Curvelets are a multiscale system with very high directional sensitivity. A new detection algorithm is herein described which operates on a curvelet decomposition of acoustic imagery. The algorithm detects the presenc...
详细信息
Curvelets are a multiscale system with very high directional sensitivity. A new detection algorithm is herein described which operates on a curvelet decomposition of acoustic imagery. The algorithm detects the presence of cylindrical targets through a statistical mapping of curvelet coefficients. The coefficients are calculated as an inner product between image features and a curvelet basis element. The similarity in appearance between cylindrical targets and curvelet basis elements yield an accurate detection algorithm with a very low false alarm rate.
Derived from statistical conditional optimization criteria, the auxiliary-vector (AV) detection algorithm starts from the target vector and adding non-orthogonal auxiliary vector components generates an infinite seque...
详细信息
Derived from statistical conditional optimization criteria, the auxiliary-vector (AV) detection algorithm starts from the target vector and adding non-orthogonal auxiliary vector components generates an infinite sequence of tests that converges to the ideal matched filter (MF) processor for any positive definite input autocorrelation matrix. When the input autocorrelation matrix is replaced by a conventional sample-average estimate, the algorithm effectively generates a sequence of estimators of the ideal matched filter that offer exceptional bias/covariance balance for any given finite-size observation data record. In this work, the AV algorithm is evaluated on collected airborne phased-array radar data from the MCARM program and is seen to outperform in probability of detection (for any given false alarm rate) all known and tested adaptive detectors (for example AMF, generalized likelihood ratio test, the multistage Wiener filter algorithm, etc.).
We present an approach to decomposing branching volume data into sub-branches. First, a metric is proposed for evaluating local convexities in volumetric data, and it is a criterion for global selection of tip points....
详细信息
We present an approach to decomposing branching volume data into sub-branches. First, a metric is proposed for evaluating local convexities in volumetric data, and it is a criterion for global selection of tip points. Second, a multi-path growing strategy is adopted to segment the volumes based on a DFS transformation starting from the tips. Experiments show that this approach is capable of generating desirable components and reasonable segmentation boundaries of a volume.
An approach for the detection of straight and curved curbs (border of relevant traffic isles, sidewalks, etc) is presented, in the context of urban driving assistance systems. A rectangular elevation map is built from...
详细信息
An approach for the detection of straight and curved curbs (border of relevant traffic isles, sidewalks, etc) is presented, in the context of urban driving assistance systems. A rectangular elevation map is built from 3D dense stereo data. Edge detection is applied to the elevation map in order to highlight height variations. We propose a method to reduce significantly the 3D noise from dense stereo, using a multiframe persistence me persistence map: temporal filtering is performed for edge points, based on the ego car motion, and only persistent points are validated. The Hough accumulator for lines is built with the persistent edge points. A scheme for extracting straight curbs (as curb segments) and curved curbs (as chains of curb segments) is proposed. Each curb segment is refined using a RANSAC approach to fit optimally the 3D data of the curb. The algorithm was evaluated in an urban scenario. It works in real-time and provides robust detection of curbs.
While recent years have seen progress in face recognition from 3D images, nonfrontal head pose is still a challenge to existing techniques. We introduce a new system for 3D face recognition that is robust to facial po...
详细信息
While recent years have seen progress in face recognition from 3D images, nonfrontal head pose is still a challenge to existing techniques. We introduce a new system for 3D face recognition that is robust to facial pose variation. Large degrees of facial pose variation may lead to a significant fraction of the features visible in frontal images being occluded. High accuracy automatic feature and pose detection is performed by a new technique called rotated profile signatures (RPS). Experiments are performed on the largest available database of 3D faces acquired under varying pose. This database contains over 7,300 total images of 406 unique subjects gathered at the University of Notre Dame. Experimental results show that the RPS detection algorithm is capable of performing nose detection with greater than 96.5% accuracy across the pose variation represented in the data set used.
In this paper, we present a detection algorithm for MIMO system with nonbinary modulation scheme. The proposed method is based on rectangular searching. It restricts the searching area to a certain rectangle when sear...
