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Low-rank and sparse representation based methods have attracted wide attention in background subtraction and moving object detection, where moving objects in the scene are modeled as pixel-wise sparse outliers. Since in real scenarios moving objects are also structurally sparse, recently researchers have attempted to extract moving objects using structured sparse outliers. Although existing methods...
Illumination changes are a typical problem for many outdoor long-term applications such as visual place recognition. Keypoints may fail to match between images taken at the same location but different times of the day. Although recently some methods are presented for creating shadow-free image representations, all of them have the limitation in terms of dealing with night images and non-Planckian...
The paper proposes the integration of a structure lighting system on a gantry to improve its flexibility, efficiency and accuracy of 3D reconstruction for face modeling. A method for the integrated system calibration to calculate the correspondences between the coordinate systems of the camera, the light source and the rotational axis is also proposed. Parameters obtained from calibration are used...
A simple and reliable keypoint matching method is proposed in this paper. Our research is motivated by the desire to improve the performance of multi-view geometry (MVG) based verification in visual loop closure detection under significant illumination change, where traditional methods may fail due to their inability to either find a sufficient number of correctly matched keypoints or identify correct...
In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously...
In this paper, an efficient field-programmable gate array (FPGA) implementation of the JPEG baseline image compression encoder is presented for wearable devices in health and wellness applications. In order to gain flexibility in developing FPGA-specific software and balance between real-time performance and resources utilization, A High Level Synthesis (HLS) tool is utilized in our system design...
This paper is concerned with the detection of moving objects using a pan-tilt camera and a background subtraction algorithm. Traditionally, motion compensation is performed on the current image to align its pixels with their background models in previous frames. Pixel misalignment however can occur during motion compensation. Although this problem can be alleviated by using pixel motion such as the...
Position localization is essential for visually impaired individuals to live independently. Comparing with outdoor environment in which the global positioning system (GPS) can be utilized, indoor positioning is more difficult due to the absence of the GPS signal and complex or unfamiliar building structure. In this paper, a novel landmark-based assistive system is presented for indoor positioning...
In recent years, various background subtraction methods have been proposed and used in vision systems for moving object detection and tracking from moving cameras; however, most of them have difficulty in handling small and distant objects in complicated non-flat scenes. This paper presents a robust method to effectively segment moving objects from videos, captured by a camera on a moving platform...
In this paper we present a novel method that estimates the motion parameters of a monocular camera, which is under unconstrained movement. Different from the traditional works which tackle the problem by establishing motion correspondences, or by calculating optical flows within the image sequence, the proposed method estimates the motion parameters directly by using the information of spatio-temporal...
We propose a method for egomotion estimation from images obtained by a pair of stereo cameras for the reconstruction of 3D scene. The proposed method improves feature matching by using two eliminating criteria to filter out unlikely matching points and restricts the search window according to the epipolar constraint. The method also improves calculated motion by using bundle adjustment to integrate...
This paper investigates the problem of robot visual homing — the navigation to a goal location by a mobile robot using visual sensory input. The visual homing approach taken is to consider the flow vectors between a robot's current view and a desired milestone view. The flow vectors can be used to determine an angular velocity command that attempts to align the two views under a constant forward speed...
Detection of birds in air is an important problem across multiple applications including aviation safety, avian protection, and ecological science of migrant bird species. In this paper we describe a real-time detection system of birds in flight. Using a single fixed camera, our bird detection system is based on background subtraction and tracking through point correspondence. We make use of Zivkovic's...
To achieve the calibration parameters of vision measurement system, this paper presents a new camera calibration method based on grid recognition. The calibration is implemented by acquiring the corresponding relations between the world coordinates and pixel coordinates of the planar gridding target image captured by camera. Meanwhile, the pixel coordinates of the target image are detected separately...
In appearance based SLAM (Simultaneous Localisation and Mapping), a robot typically represents its environment through a set of acquired images that are associated with nodes in a topological map. Rather than storing every acquired image, which can be memory intensive, a selection of images (keyframes) representative of the places visited can be stored. Keyframe detection (i.e. choosing when to add...
One of the main problems associated with vision-based SLAM is the difficulty to find high-quality and indistinguishable landmarks which are detectable across significant viewpoint changes. Most of the current visual SLAM systems utilize the feature extraction methods that have been proposed for the offline computer vision tasks, which are either too slow for a real-time SLAM or not robust enough against...
The indoor air pollution produced by the ventilating system of the central air-conditioning draws many people's attention. In this paper, a new style of the central air-conditioning pipe aseptic sampling inspection robotic system is developed. The entire system comprises three parts: the caterpillar robot, computer and control box. Through real-time video transferred from cameras on robot, operators...
This paper introduces the design and realization of a wearable device for dietary and physical activity monitoring. This design is based on technological advances in microelectronics and our previous prototypes which have verified the system concept. From our results, it is shown that the device meets all functional requirements as well as size and power consumption constraints essential to participants'...
A new image based activity recognition method for a person wearing a video camera below the neck is presented in this paper. The wearable device is used to capture video data in front of the wearer. Although the wearer never appears in the video, his or her physical activity is analyzed and recognized using the recorded scene changes resulting from the motion of the wearer. Correspondence features...
This paper presents a novel approach of using stereovision or pseudo-stereovision to generate touch screen experience. A pair of digital cameras or a set of a digital camera and a mirror is mounted at the corners of a computer display. Algorithms are presented to generate the positions of the pointers when they are close to the screen. The paper also proposes to use positions, velocities and accelerations...
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