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A comparative evaluation of length estimators of digital curves

D. Coeurjolly, R. Klette
2004 IEEE Transactions on Pattern Analysis and Machine Intelligence  
This paper compares previously published length estimators in image analysis having digitized curves as input.  ...  This paper also suggests a new gradient-based method for length estimation, and combines a previously proposed length estimator for straight segments with a polygonalization method.  ...  Coeurjolly was a member of the ERIC Laboratory (Université Lumière Lyon 2).  ... 
doi:10.1109/tpami.2004.1262194 pmid:15376899 fatcat:psisn6pwwnhofoyvcxyaamjpcu

Direct digital radiography versus conventional radiography for estimation of canal length in curved canals

Seiedeh Tahereh Mohtavipour, Zahra Dalili, Nasim Gheshlaghi Azar
2011 Imaging Science in Dentistry  
Purpose : The purpose of this study was to compare the conventional and digital radiography in the estimation of working length in mandibular molars.  ...  After the placement of a 15 K-file, radiographs were taken with a conventional film (Fspeed) and a digital sensor. Canal lengths were measured in these images by two observers.  ...  oxide semiconductor) digital sensor in the evaluation of working length of canals especially in curved canals.  ... 
doi:10.5624/isd.2011.41.1.7 pmid:21977467 pmcid:PMC3174458 fatcat:ts7kxs3vxjdirgiqyv4n235pja

Analysis and Comparative Evaluation of Discrete Tangent Estimators [chapter]

Jacques-Olivier Lachaud, Anne Vialard, François de Vieilleville
2005 Lecture Notes in Computer Science  
This paper presents a comparative evaluation of tangent estimators based on digital line recognition on digital curves.  ...  We further propose a new estimator mixing the qualities of existing ones and outperforming them on most mentioned points.  ...  For instance, the length of a digital contour is accurately estimated from tangents by integration [3, 9] .  ... 
doi:10.1007/978-3-540-31965-8_23 fatcat:newmxoy5vfgchci4wqaicm57ze

Accuracy of an Intraoral Digital System for File Length Measurement

Seyedeh Tahereh Mohtavipour, Shiva Sadeghi, Seyedeh Saeedeh Mohtavipour, Aliehsadat Javadzadeh Haghighat, Maryam Rezvani, Bahar Mamoud Khalesi
2016 Journal of Dentomaxillofacial Radiology Pathology and Surgery  
Digital radiography has enabled accurate measurement of curved canal length.  ...  In this study, we evaluated the accuracy of calibration of a complementary metal oxide semiconductor (CMOS) digital system for file length measurement Materials and methods: In this in vitro study, 45extracted  ...  Conclusion The authors are thankful to the staff of Oral and Maxillofacial Radiology Department of Guilan Dental School.  ... 
doi:10.18869/acadpub.3dj.4.4.16 fatcat:ulzpilqnj5c6rnn2acb4hypqq4

Continuous Characterization of the Planform Geometry and Curvature of Meandering Rivers

İnci Güneralp, Bruce L. Rhoads
2007 Geographical Analysis  
This article presents and evaluates a methodology that provides a continuous functional representation of the planform geometry and curvature of meandering rivers.  ...  The arc-length parameterized PCS-interpolated curve is then used to compute analytically the channel CL location and curvature for any value of the streamwise axis.  ...  We thank Burak Gü neralp for his contribution to the development of the code for arc-length parameterization. Geographical Analysis  ... 
doi:10.1111/j.0016-7363.2007.00711.x fatcat:erm5dgykqbhy5mm5nwsogamdny

New software: comparison between three software programs for root canal length measurement

D Goodarzi Pour, H Razmi, S Jabedar Maralani, S Zeighami
2008 Dentomaxillofacial Radiology  
Objectives: The purpose of this study was to design a software program to estimate the curved root canal working length by using curved line software and comparing its accuracy with Trophy and Cygnus software  ...  Canal length was measured with newly developed software that uses a curved line, as well as with Cygnus and Trophy software, both of which use a sequence of straight lines, and their accuracies were compared  ...  It was then extracted and the length of the canal was measured using a digital caliper with a standard error of 0.02 mm.  ... 
doi:10.1259/dmfr/16010494 pmid:18460577 fatcat:c4lokr5marefzazegtejgl5pzi

About Multigrid Convergence of Some Length Estimators [chapter]

Loïc Mazo, Étienne Baudrier
2014 Lecture Notes in Computer Science  
An interesting property for curve length digital estimators is the convergence toward the continuous length and the associate convergence speed when the digitization step h tends to 0.  ...  Furthermore, assuming a sequence of functions G h : hZ → hZ discretizing a given Euclidean function as h tends to 0, sparse length estimation computational complexity in the optimal setting is a O(h −  ...  We focus in this paper on one classical digital problem: the length estimation. The problem is to estimate the length of a continuous curve S knowing a digitization of S.  ... 
doi:10.1007/978-3-319-09955-2_18 fatcat:hvwfz2ylx5c6xmdn5e5mxtfn5q

Root canal curvature as a prognostic factor influencing the diagnostic accuracy of radiographic working length determination and postoperative canal axis modification: an in vitro comparative study

