Keyframe Tagging: Unambiguous Content Delivery for Augmented Reality Environments

Context: When considering the use of Augmented Reality to provide navigation cues in a completely unknown environment, the content must be delivered into the environment with a repeatable level of accuracy such that the navigation cues can be understood and interpreted correctly by the user. Aims: This thesis aims to investigate whether a still image based reconstruction of an Augmented Reality environment can be used to develop a content delivery system that providers a repeatable level of accuracy for content placement. It will also investigate whether manipulation of the properties of a Spatial Marker object is sufficient to reduce object selection ambiguity in an Augmented Reality environment. Methods: A series of experiments were conducted to test the separate aspects of these aims. Participants were required to use the developed Keyframe Tagging tool to introduce virtual navigation markers into an Augmented Reality environment, and also to identify objects within an Augmented Reality environment that was signposted using different Virtual Spatial Markers. This tested the accuracy and repeatability of content placement of the approach, while also testing participants’ ability to reliably interpret virtual signposts within an Augmented Reality environment. Finally the Keyframe Tagging tool was tested by an expert user against a pre-existing solution to evaluate the time savings offered by this approach against the overall accuracy of content placement. Results: The average accuracy score for content placement across 20 participants was 64%, categorised as “Good” when compared with an expert benchmark result, while no tags were considered “incorrect” and only 8 from 200 tags were considered to have “Poor” accuracy, supporting the Keyframe Tagging approach. In terms of object identification from virtual cues, some of the predicted cognitive links between virtual marker property and target object did not surface, though participants reliably identified the correct objects across several trials. Conclusions: This thesis has demonstrated that accurate content delivery can be achieved through the use of a still image based reconstruction of an Augmented Reality environment. By using the Keyframe Tagging approach, content can be placed quickly and with a sufficient level of accuracy to demonstrate its utility in the scenarios outlined within this thesis. There are some observable limitations to the approach, which are discussed with the proposals for further work in this area

Analysis and Development of Augmented Reality Applications for the Dissemination of Cultural Heritage