详细信息
In this paper, we present a detection algorithm for MIMO system with nonbinary modulation scheme. The proposed method is based on rectangular searching. It restricts the searching area to a certain rectangle when searching the candidate symbols for each symbol. It has considerably reduced computational complexity compared to ML (maximum likelihood) algorithm because only a small part of candidate constellation points are located in the searching rectangle. However, to our surprise, Simulation results show that the BER (bit error rate) performance of the proposed method outperforms the ML (maximum likelihood) algorithm when the SNR is between -10 dB and 15 dB. The reasons responsible for this unusual phenomena are also given.
A lane detection system is an important component of many intelligent transportation systems. In this paper, we present a robust and real-time lane tracking algorithm for any curved road. We use Non Uniform B-Spline (...
详细信息
A lane detection system is an important component of many intelligent transportation systems. In this paper, we present a robust and real-time lane tracking algorithm for any curved road. We use Non Uniform B-Spline (NUBS) interpolation method to construct the boundaries road lane. First, the Canny filter is employed to obtain edge map. Second, we apply parallel thinning algorithm into edge map to get the skeleton image. Once skeleton image is obtained, we introduce a new algorithm based on Vector Lane Concept to extract feature edge points that play the role as control points for NUBS interpolation process to represent left and right lane, separated. Finally, we estimate the curvature of left and right lane boundary for lane tracking. The result of this method can be used for Autonomous Guided Vehicles (AGV) system application.
Traffic anomaly detection using high performance measurement systems offers the possibility of improving the speed of detection and enabling detection of important, short-lived anomalies. In this paper we investigate ...
详细信息
Traffic anomaly detection using high performance measurement systems offers the possibility of improving the speed of detection and enabling detection of important, short-lived anomalies. In this paper we investigate the problem of detecting anomalies using traffic measurements with fine-grained timestamps. We develop a new detection algorithm (called S3) that utilizes a Bayes Net to efficiently consider multiple input signals and to explicitly define what is considered "anomalous''. The input signals considered by S3 are traffic volumes and correlations between ingress/egress packet and bit rates. These complementary signals enable identification of an expanded range of anomalies. Using a set of high precision traffic measurements collected at our campus border router over a 10 month period and an annotated anomaly log supplied by our network operators, we show that S3 is highly accurate, identifying 86% of the anomalies listed in the log. Compared with well known time series-based and wavelet-based detectors, this represents over a 20% improvement inaccuracy. Investigation of events identified by S3 that did not appear in the operator log indicate many are, in fact, true positives. Deployment of S3 in an operational environment supports this by showing zero false positives during initial tests.
Motion compensated error of the static text in the frame rate conversion (FRC) is most annoying artifact because people cannot read it. In this paper, we present a novel static text region detection algorithm for prev...
详细信息
ISBN:
(纸本)9781424421749
Motion compensated error of the static text in the frame rate conversion (FRC) is most annoying artifact because people cannot read it. In this paper, we present a novel static text region detection algorithm for preventing the motion compensation error in FRC. We use some consistent properties of the static text that the color of the text is spatio-temporally consistent and the orientation of the text boundary is preserved in consecutive frames. We observe whether each pixelpsilas consistency is preserved for several frames, and then we decide it as a static text. Our algorithm can not only perfectly extract the static text region but also easily be implemented in hardware because of its ease.
A novel vision-based road detection method was proposed in this paper to realize visual guiding navigation for ground mobile vehicles in outdoor environments. The road region was first segmented from the jumbled backg...
详细信息
A novel vision-based road detection method was proposed in this paper to realize visual guiding navigation for ground mobile vehicles in outdoor environments. The road region was first segmented from the jumbled backgrounds by using an adaptive threshold segmentation algorithm named OTSU. Subsequently, the Canny edges extracted in grey images would be filtered in the road region so that the road boundary could be recognized accurately by reducing the unnecessary disturbances from the useless edge existed in background By combining the detection algorithm of both road region and road boundary, the road detection method proposed in this paper was robust against strong shadows, surface dilapidation and illumination variations. It has been tested on real ground mobile vehicle and performed well in real road environments.
暂无评论