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Calibration Update Technique for a Zoom Lens [chapter]

Marina Kolesnik
<span title="">1999</span> <i title="Springer Berlin Heidelberg"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/2w3awgokqne6te4nvlofavy5a4" style="color: black;">Lecture Notes in Computer Science</a> </i> &nbsp;
A technique for a zoom lens camera is presented that enable to update continuously camera intrinsic parameters while zooming.  ...  We give an error estimate to show how the uncertainty in the localization of corresponding points in the image frames may affect the accuracy of the updated value of the focal length.  ...  Paar (JOANNEUM Research, Austria) for his professional support in removing optical distortions from the original images.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/3-540-48375-6_53">doi:10.1007/3-540-48375-6_53</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/j4jopracljeufp2yhcmynrthq4">fatcat:j4jopracljeufp2yhcmynrthq4</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20170808182520/http://mitarbeiter.fit.fraunhofer.de/~kolesnik/papers/pdf/caip99.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/2e/95/2e95a931673665db5376f8b6569eba2e06d16cf6.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/3-540-48375-6_53"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> springer.com </button> </a>

A neural approach to zoom-lens camera calibration from data with outliers

Moumen Ahmed, Aly Farag
<span title="">2002</span> <i title="Elsevier BV"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/z7tk7kanxjcz7hgk77ae6t3ofy" style="color: black;">Image and Vision Computing</a> </i> &nbsp;
In this paper, we present a neural framework for zoom-lens camera calibration that can capture complex variations in the camera model parameters across continuous ranges in the lens control space, while  ...  Camera systems with zoom lenses are inherently more useful than those with passive lenses due to their flexibility and controllability. However, their calibration raises several challenges.  ...  However, calibrating cameras with zoom lenses is rather difficult and raises several challenges. First, the dimensionality of data collected for calibration is large.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1016/s0262-8856(02)00051-3">doi:10.1016/s0262-8856(02)00051-3</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/q3tltpzn5bddvl5ujeazda6k5q">fatcat:q3tltpzn5bddvl5ujeazda6k5q</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20060111202722/http://mecca.louisville.edu:80/wwwcvip/research/publications/Pub_Pdf/2002/2.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/d2/77/d27757f785dadc7f054effc1efc520cf5a991488.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1016/s0262-8856(02)00051-3"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> elsevier.com </button> </a>

A Flexible, Generic Photogrammetric Approach to Zoom Lens Calibration

Zheng Wang, Jon Mills, Wen Xiao, Rongyong Huang, Shunyi Zheng, Zhenhong Li
<span title="2017-03-06">2017</span> <i title="MDPI AG"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/kay2tsbijbawliu45dnhvyvgsq" style="color: black;">Remote Sensing</a> </i> &nbsp;
Zoom lens calibration was performed with images taken at four different zoom settings spread throughout the zoom range of a lens.  ...  Compared with prime lenses, zoom lenses have inherent advantages in terms of operational flexibility.  ...  Author Contributions: Zheng Wang realized his Master's thesis project entitled "Zoom lens calibration and its accuracy analysis in close-range photogrammetry" in the school of Remote Sensing Science and  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.3390/rs9030244">doi:10.3390/rs9030244</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/m3ecwzs64jhv7hvzn4zzpg2otu">fatcat:m3ecwzs64jhv7hvzn4zzpg2otu</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20190303151610/http://pdfs.semanticscholar.org/af5f/f16b5dcacbee30aeb39ebe57b2ffd426e389.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/af/5f/af5ff16b5dcacbee30aeb39ebe57b2ffd426e389.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.3390/rs9030244"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="unlock alternate icon" style="background-color: #fb971f;"></i> mdpi.com </button> </a>

