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PTZ Camera-Based Displacement Sensor System with Perspective Distortion Correction Unit for Early Detection of Building Destruction

View Article: PubMed Central - PubMed

ABSTRACT

This paper presents a pan-tilt-zoom (PTZ) camera-based displacement measurement system, specially based on the perspective distortion correction technique for the early detection of building destruction. The proposed PTZ-based vision system rotates the camera to monitor the specific targets from various distances and controls the zoom level of the lens for a constant field of view (FOV). The proposed approach adopts perspective distortion correction to expand the measurable range in monitoring the displacement of the target structure. The implemented system successfully obtains the displacement information in structures, which is not easily accessible on the remote site. We manually measured the displacement acquired from markers which is attached on a sample of structures covering a wide geographic region. Our approach using a PTZ-based camera reduces the perspective distortion, so that the improved system could overcome limitations of previous works related to displacement measurement. Evaluation results show that a PTZ-based displacement sensor system with the proposed distortion correction unit is possibly a cost effective and easy-to-install solution for commercialization.

No MeSH data available.


Flow chart depicting the construction of preset data.
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sensors-17-00430-f003: Flow chart depicting the construction of preset data.

Mentions: Constructing preset data is achieved through the following steps. First, the measurable plane for a marker is located by manually using the pan-tilt-zoom functions of the PTZ camera, with the relevant PTZ coordinates then entered into the preset data. Second, a specific minimum bounding rectangle (MBR) based on the marker, has to be manually registered by the administrator monitoring the target building. Third, feature points are extracted from the template image with the central point of the four most outer points, which are used to eliminate perspective distortion. Finally, from this, a homography is calculated, for which the details are explained in Section 2.1.4. Figure 3 depicts the flow of steps used in constructing preset data.


PTZ Camera-Based Displacement Sensor System with Perspective Distortion Correction Unit for Early Detection of Building Destruction
Flow chart depicting the construction of preset data.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5375716&req=5

sensors-17-00430-f003: Flow chart depicting the construction of preset data.
Mentions: Constructing preset data is achieved through the following steps. First, the measurable plane for a marker is located by manually using the pan-tilt-zoom functions of the PTZ camera, with the relevant PTZ coordinates then entered into the preset data. Second, a specific minimum bounding rectangle (MBR) based on the marker, has to be manually registered by the administrator monitoring the target building. Third, feature points are extracted from the template image with the central point of the four most outer points, which are used to eliminate perspective distortion. Finally, from this, a homography is calculated, for which the details are explained in Section 2.1.4. Figure 3 depicts the flow of steps used in constructing preset data.

View Article: PubMed Central - PubMed

ABSTRACT

This paper presents a pan-tilt-zoom (PTZ) camera-based displacement measurement system, specially based on the perspective distortion correction technique for the early detection of building destruction. The proposed PTZ-based vision system rotates the camera to monitor the specific targets from various distances and controls the zoom level of the lens for a constant field of view (FOV). The proposed approach adopts perspective distortion correction to expand the measurable range in monitoring the displacement of the target structure. The implemented system successfully obtains the displacement information in structures, which is not easily accessible on the remote site. We manually measured the displacement acquired from markers which is attached on a sample of structures covering a wide geographic region. Our approach using a PTZ-based camera reduces the perspective distortion, so that the improved system could overcome limitations of previous works related to displacement measurement. Evaluation results show that a PTZ-based displacement sensor system with the proposed distortion correction unit is possibly a cost effective and easy-to-install solution for commercialization.

No MeSH data available.