Search results

1 – 10 of over 6000
To view the access options for this content please click here
Article

David Page, Andreas Koschan, Sophie Voisin, Ngozi Ali and Mongi Abidi

Investigate the use of two imaging‐based methods – coded pattern projection and laser‐based triangulation – to generate 3D models as input to a rapid prototyping pipeline.

Abstract

Purpose

Investigate the use of two imaging‐based methods – coded pattern projection and laser‐based triangulation – to generate 3D models as input to a rapid prototyping pipeline.

Design/methodology/approach

Discusses structured lighting technologies as suitable imaging‐based methods. Two approaches, coded‐pattern projection and laser‐based triangulation, are specifically identified and discussed in detail. Two commercial systems are used to generate experimental results. These systems include the Genex Technologies 3D FaceCam and the Integrated Vision Products Ranger System.

Findings

Presents 3D reconstructions of objects from each of the commercial systems.

Research limitations/implications

Provides background in imaging‐based methods for 3D data collection and model generation. A practical limitation is that imaging‐based systems do not currently meet accuracy requirements, but continued improvements in imaging systems will minimize this limitation.

Practical implications

Imaging‐based approaches to 3D model generation offer potential to increase scanning time and reduce scanning complexity.

Originality/value

Introduces imaging‐based concepts to the rapid prototyping pipeline.

Details

Assembly Automation, vol. 25 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

To view the access options for this content please click here
Article

Mohammad Vaezi, Chee Kai Chua and Siaw Meng Chou

Today, medical models can be made by the use of medical imaging systems through modern image processing methods and rapid prototyping (RP) technology. In ultrasound imaging

Abstract

Purpose

Today, medical models can be made by the use of medical imaging systems through modern image processing methods and rapid prototyping (RP) technology. In ultrasound imaging systems, as images are not layered and are of lower quality as compared to those of computerized tomography (CT) and magnetic resonance imaging (MRI), the process for making physical models requires a series of intermediate processes and it is a challenge to fabricate a model using ultrasound images due to the inherent limitations of the ultrasound imaging process. The purpose of this paper is to make high quality, physical models from medical ultrasound images by combining modern image processing methods and RP technology.

Design/methodology/approach

A novel and effective semi‐automatic method was developed to improve the quality of 2D image segmentation process. In this new method, a partial histogram of 2D images was used and ideal boundaries were obtained. A 3D model was achieved using the exact boundaries and then the 3D model was converted into the stereolithography (STL) format, suitable for RP fabrication. As a case study, the foetus was chosen for this application since ultrasonic imaging is commonly used for foetus imaging so as not to harm the baby. Finally, the 3D Printing (3DP) and PolyJet processes, two types of RP technique, were used to fabricate the 3D physical models.

Findings

The physical models made in this way proved to have sufficient quality and shortened the process time considerably.

Originality/value

It is still a challenge to fabricate an exact physical model using ultrasound images. Current commercial histogram‐based segmentation method is time‐consuming and results in a less than optimum 3D model quality. In this research work, a novel and effective semi‐automatic method was developed to select the threshold optimum value easily.

Details

Rapid Prototyping Journal, vol. 18 no. 4
Type: Research Article
ISSN: 1355-2546

Keywords

To view the access options for this content please click here
Article

Kinjiro Amano, Eric C.W. Lou and Rodger Edwards

Building information modelling (BIM) is a digital representation of the physical and functional characteristics of a building. Its use offers a range of benefits in terms…

Abstract

Purpose

Building information modelling (BIM) is a digital representation of the physical and functional characteristics of a building. Its use offers a range of benefits in terms of achieving the efficient design, construction, operation and maintenance of buildings. Applying BIM at the outset of a new build project should be relatively easy. However, it is often problematic to apply BIM techniques to an existing building, for example, as part of a refurbishment project or as a tool supporting the facilities management strategy, because of inadequacies in the previous management of the dataset that characterises the facility in question. These inadequacies may include information on as built geometry and materials of construction. By the application of automated retrospective data gathering for use in BIM, such problems should be largely overcome and significant benefits in terms of efficiency gains and cost savings should be achieved.

Design/methodology/approach

Laser scanning can be used to collect geometrical and spatial information in the form of a 3D point cloud, and this technique is already used. However, as a point cloud representation does not contain any semantic information or geometrical context, such point cloud data must refer to external sources of data, such as building specification and construction materials, to be in used in BIM.

Findings

Hyperspectral imaging techniques can be applied to provide both spectral and spatial information of scenes as a set of high-resolution images. Integrating of a 3D point cloud into hyperspectral images would enable accurate identification and classification of surface materials and would also convert the 3D representation to BIM.

Originality/value

This integrated approach has been applied in other areas, for example, in crop management. The transfer of this approach to facilities management and construction would improve the efficiency and automation of the data transition from building pathology to BIM. In this study, the technological feasibility and advantages of the integration of laser scanning and hyperspectral imaging (the latter not having previously been used in the construction context in its own right) is discussed, and an example of the use of a new integration technique is presented, applied for the first time in the context of buildings.