CORRECTING DISTORTION OF IMAGE BY IMAGE REGISTRATION WITH THE IMPLICIT FUNCTION THEOREM

TORU TAMAKI, TSUYOSHI YAMAMURA, NOBORU OHNISHI
<span title="">2002</span> <i title="World Scientific Pub Co Pte Lt"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/cgri2crepjeqdadllyir5746ei" style="color: black;">International Journal of Image and Graphics</a> </i> &nbsp;
We propose a method for correcting image distortion due to camera lenses by calibrating intrinsic camera parameters.  ...  To avoid local minima, we first estimate parameters for view change and employ coarse-tofine minimization.  ...  In this paper, we propose a new method for correcting image distortion due to camera lenses by calibrating intrinsic camera parameters.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1142/s0219467802000640">doi:10.1142/s0219467802000640</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/z4zbyjcmlnbjpg7harbv2h2w2a">fatcat:z4zbyjcmlnbjpg7harbv2h2w2a</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20190313113309/http://staff.itee.uq.edu.au/lovell/aprs/accv2002/accv2002_proceedings/Tamaki521.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/3b/50/3b50431bf12b22cd434f12ca6b3ecd8342b53faf.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1142/s0219467802000640"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> worldscientific.com </button> </a>

Keeping a Pan-Tilt-Zoom Camera Calibrated

Ziyan Wu, Richard J. Radke
<span title="">2013</span> <i title="Institute of Electrical and Electronics Engineers (IEEE)"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/3px634ph3vhrtmtuip6xznraqi" style="color: black;">IEEE Transactions on Pattern Analysis and Machine Intelligence</a> </i> &nbsp;
To solve this problem, we propose a complete model for a pan-tilt-zoom camera that explicitly reflects how focal length and lens distortion vary as a function of zoom scale.  ...  We evaluate the calibration and dynamic correction algorithms on both experimental and real-world datasets, demonstrating the effectiveness of the techniques.  ...  [20] introduced a technique for modeling intrinsic parameters as a function of lens settings based on moving least squares.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1109/tpami.2012.250">doi:10.1109/tpami.2012.250</a> <a target="_blank" rel="external noopener" href="https://www.ncbi.nlm.nih.gov/pubmed/23787349">pmid:23787349</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/oghzxmeq5behzhd23u4inawlz4">fatcat:oghzxmeq5behzhd23u4inawlz4</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20140514094438/http://www.ecse.rpi.edu:80/~rjradke/papers/wu-pami12.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/41/b1/41b1473919d2e5b056d41f9875a2ea2bd0d3a269.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1109/tpami.2012.250"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> ieee.com </button> </a>

Variable zoom system with aberration correction capability

Yang Lu, Christopher R. Stockbridge, Samuel M. Hoffman, Thomas G. Bifano
<span title="2012-07-10">2012</span> <i title="Informa UK Limited"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/nik7iflojred5n6fjdhy5abuzu" style="color: black;">Journal of Modern Optics</a> </i> &nbsp;
Zoom is achieved by simultaneously adjusting focal lengths of the two DMs, which are inserted between an infinity-corrected microscope objective and a tube lens.  ...  In this configuration, the DM shapes are controlled to provide 2.5Â zoom capability, to allow dynamic focus control and to compensate for aberrations of the fixed optical components.  ...  Acknowledgements The authors thank Boston Micromachines Corporation for providing DMs used in the experiments. Dr Thomas Bifano acknowledges a financial interest in Boston Micromachines Corporation.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1080/09500340.2012.681708">doi:10.1080/09500340.2012.681708</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/kk7kaiqpb5ealdtz64esukru4e">fatcat:kk7kaiqpb5ealdtz64esukru4e</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20120714010954/http://people.bu.edu/bifano/PDF_files/Lu_2012.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/68/16/6816c53b931da3ded28a9a3d204e34ca0bd894be.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1080/09500340.2012.681708"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> tandfonline.com </button> </a>

Accurate and Practical Calibration of Multiple Pan-Tilt-Zoom Cameras for Live Broadcasts: Supplementary Material