Tesis por compendio[ES] La RA consiste en la superposición de elementos virtuales sobre el entorno real, de manera que el usuario percibe estos elementos como si formaran parte de la realidad que está visualizando. Las aplicaciones de RA en dispositivos móviles permiten visualizar el contenido virtual a través de la cámara del dispositivo. La RA es una herramienta de divulgación muy potente ya que permite añadir a la realidad cualquier tipo de información, desde un simple texto informativo a un modelo 3D interactivo. Tiene infinitas utilidades, puede servir de guía en un museo, puede mostrar la recreación de un monumento destruido, o como en el caso de estudio aquí presentado, ayudar a la interpretación de pinturas rupestres. Esta tesis parte de la idea de que la RA puede mejorar mucho la interpretación del arte rupestre sin alterar ni dañar las pinturas. Puede servir para atraer a un público mayor, dar a conocer la historia de las pinturas rupestres y que al mismo tiempo el visitante tenga una experiencia mucho más enriquecedora. A lo largo de la tesis se ha estudiado en profundidad la técnica de visualización de RA mediante dispositivos móviles. Se han analizado las diferentes librerías de programación mediante casos de estudio en entornos reales y examinado los factores que pueden afectar al reconocimiento de las pinturas. Se ha desarrollado una aplicación de RA aplicada a un caso real de pinturas rupestres y posteriormente ha sido evaluada por un grupo de personas. Finalmente, se ha estudiado el efecto de la luz solar y sus cambios a lo largo del día sobre el reconocimiento de imágenes en entornos al aire libre. Este trabajo proporciona un punto de partida para el desarrollo de aplicaciones de RA aplicadas a la difusión del patrimonio cultural, especialmente centrado en el arte rupestre, un entorno que sufre de unas dificultades añadidas debido a su localización, dificultad de reconocimiento de puntos característicos en las pinturas y los cambios en la luz solar, problemas que se han tratado de resolver a lo largo del estudio. Las principales conclusiones han sido muy favorables, partiendo de librerías de programación disponibles y gratuitas. Se han podido desarrollar un conjunto de aplicaciones de RA en diferentes lugares. Las valoraciones han sido muy positivas, los usuarios que han probado las aplicaciones afirman que la interpretación de las pinturas les resulta más fácil y consiguen entender mejor el propósito de las mismas. El principal inconveniente encontrado es la falta de conocimiento sobre esta técnica y la pérdida de realismo en algunos casos debido a la oclusión, es decir, que los objetos virtuales no se posicionen por detrás de los objetos reales. La buena noticia es que esta tecnología evoluciona muy rápido y durante el desarrollo de la tesis ha habido avances muy grandes, entre ellos, el desarrollo de nuevas librerías de programación desarrolladas por Google y Apple, que proporcionan las herramientas necesarias para crear aplicaciones muy potentes e immersivas, donde el usuario se sentirá parte de los entornos creados.[CA] La RA consisteix en la superposició d'elements virtuals sobre l'entorn real, de manera que l'usuari percep aquests elements com si formaren part de la realitat que està visualitzant. Les aplicacions de RA en dispositius mòbils permeten visualitzar el contingut virtual a través de la cambra del dispositiu. La RA és una eina de divulgació molt potent ja que permet afegir a la realitat qualsevol tipus d'informació, des d'un simple text informatiu a un model 3D interactiu. Té infinites utilitats, pot servir de guia en un museu, pot mostrar la recreació d'un monument destruït, o com en el cas d'estudi ací presentat, ajudar a la interpretació de pintures rupestres. Aquesta tesi parteix de la idea que la RA pot millorar molt la interpretació de l'art rupestre sense alterar ni danyar les pintures. Pot servir per a atraure a un públic major, donar a conéixer la història de les pintures rupestres i que al mateix temps el visitant tinga una experiència molt més enriquidora. Al llarg de la tesi s'ha estudiat en profunditat la tècnica de visualització de RA mitjançant dispositius mòbils. S'han analitzat les diferents llibreries de programació mitjançant casos d'estudi en entorns reals i analitzat els factors que poden afectar el reconeixement de les pintures. S'ha desenvolupat una aplicació de RA aplicada a un cas real de pintures rupestres i posteriorment ha sigut avaluada per un grup de persones. Finalment, s'ha estudiat l'efecte de la llum solar i els seus canvis al llarg del dia sobre el reconeixement d'imatges en entorns a l'aire lliure. Aquest treball proporciona un punt de partida per al desenvolupament d'aplicacions de RA aplicades a la difusió del patrimoni cultural, especialment centrat en l'art rupestre, un entorn que pateix d'unes dificultats afegides a causa de la seua localització, dificultat de reconeixement de punts característics en les pintures i els canvis en la llum solar, problemes que s'han tractat de resoldre al llarg de l'estudi. Les principals conclusions han sigut molt favorables, partint de llibreries de programació disponibles i gratuïtes. S'han pogut desenvolupar un conjunt d'aplicacions de RA en diferents llocs. Les valoracions han sigut molt positives, els usuaris que han provat les aplicacions afirmen que la interpretació de les pintures els resulta més fàcil i aconsegueixen entendre millor el propòsit d'aquestes. El principal inconvenient trobat és la falta de coneixement sobre aquesta tècnica i la perduda de realisme en alguns casos a causa de l'oclusió, és a dir, que els objectes virtuals no es posicionen per darrere dels objectes reals. La bona notícia és que aquesta tecnologia evoluciona molt ràpid i durant el desenvolupament de la tesi hi ha hagut avanços molt grans, entre ells, el desenvolupament de noves llibreries de programació per Google i Apple, que proporcionen les eines necessàries per a crear aplicacions molt potents i immersives, on l'usuari se sentirà part dels entorns creats.[EN] AR consists of superimposing virtual elements on the real environment, so that the user perceives these elements as if they were part of the reality they are looking at. AR applications on smartphones allow virtual content to be visualised through the device's camera. AR is a very powerful tool for dissemination as it allows any type of information to be added to reality, from a simple informative text to an interactive 3D model. It can be used as a guide in a museum, it can show the recreation of a destroyed monument, or, as in the case study presented here, it can help in the interpretation of cave paintings. This thesis is based on the idea that AR can greatly enhance the interpretation of rock art without affecting or damaging the paintings. It can be used to attract a wider audience, to introduce the history of the rock art paintings and at the same time provide the visitor with a much more enriching experience. Throughout the thesis, the technique of AR visualisation using mobile devices has been studied in-depth. The different programming libraries have been analysed by means of case studies in real environments as well as the factors that can affect the paintings recognition. An AR application applied to a real case of rock art paintings has been developed and subsequently evaluated by a group of people. Finally, the effect of sunlight and its changes throughout the day on image recognition in outdoor environments has been studied. This work provides a starting point for the AR applications development applied to the dissemination of cultural heritage, especially focused on rock art, an environment that suffers from additional difficulties due to its location, the difficulty of characteristic points recognition and changes in sunlight, problems that have been tried to solve throughout the study. The main outcomes have been very favourable, using freely available programming libraries, and it has been possible to develop a set of AR applications in different places. The evaluations have been very positive, with users who have tested the applications confirming that the interpretation of the paintings is easier for them and they can better understand the purpose of the paintings. The major drawback is the lack of knowledge about this technique and the loss of realism in some cases due to occlusion, i.e. the virtual objects are not positioned behind the real objects. The good news is that this technology is evolving very fast and during the development of the thesis there have been great advances, among them, the development of new programming libraries developed by Google and Apple, which provide the necessary tools to create very powerful and immersive applications, where the user will feel part of the virtual environments created.Blanco Pons, S. (2021). Analysis and Development of Augmented Reality Applications for the Dissemination of Cultural Heritage [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/178895TESISCompendi

