|
|
Angel Sappa, Rosa Herrero, Fadi Dornaika, David Geronimo and Antonio Lopez. 2007. Road Approximation in Euclidean and v-Disparity Space: A Comparative Study. Computer Aided Systems Theory,.1105–1112. (LNCS.)
Abstract: This paper presents a comparative study between two road approximation techniques—planar surfaces—from stereo vision data. The first approach is carried out in the v-disparity space and is based on a voting scheme, the Hough transform. The second one consists in computing the best fitting plane for the whole 3D road data points, directly in the Euclidean space, by using least squares fitting. The comparative study is initially performed over a set of different synthetic surfaces
(e.g., plane, quadratic surface, cubic surface) digitized by a virtual stereo head; then real data obtained with a commercial stereo head are used. The comparative study is intended to be used as a criterion for fining the best technique according to the road geometry. Additionally, it highlights common problems driven from a wrong assumption about the scene’s prior knowledge.
|
|
|
|
Angel Sappa, Rosa Herrero, Fadi Dornaika, David Geronimo and Antonio Lopez. 2007. Road Approximation in Euclidean and v-Disparity Space: A Comparative Study. EUROCAST2007, Workshop on Cybercars and Intelligent Vehicles.368–369.
Abstract: This paper presents a comparative study between two road approximation techniques—planar surfaces—from stereo vision data. The first approach is carried out in the v-disparity space and is based on a voting scheme, the Hough transform. The second one consists in computing the best fitting plane for the whole 3D road data points, directly in the Euclidean space, by using least squares fitting. The comparative study is initially performed over a set of different synthetic surfaces
(e.g., plane, quadratic surface, cubic surface) digitized by a virtual stereo head; then real data obtained with a commercial stereo head are used. The comparative study is intended to be used as a criterion for fining the best technique according to the road geometry. Additionally, it highlights common problems driven from a wrong assumption about the scene’s prior knowledge.
|
|
|
|
Angel Sappa, David Geronimo, Fadi Dornaika and Antonio Lopez. 2006. Real Time Vehicle Pose Using On-Board Stereo Vision System. International Conference on Image Analysis and Recognition.205–216.
Abstract: This paper presents a robust technique for a real time estimation of both camera’s position and orientation—referred as pose. A commercial stereo vision system is used. Unlike previous approaches, it can be used either for urban or highway scenarios. The proposed technique consists of two stages. Initially, a compact 2D representation of the original 3D data points is computed. Then, a RANSAC based least squares approach is used for fitting a plane to the road. At the same time,
relative camera’s position and orientation are computed. The proposed technique is intended to be used on a driving assistance scheme for applications such as obstacle or pedestrian detection. Experimental results on urban environments with different road geometries are presented.
|
|
|
|
Joan Serrat, Ferran Diego, Felipe Lumbreras and Jose Manuel Alvarez. 2007. Synchronization of Video Sequences from Free-moving Cameras. In J. Marti et al., ed. 3rd Iberian Conference on Pattern Recognition and Image Analysis.620–627. (LNCS.)
|
|
|
|
Angel Sappa, Fadi Dornaika, David Geronimo and Antonio Lopez. 2008. Registration-based Moving Object Detection from a Moving Camera. IROS2008 2nd Workshop on Perception, Planning and Navigation for Intelligent Vehicles.65–69.
Abstract: This paper presents a robust approach for detecting moving objects from on-board stereo vision systems. It relies on a feature point quaternion-based registration, which avoids common problems that appear when computationally expensive iterative-based algorithms are used on dynamic environments. The proposed approach consists of three stages. Initially, feature points are extracted and tracked through consecutive frames. Then, a RANSAC based approach is used for registering
two 3D point sets with known correspondences by means of the quaternion method. Finally, the computed 3D rigid displacement is used to map two consecutive frames into the same coordinate system. Moving objects correspond to those areas with large registration errors. Experimental results, in different scenarios, show the viability of the proposed approach.
|
|
|
|
Angel Sappa, Fadi Dornaika, David Geronimo and Antonio Lopez. 2007. Efficient On-Board Stereo Vision Pose Estimation. Computer Aided Systems Theory, Selected paper from.1183–1190. (LNCS.)
Abstract: This paper presents an efficient technique for real time estimation of on-board stereo vision system pose. The whole process is performed in the Euclidean space and consists of two stages. Initially, a compact representation of the original 3D data points is computed. Then, a RANSAC based least squares approach is used for fitting a plane to the 3D road points. Fast RANSAC fitting is obtained by selecting points according to a probability distribution function that takes into account the density of points at a given depth. Finally, stereo camera position
and orientation—pose—is computed relative to the road plane. The proposed technique is intended to be used on driver assistance systems for applications such as obstacle or pedestrian detection. A real time performance is reached. Experimental results on several environments and comparisons with a previous work are presented.
|
|
|
|
Joan Serrat, Ferran Diego, Jose Manuel Alvarez and Felipe Lumbreras. 2007. Alignment of Videos Recorded from Moving Vehicles. in 14th International Conference on Image Analysis and Processing,.512–517.
|
|
|
|
Angel Sappa and Boris X. Vintimilla. 2006. Edge Point Linking by Means of Global and Local Schemes. IEEE Int. Conf. on Signal-Image Technology and Internet-Based Systems, Hammamet, Tunisia, December 2006, pp. 551-560..
|
|
|
|
Joan Serrat, J. Argemi and Juan J. Villanueva. 1991. Automatization of TW2 method using a knowledge-based image analysis system. VIth International Congress of Auxology..
|
|
|
|
Angel Sappa and Mohammad Rouhani. 2009. Efficient Distance Estimation for Fitting Implicit Quadric Surfaces. 16th IEEE International Conference on Image Processing.3521–3524.
Abstract: This paper presents a novel approach for estimating the shortest Euclidean distance from a given point to the corresponding implicit quadric fitting surface. It first estimates the orthogonal orientation to the surface from the given point; then the shortest distance is directly estimated by intersecting the implicit surface with a line passing through the given point according to the estimated orthogonal orientation. The proposed orthogonal distance estimation is easily obtained without increasing computational complexity; hence it can be used in error minimization surface fitting frameworks. Comparisons of the proposed metric with previous approaches are provided to show both improvements in CPU time as well as in the accuracy of the obtained results. Surfaces fitted by using the proposed geometric distance estimation and state of the art metrics are presented to show the viability of the proposed approach.
|
|
