Giovanna Sansoni | University of Brescia (original) (raw)

Papers by Giovanna Sansoni

Research paper thumbnail of Hand gesture recognition for collaborative workstations: a smart command system prototype

New Trends in Image Analysis and Processing – ICIAP 2019, 2019

Human-machine collaboration is a key aspect in modern industries, which must be compliant to the ... more Human-machine collaboration is a key aspect in modern industries, which must be compliant to the Industry 4.0 paradigm. Although the collaboration can be achieved using a Collaborative Robot in a purposely designed workstation , this solution is not always neither feasible nor affordable for the specific task to be carried out in the workstation. On the other hand, using a smart HMI to make an industrial robot a "smart" robot can be a better and affordable solution depending on the task. In this work we present the preliminary development and characteristics of an experimental HMI for smart manufacturing developed in MATLAB and ROS Industrial. The collaboration between humans and robots is achieved by leveraging the Faster R-CNN Object Detector to robustly detect and recognize the hand gestures performed in real-time. The system is based on a state machine to carry out simple tasks such as the repeated movement of the robot following a given trajectory and a pick and place task where the robot interactively reaches a given point and a jog modality.

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Research paper thumbnail of A 3D vision system based on one-shot projection and phase demodulation for fast profilometry

Measurement Science & Technology, 2005

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Research paper thumbnail of A three-dimensional imaging system for industrial applications with improved flexibility and robustness

Journal of Optics-nouvelle Revue D Optique, 1999

Procedures developed to enhance the flexibility and the robustness of an optical whole-field prof... more Procedures developed to enhance the flexibility and the robustness of an optical whole-field profilometer are presented. The system is based on the projection of structured light and on active triangulation. In order to comply with a sufficiently wide typology of targets, three different techniques to perform light coding have been integrated on the system, each one followed by a specific triangulation algorithm, which accounts for the influence of the system's crossed-optical-axes geometry. In order to guarantee a sufficient robustness and simplicity of use, the system has been equipped with a procedure for the automatic determination of the measurement parameters, both geometrical and optical, as well as for the necessary image preprocessing. The developed procedures increase the measurement performance both in terms of resolution and of extension of the measurement range, and keep the complexity of the system compatible with its use in the industrial field.

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Research paper thumbnail of Machine vision: Optical digitization of free-form, complex surfaces using the projection of structured light

Optics & Photonics News, 2000

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Research paper thumbnail of Three-Dimensional Vision Based on a Combination of Gray-Code and Phase-Shift Light Projection: Analysis and Compensation of the Systematic Errors

Applied Optics, 1999

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Research paper thumbnail of Combination of a Vision System and a Coordinate Measuring Machine for the Reverse Engineering of Freeform Surfaces

International Journal of Advanced Manufacturing Technology, 2001

... step can be automatically exported as an IGES file and used in the subsequent digitisation ph... more ... step can be automatically exported as an IGES file and used in the subsequent digitisation phase. ... 6. The off-line measuring programming was then performed by using tools available in the ... 6. SF El-Hakim and N. Pizzi, “Multicamera vision-based approach to flexible feature ...

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Research paper thumbnail of 3D Range Optical Sensor: analysis of the Measurement Errors and Development of Procedures for Their Compensation

In this paper, the analysis of the measurement errors in an optical sensor for the achievement of... more In this paper, the analysis of the measurement errors in an optical sensor for the achievement of 3D range images is presented together with the procedures developed for their compensation. The optical sensor performs the 3D measurement by means of the active ...

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Research paper thumbnail of 3D vision based on the combination of Gray code and phase phase shift light projection

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Research paper thumbnail of Three-dimensional imaging of surfaces for industrial applications: integration of structured light projection, Gray code projection, and projector-camera calibration for improved performance

In this paper, two measurement procedures, aimed at the improvement of the performance of an opti... more In this paper, two measurement procedures, aimed at the improvement of the performance of an optical whole field profilometer based on grating projection, are presented. The first procedure is based on the Gray code method. It performs a space encoding of the measurement area and yields 3-D range images in which even sharp discontinuities of the object shape can be measured. The second procedure performs the calibration of the optical components of the system, in order to describe the 3-D profile in a global coordinate system, and limiting the use of a reference surface only during the calibration of the profilometer. In the paper, the two procedures are detailed and some interesting experimental results are reported.