Progress in industrial photogrammetry by means of markerless solutions

174 p.La siguiente tesis está enfocada al desarrollo y uso avanzado de metodologías fotogramétrica sin dianas en aplicaciones industriales. La fotogrametría es una técnica de medición óptica 3D que engloba múltiples configuraciones y aproximaciones. En este estudio se han desarrollado procedimientos de medición, modelos y estrategias de procesamiento de imagen que van más allá que la fotogrametría convencional y buscan el emplear soluciones de otros campos de la visión artificial en aplicaciones industriales. Mientras que la fotogrametría industrial requiere emplear dianas artificiales para definir los puntos o elementos de interés, esta tesis contempla la reducción e incluso la eliminación de las dianas tanto pasivas como activas como alternativas prácticas. La mayoría de los sistemas de medida utilizan las dianas tanto para definir los puntos de control, relacionar las distintas perspectivas, obtener precisión, así como para automatizar las medidas. Aunque en muchas situaciones el empleo de dianas no sea restrictivo existen aplicaciones industriales donde su empleo condiciona y restringe considerablemente los procedimientos de medida empleados en la inspección. Un claro ejemplo es la verificación y control de calidad de piezas seriadas, o la medición y seguimiento de elementos prismáticos relacionados con un sistema de referencia determinado. Es en este punto donde la fotogrametría sin dianas puede combinarse o complementarse con soluciones tradicionales para tratar de mejorar las prestaciones actuales

Non-contact measures to monitor hand movement of people with rheumatoid arthritis using a monocular RGB camera

Hand movements play an essential role in a person’s ability to interact with the environment. In hand biomechanics, the range of joint motion is a crucial metric to quantify changes due to degenerative pathologies, such as rheumatoid arthritis (RA). RA is a chronic condition where the immune system mistakenly attacks the joints, particularly those in the hands. Optoelectronic motion capture systems are gold-standard tools to quantify changes but are challenging to adopt outside laboratory settings. Deep learning executed on standard video data can capture RA participants in their natural environments, potentially supporting objectivity in remote consultation. The three main research aims in this thesis were 1) to assess the extent to which current deep learning architectures, which have been validated for quantifying motion of other body segments, can be applied to hand kinematics using monocular RGB cameras, 2) to localise where in videos the hand motions of interest are to be found, 3) to assess the validity of 1) and 2) to determine disease status in RA. First, hand kinematics for twelve healthy participants, captured with OpenPose were benchmarked against those captured using an optoelectronic system, showing acceptable instrument errors below 10°. Then, a gesture classifier was tested to segment video recordings of twenty-two healthy participants, achieving an accuracy of 93.5%. Finally, OpenPose and the classifier were applied to videos of RA participants performing hand exercises to determine disease status. The inferred disease activity exhibited agreement with the in-person ground truth in nine out of ten instances, outperforming virtual consultations, which agreed only six times out of ten. These results demonstrate that this approach is more effective than estimated disease activity performed by human experts during video consultations. The end goal sets the foundation for a tool that RA participants can use to observe their disease activity from their home.Open Acces

Towards markerless orthopaedic navigation with intuitive Optical See-through Head-mounted displays

