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This paper proposes a novel velocity estimation approach for single image points, while both the camera and the observed object may be in motion. In order to obtain absolute velocities, a flow-stereo setup is utilized, but no explicit depth reconstruction is carried out. Omitting the calculation in the Cartesian space increases the robustness of the estimation, which is shown in a comparison between...
Humanitarian demining requires a variety of methods and instrumentation for effective mine clearance, since a wide range of materials are used in mine manufacturing. However, landmines release vapours over time that can be detected, for example, by sniffer dogs. Optical sensor systems are especially suited to this application due to the potential for lightweight, portable, low-cost systems that nevertheless...
In this paper, we propose an optimization scheme to detect outliers in a visual odometry pipeline that is purely based on the optical flow of one monocular camera without requiring information about depth. First, we review different optical flow error measures and uncover the different sensitivity changes of the endpoint error for optical flow to the directional and the absolute error components....
In the context of optical-aided navigation and visual Simultaneous Localization And Mapping (SLAM) for satellite-denied aircraft navigation, this paper extends the monocular SLAM approach by the use of multiple sensors with different viewing directions. Downward optical sensors see other movements than forward-looking cameras, hence it is straightforward to combine the benefits of both. This combination...
This paper presents an improved dynamic output feedback image-based visual servoing (IBVS) law for a quadrotor in comparison with our previous work (“Dynamic Visual Servoing of a Rotary-wing Unmanned Aerial Vehicle Without Velocity Measurement,” in AIAA Guidance, Navigation, and Control Conference, Grapevine, Texas, January, 2017). The controller enables the quadrotor to regulate its position and...
This paper presents the development of an object path following algorithm for a quadcopter using on-board vision and localization. This development aims to increase capabilities of autonomous unmanned aerial vehicles (UAV), with the use of object path following. By following an object's path, reliance on obstacle avoidance strategies can be reduced, under the assumption that the object's path is free...
Mapping special images in video scene has practical important applications in the fields of advertising and television production, while there have been few reports on how to map in the background of video scene without impacting foreground targets which makes the result more realistic. We propose a method to embed images on certain location in video scene of fixed viewing angle. We first build background...
In the last decades, Remotely Piloted Aircraft Systems (RPAS) have been developed for many civil applications, such as surveillance and terrain monitoring, Search and Rescue (S&R), topography, photogrammetry and law enforcement missions, and widely media and entertainment applications. Moreover, the use of the unmanned configuration is becoming very promising for smart farming or precision agriculture...
In this paper, we present a 3D imaging system providing a semi-dense depth map, using a passive, low-power, compact, static, monocular camera. The demonstrated depth estimation system reconstructs 32 depth-levels in real-time at 25FPS drawing less than 1.9W of power. This is achieved by performing computation on an analog focal-plane processor that analyses frames captured through a vibrating liquid...
Asynchronous event-based sensors present new challenges in basic robot vision problems like feature tracking. The few existing approaches rely on grouping events into models and computing optical flow after assigning future events to those models. Such a hard commitment in data association attenuates the optical flow quality and causes shorter flow tracks. In this paper, we introduce a novel soft...
The article deals with algorithm design for object detection and identification using common mobile phone optical sensor. Final algorithm was implemented into the robotic device for visual navigation. Mobile phone platform is based on Android operating system. Several measurements were realised for evaluation of accuracy of object detection depending on different distances. Article includes the description...
Perception systems for outdoor robotics have to deal with varying environmental conditions. Variations in illumination in particular, are currently the biggest challenge for vision-based perception. In this paper we present an approach for radiometric characterization of multispectral cameras. To enable spatio-temporal mapping we also present a procedure for in-situ illumination estimation, resulting...
The primary focus of this work is to examine how robots can achieve more robust sequential manipulation through the use of pre-touch sensors. The utility of close-range proximity sensing is evaluated through a robotic system that uses a new optical time-of-flight pre-touch sensor to complete a highly precise and sequential task — solving the Rubik's cube. The techniques used in this task are then...
Onboard vision sensing is a current challenge in micro-scale robotics. Small flapping-wing robots such as the RoboBee present significant constraints on power, weight, and image quality for an onboard vision sensor. Here we report the integration of a 1 × 1 × 1.7 mm camera capable of video capture in flight. Inspired by gaze stabilization in insects, we designed and fabricated a one degree of freedom...
Experiments with a simple plane wave generator consisting of two cylindrical explosive charges and a metal ring are presented in this work. Detonation front curvature emerging from the second charge is measured using high-speed camera and Optimex fiber based device. The results are compared with LS-DYNA simulations.
Light field (or plenoptic) imaging has become an attractive research field due to its post-capture capabilities, including refocusing, perspective change and depth estimation. Micro-lens array based cameras that recently emerged have made the light field acquisition process a practical task. In this paper, we propose to convert such a plenoptic camera into a high-dynamic range camera through a minor...
Advanced Driver Assistance Systems (ADAS) enhance the ability of a vehicle driver to avoid possible road accidents resulting in a safer driving experience. Front camera ADAS is probably the most challenging of all. These systems require high computational processing, in the range of hundreds of GOPS, within a 4 Watt power budget driven by thermal constraints of small enclosed assembly of the final...
Purple Fringes are aberrations or defects in the camera sensor profile which are spotted in the vicinity of edges near high contrast regions. Since these defects are very device centric, they become potential Forensic Tools for detection and identification of splicing operations in natural images. In existing literature, these fringe patterns are localized and mapped to what are known as Directive...
This paper explores a digital image algorithm to stabilize videos recorded from a fixed camera (without stabilized machanical tools) on a small size drone. In particular, this paper focuses on implementation of the Speed-Up Robust Feature (SURF) method. The fundamental concept is to match 2 pictures, one obtained from the current image frame and another from the previous (or reference) frame. The...
In this paper, we propose a novel moving-objects detection method which, in contrast to state-of-the-art moving-objects detection methods, takes static feature points into consideration during detection. It benefits both the tracking and mapping approaches in real-time Simultaneous Localization and Mapping (SLAM) system whose localization depends on static objects primarily. Our method obtains accurate...
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