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Many applications use multiple cameras to simultaneously capture imagery of a scene from a rigid, moving camera system over time. Multiple cameras often provide unique viewing angles but also additional levels of detail of a scene at different spatio-temporal resolutions. However, in order to benefit from this added information the sources must often be temporally aligned. As a result of cost and...
Surveying a large amount of small sub-kilometer craters in planetary images is a challenging task due to their non-distinguishable features. In this paper, we integrate the LASSO (Least Absolute Shrinkage and Selection Operator) method with the Bayesian network classifier and propose an L1 Regularized Bayesian Network Classifier (L1-BNC) algorithm for this task. The L1-BNC algorithm uses the LASSO...
There has been much research about using curvelet transform for retinal analysis. Other multiscale geometrical tools, such as contourlet and wavelet, have also been used for retinal analysis, thus it is interesting to know which method performs best, especially under illumination and contrast changes. In this paper, we make a systematic comparison of curvelet and contourlet for retinal image analysis,...
LIDAR-only and camera-only approaches to global localization in planetary environments have relied heavily on availability of elevation data. The low-resolution nature of available DEMs limits the accuracy of these methods. Availability of new high-resolution planetary imagery motivates the rover localization method presented here. The method correlates terrain appearance with orthographic imagery...
Ultra-wide band (UWB) pulse radar has a definite advantage over optical ranging techniques in harsh optical environments, such as a dark smog or strong backlight. In security or rescue situations with blurry visibility, it is particularly promising for identifying human bodies. One of the most promising approaches for this type of application is the recently proposed range points migration (RPM) method,...
A bonding technique, capable of sub-micron and finer alignment accuracy, has been developed for electronics-optics heterogeneous integration applications. The technique is based on the principle of misalignment self-correction using bump (convex) and hollow (concave) elements, to align one die (i.e. a chip) to another one (i.e. a substrate) during the stacking process. Conductive hollow pad and Au...
A variety of plasma applications make use of pulsed gas jets. In some cases like a z-pinch1, one requirement is for cylindrical symmetry in the mass distribution delivered by a nozzle system. In other cases like astrophysical simulations2 or laser wakefield accelerators (LWA)3, controlled asymmetry is desired. Hence there is a need for diagnostic methods to assess the 3D geometry of the cold gas flow...
In change detection analysis, it is important to reduce the influence of image misalignment in order to produce image changes that are relevant to the user. The accuracy of change detection solely depends on the image registration accuracy yet image misalignment is still a major challenge in change detection analysis. In change detection analysis, if change detection is performed on misaligned images,...
This paper demonstrates the relationship between detection errors and resolutions (ρ- and θ- directions) when the Hough Transform (HT) is employed to detect straight segments in images. The inflexion of the error-resolution curve was uncovered. To comprehensively study the location of the inflexion, the effects of several factors are considered, such as the positions (ρ and θ), widths and lengths...
This paper describes a novel unsupervised approach to change detection in multi-temporal hyperspectral remote sensing images based on hierarchical spectral analysis and dimensionality reduction. The uniform feature design (UFD) strategy is implemented on original hyperspectral data for decreasing the data dimensionality and building different levels of data sets from coarse to fine spectral resolutions...
The discrete nature of disparities observed by stereo systems results in complex behaviour of speeds measured by them and affects the efficacy of a stereo based driver assistance system. We describe a tool for a safety engineer which permits the safety of these systems to be estimated. It is based on a model which considers the true error in measured velocities of objects. Outputs from this tool show...
Computer stereo vision is an important technique for robotic navigation and other mobile scenarios where depth perception is needed, but it usually requires two cameras with a known horizontal displacement. In this paper, we present a solution for mobile devices with just one camera, which is a first step towards making computer stereo vision available to a wide range of devices that are not equipped...
In this paper we present an analysis of image features used to discriminate arteries and veins in digital fundus images. Methods proposed in the literature to analyze the vasculature of the retina and compute diagnostic indicators like the Arteriolar to Venular ratio (AVR), use, in fact, different approaches for this classification task, extracting different color features and exploiting different...
Recent advances in remote sensing techniques made research possible in those areas where human hands are inaccessible. Digital Imagery brings the virtual image of a desired location, which requires some pre-processing to bring the view to an optimal level. Accuracy level in image classification is assumed on the categorization of the pixel into one of the several land cover classes. When the recognition...
Building a photorealistic, 3D model of an object or a complete scene from image-based methods is a fundamental problem in computer vision, and has many applications in robotic perception, navigation, exploration and mapping. In this paper, we extend current state-of-the-art in the computation of depth maps by presenting an accurate and computationally efficient iterative hierarchical algorithm for...
In this paper we investigate the effectiveness of SURF features for visual terrain classification for outdoor flying robots. A quadrocopter fitted with a single camera is flown over different terrains to take images of the ground below. Each image is divided into a grid and SURF features are calculated at grid intersections. A classifier is then used to learn to differentiate between different terrain...
The study of cellular processes in three-dimensions is severely limited by the lack of imaging methodologies that allow for fast 3D tracking of cellular events and 3D superresolution imaging of sub-cellular structures. We have developed a 3D imaging modality, multifocal plane microscopy (MUM), that provides a powerful approach for 3D single molecule tracking and 3D superresolution microscopy. Here...
We present a novel shape from focus method for high-speed shape reconstruction in optical microscopy. While the traditional shape from focus approach heavily depends on the presence of surface texture, and requires a considerable amount of measurement time, our method is able to perform 3D reconstruction from only two images. Our method relies on the rapid projection of a binary pattern sequence,...
The research presented in this paper proposes a novel gender classification approach using face image. The approach extracts features from grayscale face images through Infomax ICA and subsequently selects features using k-means clustering and classifies the clustered features employing PNN. All the experimental evaluations are done on cropped face images from FERET database using 280 faces for training...
Digital Elevation Models (DEM) provides basic information on elevation of Earth's surface and are freely available from space borne SRTM (Shuttle Radar Topographic Mission) data - a mission of NASA and from ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) data - a mission of JAPAN. These data provide valuable information regarding surface topography for better understanding...
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