Details

Journal of Facilities Management, vol. 17 no. 1
Type: Research Article
ISSN: 1472-5967

Keywords

To view the access options for this content please click here
Article

Hadi Mahami, Farnad Nasirzadeh, Ali Hosseininaveh Ahmadabadian, Farid Esmaeili and Saeid Nahavandi

This paper aims to propose an automatic imaging network design to improve the efficiency and accuracy of automated construction progress monitoring. The proposed method…

Abstract

Purpose

This paper aims to propose an automatic imaging network design to improve the efficiency and accuracy of automated construction progress monitoring. The proposed method will address two shortcomings of the previous studies, including the large number of captured images required and the incompleteness and inaccuracy of generated as-built models.

Design/methodology/approach

Using the proposed method, the number of required images is minimized in two stages. In the first stage, the manual photogrammetric network design is used to decrease the number of camera stations considering proper constraints. Then the image acquisition is done and the captured images are used to generate 3D points cloud model. In the second stage, a new software for automatic imaging network design is developed and used to cluster and select the optimal images automatically, using the existing dense points cloud model generated before, and the final optimum camera stations are determined. Therefore, the automated progress monitoring can be done by imaging at the selected camera stations to produce periodic progress reports.

Findings

The achieved results show that using the proposed manual and automatic imaging network design methods, the number of required images is decreased by 65 and 75 per cent, respectively. Moreover, the accuracy and completeness of points cloud reconstruction is improved and the quantity of performed work is determined with the accuracy, which is close to 100 per cent.

Practical implications

It is believed that the proposed method may present a novel and robust tool for automated progress monitoring using unmanned aerial vehicles and based on photogrammetry and computer vision techniques. Using the proposed method, the number of required images is minimized, and the accuracy and completeness of points cloud reconstruction is improved.

Originality/value

To generate the points cloud reconstruction based on close-range photogrammetry principles, more than hundreds of images must be captured and processed, which is time-consuming and labor-intensive. There has been no previous study to reduce the large number of required captured images. Moreover, lack of images in some areas leads to an incomplete or inaccurate model. This research resolves the mentioned shortcomings.

To view the access options for this content please click here
Article

Xiangyang Ju, J. Paul Siebert, Nigel J.B. McFarlane, Jiahua Wu, Robin D. Tillett and Charles Patrick Schofield

We have succeeded in capturing porcine 3D surface anatomy in vivo by developing a high‐resolution stereo imaging system. The system achieved accurate 3D shape recovery by…

Abstract

We have succeeded in capturing porcine 3D surface anatomy in vivo by developing a high‐resolution stereo imaging system. The system achieved accurate 3D shape recovery by matching stereo pair images containing only natural surface textures at high (image) resolution. The 3D imaging system presented for pig shape capture is based on photogrammetry and comprises: stereo pair image acquisition, stereo camera calibration and stereo matching and surface and texture integration. Practical issues have been addressed, and in particular the integration of multiple range images into a single 3D surface. Robust image segmentation successfully isolated the pigs within the stereo images and was employed in conjunction with depth discontinuity detection to facilitate the integration process. The capture and processing chain is detailed here and the resulting 3D pig anatomy obtained using the system presented.

Details

Sensor Review, vol. 24 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

To view the access options for this content please click here
Article

Radosław Wajman and Robert Banasiak

The purpose of this paper is to introduce a significant modification of the sensitivity maps calculation process using electric field distribution analysis. A sensitivity…

Abstract

Purpose

The purpose of this paper is to introduce a significant modification of the sensitivity maps calculation process using electric field distribution analysis. A sensitivity matrix is typically a crucial part of a deterministic image reconstruction process in a three-dimensional capacitance tomography (3D ECT) and strictly decides about a final image quality. Commonly used sensitivity matrix computation methods mostly provide acceptable results and additionally allow to perform a recalculation of sensitivity maps according to the changing permittivity distribution.

Design/methodology/approach

The new “tunnel-based” algorithm is proposed which traces the surfaces constructed along the electric field lines. The new solution is developed and tested using experimental data.

Findings

To fully validate the new technique both linear and non-linear image reconstruction processes were performed and the criteria of image error estimation were discussed. This paper discusses some preliminary results of the image reconstruction process using the new proposed algorithm. As a result of this research, an increased accuracy of the new method is proved.

Originality/value

The presented results of image reconstruction with new sensitivity matrix in comparison with the classic matrix proved that the new solution is able to improve the convergence and stability of image reconstruction process for 3D ECT imaging.

Details

Sensor Review, vol. 34 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

To view the access options for this content please click here
Article

Christine Connolly

To explore the phenomenon of stereoscopic vision and its exploitation in engineering and other professional applications, and in entertainment.

Abstract

Purpose

To explore the phenomenon of stereoscopic vision and its exploitation in engineering and other professional applications, and in entertainment.

Design/methodology/approach

Starts with a review of how stereo vision works, and the techniques used in 3D movies to present the illusion of depth and movement at right angles to the screen. Looks at some engineering products that build on these techniques, and then at the development of 3D television, based on a different image separation method. Finally looks at developments in stereo machine vision.