Bestoon Mohammed Faraj
2021 BMC Oral Health  
There was no significant relation of the degree of canal curvature angle to the accuracy of radiographic working length estimated on CBCT and digital periapical radiographic techniques (P > 0.05).  ...  A standardized digital periapical radiographic method performed similarly to the CBCT technique near to its true working length.  ...  a quantitative evaluation, under the scrutiny of CBCT and digital radiographic imaging.  ... 
doi:10.1186/s12903-021-01446-x pmid:33653318 fatcat:gjl3emlpxrfbnhezuapfj2hmde

Multigrid Convergence of Discrete Geometric Estimators [chapter]

David Coeurjolly, Jacques-Olivier Lachaud, Tristan Roussillon
2012 Lecture Notes in Computational Vision and Biomechanics  
A representative subsets of estimators have been implemented in a common framework (the library DGtal), and have been experimentally evaluated for several classes of shapes.  ...  We present here global geometric estimators of area, length, moments, as well as local geometric estimators of tangent and curvature.  ...  In Sect. 6, we discuss on implementation details of both the estimator and the comparative evaluation framework.  ... 
doi:10.1007/978-94-007-4174-4_13 fatcat:ym22kbvxdfh35hz22yqe6yrbem

Preterm Prediction Study

R B. Newman, R L. Goldenberg, J D. Iams, P J. Meis, B M. Mercer, A H. Moawad, E Thom, M Miodovnik, S N. Caritis, M Dombrowski
2008 Obstetrics and Gynecology  
OBJECTIVE-To prospectively compare digital Cervical Score with Bishop Score as a predictor of spontaneous preterm delivery before 35 weeks of gestation.  ...  Patients underwent digital cervical examinations at 22-24 and 26-29 weeks of gestation for calculation of Bishop Score and Cervical Score.  ...  Acknowledgments Supported by grants from the National Institute of Child Health and Human Development (HD21410, HD21414, HD27860, HD27861, HD27869, HD27883, HD27889, HD27905, HD27915, HD27917, HD19897  ... 
doi:10.1097/aog.0b013e3181842087 pmid:18757646 pmcid:PMC2728002 fatcat:2rjfzakl6nffbdjaljqcwiiwk4

3D CENTRAL LINE EXTRACTION OF FOSSIL OYSTER SHELLS

A. Djuricic, E. Puttonen, M. Harzhauser, O. Mandic, B. Székely, N. Pfeifer
2016 ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils.  ...  of cubic spline curve; and v) integration of the central line into the corresponding 3D point cloud.  ...  Eetu Puttonen was financed by Academy of Finland grant no. 292757 ["New Applications for Ubiquitous Multi and Hyper Spectral Mobile Mapping Systems"].  ... 
doi:10.5194/isprsannals-iii-5-121-2016 fatcat:fjohf5izfraippw4qckhgg3rsq

Length estimators for digitized contours

Leo Dorst, Arnold W.M. Smeulders
1987 Computer Vision Graphics and Image Processing  
The estimation of the length of a continuous curve from discrete data is considered. For ideal straight chaincode strings, optimal estimators are given.  ...  For curves that may be considered to be composed of circular arcs good length estimators are found. 9 1987 Academic Press, Inc. Now, the asymptotic RDEV decreases to 2.6%, a considerable improvement.  ...  There are algorithms known which perform a polygonal decomposition of a digitized curve into straight substrings of maximum length.  ... 
doi:10.1016/s0734-189x(87)80145-7 fatcat:tmfpwwnxyvbwllotgtlityvr4y

3D CENTRAL LINE EXTRACTION OF FOSSIL OYSTER SHELLS

A. Djuricic, E. Puttonen, M. Harzhauser, O. Mandic, B. Székely, N. Pfeifer
2016 ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
Photogrammetry provides a powerful tool to digitally document protected, inaccessible, and rare fossils.  ...  of cubic spline curve; and v) integration of the central line into the corresponding 3D point cloud.  ...  Eetu Puttonen was financed by Academy of Finland grant no. 292757 ["New Applications for Ubiquitous Multi and Hyper Spectral Mobile Mapping Systems"].  ... 
doi:10.5194/isprs-annals-iii-5-121-2016 fatcat:fu3lwiixhng55ftlvi64bgzjfe

An evaluation of digitally derived K-indices

Lanny R. WILSON
1987 Journal of geomagnetism and geoelectricity  
Test magnetograms, synthesized from digital one-minute values for a wide range of magnetic conditions , are shown with regular variation curves superimposed on their respective component traces.  ...  The method used for estimating the daily regular variation of the magnetic field and the computation of digital K values are discussed.  ...  Method used for estimating SR curves The digital SR curve is estimated by a least squares fit of straight lines to a sliding set of three MHVs to generate a series of intersecting lines.  ... 
doi:10.5636/jgg.39.97 fatcat:wvpvqlvh6zb3xbjzggv27ehok4

Robust estimation of physiological cross-sectional area and geometric reconstruction for human skeletal muscle

Dongwoon Lee, Kajeandra Ravichandiran, Ken Jackson, Eugene Fiume, Anne Agur
2012 Journal of Biomechanics  
To deal effectively with this non-uniformity, we propose a geometric approach in which a polygon is sought to best approximate the cross-sectional area of each fascicle by accounting for its three-dimensional  ...  From comparison of PCSA using synthetic data, we conclude that the proposed method enhances the robustness of PCSA estimation against variation in muscle architecture.  ...  Conflict of interest statement We hereby declare that no conflict of interest exists in our study.  ... 
doi:10.1016/j.jbiomech.2012.01.051 pmid:22406468 fatcat:2qrhdmltwbbipdjqs3lsdoyogi
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