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Research paper thumbnail of Advanced laser telemetry for vehicle monitoring and other industrial applications

The need to prevent train accidents inside railway tunnels has motivated the national railway Com... more The need to prevent train accidents inside railway tunnels has motivated the national railway Company Ferrovie dello Stato to launch a project aimed at installing a number of train monitoring portals at a suitable distance from the tunnel entrances. The first experimental portal, and a second operative one, have been installed by SIRTI S.p.A., respectively in Rastignano and Formia. Our company, in collaboration with the Laboratory of Optoelectronics of the University of Brescia, have been requested to develop all the multisensor architecture for the dimensional and thermal monitoring of the trains to be installed on the portals. One of the key elements of the portal is the shape acquisition sensor, based on scanning telemetry. In the second portal, based on the experience gathered from the first one, a novel shape acquisition system based on time-of-flight telemeters has been developed. This telemeter has been specifically designed for the high-speed, high-resolution monitoring of trains in railway portals, but can be adapted to a number of industrial and environmental applications. The system uses a single transmitter/receiver unit to feed, using optical fibre pairs, a number of measuring stations. It makes use of an ultrashort fibre laser operating at 400 kHz or alternatively a fibre-couple diode laser, and presents in-house developed solutions to obtain a 40 dB dynamic range, thus allowing to monitor targets within large distance/angle/colour intervals. The system has been developed, tested and installed on a train-monitoring portal in the Rome-Neaples railway.

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Research paper thumbnail of Light-induced transmission changes in liquid crystal displays for adaptive pattern projection

IEEE Transactions on Instrumentation and Measurement, 1992

ABSTRACT The changes in the transmission and contrast properties of a super-twisted nematic liqui... more ABSTRACT The changes in the transmission and contrast properties of a super-twisted nematic liquid crystal display panel, induced by the light impinging on the panel itself, have been studied. Upon illumination by laser radiation with power density close to that used in practice, the transmittance of the panel increases or decreases according to the brightness voltage that sets the transmittance level. The dynamics of the transmittance change are typically bi-exponential, with a shorter decay time on the order of a fraction of a second and a longer decay on the order of tens of seconds. The observed changes were interpreted and modeled by considering local temperature changes in the crystal because of the light impinging on it. The temperature changes produce a shift of the transmittance curve and a change of slope in its central region. The presence of the dip after the Frederickzs region accounts for the anomalous behavior of the transmittance in that portion of brightness voltages

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Research paper thumbnail of Whole-field optical profilometry: application of nonlinear processing algorithms to the enhancement of low-contrast images

A nonlinear filtering technique for the preprocessing of very low contrast images has been applie... more A nonlinear filtering technique for the preprocessing of very low contrast images has been applied to optical profilometry, as an attempt to improve the accuracy of the measurement of objects in harsh conditions. The technique is based on the application of a nonlinear architecture composed of linear Laplacian filters followed by quadratic filters which detect correlated elements. The above sequence of operators results in efficient highpass filtering, keeping at the same time the signal-to-noise ratio within acceptable limits. When applied to highly transparent or weakly diffusive surfaces, the preelaboration technique has largely improved the accuracy of the profilometer. In this paper the preelaboration technique is presented. In particular, the influence of the nonlinear image elaboration on the overall system performance is discussed.

