{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T15:32:27Z","timestamp":1777735947979,"version":"3.51.4"},"reference-count":49,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2019,2,22]],"date-time":"2019-02-22T00:00:00Z","timestamp":1550793600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology","doi-asserted-by":"publisher","award":["Grant-in-Aid for Scientfic Research (C) No. 15K00265"],"award-info":[{"award-number":["Grant-in-Aid for Scientfic Research (C) No. 15K00265"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Augmented Reality (AR) is a class of \u201cmediated reality\u201d that artificially modifies the human perception by superimposing virtual objects on the real world, which is expected to supplement reality. In visual-based augmentation, text and graphics, i.e., label, are often associated with a physical object or a place to describe it. View management in AR is to maintain the visibility of the associated information and plays an important role on communicating the information. Various view management techniques have been investigated so far; however, most of them have been designed for two dimensional see-through displays, and few have been investigated for projector-based AR called spatial AR. In this article, we propose a view management method for spatial AR, VisLP, that places labels and linkage lines based on the estimation of the visibility. Since the information is directly projected on objects, the nature of optics such as reflection and refraction constrains the visibility in addition to the spatial relationship between the information, the objects, and the user. VisLP employs machine-learning techniques to estimate the visibility that reflects human\u2019s subjective mental workload in reading information and objective measures of reading correctness in various projection conditions. Four classes are defined for a label, while the visibility of a linkage line has three classes. After 88 and 28 classification features for label and linkage line visibility estimators are designed, respectively, subsets of features with 15 and 14 features are chosen to improve the processing speed of feature calculation up to 170%, with slight degradation of classification performance. An online experiment with new users and objects showed that 76.0% of the system\u2019s judgments were matched with the users\u2019 evaluations, while 73% of the linkage line visibility estimations were matched.<\/jats:p>","DOI":"10.3390\/s19040939","type":"journal-article","created":{"date-parts":[[2019,2,22]],"date-time":"2019-02-22T11:26:14Z","timestamp":1550834774000},"page":"939","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Estimating Visibility of Annotations for View Management in Spatial Augmented Reality Based on Machine-Learning Techniques"],"prefix":"10.3390","volume":"19","author":[{"given":"Keita","family":"Ichihashi","sequence":"first","affiliation":[{"name":"Department of Computer and Information Sciences, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5294-2812","authenticated-orcid":false,"given":"Kaori","family":"Fujinami","sequence":"additional","affiliation":[{"name":"Department of Computer and Information Sciences, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,2,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1162\/pres.1997.6.4.355","article-title":"A Survey of Augmented Reality","volume":"6","author":"Azuma","year":"1997","journal-title":"Presence Teleoper. Virtual Environ."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Bimber, O., and Raskar, R. (2005). Spatial Augmented Reality: Merging Real and Virtual Worlds, A K Peters, Ltd.","DOI":"10.1201\/b10624"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Suzuki, Y., Morioka, S., and Ueda, H. (2012, January 28\u201331). Cooking Support with Information Projection Onto Ingredient. Proceedings of the 10th Asia Pacific Conference on Computer Human Interaction, Shimane, Japan.","DOI":"10.1145\/2350046.2350084"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"153047","DOI":"10.4108\/eai.28-8-2017.153047","article-title":"A Projector-Camera System for Ironing Support with Wrinkle Enhancement","volume":"4","author":"Suzuki","year":"2017","journal-title":"ICST Trans. Ambient Syst."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Funk, M., Shirazi, A.S., Mayer, S., Lischke, L., and Schmidt, A. (2015). Pick from here!