Video Frames Selection Method for 3D Reconstruction Depending on ROS-Based Monocular SLAM

2020 ◽  
pp. 351-380
Author(s):  
Yasin Maan Yousif ◽  
Iyad Hatem
Keyword(s):  
3D Reconstruction ◽  
Selection Method ◽  
Video Frames ◽  
Monocular Slam

scholarly journals THREE-DIMENSIONAL RECONSTRUCTION BASED ON IMPROVED MARCHING CUBES ALGORITHM

2020 ◽  
Vol 20 (09) ◽  
pp. 2040002
Author(s):  
MONAN WANG ◽  
HAIYANG LUO ◽  
QI CUI
Keyword(s):  
3D Reconstruction ◽  
Medical Image ◽  
Interpolation Method ◽  
Three Dimensional ◽  
Linear Interpolation ◽  
Selection Method ◽  
Marching Cubes ◽  
Dimensional Reconstruction ◽  
Message Mapping ◽  
Opening And Closing

Based on the standard Marching Cubes (MC) algorithm, this paper proposes an improved MC algorithm. First, the original 15 topological configurations in the MC algorithm are increased to 24, which effectively avoid the generation of voids phenomenon. To further improve the speed of three-dimensional (3D) reconstruction, in this paper, the midpoint selection method is used instead of the linear interpolation method, and the 24 configurations are divided into three types. Each class corresponds to a thread. The multi-thread parallel processing is used to improve the calculation speed. The critical region is used to realize multi-thread synchronization, and then we designed a protocol mapping table according to the idea of the message mapping table. The function pointer is triggered by macro. Processing function is called by function pointer and completes the encapsulation of the protocol mapping table, which maintains the opening and closing principle of the class and ensures the scalability of the class. Through the improved MC algorithm accuracy verification and reconstruction speed verification, it is concluded that the improved MC algorithm can make up for the voids problem. By comparing the calculation time under the two platforms of Windows and Linux, the reconstruction speed of the improved MC algorithm is approximately 30% faster than the standard MC algorithm and 40% faster than the Masala algorithm. Finally, the algorithm is applied to the medical image 3D reconstruction system, and the accuracy and applicability of the algorithm are demonstrated by two sets of examples.

Camera-Agnostic Monocular SLAM and Semi-dense 3D Reconstruction

2016 ◽  
pp. 285-296
Author(s):  
Martin Rünz ◽  
Frank Neuhaus ◽  
Christian Winkens ◽  
Dietrich Paulus
Keyword(s):  
3D Reconstruction ◽  
Monocular Slam ◽  
Dense 3D Reconstruction

scholarly journals Novel experimental and software methods for image reconstruction and localization in capsule endoscopy

2018 ◽  
Vol 06 (02) ◽  
pp. E205-E210 ◽  
Author(s):  
Anastasios Koulaouzidis ◽  
Dimitris Iakovidis ◽  
Diana Yung ◽  
Evangelos Mazomenos ◽  
Federico Bianchi ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Capsule Endoscopy ◽  
Visual Information ◽  
Estimation Algorithm ◽  
Absolute Error ◽  
Cylindrical Shape ◽  
Surface Geometry ◽  
Video Frames ◽  
Reconstruction Methods ◽  
Technological Limitations

Abstract Background and study aims Capsule endoscopy (CE) is invaluable for minimally invasive endoscopy of the gastrointestinal tract; however, several technological limitations remain including lack of reliable lesion localization. We present an approach to 3D reconstruction and localization using visual information from 2D CE images. Patients and methods Colored thumbtacks were secured in rows to the internal wall of a LifeLike bowel model. A PillCam SB3 was calibrated and navigated linearly through the lumen by a high-precision robotic arm. The motion estimation algorithm used data (light falling on the object, fraction of reflected light and surface geometry) from 2D CE images in the video sequence to achieve 3D reconstruction of the bowel model at various frames. The ORB-SLAM technique was used for 3D reconstruction and CE localization within the reconstructed model. This algorithm compared pairs of points between images for reconstruction and localization. Results As the capsule moved through the model bowel 42 to 66 video frames were obtained per pass. Mean absolute error in the estimated distance travelled by the CE was 4.1 ± 3.9 cm. Our algorithm was able to reconstruct the cylindrical shape of the model bowel with details of the attached thumbtacks. ORB-SLAM successfully reconstructed the bowel wall from simultaneous frames of the CE video. The “track” in the reconstruction corresponded well with the linear forwards-backwards movement of the capsule through the model lumen. Conclusion The reconstruction methods, detailed above, were able to achieve good quality reconstruction of the bowel model and localization of the capsule trajectory using information from the CE video and images alone.

