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A semi-automatic image-based close range 3D modeling pipeline using a multi-camera configuration.

Rau JY, Yeh PC - Sensors (Basel) (2012)

Bottom Line: This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object.The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner.The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333.

View Article: PubMed Central - PubMed

Affiliation: Department of Geomatics, National Cheng-Kung University, No.1, University Road, Tainan 701, Taiwan. jyrau@mail.ncku.edu.tw

ABSTRACT
The generation of photo-realistic 3D models is an important task for digital recording of cultural heritage objects. This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object. Multiple digital single lens reflex (DSLR) cameras are adopted and fixed with invariant relative orientations. Instead of photo-triangulation after image acquisition, calibration is performed to estimate the exterior orientation parameters of the multi-camera configuration which can be processed fully automatically using coded targets. The calibrated orientation parameters of all cameras are applied to images taken using the same camera configuration. This means that when performing multi-image matching for surface point cloud generation, the orientation parameters will remain the same as the calibrated results, even when the target has changed. Base on this invariant character, the whole 3D modeling pipeline can be performed completely automatically, once the whole system has been calibrated and the software was seamlessly integrated. Several experiments were conducted to prove the feasibility of the proposed system. Images observed include that of a human being, eight Buddhist statues, and a stone sculpture. The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner. The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333. It demonstrates the feasibility of the proposed low-cost image-based 3D modeling pipeline and its applicability to a large quantity of antiques stored in a museum.

No MeSH data available.


Stability analysis for SONY A850 and A900 cameras using 50 mm and 85 mm lenses.
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f11-sensors-12-11271: Stability analysis for SONY A850 and A900 cameras using 50 mm and 85 mm lenses.

Mentions: The purpose of the last experiment is to compare different cameras with different lenses. Here the SONY A850 and A900 cameras with SAL50F14 50 mm and SAL85F28 85 mm lenses are utilized. The SAL85F28 lens can be setup in manual focusing (MF) mode so that no initialization (refocusing at infinite) will be performed after rebooting the camera. There are four combinations obtained by using these two cameras and two lenses. The stability testing is applied for the same camera by comparing the single camera calibration results with the round table fixed or rotated. When the round table is fixed, a 90 degrees convergent angle is constructed from six viewing directions. The camera's roll angles are changed by 0 and ±90 degrees at each location. It results in a total of 18 images for camera calibration. The change significance plot is shown in Figure 11. It can be seen that the 85 mm lens has a manual focusing functionality achieve higher stability in its internal geometry and is independent to the camera used. Thus, it is suggested that a lens with this capability should be considered for high precision 3D modeling purposes.


A semi-automatic image-based close range 3D modeling pipeline using a multi-camera configuration.

Rau JY, Yeh PC - Sensors (Basel) (2012)

Stability analysis for SONY A850 and A900 cameras using 50 mm and 85 mm lenses.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472884&req=5

f11-sensors-12-11271: Stability analysis for SONY A850 and A900 cameras using 50 mm and 85 mm lenses.
Mentions: The purpose of the last experiment is to compare different cameras with different lenses. Here the SONY A850 and A900 cameras with SAL50F14 50 mm and SAL85F28 85 mm lenses are utilized. The SAL85F28 lens can be setup in manual focusing (MF) mode so that no initialization (refocusing at infinite) will be performed after rebooting the camera. There are four combinations obtained by using these two cameras and two lenses. The stability testing is applied for the same camera by comparing the single camera calibration results with the round table fixed or rotated. When the round table is fixed, a 90 degrees convergent angle is constructed from six viewing directions. The camera's roll angles are changed by 0 and ±90 degrees at each location. It results in a total of 18 images for camera calibration. The change significance plot is shown in Figure 11. It can be seen that the 85 mm lens has a manual focusing functionality achieve higher stability in its internal geometry and is independent to the camera used. Thus, it is suggested that a lens with this capability should be considered for high precision 3D modeling purposes.

Bottom Line: This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object.The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner.The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333.

View Article: PubMed Central - PubMed

Affiliation: Department of Geomatics, National Cheng-Kung University, No.1, University Road, Tainan 701, Taiwan. jyrau@mail.ncku.edu.tw

ABSTRACT
The generation of photo-realistic 3D models is an important task for digital recording of cultural heritage objects. This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object. Multiple digital single lens reflex (DSLR) cameras are adopted and fixed with invariant relative orientations. Instead of photo-triangulation after image acquisition, calibration is performed to estimate the exterior orientation parameters of the multi-camera configuration which can be processed fully automatically using coded targets. The calibrated orientation parameters of all cameras are applied to images taken using the same camera configuration. This means that when performing multi-image matching for surface point cloud generation, the orientation parameters will remain the same as the calibrated results, even when the target has changed. Base on this invariant character, the whole 3D modeling pipeline can be performed completely automatically, once the whole system has been calibrated and the software was seamlessly integrated. Several experiments were conducted to prove the feasibility of the proposed system. Images observed include that of a human being, eight Buddhist statues, and a stone sculpture. The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner. The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333. It demonstrates the feasibility of the proposed low-cost image-based 3D modeling pipeline and its applicability to a large quantity of antiques stored in a museum.

No MeSH data available.