A PBeL for training non-experts in mobile-based photogrammetry and accurate 3-D recording of small-size/non-complex objects

Sanz, Juan Ortiz; Docampo, María Luz Gil; Rego-Sanmartín, T.; Arza-García, Marcos; Tucci, Grazia

doi:10.1016/j.measurement.2021.109338

Cited by 12 publications

(8 citation statements)

References 69 publications

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“…Further consideration should be made to the continual improvement and development in both the photogrammetry and smartphone industry, meaning that it could become more accessible and relevant as its popularity grows [41].…”

Section: Discussionmentioning

confidence: 99%

The Use of Smartphone Photogrammetry to Digitise Transtibial Sockets: Optimisation of Method and Quantitative Evaluation of Suitability

Cullen

Mackay

Mohagheghi

et al. 2021

Sensors

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The fit of a lower limb prosthetic socket is critical for user comfort and the quality of life of lower limb amputees. Sockets are conventionally produced using hand-crafted patient-based casting techniques. Modern digital techniques offer a host of advantages to the process and ultimately lead to improving the lives of amputees. However, commercially available scanning equipment required is often expensive and proprietary. Smartphone photogrammetry could offer a low cost alternative, but there is no widely accepted imaging technique for prosthetic socket digitisation. Therefore, this paper aims to determine an optimal imaging technique for whole socket photogrammetry and evaluate the resultant scan measurement accuracy. A 3D printed transtibial socket was produced to create digital and physical twins, as reference models. The printed socket was photographed from 360 positions and simplified genetic algorithms were used to design a series of experiments, whereby a collection of photos were processed using Autodesk ReCap. The most fit technique was used to assess accuracy. The accuracy of the socket wall volume, surface area and height were 61.63%, 99.61% and 99.90%, respectively, when compared to the digital reference model. The scanned model had a wall thickness ranging from 2.075 mm at the top to 7.758 mm towards the base of the socket, compared to a consistent thickness of 2.025 mm in the control model. The technique selected did not show sufficient accuracy for clinical application due to the degradation of accuracy nearer to the base of the socket interior. However, using an internal wall thickness estimation, scans may be of sufficient accuracy for clinical use; assuming a uniform wall thickness.

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Section: Discussionmentioning

confidence: 99%

The Use of Smartphone Photogrammetry to Digitise Transtibial Sockets: Optimisation of Method and Quantitative Evaluation of Suitability

Cullen

Mackay

Mohagheghi

et al. 2021

Sensors

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“…There are many alternatives for free SfM software that allow for cloud, desktop, or even smartphone-based processing [ 11 ]. We selected MVE (Multi-View Environment developed by Simon Fuhrmann and others in TU Darmstadt, Germany) [ 30 ] because of its low hardware requirements, thereby making it accessible to more potential users.…”

Section: Methodsmentioning

confidence: 99%

“…Structure from motion (SfM) is a photogrammetry-based framework for the 3D shape reconstruction of an object from images taken from different perspectives. Even though the reconstruction process is very complex, this framework has become very popular even among amateurs, thanks to the highly automated and user-friendly software that is freely available for use [ 11 ]. It is also extensively utilized in research studies across different fields and scales.…”

Section: Introductionmentioning

confidence: 99%

Photogrammetry-Based Volume Measurement Framework for the Particle Density Estimation of LECA

et al. 2022

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This paper presents a photogrammetry-based volume measurement framework for the particle density estimation of Lightweight expanded clay aggregate (LECA). The results are compared with computed tomography (CT) and Archimedes’ method measurements. All of the steps required in order to apply the proposed approach are explained. Next, we discuss how the interpretation of open pores affects the results of volume measurements. We propose to process the shapes obtained from different methods by applying an Ambient Occlusion algorithm with the same threshold, t = 0.175. The difference between the CT and SfM methods is less than 0.006 g/cm3, proving that the photogrammetry-based approach is accurate enough. The Archimedes’ method significantly overestimates the density of the particles. Nevertheless, its accuracy is acceptable for most engineering purposes. Additionally, we evaluate the accuracy of shape reconstruction (in terms of the Hausdorff distance). For 95% of the grain’s surface, the maximum error is between 0.073 mm and 0.129 mm (depending on the grain shape). The presented approach is helpful for measuring the particle density of porous aggregates. The proposed methodology can be utilized in order to estimate intergranular porosity, which is valuable information for the calibration of DEM models.