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Research paper thumbnail of Infield performance of an optical digitizer for the reverse engineering of free-form surfaces

International Journal of Advanced Manufacturing Technology, 2005

The use of OPL-3D, a robust, flexible and easy-to-use optical digitizer, in conjunction with reve... more The use of OPL-3D, a robust, flexible and easy-to-use optical digitizer, in conjunction with reverse engineering procedures is presented. The optical digitizer is used as a stand-alone (i.e., not in tandem with popular CMM’s) system, whose output point clouds can be manipulated, by means of both specifically-designed software and high-performance commercial software, to produce mesh surfaces and NURBS of the acquired shape. The digitizer-process combination yields accurate digital replicas of the target object, the accuracy of the whole combination being on the order of 1/1500 of the measurement range. The speed of acquisition, combined with the above high accuracy, the ease of use and the fact that recalibration is seldom required makes the digitizer ideal for reverse engineering in an enormous number of applications ranging from automotive to biomedical.

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Research paper thumbnail of Adaptive whole-field optical profilometry: a study of the systematic errors

IEEE Transactions on Instrumentation and Measurement, 1995

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Research paper thumbnail of Virtual and physical prototyping by means of a 3D optical digitizer: Application to facial prosthetic reconstruction

Virtual and Physical Prototyping, 2009

In this article, optical 3D acquisition, reverse engineering and rapid prototyping are proposed f... more In this article, optical 3D acquisition, reverse engineering and rapid prototyping are proposed for virtual sculpturing and fabrication of facial prostheses. A novel approach to the direct mould production by means of rapid prototyping fabrication is introduced. Full coverage of the ...

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Research paper thumbnail of Calibration and performance evaluation of a 3-D imaging sensor based on the projection of structured light

IEEE Transactions on Instrumentation and Measurement, 2000

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Research paper thumbnail of State-of-The-Art and Applications of 3D Imaging Sensors in Industry, Cultural Heritage, Medicine, and Criminal Investigation

Sensors, 2009

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Research paper thumbnail of OPL3D: A novel, portable optical digitizer for fast acquisition of free-form surfaces

Review of Scientific Instruments, 2003

The paper presents OPL-3D, a novel, powerful three-dimensional optical digitizer based on structu... more The paper presents OPL-3D, a novel, powerful three-dimensional optical digitizer based on structured, incoherent light illumination, developed in our laboratory for noncontact acquisition and digitization of free forms in space. The system exploits active stereovision using time multiplexing based on a combination of Gray code and phase-shifting techniques. The system has been specifically designed for applications to reverse engineering and rapid prototyping of free-form shapes, as well as for applications to measurement and quality control. Suitable estimation of the measurement parameters, as well as specifically developed two-dimensional image analysis, allows us to retrieve very dense point clouds in a few seconds. Special care has been devoted to the implementation of easy-to-use fast calibration procedures, and to enhancement of the flexibility of the system to the measuring problem as well as its portability. A kernel for elaboration of the views and for their alignment is provided. OPL-3D exhibits low-measurement uncertainty (120 μm) over large measurement areas (450 mm×340 mm), linearly scalable in the case of smaller areas. The output formats of the data files are fully compatible with the formats commonly used by elaboration environments dedicated to the production of polygonal models and to computer-aided design models of the shapes. The performance of OPL-3D has been tested in a number of applications, ranging from industry to biomedicine and virtual reality.

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Research paper thumbnail of A special case of 3-D optical measurements and reverse engineering for automotive applications: the Ferrari 250 Mille Miglia

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Research paper thumbnail of Development and characterization of a 3D measuring system based on integration of gray code and phase-shift light projection

In this paper, a 3D measurement procedure is presented, which combines the gray code light projec... more In this paper, a 3D measurement procedure is presented, which combines the gray code light projection technique and the phase shift method. The aim is the improvement of the performance of a 3D imaging system based on structured light projection. The measuring procedure based on gray code light projection demonstrates the ability of measuring objects presenting marked discontinuities of shape, such as steep slopes, grooves and holes: the experimental tests performed show that the measurement accuracy is up to 0.42% and the precision is 0.3% of the measuring range. The accuracy of the measurement is mainly limited by its resolution. To increase the system performances, the ability of the phase shift method to achieve higher resolution has been used: the height values given by these two methods are combined in a procedure which shows increased resolution and accuracy on an extended measuring range. The basic aspects of the two basic techniques for 3D imaging and profiling are here discussed. The combined procedure which integrates them is detailed, and some relevant experimental results are reported.

