2002 ◽  
Vol 02 (02) ◽  
pp. 287-307 ◽  
Author(s):  
YONG LIU ◽  
CHENG-KE WU ◽  
HUNG-TAT TSUI

This paper presents an approach for reconstructing a realistic 3D model of a building from its uncalibrated video sequences taken by a hand-held camera. The novelty of this approach lies in the integration of some prior scene knowledge in the different stages of the Structure From Motion problem (SFM). First, the coplanarity of buildings is considered in the calculation of the fundamental matrices to deal with the critical configurations. Second, the line parallelism and plane orthogonality are transformed to the constraints on the absolute quadric during camera auto-calibration. This makes some critical cases solvable and the reconstruction more Euclidean. The approach is implemented and validated using simulated data and real image data. The experimental results at the end of the paper show the effectiveness of our approach.


2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Shengyong Chen ◽  
Yuehui Wang ◽  
Carlo Cattani

Construction of three-dimensional structures from video sequences has wide applications for intelligent video analysis. This paper summarizes the key issues of the theory and surveys the recent advances in the state of the art. Reconstruction of a scene object from video sequences often takes the basic principle of structure from motion with an uncalibrated camera. This paper lists the typical strategies and summarizes the typical solutions or algorithms for modeling of complex three-dimensional structures. Open difficult problems are also suggested for further study.


2020 ◽  
Vol 52 ◽  
pp. 55-61
Author(s):  
Ettore Potente ◽  
Cosimo Cagnazzo ◽  
Alessandro Deodati ◽  
Giuseppe Mastronuzzi

2020 ◽  
Vol 2020 (4) ◽  
pp. 116-1-116-7
Author(s):  
Raphael Antonius Frick ◽  
Sascha Zmudzinski ◽  
Martin Steinebach

In recent years, the number of forged videos circulating on the Internet has immensely increased. Software and services to create such forgeries have become more and more accessible to the public. In this regard, the risk of malicious use of forged videos has risen. This work proposes an approach based on the Ghost effect knwon from image forensics for detecting forgeries in videos that can replace faces in video sequences or change the mimic of a face. The experimental results show that the proposed approach is able to identify forgery in high-quality encoded video content.


2013 ◽  
Vol 22 (5-6) ◽  
pp. 387-404
Author(s):  
Guerchi Maher ◽  
Makram Zghibi

Abstract Our research focuses on describing what is really happening when a teacher wants to transmit to pupils - girls and boys - knowledge socially marked as masculine. To describe the processes involved in effective didactic interactions between a teacher a pupil and knowledge, we opted for qualitative methodology, consisting on a close observation of the didactic interactions of a teacher with his pupils (girls and boys). Analysis of the interviews focused especially on the nature of knowledge actually transmitted for girls and boys. The studied video sequences permitted to study the didactic interactions more precisely as are actually happening on the pitch. Both tools allowed us to identify the educational intentions of teachers (specialist or not); women or men in the teaching of football. The results show that teachers’ conceptions influence implicitly or explicitly the modalities of their interventions and the nature of football knowledge transmitted to pupils. This makes us think that the impact of social facts (backgrounds) on Tunisian teachers is great. This phenomenon may lock the physical education teacher in some representations modeling masculine and feminine stereotypes and affect his didactic and teaching contribution. Therefore, the teacher must be aware of the impact of the connotation that may have certain “masculine” practices on his interventions and consequently over the pupils learning (either boys or girls).


2020 ◽  
Author(s):  
Kalima Mendes Pitombeira ◽  
◽  
Antonio Aderson dos Reis Filho ◽  

1976 ◽  
Author(s):  
William B. Thompson

Sign in / Sign up

Export Citation Format

Share Document