Masanori Kano, Hidehiko Okubo, Masaki Takahashi, Kensuke Ikeya, Kensuke Hisatomi, Tomoyuki Mishina
<span title="">2020</span> <i title="Institute of Electrical and Electronics Engineers (IEEE)"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/q7qi7j4ckfac7ehf3mjbso4hne" style="color: black;">IEEE Access</a> </i> &nbsp;
CONCLUSION We proposed an accurate and practical camera calibration method for multiple PTZ cameras for live broadcasts of events, such as a sports event.  ...  The demonstration proved that the camera calibration method has sufficient accuracy and operability for a live sports graphics system. VII.  ...  The method enables accurate CG synthesis for the calibration pattern used for estimation with a 13× zoom lens, but it also has some issues.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1109/access.2020.3017238">doi:10.1109/access.2020.3017238</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/lqvg77xecra75c6somrqi3vhym">fatcat:lqvg77xecra75c6somrqi3vhym</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20200818134234/https://ieeexplore.ieee.org/ielx7/6287639/6514899/09169866.pdf?tp=&amp;arnumber=9169866&amp;isnumber=6514899&amp;ref=" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/c5/e1/c5e172f97f60a96fb113da40fdf2b0b884bcd805.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1109/access.2020.3017238"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="unlock alternate icon" style="background-color: #fb971f;"></i> ieee.com </button> </a>

Probing Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices via Laser Flash Photolysis of Photoactivatable Nicotine

Matthew C. Arvin, David L. Wokosin, Sambashiva Banala, Luke D. Lavis, Ryan M. Drenan
<span title="2019-01-25">2019</span> <i title="MyJove Corporation"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/fun2ww7r2rhm5k7oxcmmrgntwi" style="color: black;">Journal of Visualized Experiments</a> </i> &nbsp;
Patch-clamped neurons in brain slices are filled with dye to visualize their morphology during 2-photon laser scanning microscopy, and nicotine uncaging is executed with a light flash by focusing a 405  ...  This method allows for detailed analysis of nAChR functional distribution in complex tissue preparations, promising to enhance the understanding of cholinergic neurotransmission.  ...  The software will scale, and update, all subsequent MarkPoints experiments performed at zoom settings different from the spatial calibration zoom. 7.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.3791/58873">doi:10.3791/58873</a> <a target="_blank" rel="external noopener" href="https://www.ncbi.nlm.nih.gov/pubmed/30735191">pmid:30735191</a> <a target="_blank" rel="external noopener" href="https://pubmed.ncbi.nlm.nih.gov/PMC6494620/">pmcid:PMC6494620</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/mmhx4zsfpbhtbn4jrq7jnymipq">fatcat:mmhx4zsfpbhtbn4jrq7jnymipq</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20190502002851/https://www.jove.com/pdf/58873/jove-protocol-58873-probing-nicotinic-acetylcholine-receptor-function-mouse-brain-slices" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/da/87/da87ee66f5855c9eadb4b883b7a6f3daaf66a0ed.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.3791/58873"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> Publisher / doi.org </button> </a> <a target="_blank" rel="external noopener" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6494620" title="pubmed link"> <button class="ui compact blue labeled icon button serp-button"> <i class="file alternate outline icon"></i> pubmed.gov </button> </a>

Zoom tracking and its applications

Jeffrey A. Fayman, Oded Sudarsky, Ehud Rivlin, Michael Rudzsky
<span title="">2001</span> <i title="Springer Nature"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/lvjqpr55r5fcfpfbeu7qp2jwgm" style="color: black;">Machine Vision and Applications</a> </i> &nbsp;
We present a new active vision technique called zoom tracking.  ...  Two methods for performing zoom tracking are presented: a closed-loop visual feedback algorithm based on optical flow, and use of depth information obtained from an autofocus camera's range sensor.  ...  However, it is still inadequate for modeling zoom lenses at a close range. The thick-lens model represents a lens by two planes called the principle planes.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/pl00013268">doi:10.1007/pl00013268</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/7rt65rwzy5avlk3hebvtdi7bya">fatcat:7rt65rwzy5avlk3hebvtdi7bya</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20070418153358/http://www.cs.technion.ac.il/~ehudr/publications/pdf/FaymanSRR01a.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/26/d5/26d5464feccc12c24158015bb7a00fdebf487279.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/pl00013268"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> springer.com </button> </a>