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Research paper thumbnail of Hand gesture recognition for collaborative workstations: a smart command system prototype

New Trends in Image Analysis and Processing – ICIAP 2019, 2019

Human-machine collaboration is a key aspect in modern industries, which must be compliant to the ... more Human-machine collaboration is a key aspect in modern industries, which must be compliant to the Industry 4.0 paradigm. Although the collaboration can be achieved using a Collaborative Robot in a purposely designed workstation , this solution is not always neither feasible nor affordable for the specific task to be carried out in the workstation. On the other hand, using a smart HMI to make an industrial robot a "smart" robot can be a better and affordable solution depending on the task. In this work we present the preliminary development and characteristics of an experimental HMI for smart manufacturing developed in MATLAB and ROS Industrial. The collaboration between humans and robots is achieved by leveraging the Faster R-CNN Object Detector to robustly detect and recognize the hand gestures performed in real-time. The system is based on a state machine to carry out simple tasks such as the repeated movement of the robot following a given trajectory and a pick and place task where the robot interactively reaches a given point and a jog modality.

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Research paper thumbnail of A 3D vision system based on one-shot projection and phase demodulation for fast profilometry

Measurement Science & Technology, 2005

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Research paper thumbnail of A three-dimensional imaging system for industrial applications with improved flexibility and robustness

Journal of Optics-nouvelle Revue D Optique, 1999

Procedures developed to enhance the flexibility and the robustness of an optical whole-field prof... more Procedures developed to enhance the flexibility and the robustness of an optical whole-field profilometer are presented. The system is based on the projection of structured light and on active triangulation. In order to comply with a sufficiently wide typology of targets, three different techniques to perform light coding have been integrated on the system, each one followed by a specific triangulation algorithm, which accounts for the influence of the system's crossed-optical-axes geometry. In order to guarantee a sufficient robustness and simplicity of use, the system has been equipped with a procedure for the automatic determination of the measurement parameters, both geometrical and optical, as well as for the necessary image preprocessing. The developed procedures increase the measurement performance both in terms of resolution and of extension of the measurement range, and keep the complexity of the system compatible with its use in the industrial field.

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Research paper thumbnail of Machine vision: Optical digitization of free-form, complex surfaces using the projection of structured light

Optics & Photonics News, 2000

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Research paper thumbnail of Three-Dimensional Vision Based on a Combination of Gray-Code and Phase-Shift Light Projection: Analysis and Compensation of the Systematic Errors

Applied Optics, 1999

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Research paper thumbnail of Combination of a Vision System and a Coordinate Measuring Machine for the Reverse Engineering of Freeform Surfaces

International Journal of Advanced Manufacturing Technology, 2001

... step can be automatically exported as an IGES file and used in the subsequent digitisation ph... more ... step can be automatically exported as an IGES file and used in the subsequent digitisation phase. ... 6. The off-line measuring programming was then performed by using tools available in the ... 6. SF El-Hakim and N. Pizzi, “Multicamera vision-based approach to flexible feature ...

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Research paper thumbnail of 3D Range Optical Sensor: analysis of the Measurement Errors and Development of Procedures for Their Compensation

In this paper, the analysis of the measurement errors in an optical sensor for the achievement of... more In this paper, the analysis of the measurement errors in an optical sensor for the achievement of 3D range images is presented together with the procedures developed for their compensation. The optical sensor performs the 3D measurement by means of the active ...

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Research paper thumbnail of 3D vision based on the combination of Gray code and phase phase shift light projection

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Three-dimensional imaging of surfaces for industrial applications: integration of structured light projection, Gray code projection, and projector-camera calibration for improved performance

In this paper, two measurement procedures, aimed at the improvement of the performance of an opti... more In this paper, two measurement procedures, aimed at the improvement of the performance of an optical whole field profilometer based on grating projection, are presented. The first procedure is based on the Gray code method. It performs a space encoding of the measurement area and yields 3-D range images in which even sharp discontinuities of the object shape can be measured. The second procedure performs the calibration of the optical components of the system, in order to describe the 3-D profile in a global coordinate system, and limiting the use of a reference surface only during the calibration of the profilometer. In the paper, the two procedures are detailed and some interesting experimental results are reported.

