Fringe projection profilometry for recovering 2.5D shape of ancient coins

The development of a three-dimensional surface profilometer using digital fringe projection technology and phase-shifting principle is presented. Accurate and high-speed three-dimensional profile measurement plays a key role in determining the success of process automation and productivity. By integrating a digital micromirror device (DMD) with the developed system, exclusive advantages in projecting flexible and accurate structured-light patterns onto the object surface to be measured can be obtained. Furthermore, the developed system consists of a specially designed micro-projecting optical unit for generating flexibly optimal structured-light to accommodate requirements in terms of measurement range and resolution. Its wide angle image detection design also improves measurement resolution for detecting deformed fringe patterns. This resolves the problem in capturing effective deformed fringe patterns for phase shifting, especially when a coaxial optical layout of a stereomicroscope is employed. Experimental results verified that the maximum error was within a reasonable range of the measured depth. The developed system and the method can provide a useful and effective tool for 3D full field surface measurement ranging from µm up to cm scale.

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3D MODELING FOR UNDERWATER ARCHAEOLOGICAL DOCUMENTATION: METRIC VERIFICATIONS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xl-5-w5-73-2015 ◽

2015 ◽

Vol XL-5/W5 ◽

pp. 73-77

Author(s):

S. D’Amelio ◽

V. Maggio ◽

B. Villa

Keyword(s):

Cultural Heritage ◽

3D Modeling ◽

Video Sequence ◽

Reference Model ◽

Comparative Method ◽

Three Dimensional ◽

Laser Scanner ◽

Dimensional Model ◽

Three Dimensional Model ◽

Underwater Environment

The survey in underwater environment has always presented considerable difficulties both operative and technical and this has sometimes made it difficult to use the techniques of survey commonly used for the documentation of Cultural Heritage in dry environment. The work of study concerns the evaluation in terms of capability and accuracy of the Autodesk123DCatch software for the reconstruction of a three-dimensional model of an object in underwater context. The subjects of the study are models generated from sets of photographs and sets of frames extracted from video sequence. The study is based on comparative method, using a reference model, obtained with laser scanner technique.

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Phase Demodulation Method for Fringe Projection Measurement Based on Improved Variable-Frequency Coded Patterns

Sensors ◽

10.3390/s21134463 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4463

Author(s):

Shanshan Lv ◽

Mingshun Jiang ◽

Chenhui Su ◽

Lei Zhang ◽

Faye Zhang ◽

...

Keyword(s):

Critical Role ◽

Three Dimensional ◽

Surface Profile ◽

Phase Region ◽

Fringe Projection ◽

Measurement Technology ◽

Variable Frequency ◽

Profile Measurement ◽

Imaging Model ◽

Phase Demodulation

The phase-to-height imaging model, as a three-dimensional (3D) measurement technology, has been commonly applied in fringe projection to assist surface profile measurement, where the efficient and accurate calculation of phase plays a critical role in precise imaging. To deal with multiple extra coded patterns and 2π jump error caused to the existing absolute phase demodulation methods, a novel method of phase demodulation is proposed based on dual variable-frequency (VF) coded patterns. In this paper, the frequency of coded fringe is defined as the number of coded fringes within a single sinusoidal fringe period. First, the effective wrapped phase (EWP) as calculated using the four-step phase shifting method was split into the wrapped phase region with complete period and the wrapped phase region without complete period. Second, the fringe orders in wrapped phase region with complete period were decoded according to the frequency of the VF coded fringes and the continuous characteristic of the fringe order. Notably, the sampling frequency of fast Fourier transform (FFT) was determined by the length of the decoding interval and can be adjusted automatically with the variation in height of the object. Third, the fringe orders in wrapped phase region without complete period were decoded depending on the consistency of fringe orders in the connected region of wrapped phase. Last, phase demodulation was performed. The experimental results were obtained to confirm the effectiveness of the proposed method in the phase demodulation of both discontinuous objects and highly abrupt objects.