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“…In the recent years, several virtuous examples to introduce the main concepts of Geomatics disciplines have been successfully carried out, which addressed to students (Gil-Docampo et al 2019;Tucci et al 2019), technicians (Tucci et al 2018), and non-specialist public (Bonacini et al 2015;Ortiz-Sanz et al 2021). In this context, mainly photogrammetry has gained more and more popularity, also thanks to the spread of "toy drones" and automatic photogrammetric software (desktop, mobile app, and online), that allow the users to obtain realistic and pleasant 3D models without the necessity of knowing the basic concepts of photogrammetry but only taking pictures in the appropriate way, at least paying attention to the overlapping of images and the light conditions (Tucci et al 2020).…”

Section: Innovative Didactics In Geomatics Disciplinesmentioning

confidence: 99%

“…The main resistance in studying and deepening Geomatics concepts comes from the perceived hostility and complexity of the topics, which are often considered too theoretical or specialized. In this sense, innovative didactic methods, concerning both teaching-learning processes (König et al 2012;Tucci et al 2020) and introduction of technological devices (Mills 2015;Luhmann 2016;Ortiz-Sanz et al 2021) are beneficial in making people approach geomatics topics in a smoother and more engaging way and in moving the role of the teacher to facilitator of the learning process, reducing the gap between teacher and students. Moreover, the learning strategies that promote collaboration and direct interaction between students have the further advantage of helping them in building and strengthen their soft skills: teamwork, communication, problem-solving, creativity.…”

Section: Innovative Didactics In Geomatics Disciplinesmentioning

confidence: 99%

Innovations in geomatics teaching during the COVID-19 emergency

et al. 2022

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The approach in the teaching process is changing, thanks to the increased awareness that a higher students’ involvement leads to a better quality of their learning. The aim is to make the students more participative, avoiding a unidirectional lesson and encouraging their wish to keep updated on the course advancements. However, innovative teaching methodologies are not yet widespread, mainly in STEM (Science, Technology, Engineering, and Mathematics) disciplines. At the University of Genoa, the experimentation of innovative teaching techniques has been significant and worthy especially because it was planned before the COVID-19 emergency and applied in the scenario of forced remote teaching. Thanks to the introduction of novel technological instruments, several techniques have been exploited to realize interactive lessons and promoting students’ involvement. The present work discloses the employed techniques and frames them within the state of the art of innovative teaching, highlighting their contribution in the teaching activities related to the Geomatics field of knowledge. The acquired experiences in Geomatics dissemination and a critical analysis, including teachers’ and students’ perception about the tested innovative teaching/learning tools, are also reported. In general, the innovations introduced in teaching and learning processes during the COVID-19 sanitary emergency were warmly received by the entire community, including teachers, students, and teaching assistants.

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A PBeL for training non-experts in mobile-based photogrammetry and accurate 3-D recording of small-size/non-complex objects

Cited by 12 publications

References 69 publications

The Use of Smartphone Photogrammetry to Digitise Transtibial Sockets: Optimisation of Method and Quantitative Evaluation of Suitability

The Use of Smartphone Photogrammetry to Digitise Transtibial Sockets: Optimisation of Method and Quantitative Evaluation of Suitability

Photogrammetry-Based Volume Measurement Framework for the Particle Density Estimation of LECA

Innovations in geomatics teaching during the COVID-19 emergency

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