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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 a SONY A850 camera using a 50 mm lens in different situations.
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f10-sensors-12-11271: Stability analysis for a SONY A850 camera using a 50 mm lens in different situations.

Mentions: In the second experiment, single camera calibration is performed after detaching, rebooting, and refocusing (at 1.5 m and infinity) the lens with 0, 5, 10, 15 and 20 times. Since the adopted SAL50F14 lens will perform initialization every time when the camera is rebooted, i.e., the focal distance is reset to infinity. Although, the principal distance is fixed by using a tape to fix the ring on the lens, it is necessary to investigate its stability and its influence on the camera's internal geometry. The change significance plot is shown in Figure 10. It can be seen that the detachment of lens will introduce significant change in its IOPs, particularly for the principal point coordinates. For the task of refocusing and rebooting, for most of the time the APs do not change a lot, but sometimes the principal point coordinates will change significantly. Thus, it is suggested that refocusing or detaching the lens during image acquisition should be avoided. Even rebooting the camera is not recommended, particularly when the lens has initialization functionality.


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 a SONY A850 camera using a 50 mm lens in different situations.
© Copyright Policy
Related In: Results  -  Collection

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

f10-sensors-12-11271: Stability analysis for a SONY A850 camera using a 50 mm lens in different situations.
Mentions: In the second experiment, single camera calibration is performed after detaching, rebooting, and refocusing (at 1.5 m and infinity) the lens with 0, 5, 10, 15 and 20 times. Since the adopted SAL50F14 lens will perform initialization every time when the camera is rebooted, i.e., the focal distance is reset to infinity. Although, the principal distance is fixed by using a tape to fix the ring on the lens, it is necessary to investigate its stability and its influence on the camera's internal geometry. The change significance plot is shown in Figure 10. It can be seen that the detachment of lens will introduce significant change in its IOPs, particularly for the principal point coordinates. For the task of refocusing and rebooting, for most of the time the APs do not change a lot, but sometimes the principal point coordinates will change significantly. Thus, it is suggested that refocusing or detaching the lens during image acquisition should be avoided. Even rebooting the camera is not recommended, particularly when the lens has initialization functionality.

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.