scholarly journals 3D Reconstruction through Fusion of Cross-View Images

2020 ◽  
Author(s):  
Rongjun Qin ◽  
Shuang Song ◽  
Xiao Ling ◽  
Mostafa Elhashash
Keyword(s):  
Remote Sensing ◽  
Computer Vision ◽  
3D Reconstruction ◽  
Satellite Images ◽  
Important Application ◽  
Project Work ◽  
Imaging Geometry ◽  
Perspective Geometry ◽  
3D Data ◽  
Video Frames

3D recovery from multi-stereo and stereo images, as an important application of the image-based perspective geometry, serves many applications in computer vision, remote sensing, and Geomatics. In this chapter, the authors utilize the imaging geometry and present approaches that perform 3D reconstruction from cross-view images that are drastically different in their viewpoints. We introduce our project work that takes ground-view images and satellite images for full 3D recovery, which includes necessary methods in satellite and ground-based point cloud generation from images, 3D data co-registration, fusion, and mesh generation. We demonstrate our proposed framework on a dataset consisting of twelve satellite images and 150 k video frames acquired through a vehicle-mounted Go-pro camera and demonstrate the reconstruction results. We have also compared our results with results generated from an intuitive processing pipeline that involves typical geo-registration and meshing methods.

Detection, Averaging, and 3D Reconstruction of Biological Specimens on Hypercubes (Transputer-based) Computers

1990 ◽  
Vol 48 (1) ◽  
pp. 454-455
Author(s):  
Jose-Maria Carazo ◽  
I. Benavides ◽  
S. Marco ◽  
J.L. Carrascosa ◽  
E.L. Zapata
Keyword(s):  
3D Reconstruction ◽  
3D Structure ◽  
Three Dimensional ◽  
Software Tools ◽  
Mapping Method ◽  
Computer Architectures ◽  
Parallel Computer ◽  
Reconstruction Process ◽  
Computing Power ◽  
Order Of Magnitude

Obtaining the three-dimensional (3D) structure of negatively stained biological specimens at a resolution of, typically, 2 - 4 nm is becoming a relatively common practice in an increasing number of laboratories. A combination of new conceptual approaches, new software tools, and faster computers have made this situation possible. However, all these 3D reconstruction processes are quite computer intensive, and the middle term future is full of suggestions entailing an even greater need of computing power. Up to now all published 3D reconstructions in this field have been performed on conventional (sequential) computers, but it is a fact that new parallel computer architectures represent the potential of order-of-magnitude increases in computing power and should, therefore, be considered for their possible application in the most computing intensive tasks.We have studied both shared-memory-based computer architectures, like the BBN Butterfly, and local-memory-based architectures, mainly hypercubes implemented on transputers, where we have used the algorithmic mapping method proposed by Zapata el at. In this work we have developed the basic software tools needed to obtain a 3D reconstruction from non-crystalline specimens (“single particles”) using the so-called Random Conical Tilt Series Method. We start from a pair of images presenting the same field, first tilted (by ≃55°) and then untilted. It is then assumed that we can supply the system with the image of the particle we are looking for (ideally, a 2D average from a previous study) and with a matrix describing the geometrical relationships between the tilted and untilted fields (this step is now accomplished by interactively marking a few pairs of corresponding features in the two fields). From here on the 3D reconstruction process may be run automatically.

Structural Studies on the Eukaryotic Ribosome

1990 ◽  
Vol 48 (1) ◽  
pp. 256-257
Author(s):  
Adriana Verschoor ◽  
Ronald Milligan ◽  
Suman Srivastava ◽  
Joachim Frank
Keyword(s):  
Chick Embryo ◽  
3D Reconstruction ◽  
Single Particle ◽  
Mass Density ◽  
Particle Surface ◽  
Uranyl Acetate ◽  
Electron Microscopic ◽  
Eukaryotic Ribosome ◽  
Negative Stain ◽  
Reconstruction Methods