The potential of image-guided orthopaedic navigation to improve surgical outcomes has been well-recognised during the last two decades. According to the tracked pose of target bone, the anatomical information and preoperative plans are updated and displayed to surgeons, so that they can follow the guidance to reach the goal with higher accuracy, efficiency and reproducibility. Despite their success, current orthopaedic navigation systems have two main limitations: for target tracking, artificial markers have to be drilled into the bone and calibrated manually to the bone, which introduces the risk of additional harm to patients and increases operating complexity; for guidance visualisation, surgeons have to shift their attention from the patient to an external 2D monitor, which is disruptive and can be mentally stressful. Motivated by these limitations, this thesis explores the development of an intuitive, compact and reliable navigation system for orthopaedic surgery. To this end, conventional marker-based tracking is replaced by a novel markerless tracking algorithm, and the 2D display is replaced by a 3D holographic Optical see-through (OST) Head-mounted display (HMD) precisely calibrated to a user's perspective. Our markerless tracking, facilitated by a commercial RGBD camera, is achieved through deep learning-based bone segmentation followed by real-time pose registration. For robust segmentation, a new network is designed and efficiently augmented by a synthetic dataset. Our segmentation network outperforms the state-of-the-art regarding occlusion-robustness, device-agnostic behaviour, and target generalisability. For reliable pose registration, a novel Bounded Iterative Closest Point (BICP) workflow is proposed. The improved markerless tracking can achieve a clinically acceptable error of 0.95 deg and 2.17 mm according to a phantom test. OST displays allow ubiquitous enrichment of perceived real world with contextually blended virtual aids through semi-transparent glasses. They have been recognised as a suitable visual tool for surgical assistance, since they do not hinder the surgeon's natural eyesight and require no attention shift or perspective conversion. The OST calibration is crucial to ensure locational-coherent surgical guidance. Current calibration methods are either human error-prone or hardly applicable to commercial devices. To this end, we propose an offline camera-based calibration method that is highly accurate yet easy to implement in commercial products, and an online alignment-based refinement that is user-centric and robust against user error. The proposed methods are proven to be superior to other similar State-of- the-art (SOTA)s regarding calibration convenience and display accuracy. Motivated by the ambition to develop the world's first markerless OST navigation system, we integrated the developed markerless tracking and calibration scheme into a complete navigation workflow designed for femur drilling tasks during knee replacement surgery. We verify the usability of our designed OST system with an experienced orthopaedic surgeon by a cadaver study. Our test validates the potential of the proposed markerless navigation system for surgical assistance, although further improvement is required for clinical acceptance.Open Acces

Design and implementation of an augmented reality application for rock art visualization in Cova dels Cavalls (Spain)

[EN] Prehistoric rock art paintings, specifically rock-shelters exposed to environmental and anthropogenic factors, are usually faint and severely damaged, being them difficult to identify and understand by visitors. Augmented Reality (AR) supplements reality with virtual information superimposed onto the real world. This sensor-based technology in smartphones/tablets can improve the paintings experience displaying the 2D digital tracings overlapped onto the real scene (rock with faint paintings). This paper presents an AR application (app) developed in Cova dels Cavalls that shows a recreation of a possible original composition full of motifs with descriptive information to improve current guided tour user experiences. This case study aims to evaluate the rock art AR app targeting non-expert visitors as a means of improving rock art knowledge and sensibility of a fragile archaeological UNESCO Work Heritage site. To achieve this, a variety of participants with different backgrounds and interests tested the AR app on site and answered a complete questionnaire about the use of AR mobile apps. Overall, the results showed great acceptance of this AR app, mainly because in addition to adding new information interactively, it helps to identify the rock art motifs, as well as to recognise them quickly, improving their understanding.The authors gratefully acknowledge the support from the Spanish Ministerio de Economia y Competitividad to the project HAR201459873-R. The authors acknowledge the authorisation of the Conselleria d'Educacio, Investigacio, Cultura i Esports the chance to carry out research at this exceptional archaeological site.Blanco-Pons, S.; Carrión-Ruiz, B.; Lerma, JL.; Villaverde, V. (2019). Design and implementation of an augmented reality application for rock art visualization in Cova dels Cavalls (Spain). Journal of Cultural Heritage. 39:177-185. https://doi.org/10.1016/j.culher.2019.03.014S1771853