\u2014An Interactive Mobile Cart using In-Situ Projection for Order Picking. Proceedings of the 2015 ACM International Joint Conference on Pervasive and Ubiquitous Computing\u2014UbiComp \u201915, Osaka, Japan, 7\u201311 September 2015, ACM Press.","DOI":"10.1145\/2750858.2804268"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1279","DOI":"10.1007\/s00170-016-9164-5","article-title":"Use of projector based augmented reality to improve manual spot-welding precision and accuracy for automotive manufacturing","volume":"89","author":"Doshi","year":"2017","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"509","DOI":"10.1007\/s00170-017-0846-4","article-title":"Evaluating the effectiveness of spatial augmented reality in smart manufacturing: A solution for manual working stations","volume":"94","author":"Uva","year":"2018","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.compedu.2017.04.003","article-title":"Augmented reality and pedestrian navigation through its implementation in m-learning and e-learning: Evaluation of an educational program in Chile","volume":"111","year":"2017","journal-title":"Comput. Educ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1007\/s12652-011-0079-6","article-title":"A Tangible Experiment Support System with Presentation Ambiguity for Safe and Independent Chemistry Experiments","volume":"3","author":"Sokan","year":"2012","journal-title":"J. Ambient Intell. Humaniz. Comput."},{"key":"ref_10","first-page":"355","article-title":"Using an Augmented Reality Enhanced Tabletop System to Promote Learning of Mathematics: A Case Study with Students with Special Educational Needs","volume":"13","year":"2017","journal-title":"EURASIA J. Math. Sci. Technol. Educ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1415","DOI":"10.1109\/TVCG.2012.321","article-title":"View Management of Projected Labels on Nonplanar and Textured Surfaces","volume":"19","author":"Iwai","year":"2013","journal-title":"IEEE Trans. Vis. Comput. Graph."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Murata, S., Suzuki, M., and Fujinami, K. (2013). A Wearable Projector-based Gait Assistance System and Its Application for Elderly People. Proceedings of the 2013 ACM International Joint Conference on Pervasive and Ubiquitous Computing, Zurich, Switzerland, 8\u201312 September 2013, ACM.","DOI":"10.1145\/2493432.2493472"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Amano, T., and Kato, H. (2010, January 13\u201318). Appearance control by projector camera feedback for visually impaired. Proceedings of the 2010 IEEE Computer Society Conference on Computer Vision and Pattern Recognition-Workshops, San Francisco, CA, USA.","DOI":"10.1109\/CVPRW.2010.5543478"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"152550","DOI":"10.4108\/eai.17-5-2017.152550","article-title":"A Projector-Camera System for Augmented Card Playing and a Case Study with the Pelmanism Game","volume":"4","author":"Tanaka","year":"2017","journal-title":"ICST Trans. Ambient Syst."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Azuma, R., and Furmanski, C. (2003). Evaluating Label Placement for Augmented Reality View Management. Proceedings of the 2nd IEEE\/ACM International Symposium on Mixed and Augmented Reality, IEEE Computer Society.","DOI":"10.1109\/ISMAR.2003.1240689"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Bell, B., Feiner, S., and H\u00f6llerer, T. (2001). View Management for Virtual and Augmented Reality. Proceedings of the 14th Annual ACM Symposium on User Interface Software and Technology, Orlando, FL, USA, 11\u201314 November 2001, ACM.","DOI":"10.1145\/502348.502363"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1364\/OE.6.000081","article-title":"Discriminability measures for predicting readability of text on textured backgrounds","volume":"6","author":"Scharff","year":"2000","journal-title":"Opt. Express"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1162\/pres.2006.15.1.16","article-title":"The Effects of Text Drawing Styles, Background Textures, and Natural Lighting on Text Legibility in Outdoor Augmented Reality","volume":"15","author":"Gabbard","year":"2006","journal-title":"Presence Teleoper. Virtual Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1145\/2636242.2636246","article-title":"Managing mobile text in head mounted displays: Studies on visual preference and text placement","volume":"18","author":"Orlosky","year":"2014","journal-title":"ACM SIGMOBILE Mob. Comput. Commun. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Makita, K., Kanbara, M., and Yokoya, N. (July, January 28). View management of annotations for wearable augmented reality. Proceedings of the 2009 IEEE International Conference on Multimedia and Expo, New York, NY, USA.","DOI":"10.1109\/ICME.2009.5202661"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"891","DOI":"10.1016\/j.jvlc.2014.10.030","article-title":"Nonoverlapped view management for augmented reality by tabletop projection","volume":"25","author":"Sato","year":"2014","journal-title":"J. Vis. Lang. Comput."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Kohei Tanaka, K., Kishino, Y., Miyamae, M., Terada, T., and Nishio, S. (2008, January 15\u201318). An information layout method for an optical see-through head mounted display focusing on the viewability. Proceedings of the 2008 7th IEEE\/ACM International Symposium on Mixed and Augmented Reality, Cambridge, UK.","DOI":"10.1109\/ISMAR.2008.4637340"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1559\/152304075784313304","article-title":"Positioning Names on Maps","volume":"2","author":"Imhof","year":"1975","journal-title":"Am. Cartogr."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.compind.2015.02.008","article-title":"Text legibility for projected Augmented Reality on industrial workbenches","volume":"70","author":"Fiorentino","year":"2015","journal-title":"Comput. Ind."},{"key":"ref_25","unstructured":"Mann, S. (2019, January 31). Mediated Reality with Implementations for Everyday Life. Available online: http:\/\/wearcam.org\/presence_connect\/."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1186\/s41074-017-0028-1","article-title":"A survey of diminished reality: Techniques for visually concealing, eliminating, and seeing through real objects","volume":"9","author":"Mori","year":"2017","journal-title":"IPSJ Trans. Comput. Vis. Appl."},{"key":"ref_27","unstructured":"Shibata, F., Nakamoto, H., Sasaki, R., Kimura, A., and Tamura, H. (2008). A View Management Method for Mobile Mixed Reality Systems. Proceedings of the 14th Eurographics Conference on Virtual Environments, Eindhoven, The Netherlands, 29\u201330 May 2008, Eurographics Association."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Leykin, A., and Tuceryan, M. (2004, January 2\u20134). Automatic determination of text readability over textured backgrounds for augmented reality systems. Proceedings of the 3rd IEEE\/ACM International Symposium on Mixed and Augmented Reality Systems, Arlington, VA, USA.","DOI":"10.1145\/1044588.1044683"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Achanta, R., Hemami, S., Estrada, F., and Susstrunk, S. (2009, January 22\u201325). Frequency-tuned salient region detection. Proceedings of the 2009 IEEE Conference on Computer Vision and Pattern Recognition, Miami, FL, USA.","DOI":"10.1109\/CVPRW.2009.5206596"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Chang, M.M.L., Ong, S.K., and Nee, A.Y.C. (2016). Automatic Information Positioning Scheme in AR-assisted Maintenance Based on Visual Saliency, Springer.","DOI":"10.1007\/978-3-319-40621-3_33"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Ens, B.M., Finnegan, R., and Irani, P.P. (2014). The personal cockpit: A spatial interface for effective task switching on head-worn. Proceedings of the 32nd Annual ACM conference on Human factors in Computing Systems\u2013CHI\u201914, Toronto, ON, Canada, 26 April\u20131 May 2014, ACM Press.","DOI":"10.1145\/2556288.2557058"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Li, G., Liu, Y., Wang, Y., and Xu, Z. (2017). Evaluation of labelling layout method for image-driven view management in augmented reality. Proceedings of the 29th Australian Conference on Computer-Human Interaction\u2014OZCHI \u201917, Brisbane, Australia, 28 November\u20131 December 2017, ACM Press.","DOI":"10.1145\/3152771.3152800"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Grasset, R., Langlotz, T., Kalkofen, D., Tatzgern, M., and Schmalstieg, D. (2012). Image-driven View Management for Augmented Reality Browsers. Proceedings of the 2012 IEEE International Symposium on Mixed and Augmented Reality (ISMAR), Atlanta, GA, USA, 5\u20138 November 2012, IEEE Computer Society.","DOI":"10.1109\/ISMAR.2012.6402555"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Siriborvornratanakul, T., and