Pages
- 1
- 2
- document
-
Bakker, B. (author), Whiteson, S. (author), Kester, L.J.H.M. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)Traffic light control is one of the main means of controlling road traffic. Improving traffic control is important because it can lead to higher traffic throughput and reduced traffic congestion. This chapter describes multiagent reinforcement learning techniques for automatic optimization of traffic light controllers. Such techniques are...bookPart 2010
- document
-
van Dorp, Ph. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)Human motion estimation is an important issue in automotive, security or home automation applications. Radar systems are well suited for this because they are robust, are independent of day or night conditions and have accurate range and speed domain. The human response in a radar range-speed-time measurement behaves like an extended target...article 2010
- document
-
TNO Defensie en Veiligheid (author), Withagen, P.J. (author), Schutte, K. (author), Groen, F.C.A. (author)Changing image intensities causes problems for many computer vision applications operating in unconstrained environments. We propose generally applicable algorithms to correct for global differences in intensity between images recorded with a static or slowly moving camera, regardless of the cause of intensity variation. The proposed intensity...article 2010
- document
-
Dubbelman, G. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)This contribution addresses the problem of bias in stereo based motion estimation. Using a biased estimator within a visual-odometry system will cause significant drift on large trajectories. This drift is often minimized by exploiting auxiliary sensors, (semi-)global optimization or loop-closing. In this paper it is shown that bias in the...conference paper 2009
- document
-
Withagen, P.J. (author), Groen, F.C.A. (author), Schutte, K. (author), TNO Defensie en Veiligheid (author)Shadow detection is an important aspect of foreground/ background classification. Many techniques exist, most of them assuming that casting a shadow results only in a change in intensity and no change in color. In this paper we show that in most practical indoor and outdoor situations there will also be a color shift. We propose an algorithm for...conference paper 2008
- document
-
van Dorp, Ph. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)Radar can be an extremely useful sensing technique to observe persons. It perceives persons behind walls or at great distances and in situations where persons have no or poor visibility. Human motion modulates the radar signal which can be observed in the spectrogram of the received signal. Extraction of these movements enables the animation of...article 2008
- document
-
Dubbelman, G. (author), van der Mark, W. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)A novel robust visual-odometry technique, called EM-SE(3) is presented and compared against using the random sample consensus (RANSAC) for ego-motion estimation. In this contribution, stereo-vision is used to generate a number of minimal-set motion hypothesis. By using EM-SE(3), which involves expectation maximization on a local linearization of...conference paper 2008
- document
-
Dubbelman, G. (author), van der Mark, W. (author), van den Heuvel, J.C. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)We have developed a stereo vision based obstacle detection (OD) system that can be used to detect obstacles in off-road terrain during both day and night conditions. In order to acquire enough depth estimates for reliable OD during low visibility conditions, we propose a stereo disparity (depth) estimation approach that uses fine-to-coarse...conference paper 2007
- document
-
van der Mark, W. (author), van den Heuvel, J.C. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)Autonomous robot vehicles that operate in offroad terrain should avoid obstacle hazards. In this paper we present a stereo vision based method that is able to cluster reconstructed terrain points into obstacles by evaluating their relative angles and distances. In our approach, constraints are enforced on these geometric properties by a set of...conference paper 2007
- document
-
Withagen, P.J. (author), Groen, F.C.A. (author), Schutte, K. (author), TNO Defensie en Veiligheid (author)In this article, we will analyze a range of different types of cameras for its use in measurements. We verify a general model of a charged coupled device camera using experiments. This model includes gain and offset, additive and multiplicative noise, and gamma correction. It is shown that for several cameras, except a typical consumer webcam,...article 2007
- document
-
