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Dewarping Book Page Spreads Captured with a Mobile Phone Camera [chapter]

Chelhwon Kim, Patrick Chiu, Surendar Chandra
2014 Lecture Notes in Computer Science  
Capturing book images is more convenient with a mobile phone camera than with more specialized flat-bed scanners or 3D capture devices.  ...  We built an application for the iPhone 4S that captures a sequence of hi-res (8 MP) images of a page spread as the user sweeps the device across the book.  ...  The dewarping method in our system is based on a cylindrical model, which for non-3D images performed the best (though the difference was not statistically significant) in the Document Image Dewarping  ... 
doi:10.1007/978-3-319-05167-3_8 fatcat:prlipe2x75cx3o5ulg46a7t2te

Generic Document Image Dewarping by Probabilistic Discretization of Vanishing Points

Gilles Simon, Salvatore Tabbone
2021 2020 25th International Conference on Pattern Recognition (ICPR)  
In this paper we propose a generic approach based on vanishing points (VP) to reconstruct the 3D shape of document pages.  ...  Document images dewarping is still a challenge especially when documents are captured with one camera in an uncontrolled environment.  ...  Other approaches do not try to get a model of a 3D surface since they are based on 2D geometric features estimation [11] , [12] , [13] . These methods locally estimate a curve to line dewarping.  ... 
doi:10.1109/icpr48806.2021.9412649 fatcat:vbpiduiad5cijmelrnnyfftdke

Warped Document Image Correction Based on Checkboard Pattern and Geometric Transformation

Marian Labib, Khalid Amin, mina ibrahim
2021 IJCI. International Journal of Computers and Information  
The dewarping process transforms the warped document image according to the geometric transformation defined by the calculated mapping function.  ...  In this paper, we propose document image dewarping method based on checkboard calibration pattern and geometric transformation.  ...  Additional approaches for reconstructing the document's surface shape based on the basis of the shading techniques were suggested.  ... 
doi:10.21608/ijci.2021.53176.1036 fatcat:bcvzyf557zfrnasc2djynymp6y

Document image dewarping using robust estimation of curled text lines

A. Ulges, C.H. Lampert, T.M. Breuel
2005 Eighth International Conference on Document Analysis and Recognition (ICDAR'05)  
For images of non-planar paper surfaces like books, page curl causes additional distortion, which poses an even greater problem due to its nonlinearity.  ...  Results are presented showing that the algorithm produces visually pleasing output and increases OCR accuracy, thus having the potential to become a general purpose preprocessing tool for camera based  ...  Our approach Our algorithm performs a line-by-line dewarping of the observed paper surface.  ... 
doi:10.1109/icdar.2005.90 dblp:conf/icdar/UlgesLB05 fatcat:eqz5aln2z5hrhg7pszuc2kcud4

Multiview Rectification of Folded Documents [article]

Shaodi You, Yasuyuki Matsushita, Sudipta Sinha, Yusuke Bou and Katsushi Ikeuchi
2016 arXiv   pre-print
Our main contribution is a new robust rectification method based on ridge-aware 3D reconstruction of a paper sheet and unwrapping the reconstructed surface using properties of developable surfaces via  ...  In contrast, our method uses regular images and is based on general developable surface models that can represent a wide variety of paper deformations.  ...  We address these issues by developing a robust ridge-aware surface reconstruction method for sparse 3D points.  ... 
arXiv:1606.00166v1 fatcat:ulwkig5ug5ed7iknvtjevx75ee

XDOCS: An Application to Index Historical Documents [chapter]

Federico Bolelli, Guido Borghi, Costantino Grana
2017 Communications in Computer and Information Science  
In this paper, the core elements of XDOCS, i.e. page dewarping and word spotting technique, are described and two new applications, i.e. annotation/indexing and search tool, are presented.  ...  The XDOCS project is created with the main goal of making available and extending the usability of historical documents for a great variety of audience, like scholars, institutions and libraries.  ...  Acknowledgement The XDOCS project is currently underway at SATA s.r.l. in collaboration with the University of Modena and Reggio-Emilia, and co-funded by the Emilia-Romagna regional administration.  ... 
doi:10.1007/978-3-319-73165-0_15 fatcat:a7fc64sgqzew5ftcjzw4lglixa

Active Flattening of Curved Document Images via Two Structured Beams

Gaofeng Meng, Ying Wang, Shenquan Qu, Shiming Xiang, Chunhong Pan
2014 2014 IEEE Conference on Computer Vision and Pattern Recognition  
The developable surface is finally flattened onto a plane by solving a system of ordinary differential equations.  ...  A developable surface is then interpolated to the curves by finding the correspondence between them.  ...  This work was supported in part by the Projects of the National Natural Science Foundation of China (Grant No.61370039, 61305049, 61272331, 61175025).  ... 
doi:10.1109/cvpr.2014.497 dblp:conf/cvpr/MengWQXP14 fatcat:oqnzoywhpbgyzo7ef6k64zrrua

In-flight wing deformation measurements on a glider

J. Bakunowicz, R. Meyer
2016 Aeronautical Journal  
Taking a glider as a versatile test bed example, this paper presents a transnational measurement campaign within the framework of a collaborative project funded by the European Commission.  ...  This project Advanced In-Flight Measurement Techniques 2 (AIM²) is a follow-up of Advanced In-Flight Measurement Techniques (AIM) and dedicated to developing and enhancing promising optical metrology for  ...  ACKNOWLEDGMENTS The work and results presented in this paper were co-financed by the European Commission, 7 th Framework Program within the AIM² (Advanced In-Flight Measurement 2) project, Grant Agreement  ... 
doi:10.1017/aer.2016.98 fatcat:qyjsywxazbeazmh4pirrtt2o2u

