{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T21:37:18Z","timestamp":1770068238047,"version":"3.49.0"},"publisher-location":"New York, NY, USA","reference-count":27,"publisher":"ACM","license":[{"start":{"date-parts":[[2009,4,20]],"date-time":"2009-04-20T00:00:00Z","timestamp":1240185600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2009,4,20]]},"DOI":"10.1145\/1526709.1526822","type":"proceedings-article","created":{"date-parts":[[2009,4,21]],"date-time":"2009-04-21T14:17:17Z","timestamp":1240323437000},"page":"841-850","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":94,"title":["What's up CAPTCHA?"],"prefix":"10.1145","author":[{"given":"Rich","family":"Gossweiler","sequence":"first","affiliation":[{"name":"Google, Inc, Mountain View, CA, USA"}]},{"given":"Maryam","family":"Kamvar","sequence":"additional","affiliation":[{"name":"Google, Inc, Mountain View, CA, USA"}]},{"given":"Shumeet","family":"Baluja","sequence":"additional","affiliation":[{"name":"Google, Inc, Mountain View, CA, USA"}]}],"member":"320","published-online":{"date-parts":[[2009,4,20]]},"reference":[{"key":"e_1_3_2_1_1_1","doi-asserted-by":"publisher","DOI":"10.1109\/ITNG.2008.12"},{"key":"e_1_3_2_1_2_1","volume-title":"Eurocrypt","author":"von Ahn L.","year":"2003","unstructured":"von Ahn , L. , Blum , M. , Hopper , N. and Langford , J . CAPTCHA: Using Hard AI Problems for Security. Advances in Cryptology , Eurocrypt 2003 . Pages 294--311. von Ahn, L., Blum, M., Hopper, N. and Langford, J. CAPTCHA: Using Hard AI Problems for Security. Advances in Cryptology, Eurocrypt 2003. Pages 294--311."},{"key":"e_1_3_2_1_3_1","volume-title":"The 2008 International Conference of Signal and Image Engineering","author":"Huang S.Y.","year":"2008","unstructured":"Huang , S.Y. , Lee , Y.K. , Bell , G. Ou , Z.h. ( 2008 ) \" A Projection-based Segmentation Algorithm for Breaking MSN and YAHOO CAPTCHAs \", The 2008 International Conference of Signal and Image Engineering Huang, S.Y., Lee, Y.K., Bell, G. Ou, Z.h. (2008) \"A Projection-based Segmentation Algorithm for Breaking MSN and YAHOO CAPTCHAs\", The 2008 International Conference of Signal and Image Engineering"},{"key":"e_1_3_2_1_4_1","first-page":"265","volume-title":"Advances in Neural Information Processing Systems 17","author":"Chellapilla K.","unstructured":"Chellapilla K. , Simard , P. \" Using Machine Learning to Break Visual Human Interaction Proofs (HIPs),\" in L. K. Saul , Y. Weiss , and L. Bottou , editors , Advances in Neural Information Processing Systems 17 , pp. 265 -- 272 . MIT Press Chellapilla K., Simard, P. \"Using Machine Learning to Break Visual Human Interaction Proofs (HIPs),\" in L. K. Saul, Y. Weiss, and L. Bottou, editors, Advances in Neural Information Processing Systems 17, pp. 265--272. MIT Press"},{"key":"e_1_3_2_1_5_1","volume-title":"Computer Vision and Pattern Recognition (CVPR-2003).","author":"Mori G.","year":"2003","unstructured":"Mori , G. , Malik , J. ( 2003 ) \" Recognizing Objects in Adversarial Clutter: Breaking a Visual CAPTCHA \", in Computer Vision and Pattern Recognition (CVPR-2003). Mori, G., Malik, J. (2003) \"Recognizing Objects in Adversarial Clutter: Breaking a Visual CAPTCHA\", in Computer Vision and Pattern Recognition (CVPR-2003)."},{"key":"e_1_3_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1145\/1315245.1315291"},{"key":"e_1_3_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1145\/1455770.1455838"},{"key":"e_1_3_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1145\/1054972.1055070"},{"key":"e_1_3_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/1408664.1408671"},{"key":"e_1_3_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-540-30144-8_23"},{"key":"e_1_3_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/985692.985733"},{"key":"e_1_3_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1109\/TIP.2002.801590"},{"key":"e_1_3_2_1_13_1","first-page":"17","volume-title":"Content-Based Image Orientation Detection with Support Vector Machines\" in IEEE Workshop on Content-Based Access of Image and Video Libraries","author":"Wang Y.","year":"2001","unstructured":"Wang , Y. & Zhang , H. ( 2001 ), \" Content-Based Image Orientation Detection with Support Vector Machines\" in IEEE Workshop on Content-Based Access of Image and Video Libraries . pp 17 -- 23 . Wang, Y. & Zhang, H. (2001), \"Content-Based Image Orientation Detection with Support Vector Machines\" in IEEE Workshop on Content-Based Access of Image and Video Libraries. pp 17--23."