Search results for "Motion detection"

Static and Dynamic Objects Analysis as a 3D Vector Field

2017

International audience; In the context of scene modelling, understanding, and landmark-based robot navigation, the knowledge of static scene parts and moving objects with their motion behaviours plays a vital role. We present a complete framework to detect and extract the moving objects to reconstruct a high quality static map. For a moving 3D camera setup, we propose a novel 3D Flow Field Analysis approach which accurately detects the moving objects using only 3D point cloud information. Further, we introduce a Sparse Flow Clustering approach to effectively and robustly group the motion flow vectors. Experiments show that the proposed Flow Field Analysis algorithm and Sparse Flow Clusterin…

2015

Visuo-auditory sensory substitution systems are augmented reality devices that translate a video stream into an audio stream in order to help the blind in daily tasks requiring visuo-spatial information. In this work, we present both a new mobile device and a transcoding method specifically designed to sonify moving objects. Frame differencing is used to extract spatial features from the video stream and two-dimensional spatial information is converted into audio cues using pitch, interaural time difference and interaural level difference. Using numerical methods, we attempt to reconstruct visuo-spatial information based on audio signals generated from various video stimuli. We show that de…

Optimal Filter Estimation for Lucas-Kanade Optical Flow

2012

Optical flow algorithms offer a way to estimate motion from a sequence of images. The computation of optical flow plays a key-role in several computer vision applications, including motion detection and segmentation, frame interpolation, three-dimensional scene reconstruction, robot navigation and video compression. In the case of gradient based optical flow implementation, the pre-filtering step plays a vital role, not only for accurate computation of optical flow, but also for the improvement of performance. Generally, in optical flow computation, filtering is used at the initial level on original input images and afterwards, the images are resized. In this paper, we propose an image filt…

SOM-Based Class Discovery for Emotion Detection Based on DEAP Dataset

2018

This paper investigates the possibility of identifying classes by clustering. This study includes employing Self-Organizing Maps (SOM) in identifying clusters from EEG signals that could then be mapped to emotional classes. Beginning by training varying sizes of SOM with the EEG data provided from the public dataset: DEAP. The produced graphs showing Neighbor Distance, Sample Hits, and Weight Position are examined. Following that, the ground-truth label provided in DEAP is tested, in order to identify correlations between the label and the clusters produced by the SOM. The results show that there is a potential of class discovery using SOM-based clustering. It is then concluded that by eval…

On the advantages of combining differential algorithms and log-polar vision for detection of self-motion from a mobile robot

2001

Abstract This paper describes the design and implementation on programmable hardware (FPGAs) of an algorithm for the detection of self-mobile objects as seen from a mobile robot. In this context, ‘self-mobile’ refers to those objects that change in the image plane due to their own movement, and not to the movement of the camera on board of the mobile robot. The method consists on adapting the original algorithm from Chen and Nandhakumar [A simple scheme for motion boundary detection, in: Proceedings of the IEEE International Conference on Systems, Man and Cybernetics, 1994] by using foveal images obtained with a special camera whose optical axis points towards the direction of advance. It i…

Dynamic Distributed Intrusion Detection for Secure Multi-Robot Systems

2009

A general technique to build a dynamic and distributed intrusion detector for a class of multi–agent systems is proposed in this paper, by which misbehavior in the motion of one or more agents can be discovered. Previous work from the authors has focused on how to distinguish the behavior of a misbehaving agent in a completely distributed way, by developing a solution where agents act as local monitors of their neighbors and use locally sensed information as well as data received from other monitors at a particular time. In this work, we improve the system detection capability by allowing monitors to use information collected at different instants and thus realizing a dynamic state observer…

Towards 3D Television Through Fusion of Kinect and Integral-Imaging Concepts

2015

We report a new procedure for the capture and processing of light proceeding from 3D scenes of some cubic meters in size. Specifically we demonstrate that with the information provided by a kinect device it is possible to generate an array of microimages ready for their projection onto an integral-imaging monitor. We illustrate our proposal with some imaging experiment in which the final result are 3D images displayed with full parallax.

Wavelength dependence of the optomotor response in zebrafish (Danio rerio)

2003

Abstract The action spectrum of motion detection in zebrafish (Danio rerio) was measured using the optomotor response in the light adapted state. The function has a single maximum at 550–600 nm, and is similar to the spectral sensitivity function of the L-cone type in the mid and long wavelength range. At shorter wavelengths the values of three of the five fish tested are lower. As in goldfish [Vis. Res. 36 (1996) 4025], the result indicates a dominance of the L-cone type with an inhibitory influence of M- or S-cones. Experiments with a red/green striped cylinder showed that the optomotor response was at minimum whenever the L-cone type was not modulated by the moving pattern. This demonstr…

Methods cooperation for multiresolution motion estimation

2002

For a medical application, we are interested in an estimation of optical flow on a patient's face, particularly around the eyes. Among the methods of optical flow estimation, gradient estimation and block matching are the main methods. However, the gradient-based approach can only be applied for small displacements (one or two pixels). Gener- ally, the process of block matching leads to good results only if the searching strategy is judiciously selected. Our approach is based on a Markov random field model, combined with an algorithm of block match- ing in a multiresolution scheme. The multiresolution approach allows de- tection of a large range of speeds. The large displacements are detect…

An Integrated Neural and Algorithmic System for Optical Flow Computation

1997

Motion detection plays a central role in several visual environments: knowledge of object velocities and trajectories is fundamental in scene interpretation and segmentation. This task appears a simple problem, but detecting moving objects is very difficult, in fact this is a problem that cannot be considered completely solved today [1] [2] [3].