DocUNet: Document Image Unwarping via a Stacked U-Net

Ke Ma, Zhixin Shu, Xue Bai, Jue Wang, Dimitris Samaras
2018 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition  
Because large-scale real-world data with ground truth deformation is difficult to obtain, we create a synthetic dataset with approximately 100 thousand images by warping non-distorted document images.  ...  In this paper, we develop the first learning-based method to achieve this goal.  ...  This work was supported by a gift from Adobe, Partner University Fund, and the SUNY2020 Infrastructure Transportation Security Center.  ... 
doi:10.1109/cvpr.2018.00494 dblp:conf/cvpr/MaSBWS18 fatcat:zpcvr3rjkrgg3kk5omq35c23si

Hydrodynamic stress maps on the surface of a flexible fin-like foil

Paule Dagenais, Christof M Aegerter
2021 PLoS ONE  
We determine the time dependence of pressure and shear stress distributions on the surface of a pitching and deforming hydrofoil from measurements of the three dimensional flow field.  ...  The consistency of the force time-dependence is verified using a control volume analysis.  ...  The 3D field of particle positions is reconstructed by overlapping the three viewing angles based on a triplet search algorithm.  ... 
doi:10.1371/journal.pone.0244674 pmid:33434237 pmcid:PMC7802974 fatcat:u5v6mvs66feifnzrfolalud6pu

Book Scanner Dewarping with Weak 3d Measurements and a Simplified Surface Model [chapter]

Erik Lilienblum, Bernd Michaelis
Discrete Geometry for Computer Imagery  
For book scanner technologies projective distortions are the main problem. In general, the use of 3d measurements of a warped surface is the best way to remove the projective distortions.  ...  In our paper we present a new technique handling this problem by introducing a simplified surface model.  ...  Acknowledgment This work was supported by AiF/Germany grants (FKZ: KF0056101SS4). We thank the company Chromasens for providing us with the book scanner for research purposes.  ... 
doi:10.1007/978-3-540-79126-3_47 dblp:conf/dgci/LilienblumM08 fatcat:tady6xcxibfy5msklnttbr5iqu

Coanda effect of a propeller airflow and its aerodynamic impact on the thrust

Yoshitsugu NAKA, Akira KAGAMI
2020 Journal of Fluid Science and Technology  
Moreover, the pressure distribution on the propeller surface explains the decrease of the thrust.  ...  A possible reason of the decrease in thrust is found in the streamwise velocity distribution.  ...  Acknowledgement The authors acknowledge Ikuta Media Support Office at Meiji university for providing computer resources of their "PC Cluster system".  ... 
doi:10.1299/jfst.2020jfst0016 fatcat:td4ryf2eojdfngcbc2xi4xwwea

Metric Rectification of Curved Document Images

Gaofeng Meng, Chunhong Pan, Shiming Xiang, Jiangyong Duan, Nanning Zheng
2012 IEEE Transactions on Pattern Analysis and Machine Intelligence  
The core idea is to construct an isometric image mesh by exploiting the geometry of page surface and camera. Our method uses a general cylindrical surface (GCS) to model the curved page shape.  ...  In this paper, we propose a metric rectification method to restore an image from a single camera-captured document image.  ...  This work is supported by the Projects (Grant No. 61005036, 60873161, 60975037, and 90920008) of the National Natural Science Foundation of China.  ... 
doi:10.1109/tpami.2011.151 pmid:21808093 fatcat:3rj6g2jjsvhd3pem3hdztdtd4m

Eyemirror

Christian Lander, Sven Gehring, Markus Löchtefeld, Andreas Bulling, Antonio Krüger
2017 Proceedings of the 16th International Conference on Mobile and Ubiquitous Multimedia - MUM '17  
We present EyeMirror, a mobile device for calibration-free gaze approximation on surfaces (e.g., displays).  ...  Gaze is a powerful measure of people's attracted attention and reveals where we are looking within our current FOV. Hence gaze-based interfaces are gaining in importance.  ...  A well-known approach is to look for the radial edges and classify them as the limbus boundary using ellipse fitting. EyeMirror's algorithm is based on the approach by Wood et al. [46] .  ... 
doi:10.1145/3152832.3152839 dblp:conf/mum/LanderGLBK17 fatcat:l4lozo6fnzab7gwnxrmrbwv3t4

3D Geometric and Optical Modeling of Warped Document Images from Scanners

Li Zhang, Zheng Zhang, Chew Lim Tan, Tao Xia
2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR'05)  
We first build practical models namely a 3D geometric model and a 3D optical model for the practical scanning conditions to reconstruct the 3D shape of book surface.  ...  In this paper, we propose an efficient restoration method based on the discovery of the 3D shape of a book surface from the shading information in a scanned document image.  ...  Acknowledgement The research is supported in part by National University of Singapore URC grant no. R252-000-202-112 and A*STAR, Singapore, grant no. 042 101 0085.  ... 
doi:10.1109/cvpr.2005.11 dblp:conf/cvpr/Zhang0TX05 fatcat:vvk7abedgrdzzclb66aylk2x3a
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