Image Based 3D Modeling and Rendering from Single View Perspective Images

2013 ◽  
pp. 604-620
Author(s):  
S. Mohan ◽  
S. Murali

In computer vision, 3D modeling refers to the process of developing 3D representation of the real world objects with systematic procedure. The 3D models can be built based on geometric information about the object or scene to be modeled using CAD/CAM software. However, this approach needs prior knowledge of the objects in the scene like dimension, size of objects, distance from the object to camera, et cetera. To make the 3D models more photo realistic and convenient, images of the objects can be used to build the 3D models. In this chapter, the authors propose a method to extract 3D model from single view perspective image. The approach is based on edge length and exploiting symmetric objects in the scene. Later, an application of touring into picture is discussed with the proposed method.

Author(s):  
S. Mohan ◽  
S. Murali

In computer vision, 3D modeling refers to the process of developing 3D representation of the real world objects with systematic procedure. The 3D models can be built based on geometric information about the object or scene to be modeled using CAD/CAM software. However, this approach needs prior knowledge of the objects in the scene like dimension, size of objects, distance from the object to camera, et cetera. To make the 3D models more photo realistic and convenient, images of the objects can be used to build the 3D models. In this chapter, the authors propose a method to extract 3D model from single view perspective image. The approach is based on edge length and exploiting symmetric objects in the scene. Later, an application of touring into picture is discussed with the proposed method.


2019 ◽  
Vol 7 (13) ◽  
pp. 2157-2161 ◽  
Author(s):  
Manar Galal ◽  
Amira Galal Ismail ◽  
Nada Omar ◽  
Mohamed Zaazou ◽  
Mohamed Abdallah Nassar

AIM: To compare and evaluate the influence of thermomechanical treatment of Protaper Gold file versus Protaper Universal file during testing of bending and torsion using finite-element analysis. METHODS: Two nickel-titanium NiTi rotary files (ProTaper Gold and ProTaper Universal) were used in this study. The files were imaged using stereomicroscope to produce 3D models. The behaviour of the instrument during bending and torsion was numerically analysed in CAD/CAM software package. RESULTS: Under bending, ProTaper, Gold showed higher flexibility and flexural resistance than ProTaper Universal. The highest stress was related at the cutting edge of both files. While during testing of torsion, the maximum amount of stresses was related to the base of the flutes in both files. ProTaper Gold showed higher torsional resistance than the ProTaper Universal file. CONCLUSION: Thermomechanical treatment improved the mechanical response (bending and torsional resistance) of NiTi files.


Author(s):  
Rimon Elias

This chapter surveys many fundamental aspects of projective geometry that have been used extensively in computer vision literature. In particular, it discusses the role of this branch of geometry in reconstructing basic entities (e.g., 3D points, 3D lines, and planes) in 3D space from multiple images. The chapter presents the notation of different elements. It investigates the geometrical relationships when one or two cameras are observing the scene creating single-view and two-view geometry. In other words, camera parameters in terms of locations and orientations, with respect to 3D space and with respect to other cameras, create relationships. This chapter discusses these relationships and expresses them mathematically. Finally, different approaches to deal with the existence of noise or inaccuracy in general are presented.


2013 ◽  
pp. 125-144
Author(s):  
Rimon Elias

This chapter surveys many fundamental aspects of projective geometry that have been used extensively in computer vision literature. In particular, it discusses the role of this branch of geometry in reconstructing basic entities (e.g., 3D points, 3D lines, and planes) in 3D space from multiple images. The chapter presents the notation of different elements. It investigates the geometrical relationships when one or two cameras are observing the scene creating single-view and two-view geometry. In other words, camera parameters in terms of locations and orientations, with respect to 3D space and with respect to other cameras, create relationships. This chapter discusses these relationships and expresses them mathematically. Finally, different approaches to deal with the existence of noise or inaccuracy in general are presented.


Author(s):  
V. A. Mizginov ◽  
S. Y. Danilov

<p><strong>Abstract.</strong> Nowadays methods based on deep neural networks show the best performance among image recognition and object detection algorithms. Nevertheless, such methods require to have large databases of multispectral images of various objects to achieve state-of-the-art results. Therefore the dataset generation is one of the major challenges for the successful training of a deep neural network. However, infrared image datasets that are large enough for successful training of a deep neural network are not available in the public domain. Generation of synthetic datasets using 3D models of various scenes is a time-consuming method that requires long computation time and is not very realistic. This paper is focused on the development of the method for thermal image synthesis using a GAN (generative adversarial network). The aim of the presented work is to expand and complement the existing datasets of real thermal images. Today, deep convolutional networks are increasingly used for the goal of synthesizing various images. Recently a new generation of such algorithms commonly called GAN has become a promising tool for synthesizing images of various spectral ranges. These networks show effective results for image-to-image translations. While it is possible to generate a thermal texture for a single object, generation of environment textures is extremely difficult due to the presence of a large number of objects with different emission sources. The proposed method is based on a joint approach that uses 3D modeling and deep learning. Synthesis of background textures and objects textures is performed using a generative-adversarial neural network and semantic and geometric information about objects generated using 3D modeling. The developed approach significantly improves the realism of the synthetic images, especially in terms of the quality of background textures.</p>