Augmented reality application assessment for disseminating rock art

[EN] Currently, marker-based tracking is the most used method to develop augmented reality (AR) applications (apps). However, this method cannot be applied in some complex and outdoor settings such as prehistoric rock art sites owing to the fact that the usage of markers is restricted on site. Thus, natural feature tracking methods have to be used. There is a wide range of libraries to develop AR apps based on natural feature tracking. In this paper, a comparative study of Vuforia and ARToolKit libraries is carried out, analysing factors such as distance, occlusion and lighting conditions that affect user experience in both indoor and outdoor environments, and eventually the app developer. Our analysis confirms that Vuforia¿s user experience indoor is better, faster and flicker-free whether the images are properly enhanced, but it does not work properly on site. Therefore, the development of AR apps for complex outdoor environments such as rock art sites should be performed with ARToolKit.The authors gratefully acknowledge the support from the Spanish Ministerio de Economia y Competitividad to the project HAR2014-59873-R. Similarly, the authors want to express their gratitude to the General Directorate of Culture and Heritage, Conselleria d'Educacio, Investigacio, Cultura i Esport, Generalitat Valenciana for letting us access and carry out research at the archaeological site.Blanco-Pons, S.; Carrión-Ruiz, B.; Lerma, JL. (2018). Augmented reality application assessment for disseminating rock art. Multimedia Tools and Applications. 78(8):10265-10286. https://doi.org/10.1007/s11042-018-6609-xS1026510286788Alahi A., Ortiz R., Vandergheynst P (2012) FREAK: fast retina keypoint. Comput Vis Pattern Recognit 510–517 . doi: https://doi.org/10.1109/CVPR.2012.6247715Amin D, Govilkar S (2015) Comparative study of augmented reality Sdk’S. Int J Comput Sci Appl 5:11–26. https://doi.org/10.1227/01.NEU.0000297044.82035.57ARCore ARCore - Google Developer | ARCore | Google Developers. https://developers.google.com/ar/ . Accessed 26 Jun 2018ARKit ARKit - Apple Developer. https://developer.apple.com/arkit/ . Accessed 26 Jun 2018ARToolkit (2017) ARToolkit. https://archive.artoolkit.org/ . Accessed 2 Oct 2017ARToolkit (2017) About. https://artoolkit.org/about-artoolkit . Accessed 11 Apr 2017ARToolkit (2017) Documentation. https://artoolkit.org/documentation/ . Accessed 12 Apr 2017ArUco ArUco: A minimal library for Augmented Reality applications based on OpenCV | Aplicaciones de la Visión Artificial. https://www.uco.es/investiga/grupos/ava/node/26 . Accessed 19 Apr 2018Azuma R (1997) A survey of augmented reality. Presence Teleoperators Virt Environ 6:355–385 . doi: 10.1.1.30.4999Azuma R, Baillot Y, Feiner S et al (2001) Recent advances in augmented reality. Ieee Comput Graph Appl 34–47. doi: https://doi.org/10.4061/2011/908468Blanco-Novoa O, Fernandez-Carames TM, Fraga-Lamas P, Vilar-Montesinos M (2018) A practical evaluation of commercial industrial augmented reality systems in an industry 4.0 shipyard. IEEE Access 6:1–1. https://doi.org/10.1109/ACCESS.2018.2802699Blanco-Pons S, Carrión-Ruiz B, Lerma JL (2016) Review of augmented reality and virtual reality techniques in rock art. Proc 8th Int Congress Archaeol Comput Graph Cult Herit Innov ‘ARQUEOLÓGICA 2.0L: 176–183Brancati N, Caggianese G, Frucci M et al (2017) Experiencing touchless interaction with augmented content on wearable head-mounted displays in cultural heritage applications. Pers Ubiquitous Comput 21:203–217. https://doi.org/10.1007/s00779-016-0987-8Cagalaban G, Kim S (2010) Multiple object tracking in unprepared environments using combined feature for augmented reality applications. Springer, Berlin, HeidelbergCamera-Calibration Camera Calibration App for Android [ARToolkit]. https://archive.artoolkit.org/documentation/doku.php?id=4_Android:android_camera_calibration . Accessed 16 Oct 2017Carmigniani J, Furht B, Anisetti M et al (2011) Augmented reality technologies, systems and applications. Multimed Tools Appl 51:341–377. https://doi.org/10.1007/s11042-010-0660-6Carrión-Ruiz B, Blanco-Pons S, Lerma JL (2016) Digital image analysis of the visible region through simulation of rock art paintings. Proc 8th Int Congress Archaeol Comput Graph, Cult Heritage Innov ‘ARQUEOLÓGICA 2.0.’: 169–175Chen CY, Chang BR, Sen HP (2014) Multimedia augmented reality information system for museum guidance. Pers Ubiquitous Comput 18:315–322. https://doi.org/10.1007/s00779-013-0647-1CRYENGINE CRYENGINE | The complete solution for next generation game development by Crytek. https://www.cryengine.com/ . Accessed 7 Jun 2017Domingo I, Carrión B, Blanco S, Lerma JL (2015) Evaluating conventional and advanced visible image enhancement solutions to produce digital tracings at el Carche rock art shelter. Digit Appl Archaeol Cult Herit 2:79–88. https://doi.org/10.1016/j.daach.2015.01.001Dos Santos AB, Dourado JB, Bezerra A (2016) ARToolkit and Qualcomm Vuforia: An Analytical Collation. Proc - 18th Symp Virt Augment Real SVR 2016:229–233. https://doi.org/10.1109/SVR.2016.46DroidAR (2017) DroidAR by bitstars. https://bitstars.github.io/droidar/ . Accessed 10 Dec 2017Engine U (2017) Unreal Engine. https://www.unrealengine.com/ . Accessed 10 Oct 2017Fiala M (2005) ARTag, a fiducial marker system using digital techniques. Proc IEEE Comput Soc Conf Comput Vis Pattern Recogn 2:590–596. https://doi.org/10.1109/CVPR.2005.74Fischer J, Eichler M, Bartz D, Straßer W (2007) A hybrid tracking method for surgical augmented reality. Comput Graph 31:39–52. https://doi.org/10.1016/j.cag.2006.09.007González C, Vallejo D, Albusac J, Castro J (2011) Realidad Aumentada. Un enfoque práctico con ARToolKit y Blender. 2–120Gutierrez JM, Molinero MA, Soto-Martín O, Medina CR (2015) Augmented reality technology spreads information about historical graffiti in temple of Debod. Procedia Comput Sci 75:390–397. https://doi.org/10.1016/j.procs.2015.12.262Haladová ZB, Szemzö R, Kovačovský T, Žižka J (2015) Utilizing Multispectral Scanning and Augmented Reality for Enhancement and Visualization of the Wooden Sculpture Restoration Process. Procedia Comput Sci 67:340–347. https://doi.org/10.1016/j.procs.2015.09.278Jamali SS, Shiratuddin MF, Wong KW, Oskam CL (2015) Utilising mobile-augmented reality for learning human anatomy. Procedia - Soc Behav Sci 197:659–668. https://doi.org/10.1016/j.sbspro.2015.07.054Khan D, Ullah S, Rabbi I (2015) Factors affecting the design and tracking of ARToolKit markers. Comput Stand Interf 41:56–66. https://doi.org/10.1016/j.csi.2015.02.006Khan D, Ullah S, Yan D et al (2018) Robust tracking through the design of high quality fiducial markers: an optimization tool for ARToolKit. IEEE Access 4:22421–22433. https://doi.org/10.1109/ACCESS.2018.2801028Kim SL, Suk HJ, Kang JH, et al (2014) Using unity 3D to facilitate mobile augmented reality game development. Internet things (WF-IoT), 2014 IEEE World Forum 21–26 . doi: https://doi.org/10.1109/WF-IoT.2014.6803110Kounavis CD, Kasimati AE, Zamani ED (2012) Enhancing the tourism experience through mobile augmented reality: challenges and prospects. Int J Eng Bus Manag 4:1–6. https://doi.org/10.5772/51644La Delfa GC, Monteleone S, Catania V et al (2016) Performance analysis of visualmarkers for indoor navigation systems. Front Inf Technol Electron Eng 17:730–740. https://doi.org/10.1631/FITEE.1500324Liu S, Ge S, Yu H (2016) Research on Robustness recognition algorithms in augmented reality. 