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Model 3D in Service of Preservation, Restoration, Structural Analyses of the Architectural Heritage

Advances in Library and Information Science - Handbook of Research on Emerging Technologies for Digital Preservation and Information Modeling ◽

10.4018/978-1-5225-0680-5.ch021 ◽

2017 ◽

pp. 563-589

Author(s):

Elena Teresa Clotilde Marchis

Keyword(s):

Cultural Heritage ◽

Three Dimensional ◽

3D Modelling ◽

Dimensional Model ◽

Architectural Heritage ◽

Three Dimensional Model ◽

Practical Applications ◽

Final Output ◽

Methodological Guidelines ◽

The Way

This contribute aims to explore 3D modelling and its practical applications investigating scales of representation and scales of contents from architecture to landscape. The goal of this approach is to test the flexibility of modelling tools to different fields of application and to draw shared methods, even if they are applied in so different context. Changing the scale, is obvious, the language changes – because it is necessary to recompose symbolic and iconographic elements – themes and scales of representation change. So is possible to pave the way to strictly disciplinary thinking on outcomes and on instrumental and methodological guidelines for further research. The topic focuses on developing guidelines and creating a simple three-dimensional model designed to represent both the complexity of the “cultural heritage” morphology, as well as the need to manage the process of restoration in all its phases: from first findings to the restored final output.

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Model 3D in Service of Preservation, Restoration, Structural Analyses of the Architectural Heritage

Architecture and Design ◽

10.4018/978-1-5225-7314-2.ch007 ◽

2019 ◽

pp. 177-205

Author(s):

Elena Teresa Clotilde Marchis

Keyword(s):

Cultural Heritage ◽

Three Dimensional ◽

3D Modelling ◽

Dimensional Model ◽

Architectural Heritage ◽

Three Dimensional Model ◽

Practical Applications ◽

Final Output ◽

Methodological Guidelines ◽

The Way

This contribute aims to explore 3D modelling and its practical applications investigating scales of representation and scales of contents from architecture to landscape. The goal of this approach is to test the flexibility of modelling tools to different fields of application and to draw shared methods, even if they are applied in so different context. Changing the scale, is obvious, the language changes – because it is necessary to recompose symbolic and iconographic elements – themes and scales of representation change. So is possible to pave the way to strictly disciplinary thinking on outcomes and on instrumental and methodological guidelines for further research. The topic focuses on developing guidelines and creating a simple three-dimensional model designed to represent both the complexity of the “cultural heritage” morphology, as well as the need to manage the process of restoration in all its phases: from first findings to the restored final output.

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MODERN METHODS OF AERIAL PHOTOGRAPHY FOR ARCHITECTURAL AND PLANNING ANALYSIS OF CULTURAL HERITAGE OBJECTS

URBAN CONSTRUCTION AND ARCHITECTURE ◽

10.17673/vestnik.2017.04.19 ◽

2017 ◽

Vol 7 (4) ◽

pp. 110-114

Author(s):

Denis V. LITVINOV

Keyword(s):

Cultural Heritage ◽

Aerial Photography ◽

Large Scale ◽

Three Dimensional ◽

Spatial Location ◽

Three Dimensional Model ◽

The Earth ◽

Aerial Vehicle ◽

Cultural Heritage Objects ◽

Territorial Unity

In the article the results of research works of a large-scale object of cultural heritage of the Earth mound of the Krasnoyarsk fortress with application of aerial photography from the unmanned aerial vehicle are presented. The Krasnoyarsk fortress is a unique monument of military fortifi cation architecture of Russia of the fi rst half of the XVIII century and one of the largest defensive lines in Russia, created for protection of the southeastern edge of the European Russia against att acks of nomads. The results of vertical and oblique aerial photography allow to reveal the general architectural and planning composition of the Earth mound of fortress as well as to see all the area of a complex and to defi ne the territorial unity with other fortifi cation constructions. The methods of use of unmanned aerial vehicles give materials about the object in study and allow to bind its spatial location to the coordinate system of the terrain, to create three-dimensional model of the area, to compare the received images with the available historical cards and plans, which will signifi cantly facilitate the task of registering the Fortress with the security authorities and withdrawing its territory from economic use.

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