We have studied the eukaryotic ribosome from two vertebrate species (rabbit reticulocyte and chick embryo ribosomes) in several different electron microscopic preparations (Fig. 1a-d), and we have applied image processing methods to two of the types of images. Reticulocyte ribosomes were examined in both negative stain (0.5% uranyl acetate, in a double-carbon preparation) and frozen hydrated preparation as single-particle specimens. In addition, chick embryo ribosomes in tetrameric and crystalline assemblies in frozen hydrated preparation have been examined. 2D averaging, multivariate statistical analysis, and classification methods have been applied to the negatively stained single-particle micrographs and the frozen hydrated tetramer micrographs to obtain statistically well defined projection images of the ribosome (Fig. 2a,c). 3D reconstruction methods, the random conical reconstruction scheme and weighted back projection, were applied to the negative-stain data, and several closely related reconstructions were obtained. The principal 3D reconstruction (Fig. 2b), which has a resolution of 3.7 nm according to the differential phase residual criterion, can be compared to the images of individual ribosomes in a 2D tetramer average (Fig. 2c) at a similar resolution, and a good agreement of the general morphology and of many of the characteristic features is seen.Both data sets show the ribosome in roughly the same ’view’ or orientation, with respect to the adsorptive surface in the electron microscopic preparation, as judged by the agreement in both the projected form and the distribution of characteristic density features. The negative-stain reconstruction reveals details of the ribosome morphology; the 2D frozen-hydrated average provides projection information on the native mass-density distribution within the structure. The 40S subunit appears to have an elongate core of higher density, while the 60S subunit shows a more complex pattern of dense features, comprising a rather globular core, locally extending close to the particle surface.

НАРАТИВ ЯК КОНТЕНТНА ОСНОВА МІЖНАРОДНИХ СТРАТЕГІЧНИХ КОМУНІКАЦІЙ

2020 ◽  
pp. 4
Author(s):  
N. Zykun ◽  
A. Bessarab ◽  
L. Ponomarenko
Keyword(s):  
Selection Method ◽  
Historical Narrative ◽  
Neutral Position ◽  
Main Task ◽  
Grand Narrative ◽  
National Narrative ◽  
Strategic Communications ◽  
Analysis And Synthesis ◽  
The Media ◽  
International Interaction

<p><em>The article, basing on the analysis of selected media texts with reference to narrative from the leading Ukrainian newspapers «Dzerkalo Tyzhnia» (Weekly Mirror), «Den» (Day), «Ukraina Moloda» (Young Ukraine) for 2016–2020, the semantic and content characteristics of the «narrative», «strategic narrative», «small narratives» nominations has established; the directions of the semantic realization of the meaning of the narrative and its possibilities in the process of international strategic communications aimed at both external and internal audience, are outlined. It is proved that the main task of a strategic, or national, narrative is a reasoned explanation to the state population and interested audiences of specific realities, intentions, plans; justification of certain directions of state activity aimed at partners, at opponents and those occupying a neutral position.</em></p><p><em>There are divided the spheres of use of different narratological nominations: in international communications and in scientific discourse, the conceptual foundations of state identity and international interaction are referred to as strategic narrative or grand narrative, in publicistic discourse the narrative nomination is used, more rarely – historical narrative, national narrative.</em></p><p><em>The scientific novelty of the research is that the focus is on the media aspect of the use of one of the key concepts of strategic communications and the role of the media in its implementation.</em></p><p><em>The main general scientific methods used in this article are descriptive and comparative ones, as well as analysis and synthesis. The following empirical methods were also used: solid selection method (solid selection method for allocation texts with the «narrative» lexeme; quantitative method of content analysis with elements of qualitative one – for characterizing the semantic of the «narrative» term).</em></p><p><em>The results of the study can be used in the complex research of the technology of international strategic communications and in the practical activity of specialists in international strategic communications, a new trend in Ukraine, which is currently under active institutionalization.</em></p><strong><em>Key words:</em></strong><em> international strategic communications, propaganda, narrative, strategic narrative, grand narrative, «small narratives».</em>

3D reconstruction and calculation of surface area and volume of bell pepper

2007 ◽  
Vol 3 (1) ◽  
pp. 89-113
Author(s):  
Zoltán Gillay ◽  
László Fenyvesi
Keyword(s):  
3D Reconstruction ◽  
Surface Area ◽  
Three Dimensional ◽  
Reference Method ◽  
Bell Pepper ◽  
Three Dimensional Model ◽  
Acceptable Error ◽  
Volume Calculation ◽  
Bell Peppers ◽  
Area And Volume

There was a method developed that generates the three-dimensional model of not axisymmetric produce, based on an arbitrary number of photos. The model can serve as a basis for calculating the surface area and the volume of produce. The efficiency of the reconstruction was tested on bell peppers and artificial shapes. In case of bell peppers 3-dimensional reconstruction was created from 4 images rotated in 45° angle intervals. The surface area and the volume were estimated on the basis of the reconstructed area. Furthermore, a new and simple reference method was devised to give precise results for the surface area of bell pepper. The results show that this 3D reconstruction-based surface area and volume calculation method is suitable to determine the surface area and volume of definite bell peppers with an acceptable error.

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