Camera Calibration Techniques for Accurate Measurement Underwater [chapter]

Mark Shortis
<span title="">2019</span> <i title="Springer Berlin Heidelberg"> Management-Reihe Corporate Social Responsibility </i> &nbsp;
In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium.  ...  Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space.  ...  Acknowledgements This is a revised version based on a paper originally published in the online access journal Sensors (Shortis 2015) .  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/978-3-030-03635-5_2">doi:10.1007/978-3-030-03635-5_2</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/rut7m2gqfbfpjmle6vgsqb5zia">fatcat:rut7m2gqfbfpjmle6vgsqb5zia</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20190505024323/https://link.springer.com/content/pdf/10.1007%2F978-3-030-03635-5_2.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/81/13/8113181835141476d3cd3075bd9541fb2c2422ff.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/978-3-030-03635-5_2"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> springer.com </button> </a>

The impact of radial distortion on the self-calibration of rotating cameras

Ben Tordoff, David W. Murray
<span title="">2004</span> <i title="Elsevier BV"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/dsarpzh6wfgadnyijwv5l6gh2i" style="color: black;">Computer Vision and Image Understanding</a> </i> &nbsp;
This paper develops a straightforward argument based on geometrical optics to show that increasing pin-cushion radial distortion will produce a gently worsening under-estimate of the lens' focal length  ...  The first method pre-calibrates the distortion as a function of focal length, but the remainder assume no such prior knowledge.  ...  The authors are grateful to Torfi Thórhallsson for valuable discussions.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1016/j.cviu.2004.06.002">doi:10.1016/j.cviu.2004.06.002</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/ew3aywihj5hfxm3pehlilybhiu">fatcat:ew3aywihj5hfxm3pehlilybhiu</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20200319131623/http://www.robots.ox.ac.uk/ActiveVision/Publications/tordoff_murray_cviu2004/tordoff_murray_cviu2004.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/05/cc/05cc125f6377f12bd3a6be5fe3d10978f4a656bc.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1016/j.cviu.2004.06.002"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> elsevier.com </button> </a>

A 3D Imaging Framework Based on High-Resolution Photometric-Stereo and Low-Resolution Depth

Zheng Lu, Yu-Wing Tai, Fanbo Deng, Moshe Ben-Ezra, Michael S. Brown
<span title="2012-11-09">2012</span> <i title="Springer Nature"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/hfdglwo5wbbmta6wop52fam7a4" style="color: black;">International Journal of Computer Vision</a> </i> &nbsp;
The second is a method to improve the initial normal estimation by using all the available focal information for images obtained using a focal stacking technique.  ...  Our approach targets imaging scenarios based on either macro-lens photography combined with focal stacking or a large-format camera that are able to image objects with more than 600 samples per mm 2 .  ...  Both systems use four controllable lights and a mirrored sphere for light direction calibration. The photometric stereo technique in Woodham (1980) is used to obtain the surface normals.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/s11263-012-0589-5">doi:10.1007/s11263-012-0589-5</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/yqt5vfciwbh6nnrkwqzf5vh6pa">fatcat:yqt5vfciwbh6nnrkwqzf5vh6pa</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20170808134551/https://www.comp.nus.edu/~brown/pdf/ijcv2012.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/86/d7/86d7d550c2051a967ac711dfffd983588edaaca0.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/s11263-012-0589-5"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> springer.com </button> </a>

