Search results for "Point Cloud"
showing 10 items of 81 documents
Unsupervised learning of category-specific symmetric 3D keypoints from point sets
2020
Lecture Notes in Computer Science, 12370
Processing and Assessment of Spectrometric, Stereoscopic Imagery Collected Using a Lightweight UAV Spectral Camera for Precision Agriculture
2013
Imaging using lightweight, unmanned airborne vehicles (UAVs) is one of the most rapidly developing fields in remote sensing technology. The new, tunable, Fabry-Perot interferometer-based (FPI) spectral camera, which weighs less than 700 g, makes it possible to collect spectrometric image blocks with stereoscopic overlaps using light-weight UAV platforms. This new technology is highly relevant, because it opens up new possibilities for measuring and monitoring the environment, which is becoming increasingly important for many environmental challenges. Our objectives were to investigate the processing and use of this new type of image data in precision agriculture. We developed the entire pro…
Ventricular Fibrillation and Tachycardia Detection Using Features Derived from Topological Data Analysis
2022
A rapid and accurate detection of ventricular arrhythmias is essential to take appropriate therapeutic actions when cardiac arrhythmias occur. Furthermore, the accurate discrimination between arrhythmias is also important, provided that the required shocking therapy would not be the same. In this work, the main novelty is the use of the mathematical method known as Topological Data Analysis (TDA) to generate new types of features which can contribute to the improvement of the detection and classification performance of cardiac arrhythmias such as Ventricular Fibrillation (VF) and Ventricular Tachycardia (VT). The electrocardiographic (ECG) signals used for this evaluation were obtained from…
Strain fields measurement of non-rigid solid by scanning laser coupled with camera
2013
International audience; Abstract. Today, the techniques of measurement without contact by scanning laser are increasingly used. These techniques allow to measure 3D objects without contact and the measurement rates can reach few thousand points by second that is very adapted to complex shapes. To measure displacements and deformations, it is necessary to follow a solid particle in its motion between two configurations of the body before and after displacement. The method of stereovision based on grayscale patterns, obtained by applying a spray, is generally used. The results are obtained by two correlations: spatial and temporal correlations. An alternative method consists to use a scanner …
Automatic object detection in point clouds based on knowledge guided algorithms
2013
The modeling of real-world scenarios through capturing 3D digital data has been proven applicable in a variety of industrial applications, ranging from security, to robotics and to fields in the medical sciences. These different scenarios, along with variable conditions, present a challenge in discovering flexible appropriate solutions. In this paper, we present a novel approach based on a human cognition model to guide processing. Our method turns traditional data-driven processing into a new strategy based on a semantic knowledge system. Robust and adaptive methods for object extraction and identification are modeled in a knowledge domain, which has been created by purely numerical strate…
Full parallax three-dimensional display from Kinect v1 and v2
2016
We exploit the two different versions of Kinect, v1 and v2, for the calculation of microimages projected onto integral-imaging displays. Our approach is based on composing a three-dimensional (3-D) point cloud from a captured depth map and RGB information. These fused 3-D maps permit to generate an integral image after projecting the information through a virtual pinhole array. In our analysis, we take into account that each of the Kinect devices has its own inherent capacities and individualities. We illustrate our analysis with some imaging experiments, provide the distinctive differences between the two Kinect devices, and finally conclude that Kinect v2 allows the display of 3-D images …
GEOMATIC METHODOLOGIES FOR THE STUDY OF TEATRO MASSIMO IN PALERMO (ITALY)
2017
Abstract. This work illustrates the use of geomatics techniques for the documentation of Teatro Massimo in Palermo (Italy), one of the most important and big in Italy and in Europe. The theatre is characterized by a very complex structure and is realized also using innovative solution, studied at the time of the project specifically for this building; for example, an original system was realized for a natural air-conditioning system of the auditorium. Due to his complexity, the documentation of the Teatro Massimo requires studying specific survey solutions for the different parts of the building. In this paper, some studies on two of the most representative parts of the building were descri…
Low cost three-dimensional virtual model construction for remanufacturing industry
2018
Remanufactured products can save up to 80% of production and energy costs whilst generating lower CO2 emissions. The key success factors for remanufacturing are quality, lead-time and cost. Extensive work within the industry and the detailed analysis of the remanufacturing process has shown that component inspection has significant bearing on overall productivity. Remanufacturing lacks automation because activities are predominantly manual. Automation of remanufacturing process will not only decrease the number of non-remanufacturable components, through decreasing cost and increasing consistency in quality, but also attract industries to design for remanufacture. A digital model of the com…
Genetic algorithms for 3d reconstruction with supershapes
2009
Supershape model is a recent primitive that represents numerous 3D shapes with several symmetry axes. The main interest of this model is its capability to reconstruct more complex shape than superquadric model with only one implicit equation. In this paper we propose a genetic algorithms to re-construct a point cloud using those primitives. We used the pseudo-Euclidean distance to introduce a threshold to handle real data imperfection and speed up the process. Simulations using our proposed fitness functions and a fitness function based on inside-outside function show that our fitness function based on the pseudo-Euclidean distance performs better.
FROM SFM TO 3D PRINT: AUTOMATED WORKFLOW ADDRESSED TO PRACTITIONER AIMED AT THE CONSERVATION AND RESTAURATION
2017
Abstract. In In the last years there has been an increasing use of digital techniques for conservation and restoration purposes. Among these, a very dominant rule is played by the use of digital photogrammetry packages (Agisoft Photoscan, 3D Zephir) which allow to obtain in few steps 3D textured models of real objects. Combined with digital documentation technologies digital fabrication technologies can be employed in a variety of ways to assist in heritage documentation, conservation and dissemination. This paper will give to practitioners an overview on the state of the art available technologies and a feasible workflow for optimizing point cloud and polygon mesh datasets for the purpose …