25,657 research outputs found
Reconstruction from projections based on detection and estimation of objects
Caption title. "Presented at the 1983 International Conference on Acoustics, Speech and Signal Processing."Bibliography: leaf [3]National Science Foundation Grant ECS-8012668David J. Rossi, Alan S. Willsky
Reconstruction from projections based on detection and estimation of objects
Includes bibliographies.Caption title. "13 July 1983."National Science Foundation grant ECS-8012668David J. Rossi, Alan S. Willsky.pt.1. Performance analysis--pt.2. Robustness analysis
Fast tomographic inspection of cylindrical objects
This paper presents a method for improved analysis of objects with an axial
symmetry using X-ray Computed Tomography (CT). Cylindrical coordinates about an
axis fixed to the object form the most natural base to check certain
characteristics of objects that contain such symmetry, as often occurs with
industrial parts. The sampling grid corresponds with the object, allowing for
down-sampling hence reducing the reconstruction time. This is necessary for
in-line applications and fast quality inspection. With algebraic reconstruction
it permits the use of a pre-computed initial volume perfectly suited to fit a
series of scans where same-type objects can have different positions and
orientations, as often encountered in an industrial setting. Weighted
back-projection can also be included when some regions are more likely subject
to change, to improve stability. Building on a Cartesian grid reconstruction
code, the feasibility of reusing the existing ray-tracers is checked against
other researches in the same field.Comment: 13 pages, 13 figures. submitted to Journal Of Nondestructive
Evaluation (https://www.springer.com/journal/10921
Probabilistic Global Scale Estimation for MonoSLAM Based on Generic Object Detection
This paper proposes a novel method to estimate the global scale of a 3D
reconstructed model within a Kalman filtering-based monocular SLAM algorithm.
Our Bayesian framework integrates height priors over the detected objects
belonging to a set of broad predefined classes, based on recent advances in
fast generic object detection. Each observation is produced on single frames,
so that we do not need a data association process along video frames. This is
because we associate the height priors with the image region sizes at image
places where map features projections fall within the object detection regions.
We present very promising results of this approach obtained on several
experiments with different object classes.Comment: Int. Workshop on Visual Odometry, CVPR, (July 2017
Do-It-Yourself Single Camera 3D Pointer Input Device
We present a new algorithm for single camera 3D reconstruction, or 3D input
for human-computer interfaces, based on precise tracking of an elongated
object, such as a pen, having a pattern of colored bands. To configure the
system, the user provides no more than one labelled image of a handmade
pointer, measurements of its colored bands, and the camera's pinhole projection
matrix. Other systems are of much higher cost and complexity, requiring
combinations of multiple cameras, stereocameras, and pointers with sensors and
lights. Instead of relying on information from multiple devices, we examine our
single view more closely, integrating geometric and appearance constraints to
robustly track the pointer in the presence of occlusion and distractor objects.
By probing objects of known geometry with the pointer, we demonstrate
acceptable accuracy of 3D localization.Comment: 8 pages, 6 figures, 2018 15th Conference on Computer and Robot Visio
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