TNO Defensie en Veiligheid (author), Groen, F.C.A. (author), Withagen, P.J. (author), Schutte, K. (author)Shadow detection is an important aspect of foreground/background classification. Many techniques exist, most of them assuming that only the intensity changes under shadow. In this paper we show that in most practical indoor and outdoor situations there will also be a color shift. We propose an algorithm for estimating this color shift from the...report 2007
- document
-
TNO Defensie en Veiligheid (author), van Dorp, Ph. (author), Groen, F.C.A. (author)Radar observes targets, but they remain difficult to interpret due to the difficulty in analysing the radar range-speed sequences. The need for accurate analyses tools increases in case of extended target behaviour or multiple channel radars which give additional observation angles. Extended targets are targets with multiple scatterer responses...conference paper 2007
- document
-
TNO Defensie en Veiligheid (author), Withagen, P.J. (author), Schutte, K. (author), Groen, F.C.A. (author)Changing image intensities causes problems for many computer vision applications operating in unconstrained environments. We propose generally applicable algorithms to correct for global differences in intensity between images recorded with a static or slowly moving camera, regardless of the cause of intensity variation. The proposed intensity...report 2007
- document
-
Withagen, P.J. (author), Groen, F.C.A. (author), Schutte, K. (author), TNO Defensie en Veiligheid (author)CCD cameras are widely used for remote sensing and image processing applications. However, most cameras are produced to create nice images, not to do accurate measurements. Post processing operations such as gamma adjustment and automatic gain control are incorporated in the camera. When a (CCD) camera is used as measurement instrument, it is...conference paper 2005
- document
-
Jansen, P. (author), van der Mark, W. (author), van den Heuvel, J.C. (author), Groen, F.C.A. (author), TNO Defensie en Veiligheid (author)Terrain classification is an important problem that still remains to be solved for off-road autonomous robot vehicle guidance. Often, obstacle detection systems are used which cannot distinguish between solid obstacles such as rocks or soft obstacles such as tall patches of grass. Terrain classification is needed to prevent that the robot is...conference paper 2005
- document
-
van Dorp, Ph. (author), Groen, F.C.A. (author)Radars can be used to observe persons. Animation of an observed human on the basis of Frequency Modulated Continuous Wave (FMCW) radar measurements in virtual reality considerably facilitates the interpretation of the radar measurements. These radar measurements give detailed information of the motion of the human body parts. The radar...conference paper 2003
- document
-
van der Mark, W. (author), Fontijne, D. (author), Dorst, L. (author), Groen, F.C.A. (author), TNO Fysisch en Elektronisch Laboratorium (author)A method for estimating ego-motion with vehicle mounted stereo cameras is presented. This approach is based on finding corresponding features in stereo images and tracking them between succeeding stereo frames. Our approach estimates stereo ego-motion with geometric algebra techniques. Starting with a simple linear estimate of the ego-motion,...conference paper 2003
- document
-
van Dorp, Ph. (author), Groen, F.C.A. (author)Radar can be used to observe humans that are obscured by objects such as walls. These humans cannot be visually observed. The radar measurements are used to animate an obscured human in virtual reality. This requires detailed information about the motion. The radar measurements give detailed information about the movements of the human body...article 2003
- document
-
TNO Fysisch en Elektronisch Laboratorium (author), van der Mark, W. (author), van den Heuvel, J.C. (author), den Breejen, E. (author), Groen, F.C.A. (author)Vehicles that serve in the role as landmine detection robots could be an important tool for demining former conflict areas. On the LOTUS platform for humanitarian demining, different sensors are used to detect a wide range of landmine types. Reliable and accurate detection depends on correctly combining the observations from the different...conference paper 2003
- document
-
Huizing, A.G. (author), Groen, F.C.A. (author), TNO Fysisch en Elektronisch Laboratorium (author)Abstract: This chapter describes an alternative to the Bayesian approach to target classification that is based on possibility theory. A possibilistic classifier minimizes the maximum cost of the classification decision taking into account the a posteriori possibilities of the target classes given the measured target attributes. The advantage of...bookPart 2000
Pages
- 1
- 2