ISBN:
(纸本)0818672587
Automatic target recognition (ATR) applications require simultaneously a wide field of view (FOV) for better detection and situation awareness, high resolution for target recognition and threat assessment, and high frame rate for detecting brief events and disambiguating frame-to-frame correlation. Uniformly sampling the entire FOV at recognition resolution is simply wasteful in ATR scenarios with localized regions of interest (ROIs). Foveal data acquisition with space-variant sampling and context-sensitive sensor articulation is highly optimized for active ATR applications. We propose a multiscale local Zernike filter-based front end target detection technique for a commercially feasible foveal sensor topology with piecewise constant resolution profile. Anisotropic heat diffusion is employed for preprocessing of the foveal data. Expansion template matching is used to derive a detection filter that optimizes the discriminant signal-to-noise ratio (SNR). Results are presented with simulated foveal imagery derived from real uniform acuity FLIR data.
This paper presents a completely automated facial action and facial expression recognition system using 2D+3D images recorded in real-time by a structured light sensor. It is based on local feature tracking and rule-b...
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ISBN:
(纸本)9781424439942
This paper presents a completely automated facial action and facial expression recognition system using 2D+3D images recorded in real-time by a structured light sensor. It is based on local feature tracking and rule-based classification of geometric, appearance and surface curvature measurements. Good performance is achieved under relatively non-controlled conditions.
Detecting weak fire, such as overexposed and highly transparent flames, remains a significant challenge in vision-based fire detection. Convolutional Neural Network (CNN) based methods are widely used for automatic fi...
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There are many historical manuscripts written in a single hand which it would be useful to index. Examples include the W.B. DuBois collection at the University of Massachusetts and the early Presidential libraries at ...
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ISBN:
(纸本)0818672587
There are many historical manuscripts written in a single hand which it would be useful to index. Examples include the W.B. DuBois collection at the University of Massachusetts and the early Presidential libraries at the Library of Congress. Since Optical Character recognition (OCR) does not work well on handwriting, an alternative scheme based on matching the images of the words is proposed for indexing such texts. The current paper deals with the matching aspects of this process. Two different techniques for matching words are discussed. The first method matches words assuming that the transformation between the words may be modelled by a translation (shift). The second method matches words assuming that the transformation between the words may be modelled by an affine transform. Experiments are shown demonstrating the feasibility of the approach for indexing handwriting. The method should also be applicable to retrieving previously stored material from personal digital assistants (PDAs).
We have designed and implemented a real-time binocular tracking system which uses two independent cues commonly found in the primary functions of biological visual systems to robustly track moving targets in complex e...
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ISBN:
(纸本)0780342364
We have designed and implemented a real-time binocular tracking system which uses two independent cues commonly found in the primary functions of biological visual systems to robustly track moving targets in complex environments, without a-priori knowledge of the target shape or texture: a fast optical flow segmentation algorithm quickly locates independently moving objects for target acquisition and provides a reliable velocity estimate for smooth tracking. In parallel, target position is generated from the output of a zero-disparity filter where a phase-based disparity estimation technique allows dynamic control of the camera vergence to adapt the horopter geometry to the target location. The system takes advantage of the optical properties of our custom-designed foveated wide-angle lenses, which exhibit a wide field of view along with a high resolution fovea. Methods to cope with the distortions introduced by the space-variant resolution, and a robust real-time implementation on a high performance active vision head are presented.
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