Sugimoto, M. (2008). Clutter-aware Adaptive Projection Inside a Dynamic Environment. Proceedings of the 2008 ACM Symposium on Virtual Reality Software and Technology, Bordeaux, France, 27\u201329 October 2008, ACM.","DOI":"10.1145\/1450579.1450633"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Riemann, J., Khalilbeigi, M., Schmitz, M., Doeweling, S., M\u00fcller, F., and M\u00fchlh\u00e4user, M. (2016). FreeTop: Finding Free Spots for Projective Augmentation. Proceedings of the 2016 CHI Conference Extended Abstracts on Human Factors in Computing Systems\u2014CHI EA \u201916, San Jose, CA, USA, 7\u201312 May 2016, ACM Press.","DOI":"10.1145\/2851581.2892321"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Cotting, D., and Gross, M. (2006). Interactive environment-aware display bubbles. Proceedings of the 19th Annual ACM Symposium on User Interface Software and Technology\u2014UIST \u201906, Montreux, Switzerland, 15\u201318 October 2006, ACM Press.","DOI":"10.1145\/1166253.1166291"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1109\/TPAMI.1986.4767851","article-title":"A Computational Approach to Edge Detection","volume":"PAMI-8","author":"Canny","year":"1986","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_38","first-page":"82","article-title":"Me and My (Fake) Shadow","volume":"8","author":"Blinn","year":"1988","journal-title":"IEEE Comput. Graph. Appl."},{"key":"ref_39","unstructured":"W3C\/WAI (2018, December 31). Techniques for Accessibility Evaluation and Repair Tools. Available online: https:\/\/www.w3.org\/WAI\/ER\/WD-AERT\/."},{"key":"ref_40","first-page":"338","article-title":"Perception of Shitsukan: Visual Perception of Surface Qualities and Materials","volume":"66","author":"Motoyoshi","year":"2012","journal-title":"J. Inst. Image Inf. Telev. Eng."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1109\/34.368149","article-title":"Texture segmentation using fractal dimension","volume":"17","author":"Chaudhuri","year":"1995","journal-title":"IEEE Trans. Pattern Anal. Mach. Intell."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1049\/ip-vis:20010709","article-title":"Locating the eye in human face images using fractal dimensions","volume":"148","author":"Lin","year":"2001","journal-title":"IEE Proc. Vis. Image Signal Process."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"968","DOI":"10.1109\/76.736726","article-title":"Image segmentation and contour detection using fractal coding","volume":"8","author":"Ida","year":"1998","journal-title":"IEEE Trans. Circuits Syst. Video Technol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1957","DOI":"10.1016\/S0031-3203(96)00193-8","article-title":"Shape recognition using fractal geometry","volume":"30","author":"Neil","year":"1997","journal-title":"Pattern Recognit."},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Peitgen, H.O., J\u00fcrgens, H., and Saupe, D. (2004). Chaos and Fractals, Springer. [2nd ed.].","DOI":"10.1007\/b97624"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"610","DOI":"10.1109\/TSMC.1973.4309314","article-title":"Textural Features for Image Classification","volume":"3","author":"Haralick","year":"1973","journal-title":"IEEE Trans. Syst. Man Cybern."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1016\/S0146-664X(75)80008-6","article-title":"Texture analysis using gray level run lengths","volume":"4","author":"Galloway","year":"1975","journal-title":"Comput. Graphics Image Process."},{"key":"ref_48","unstructured":"Machine Learning Group at University of Waikato (2018, December 31). Weka 3\u2014Data Mining with Open Source Machine Learning Software in Java. Available online: http:\/\/www.cs.waikato.ac.nz\/ml\/weka\/."},{"key":"ref_49","unstructured":"Witten, I.H., Frank, E., and Hall, M.A. (2011). Data Mining: Practical Machine Learning Tools and Techniques, Morgan Kaufmann Publishers. [3rd ed.]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/4\/939\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:34:16Z","timestamp":1760186056000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/4\/939"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,2,22]]},"references-count":49,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2019,2]]}},"alternative-id":["s19040939"],"URL":"https:\/\/doi.org\/10.3390\/s19040939","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,2,22]]}}}