Findings

A variety of techniques exist to present left and right views of a scene to the correct eyes and stimulate 3D perception: for example, light‐filtering, alternate‐frame sequencing and optical separation. Fatigue occurs when there is crosstalk between those images, or when the images are presented at too low a frame rate. Many computer modelling software providers produce programs with 3D‐viewing capability for professional engineers. There are some exciting recent developments, such as add‐on PC stereo systems, and 3D TV.

Originality/value

Makes the general scientist aware of the wide range of professional uses of stereo vision, and of the engineering challenges behind 3D film and television.

Details

Sensor Review, vol. 26 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

To view the access options for this content please click here
Article

Seth Dillard, James Buchholz, Sarah Vigmostad, Hyunggun Kim and H.S. Udaykumar

The performance of three frequently used level set-based segmentation methods is examined for the purpose of defining features and boundary conditions for image-based…

Abstract

Purpose

The performance of three frequently used level set-based segmentation methods is examined for the purpose of defining features and boundary conditions for image-based Eulerian fluid and solid mechanics models. The focus of the evaluation is to identify an approach that produces the best geometric representation from a computational fluid/solid modeling point of view. In particular, extraction of geometries from a wide variety of imaging modalities and noise intensities, to supply to an immersed boundary approach, is targeted.

Design/methodology/approach

Two- and three-dimensional images, acquired from optical, X-ray CT, and ultrasound imaging modalities, are segmented with active contours, k-means, and adaptive clustering methods. Segmentation contours are converted to level sets and smoothed as necessary for use in fluid/solid simulations. Results produced by the three approaches are compared visually and with contrast ratio, signal-to-noise ratio, and contrast-to-noise ratio measures.

Findings

While the active contours method possesses built-in smoothing and regularization and produces continuous contours, the clustering methods (k-means and adaptive clustering) produce discrete (pixelated) contours that require smoothing using speckle-reducing anisotropic diffusion (SRAD). Thus, for images with high contrast and low to moderate noise, active contours are generally preferable. However, adaptive clustering is found to be far superior to the other two methods for images possessing high levels of noise and global intensity variations, due to its more sophisticated use of local pixel/voxel intensity statistics.

Originality/value

It is often difficult to know a priori which segmentation will perform best for a given image type, particularly when geometric modeling is the ultimate goal. This work offers insight to the algorithm selection process, as well as outlining a practical framework for generating useful geometric surfaces in an Eulerian setting.

Details

Engineering Computations, vol. 31 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

To view the access options for this content please click here
Article

Christine Connolly

The purpose of this paper is to review the progress of machine vision as it applies to automated assembly applications.

Abstract

Purpose

The purpose of this paper is to review the progress of machine vision as it applies to automated assembly applications.

Design/methodology/approach

A series of technological developments is described: 3D vision, smart cameras, near infrared (NIR) imaging and LED illumination. Associated with each are relevant assembly applications.

Findings

Advances in multi‐core processors are facilitating the development of 3D image processing algorithms for robot guidance and product inspection, which in turn enable the automation of skilful and labour‐intensive tasks. Machine vision products are becoming more capable, yet simpler to use. NIR imaging is useful for inspecting semiconductors and bottle filling. Advances in LED lighting address difficult inspection tasks at the macro and microscopic levels.

Originality/value

The paper recognises the emergence of 3D machine vision as a new tool in assembly automation. Updates engineers on other relevant machine vision advances.

Details

Assembly Automation, vol. 29 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

To view the access options for this content please click here
Article

Lu Lu, Kit-Lun Yick, Sun Pui Ng, Joanne Yip and Chi Yung Tse

The purpose of this paper is to quantitatively assess the three-dimensional (3D) geometry and symmetry of the torso for spinal deformity and the use of orthotic bracewear…

Abstract

Purpose

The purpose of this paper is to quantitatively assess the three-dimensional (3D) geometry and symmetry of the torso for spinal deformity and the use of orthotic bracewear by using non-invasive 3D body scanning technology.

Design/methodology/approach

In pursuing greater accuracy of body anthropometric measurements to improve the fit and design of apparel, 3D body scanning technology and image analysis provide many more advantages over the traditional manual methods that use contact measurements. To measure the changes in the torso geometry and profile symmetry of patients with adolescent idiopathic scoliosis, five individuals are recruited to undergo body scanning both with and without wearing a rigid brace during a period of six months. The cross-sectional areas and profiles of the reconstructed 3D torso models are examined to evaluate the level of body symmetry.

Findings

Significant changes in the cross-sectional profile are found amongst four of the patients over the different visits for measurements (p < 0.05), which are consistent with the X-rays results. The 3D body scanning system can reliably evaluate changes in the body geometry of patients with scoliosis. Nevertheless, improvements in the symmetry of the torso are found to be somewhat inconsistent among the patients and across different visits.

Originality/value

This pilot study demonstrates a practical and safe means to measure and analyse the torso geometry and symmetry so as to allow for more frequent evaluations, which would result in effective and optimal treatment of spinal deformation.

Details

Research Journal of Textile and Apparel, vol. 21 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

1 – 10 of over 6000