In this paper;we present a neural network-based face detection system. Unlike similar systems which nr-e limited to detecting upright,frontal faces, this system detects faces at any degree of rotation in the image pla...
详细信息
ISBN:
(纸本)0818684976
In this paper;we present a neural network-based face detection system. Unlike similar systems which nr-e limited to detecting upright,frontal faces, this system detects faces at any degree of rotation in the image plane. The system employs multiple networks;a "router" network first processes each input window to determine its orientation and then uses this information to prepare the window for one or more "detector" networks. We present the training methods for. both types of networks. We also perform sensitivity analysis an the networks, and present empirical results on a large test set. Finally! we present preliminary results for detecting faces rotated out of the image plane, such as profiles and semi-profiles.
Inspired by the properties of the human visual system, a new active vision system called ESCHeR (Etl Stereo Compact Head For Robot vision) has been recently implemented with foveated wide-angle lenses. The lenses exhi...
详细信息
ISBN:
(纸本)0818672587
Inspired by the properties of the human visual system, a new active vision system called ESCHeR (Etl Stereo Compact Head For Robot vision) has been recently implemented with foveated wide-angle lenses. The lenses exhibit a wide field of view along with a space-varying resolution for facilitating both detection and close observation. However, to handle such optical properties and achieve basic eye movement functions, new calibration methods are needed. Therefore, two novel and online techniques are presented that in one case perform a global identification of the optical process through artificial neural techniques and in the other case compute the physical parameters by using environmental feature-tracking and controlled rotations of the cameras. Self-alignment of the cameras is also achieved using a similar technique.
A common factor in all illusory contour figures is the perception of a surface occluding part of a background. In our previous work, we have shown we could diffuse a proper set of junction hypothesis (what is salient ...
详细信息
ISBN:
(纸本)0818672587
A common factor in all illusory contour figures is the perception of a surface occluding part of a background. In our previous work, we have shown we could diffuse a proper set of junction hypothesis (what is salient or background) to obtain a surface where their boundaries represented illusory contours. Amodal completions emerge at the overlapping surfaces. We address the problem of selecting the best image organization (set of hypothesis). We propose an optimization criteria based on a coherence measure between pairs of junctions (correlation between the diffusion of each pair). A statistical physics approach to select the best organization is applied. The experiments suggest that despite the large number of possible organizations our approach may take only a few steps (in organization space) to select the best one.
In this paper we propose a new distance measure for an identification problem and describe experiments on fingerprints preselection using eigenfeatures of ridge direction patterns. The distance is defined by likelihoo...
详细信息
ISBN:
(纸本)0818684976
In this paper we propose a new distance measure for an identification problem and describe experiments on fingerprints preselection using eigenfeatures of ridge direction patterns. The distance is defined by likelihood ratio of error distribution of feature vectors to the whole distribution of feature vector differences. In addition, we introduce "quality indexes" of feature vectors and make the distance adaptive to the quality indexes. Experiments on fingerprint preselection for ten-print cards revealed that our proposed distance is much more effective than the Mahalanobis distance. By combining the eigenfeatures and traditional classification features;0.06% false acceptance rate at 2.0% false rejection rate and one million cards/sec preselection speed on a standard workstation, have been achieved. This makes it possible to construct high performance fingerprint identification systems.
Scene classification is a major open challenge in machine vision. Most solutions proposed so far such as those based on color histograms and local texture statistics cannot capture a scene's global configuration, ...
详细信息
ISBN:
(纸本)0780342364
Scene classification is a major open challenge in machine vision. Most solutions proposed so far such as those based on color histograms and local texture statistics cannot capture a scene's global configuration, which is critical in perceptual judgments of scene similarity. We present a novel approach, ''configural recognition'', for encoding scene class structure. The approach's main feature is its use of qualitative spatial and photometric relationships within and across regions in low resolution images. The emphasis on qualitative measures leads to enhanced generalization abilities and the use of low-resolution images renders the scheme computationally efficient. We present results on a large database of natural scenes. We also describe how qualitative scene concepts may be learned from examples.
Correlation-based real-time stereo systems have been proven to be effective in applications such as robot navigation, elevation map building etc. This paper provides an in-depth analysis of the major error sources for...
详细信息
ISBN:
(纸本)0780342364
Correlation-based real-time stereo systems have been proven to be effective in applications such as robot navigation, elevation map building etc. This paper provides an in-depth analysis of the major error sources for such a real-time stereo system in the context of cross-country navigation of an autonomous vehicle. Three major types of errors: foreshortening error, misalignment error and systematic error, are identified. The combined disparity errors can easily exceed three-tenths of a pixel, which translates to significant range errors. Upon understanding these error sources, we demonstrate different approaches to either correct them or model their magnitudes without excessive additional computations. By correcting those errors, we show that the precision of the stereo algorithm can be improved by 50%.
In this paper we develop a representation for the temporal structure inherent in human actions and demonstrate an effective method for using that representation to detect the occurrence of actions. The temporal struct...
详细信息
ISBN:
(纸本)0818684976
In this paper we develop a representation for the temporal structure inherent in human actions and demonstrate an effective method for using that representation to detect the occurrence of actions. The temporal structure of the action, sub-actions, events, and sensor information is described using a constraint network based on Alien's interval algebra. We map these networks onto a simpler, 3-valued domain (past,now,fut) network - a PNF-network - to allow;fast detection of actions and sub-actions. The occurrence of an action is computed by considering the minimal domain of its PNF-network, under constraints imposed by the current state of the sensors and the previous states of the network. We illustrate the approach with Examples, showing that a major advantage of PNF propagation is the detection and removal of *** situations.
We present a novel interactive system and its user interface for removing objects in digital pictures. Our system consists of two components: (i) (partially supervised/automatic) image segmentation (2], and (ii) (guid...
详细信息
ISBN:
(纸本)0769523722
We present a novel interactive system and its user interface for removing objects in digital pictures. Our system consists of two components: (i) (partially supervised/automatic) image segmentation (2], and (ii) (guided) texture synthesis [3].
This work analyzes the problem of homography estimation for robust target matching in the context of real-time mobile vision. We present a device-friendly implementation of the Gaussian Elimination algorithm and show ...
详细信息
ISBN:
(纸本)9781479943098
This work analyzes the problem of homography estimation for robust target matching in the context of real-time mobile vision. We present a device-friendly implementation of the Gaussian Elimination algorithm and show that our optimized approach can significantly improve the homography estimation step in a hypothesize-and-verify scheme. Experiments are performed on image sequences in which both speed and accuracy are evaluated and compared with conventional homography estimation schemes.
It is widely accepted that textureless surfaces cannot be recovered using passive sensing techniques. The problem is approached by viewing image formation as a Sully three-dimensional mapping. It is shown that the len...
详细信息
ISBN:
(纸本)0780342364
It is widely accepted that textureless surfaces cannot be recovered using passive sensing techniques. The problem is approached by viewing image formation as a Sully three-dimensional mapping. It is shown that the lens encodes structural information of the scene within a compact three-dimensional space behind it. After analyzing the information content of this space and by using its properties we derive necessary and sufficient conditions for the recovery of textureless scenes. Based on these conditions, a simple procedure for recovering textureless scenes is described. We experimentally demonstrate the recovery of three textureless surfaces, namely, a line, a plane, and a paraboloid. Since textureless surfaces represent the worst case recovery scenario, all the results and the recovery procedure are naturally applicable to scenes with texture.
暂无评论