},{"key":"e_1_3_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.cviu.2003.10.006"},{"key":"e_1_3_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.5555\/832302.836857"},{"key":"e_1_3_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.1109\/TPAMI.2005.96"},{"key":"e_1_3_2_1_17_1","doi-asserted-by":"publisher","DOI":"10.1145\/1101149.1101259"},{"key":"e_1_3_2_1_18_1","volume-title":"ICIP-2003.","author":"Wang L.","year":"2003","unstructured":"Wang , L. , Liu , X. , Xia , L , Xu , G. , Bruckstein , A. , ( 2003 ) \" Image Orientation Detection with Integrated Human Perception Cues (or which way is up) \", ICIP-2003. Wang, L., Liu, X., Xia, L, Xu, G., Bruckstein, A., (2003) \"Image Orientation Detection with Integrated Human Perception Cues (or which way is up)\", ICIP-2003."},{"key":"e_1_3_2_1_19_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10044-006-0059-1"},{"key":"e_1_3_2_1_20_1","doi-asserted-by":"publisher","DOI":"10.1023\/B:VISI.0000029664.99615.94"},{"key":"e_1_3_2_1_21_1","unstructured":"Tuytelaars Tinne Mikolajczyk K. A Survey on Local Invariant Features preprint Foundations and Trends in Computer Graphics and Vision 1:1 1--106.  Tuytelaars Tinne Mikolajczyk K. A Survey on Local Invariant Features preprint Foundations and Trends in Computer Graphics and Vision 1:1 1--106."},{"key":"e_1_3_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1109\/34.982883"},{"key":"e_1_3_2_1_23_1","volume-title":"2004 ECCV Workshop on Statistical Learning and Computer Vision.","author":"Bileschi S.","unstructured":"Bileschi , S. , Leung , B. Rifkin , R. , Towards Component -based Car Detection , 2004 ECCV Workshop on Statistical Learning and Computer Vision. Bileschi, S., Leung, B. Rifkin, R., Towards Component-based Car Detection, 2004 ECCV Workshop on Statistical Learning and Computer Vision."},{"key":"e_1_3_2_1_24_1","volume-title":"International Conference on Computer Vision Theory and Applications.","author":"Rowley H.","year":"2006","unstructured":"Rowley , H. , Jing , Y. , Baluja , S. ( 2006 ), Large-Scale Image-Based Adult-Content Filtering , International Conference on Computer Vision Theory and Applications. Rowley, H., Jing, Y., Baluja, S. (2006), Large-Scale Image-Based Adult-Content Filtering, International Conference on Computer Vision Theory and Applications."},{"key":"e_1_3_2_1_25_1","volume-title":"Proceedings of the Thirteenth International Conference --","author":"Freund Y., R.","year":"1996","unstructured":"Freund , Y., R. Schapire , \"Experiments with a New Boosting Algorithm\" ( 1996 ), in Machine Learning , Proceedings of the Thirteenth International Conference -- 1996. Freund, Y., R. Schapire, \"Experiments with a New Boosting Algorithm\" (1996), in Machine Learning, Proceedings of the Thirteenth International Conference -- 1996."},{"key":"e_1_3_2_1_26_1","doi-asserted-by":"publisher","DOI":"10.1117\/1.1502259"},{"key":"e_1_3_2_1_27_1","unstructured":"Luo J. Crandall D. Singhal A. Boutell M. Gray R. \"Psychophysical Study of Image Orientation Perception\" Spatial Vision V16:5 Luo J. Crandall D. Singhal A. Boutell M. Gray R. \"Psychophysical Study of Image Orientation Perception\" Spatial Vision V16:5"}],"event":{"name":"WWW '09: The 18th International World Wide Web Conference","location":"Madrid Spain","acronym":"WWW '09","sponsor":["SIGWEB ACM Special Interest Group on Hypertext, Hypermedia, and Web","ACM Association for Computing Machinery"]},"container-title":["Proceedings of the 18th international conference on World wide web"],"original-title":[],"link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/1526709.1526822","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/1526709.1526822","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T13:29:47Z","timestamp":1750253387000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/1526709.1526822"}},"subtitle":["a CAPTCHA based on image orientation"],"short-title":[],"issued":{"date-parts":[[2009,4,20]]},"references-count":27,"alternative-id":["10.1145\/1526709.1526822","10.1145\/1526709"],"URL":"https:\/\/doi.org\/10.1145\/1526709.1526822","relation":{},"subject":[],"published":{"date-parts":[[2009,4,20]]},"assertion":[{"value":"2009-04-20","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}