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Research paper thumbnail of Advanced laser telemetry for vehicle monitoring and other industrial applications

The need to prevent train accidents inside railway tunnels has motivated the national railway Com... more The need to prevent train accidents inside railway tunnels has motivated the national railway Company Ferrovie dello Stato to launch a project aimed at installing a number of train monitoring portals at a suitable distance from the tunnel entrances. The first experimental portal, and a second operative one, have been installed by SIRTI S.p.A., respectively in Rastignano and Formia. Our company, in collaboration with the Laboratory of Optoelectronics of the University of Brescia, have been requested to develop all the multisensor architecture for the dimensional and thermal monitoring of the trains to be installed on the portals. One of the key elements of the portal is the shape acquisition sensor, based on scanning telemetry. In the second portal, based on the experience gathered from the first one, a novel shape acquisition system based on time-of-flight telemeters has been developed. This telemeter has been specifically designed for the high-speed, high-resolution monitoring of trains in railway portals, but can be adapted to a number of industrial and environmental applications. The system uses a single transmitter/receiver unit to feed, using optical fibre pairs, a number of measuring stations. It makes use of an ultrashort fibre laser operating at 400 kHz or alternatively a fibre-couple diode laser, and presents in-house developed solutions to obtain a 40 dB dynamic range, thus allowing to monitor targets within large distance/angle/colour intervals. The system has been developed, tested and installed on a train-monitoring portal in the Rome-Neaples railway.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Light-induced transmission changes in liquid crystal displays for adaptive pattern projection

IEEE Transactions on Instrumentation and Measurement, 1992

ABSTRACT The changes in the transmission and contrast properties of a super-twisted nematic liqui... more ABSTRACT The changes in the transmission and contrast properties of a super-twisted nematic liquid crystal display panel, induced by the light impinging on the panel itself, have been studied. Upon illumination by laser radiation with power density close to that used in practice, the transmittance of the panel increases or decreases according to the brightness voltage that sets the transmittance level. The dynamics of the transmittance change are typically bi-exponential, with a shorter decay time on the order of a fraction of a second and a longer decay on the order of tens of seconds. The observed changes were interpreted and modeled by considering local temperature changes in the crystal because of the light impinging on it. The temperature changes produce a shift of the transmittance curve and a change of slope in its central region. The presence of the dip after the Frederickzs region accounts for the anomalous behavior of the transmittance in that portion of brightness voltages

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Research paper thumbnail of Whole-field optical profilometry: application of nonlinear processing algorithms to the enhancement of low-contrast images

A nonlinear filtering technique for the preprocessing of very low contrast images has been applie... more A nonlinear filtering technique for the preprocessing of very low contrast images has been applied to optical profilometry, as an attempt to improve the accuracy of the measurement of objects in harsh conditions. The technique is based on the application of a nonlinear architecture composed of linear Laplacian filters followed by quadratic filters which detect correlated elements. The above sequence of operators results in efficient highpass filtering, keeping at the same time the signal-to-noise ratio within acceptable limits. When applied to highly transparent or weakly diffusive surfaces, the preelaboration technique has largely improved the accuracy of the profilometer. In this paper the preelaboration technique is presented. In particular, the influence of the nonlinear image elaboration on the overall system performance is discussed.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Infield performance of an optical digitizer for the reverse engineering of free-form surfaces

International Journal of Advanced Manufacturing Technology, 2005

The use of OPL-3D, a robust, flexible and easy-to-use optical digitizer, in conjunction with reve... more The use of OPL-3D, a robust, flexible and easy-to-use optical digitizer, in conjunction with reverse engineering procedures is presented. The optical digitizer is used as a stand-alone (i.e., not in tandem with popular CMM’s) system, whose output point clouds can be manipulated, by means of both specifically-designed software and high-performance commercial software, to produce mesh surfaces and NURBS of the acquired shape. The digitizer-process combination yields accurate digital replicas of the target object, the accuracy of the whole combination being on the order of 1/1500 of the measurement range. The speed of acquisition, combined with the above high accuracy, the ease of use and the fact that recalibration is seldom required makes the digitizer ideal for reverse engineering in an enormous number of applications ranging from automotive to biomedical.