Estimating scale using depth from focus for mobile augmented reality

Klen Čopič Pucihar, Paul Coulton
<span title="">2011</span> <i title="ACM Press"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/bhbwbuxkgzcdjd6gxdxhv5di64" style="color: black;">Proceedings of the 3rd ACM SIGCHI symposium on Engineering interactive computing systems - EICS &#39;11</a> </i> &nbsp;
In this paper we address the problem of scale by adapting a Depth From Focus (DFF) technique, which has previously been limited to high-end cameras to a commercial mobile phone.  ...  However, unlike marker based and apriori tracking systems these techniques are independent of scale which is a vital component in ensuring that augmented objects are contextually sensitive to the environment  ...  ACKNOWLEDGMENTS The authors would like to thank Nokia for the provision of software and hardware to the Mobile Radicals research group at Lancaster University which was used in this project.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1145/1996461.1996531">doi:10.1145/1996461.1996531</a> <a target="_blank" rel="external noopener" href="https://dblp.org/rec/conf/eics/PuciharC11.html">dblp:conf/eics/PuciharC11</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/im2fllp2nvfczjd3fnprutcaoe">fatcat:im2fllp2nvfczjd3fnprutcaoe</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20170706024902/http://eprints.lancs.ac.uk/39956/1/Estimating_Scale_using_Depth_From_Focus_for_Mobile_Augmented_Reality_DRAFT.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/97/84/97848229335786ca39dd560efabdf68e68369931.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1145/1996461.1996531"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> acm.org </button> </a>

Algebraic Lens Distortion Model Estimation

Luis Alvarez, Luis Gomez, J. Rafael Sendra
<span title="2010-07-28">2010</span> <i title="Image Processing On Line"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/x34froqw25f5hhzwg7htadw3xe" style="color: black;">Image Processing On Line</a> </i> &nbsp;
Unfortunately, wide-angle lenses (specially low-cost lenses) may introduce a strong barrel distortion, which makes the usual pinhole model fail. Lens distortion models try to correct such distortion.  ...  A very important property of the usual pinhole model for camera projection is that 3D lines in the scene are projected to 2D lines.  ...  Update k using a zoom factor in order for distorted and undistorted points to be as close as possible.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.5201/ipol.2010.ags-alde">doi:10.5201/ipol.2010.ags-alde</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/dvkerry6rzfo5foxtyln3kryv4">fatcat:dvkerry6rzfo5foxtyln3kryv4</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20160615185104/http://www.ipol.im:80/pub/art/2011/ags-alde/article.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/44/b4/44b4e400a06f2a354b2a7756f035b68ecae0ac8c.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.5201/ipol.2010.ags-alde"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="unlock alternate icon" style="background-color: #fb971f;"></i> Publisher / doi.org </button> </a>

Recovering the Subpixel PSF from Two Photographs at Different Distances

Mauricio Delbracio, Andrés Almansa, Pablo Musé
<span title="2013-10-23">2013</span> <i title="Image Processing On Line"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/x34froqw25f5hhzwg7htadw3xe" style="color: black;">Image Processing On Line</a> </i> &nbsp;
In this work we describe a new algorithm for the estimation of the point spread function (psf) of a digital camera from aliased photographs, that achieves subpixel accuracy.  ...  For this purpose the demo code uses the orsa-homography routines [4] , which are based on sift keypoints.  ...  Else update n := n + 1 and repeat from 2. 5. Calculate h = H λ n u n . (a) We create a sampling grid with step (λ n x , λ n y ) of size p × q.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.5201/ipol.2013.77">doi:10.5201/ipol.2013.77</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/vvhvberwo5bflhrobxufq5q4be">fatcat:vvhvberwo5bflhrobxufq5q4be</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20160423195214/http://www.ipol.im/pub/art/2013/77/article.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/1b/a0/1ba06d57b047715d3f9f478d41071cce9b0287da.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.5201/ipol.2013.77"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="unlock alternate icon" style="background-color: #fb971f;"></i> Publisher / doi.org </button> </a>
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