Author(s):  
B. Carrión-Ruiz ◽  
S. Blanco-Pons ◽  
A. Weigert ◽  
S. Fai ◽  
J. L. Lerma

<p><strong>Abstract.</strong> In recent years, Augmented Reality (AR) technology has experienced considerable progress and the combination of AR and 3D modeling opens up new opportunities regarding 3D data visualization and interaction. Consequently, the dissemination of cultural heritage can benefit from these technologies in order to display the cultural assets as realistically and interactively as possible. In this way, high-accuracy 3D models are integrated in the real world.</p><p>Nevertheless, progress has also still been limited due to several factors. The paper presents a case study based on the recreation of the Queen Victoria sculpture in an AR application. Furthermore, the environment of the sculpture is simulated by panoramic images, inside the Library of Parliament in Ottawa, Canada. The main problems for the development of an AR smartphone application from panoramic images and photogrammetric 3D data are described in this paper. The characteristics of AR systems are explained in detail, analyzing all the steps involved and the available solutions considered.</p>


2021 ◽  
Vol 10 ◽  
pp. 117957272110223
Author(s):  
Thomas Hellsten ◽  
Jonny Karlsson ◽  
Muhammed Shamsuzzaman ◽  
Göran Pulkkis

Background: Several factors, including the aging population and the recent corona pandemic, have increased the need for cost effective, easy-to-use and reliable telerehabilitation services. Computer vision-based marker-less human pose estimation is a promising variant of telerehabilitation and is currently an intensive research topic. It has attracted significant interest for detailed motion analysis, as it does not need arrangement of external fiducials while capturing motion data from images. This is promising for rehabilitation applications, as they enable analysis and supervision of clients’ exercises and reduce clients’ need for visiting physiotherapists in person. However, development of a marker-less motion analysis system with precise accuracy for joint identification, joint angle measurements and advanced motion analysis is an open challenge. Objectives: The main objective of this paper is to provide a critical overview of recent computer vision-based marker-less human pose estimation systems and their applicability for rehabilitation application. An overview of some existing marker-less rehabilitation applications is also provided. Methods: This paper presents a critical review of recent computer vision-based marker-less human pose estimation systems with focus on their provided joint localization accuracy in comparison to physiotherapy requirements and ease of use. The accuracy, in terms of the capability to measure the knee angle, is analysed using simulation. Results: Current pose estimation systems use 2D, 3D, multiple and single view-based techniques. The most promising techniques from a physiotherapy point of view are 3D marker-less pose estimation based on a single view as these can perform advanced motion analysis of the human body while only requiring a single camera and a computing device. Preliminary simulations reveal that some proposed systems already provide a sufficient accuracy for 2D joint angle estimations. Conclusions: Even though test results of different applications for some proposed techniques are promising, more rigour testing is required for validating their accuracy before they can be widely adopted in advanced rehabilitation applications.


Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1516 ◽  
Author(s):  
Francisco Troncoso-Pastoriza ◽  
Pablo Eguía-Oller ◽  
Rebeca Díaz-Redondo ◽  
Enrique Granada-Álvarez ◽  
Aitor Erkoreka

Computer vision is used in this work to detect lighting elements in buildings with the goal of improving the accuracy of previous methods to provide a precise inventory of the location and state of lamps. Using the framework developed in our previous works, we introduce two new modifications to enhance the system: first, a constraint on the orientation of the detected poses in the optimization methods for both the initial and the refined estimates based on the geometric information of the building information modelling (BIM) model; second, an additional reprojection error filtering step to discard the erroneous poses introduced with the orientation restrictions, keeping the identification and localization errors low while greatly increasing the number of detections. These enhancements are tested in five different case studies with more than 30,000 images, with results showing improvements in the number of detections, the percentage of correct model and state identifications, and the distance between detections and reference positions.


2013 ◽  
Vol 631-632 ◽  
pp. 1335-1341
Author(s):  
Shi Yong ◽  
Wen Tao Liu

In order to meet the needs of enterprises for chamfering complex parts, based on the customization of commercial CAD/CAM software, chamfer programming software is developed. According to user’s machining demands for a part, a chain of edges of a part is extracted from its 3D model. With preprocessing of the chain of edges, the continuity of the chain is estimated, and the start and end point of those edges are automatic obtained. Furthermore, with human-machine dialogue, machining parameters is set by users. By definition of the primary and secondary surfaces of the chain of edges, and interpolation of the edges, the positions of cutter location point and postures of cutter are calculated. Finally the interference of tool path is checked, and tool path is simulated. The software solves the programming problem of chamfering complex parts.


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