3rd Int Conf Inf Sci Control Eng: 547–552. doi: https://doi.org/10.1109/ICISCE.2016.123Lowe DG (2004) Distinctive image features from scale invariant keypoints. Int J Comput Vis 60:91–11020042. https://doi.org/10.1023/B:VISI.0000029664.99615.94Lytridis C, Tsinakos A, Kazanidis I (2018) ARTutor—an augmented reality platform for interactive distance learning. Educ Sci 8:6. https://doi.org/10.3390/educsci8010006Marchand E, Uchiyama H, Spindler F et al (2016) Pose estimation for augmented reality : a hands-on survey. IEEE Trans Vis Comput Graph 22:2633–2651. https://doi.org/10.1109/TVCG.2015.2513408Martínez R, Villaverde V (2002) La cova dels cavalls en el Barranc de la ValltortaMarto AGR, Sousa AA, de Gonçalves A (2017) DinofelisAR demo augmented reality based on natural features. 12a Conferência Ibérica Sist e Tecnol Informação, Lisboa 64:852–861. https://doi.org/10.1016/j.procs.2015.08.638Moreels P, Perona P (2007) Evaluation of feature detectors and descriptors based on 3D objects. Int J Comput Vis 73:263–284. https://doi.org/10.1007/s11263-006-9967-1Pierdicca R, Frontoni E, Zingaretti P et al (2015) Making visible the invisible. augmented reality visualization for 3D reconstructions of archaeological sites. Augment Virt Real Sec Int Conf AVR 2015 9254:25–37. https://doi.org/10.1007/978-3-319-22888-4Rabbi I, Ullah S, Javed M, Zen K (2014) Analysis of ARToolKit fiducial markers attributes for robust tracking. 1st Int Conf Recent Trends Inf Commun Technol Anal 281–290Radkowski R, Oliver J (2013) Natural feature tracking augmented reality for on-site assembly assistance systems. In: Shumaker R (ed) Virtual, Augmented and Mixed Reality. Systems and Applications. VAMR 2013. Lecture Notes in Computer Science. Springer, Berlin, Heidelberg, pp 281–290Ridel B, Reuter P, Laviole J et al (2014) The revealing flashlight: interactive spatial augmented reality for detail exploration of cultural heritage artifacts. J Comput Cult Herit 7(6):1–6:18. https://doi.org/10.1145/2611376Seo J, Shim J, Choi JH, et al (2011) Enhancing marker-based AR technology. Lect Notes Comput Sci (including Subser Lect Notes Artif Intell Lect Notes Bioinformatics) 6773 LNCS:97–104 . doi: https://doi.org/10.1007/978-3-642-22021-0_12Seo J, Shim J, Choi JH et al (2011) Enhancing marker-based AR technology. In: International conference on virtual and mixed reality. virtual and mixed reality - new trends. Springer, Berlin, Heidelberg, pp 97–104Siltanen S (2015) Diminished reality for augmented reality interior design. Vis Comput 33:1–16. https://doi.org/10.1007/s00371-015-1174-zSörös G, Seichter H, Rautek P, Gröller E (2011) Augmented visualization with natural feature tracking. Proc 10th Int Conf Mob Ubiquitous Multimed 4–12. doi: https://doi.org/10.1145/2107596.2107597Uchiyama H, Marchand E (2012) Object detection and pose tracking for augmented reality: recent approaches. 18th Korea-Japan Jt Work Front Comput Vis 1–8Unity Unity. https://unity3d.com/es . Accessed 12 Oct 2017Vuforia (2017) Vuforia. https://www.vuforia.com/ . Accessed 2 Oct 2017Vuforia (2017) Vuforia-VuMark. https://library.vuforia.com/articles/Training/VuMark . Accessed 4 Apr 2017Vuforia (2017) Image targets. https://library.vuforia.com/articles/Training/Image-Target-Guide . Accessed 11 Apr 2017Wang H, Qin J, Zhang F (2015) A new interaction method for augmented reality based on ARToolKit. 2015 8th Int Congr Image Signal Process 578–583. doi: https://doi.org/10.1109/CISP.2015.7407945Wang G, Wang B, Zhong F et al (2015) Global optimal searching for textureless 3D object tracking. Vis Comput 31:979–988. https://doi.org/10.1007/s00371-015-1098-7Wu S, Oerlemans A, Bakker EM, Lew MS (2017) A comprehensive evaluation of local detectors and descriptors. Signal Process Image Commun 59:150–167. https://doi.org/10.1016/J.IMAGE.2017.06.010Xu Y, Wu Y, Zhou H, View M (2018) Multi-scale Voxel Hashing and Efficient 3D Representation for Mobile Augmented Reality. Cvpr 1618–1625 . doi: https://doi.org/10.1109/CVPRW.2018.0020