The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Refraction of light underwater is a major source of error for 3D reconstruction. Use of a physically correct camera model taking into account properties of the optical system is essential for understanding the reasons why errors occur and obtaining quantitative estimates of errors. It was proven that use of the single viewpoint model of the camera leads to significant distortions in reconstruction...
Underwater images suffer from extremely unfavourable conditions. Light is heavily attenuated and scattered. Attenuation creates change in hue, scattering causes so called veiling light. General state of the art methods for enhancing image quality are either unreliable or cannot be easily used in underwater operations. On the other hand there is a well known method for haze removal in air, called Dark...
Analyzing fish and fish schools behavior can help in studying fish-fish interaction, analyzing characteristics of fish species, studying prey avoidance maneuvers of fish schools, etc. Such analysis requires the estimation of each fish's 3D location, 3D pose, and 3D shape over time. Moreover if we are interested in studying the interaction of fish by injecting visual / acoustic stimuli artificially...
Mapping of underwater environments is a critical task for a range of activities from monitoring coral reef habitats to surveying submerged archaeological sites. In recent years, optical reconstruction methods developed for terrestrial (in air) applications have increasingly been applied to the underwater environment by the marine science community. However, assumptions such as the brightness constancy...
In this paper, we deal with the most challenging task of recovering the 3D human pose from just a single monocular image, that may be a synthetic image or a real internet image. The retrieval and reconstruction of the articulated 3D pose, both are prerequisites for the analysis of the people in images/videos. We address both tasks together and propose an efficient framework for search & retrieval...
In multiview video applications, view synthesis is a computationally intensive task that needs to be done correctly and efficiently in order to deliver a seamless user experience. In order to provide fast and efficient view synthesis, in this paper, we present a cloud-based implementation that will be especially beneficial to mobile users whose devices may not be powerful enough for high quality view...
Users' Quality of Experience (QoE) in Interactive 3D Tele-Immersion (i3DTI) systems is influenced by several factors such as the quality of the "live" 3D avatars of the users, network latency, rendering methodology (head mounted display or regular TV type of display), etc. Hence, it becomes important to answer the question: "Is Visual Quality (VQ) the only factor to be considered or...
Color mapping for 3D models with captured images is a classical problem in computer vision. Typically, registration between 3D model and images is assumed to be provided, otherwise corresponding points need to be labeled. For many applications, 3D model and images are acquired from different devices, since registration cannot be directly obtained, manual labeling has to be adopted. In this paper,...
Visual Odometry (VO) is the process of calculating the motion of an agent (such as, robot and vehicle), using images captured by a single or multiple cameras embedded to it. VO is an important process to supplement autonomous navigation systems, since VO can provide accurate trajectory estimates. This process can be used to perform a 3D mapping, in order to provide more information during a vehicle...
Obstacle detection and tracking is a fundamental task for several Advanced Driver Assistance Systems (ADAS) and self-driving cars. Several approaches have been presented in the literature in the last years and many of them are based on visual sensors. In this paper we propose an approach that uses only stereo cameras to detect and track obstacles and compute visual odometry to get the vehicle's ego-velocity...
The recent adoption of the Robot Operating System (ROS) as a software standard in robotics has contributed to novel solutions for several problems on the area. One such problem is known as Simultaneous Localization and Mapping (SLAM), for which a number of algorithms from different classes are available as ROS packages ready to be used on any compatible robot. Considering that there is often a need...
Human motion capture systems are being increasingly studied in the area of computer vision and also by major entertainment industries. These systems are able to track the position and orientation of joints of the body and its trajectory in space over a period of time. They are used in various applications such as digital games, animation of virtual characters for film and television, gesture recognition,...
This paper introduces SONA (Spatiotemporal system Organized for Natural Analysis), a tabletop and tangible controller system for exploring geotagged information, and more specifically, CCTV. SONA's goal is to support a more natural method of interacting with data. Our new interactions are placed in the context of a physical security environment, closed circuit television (CCTV). We present a three-layered...
This paper presents a new calibration method for lenslet-based plenoptic cameras. While most existing approaches require the computation of sub-aperture images or depth maps which quality depends on some calibration parameters, the proposed process uses the raw image directly. We detect micro-images containing checkerboard corners and use a pattern registration method to estimate their positions with...
This article proposes a method for sensor calibration and obstacle detection in urban environments. The radar and 3D LIDAR were calibrated with relation to a stereo camera. Data from the radar, 3D LIDAR and stereo camera sensors were fused for the detection of obstacles and determination of their shapes. The data collected using both camera and 3D LIDAR are a point cloud that is segmented taking the...
This article describes the design and process of a 3D Mini Camera Lens to be utilised in multi-purpose 3D stereo reconstruction on computers, mobile devices and robots. It can also be useful for various tasks including demonstration, knowledge-sharing, online programming, database sharing, results comparison in the stereo vision research community, and recreation used by non-specialists. In contrast...
This paper presents a new line based 6-DOF monocular algorithm that uses the iSAM2, a point-based Graph SLAM approach. We extend iSAM2 to minimize the reprojection error of the line features to solve the line-based SLAM problem. A specific line representation is exploited that combines the Plücker Coordinates and the Cayley representation. The Plücker Coordinates are used for the 3D line projection...
Dermoscopy is the in vivo technique of skin surface microscopy which is frequently used in visual examination of the skin. With the rise in the usage of smartphones, many smartphone attachments have been developed that enable dermoscopy on a phone but these attachments are very expensive and are available only for high-end phones. We have developed a novel 3D printed clip-on that can convert any smartphone...
In order to understand the underwater environment, it is essential to use sensing methodologies able to perceive the three dimensional (3D) information of the explored site. Sonar sensors are commonly employed in underwater exploration. This paper presents a novel methodology able to retrieve 3D information of underwater objects. The proposed solution employs an acoustic camera, which represents the...
Calibration between Lidar sensor and RGB cameras can be applied to various fields such as object recognition and tracking, 2D-3D mapping, and simultaneous localization and mapping (SLAM). Different methods for calibrating Lidar sensor and RGB cameras have been proposed using special 3D markers or calibration patterns. However, most of these methods have disadvantages of longer processing time, and...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.