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Research paper thumbnail of Adaptive whole-field optical profilometry: a study of the systematic errors

IEEE Transactions on Instrumentation and Measurement, 1995

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Research paper thumbnail of Virtual and physical prototyping by means of a 3D optical digitizer: Application to facial prosthetic reconstruction

Virtual and Physical Prototyping, 2009

In this article, optical 3D acquisition, reverse engineering and rapid prototyping are proposed f... more In this article, optical 3D acquisition, reverse engineering and rapid prototyping are proposed for virtual sculpturing and fabrication of facial prostheses. A novel approach to the direct mould production by means of rapid prototyping fabrication is introduced. Full coverage of the ...

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Research paper thumbnail of Calibration and performance evaluation of a 3-D imaging sensor based on the projection of structured light

IEEE Transactions on Instrumentation and Measurement, 2000

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Research paper thumbnail of State-of-The-Art and Applications of 3D Imaging Sensors in Industry, Cultural Heritage, Medicine, and Criminal Investigation

Sensors, 2009

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Research paper thumbnail of OPL3D: A novel, portable optical digitizer for fast acquisition of free-form surfaces

Review of Scientific Instruments, 2003

The paper presents OPL-3D, a novel, powerful three-dimensional optical digitizer based on structu... more The paper presents OPL-3D, a novel, powerful three-dimensional optical digitizer based on structured, incoherent light illumination, developed in our laboratory for noncontact acquisition and digitization of free forms in space. The system exploits active stereovision using time multiplexing based on a combination of Gray code and phase-shifting techniques. The system has been specifically designed for applications to reverse engineering and rapid prototyping of free-form shapes, as well as for applications to measurement and quality control. Suitable estimation of the measurement parameters, as well as specifically developed two-dimensional image analysis, allows us to retrieve very dense point clouds in a few seconds. Special care has been devoted to the implementation of easy-to-use fast calibration procedures, and to enhancement of the flexibility of the system to the measuring problem as well as its portability. A kernel for elaboration of the views and for their alignment is provided. OPL-3D exhibits low-measurement uncertainty (120 μm) over large measurement areas (450 mm×340 mm), linearly scalable in the case of smaller areas. The output formats of the data files are fully compatible with the formats commonly used by elaboration environments dedicated to the production of polygonal models and to computer-aided design models of the shapes. The performance of OPL-3D has been tested in a number of applications, ranging from industry to biomedicine and virtual reality.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A special case of 3-D optical measurements and reverse engineering for automotive applications: the Ferrari 250 Mille Miglia

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Development and characterization of a 3D measuring system based on integration of gray code and phase-shift light projection

In this paper, a 3D measurement procedure is presented, which combines the gray code light projec... more In this paper, a 3D measurement procedure is presented, which combines the gray code light projection technique and the phase shift method. The aim is the improvement of the performance of a 3D imaging system based on structured light projection. The measuring procedure based on gray code light projection demonstrates the ability of measuring objects presenting marked discontinuities of shape, such as steep slopes, grooves and holes: the experimental tests performed show that the measurement accuracy is up to 0.42% and the precision is 0.3% of the measuring range. The accuracy of the measurement is mainly limited by its resolution. To increase the system performances, the ability of the phase shift method to achieve higher resolution has been used: the height values given by these two methods are combined in a procedure which shows increased resolution and accuracy on an extended measuring range. The basic aspects of the two basic techniques for 3D imaging and profiling are here discussed. The combined procedure which integrates them is detailed, and some relevant experimental results are reported.

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