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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.


Host interface to monitor displacement in real time.
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sensors-17-00430-f013: Host interface to monitor displacement in real time.

Mentions: The tests were conducted on nine markers with distances from the camera between 5 m and 72 m, by capturing the image using H.264 codec at 1920 × 1080 resolution, as shown in Table 1 and Table 2. Each marker was printed on 210 mm × 297 mm (A4-size) paper, which consisted of five red circles, spaced 69 mm from the center. The results on markers 1–9 are shown below. We measured the trajectory of displacement during a specific amount of time. Figure 13a shows the implemented host interface to monitor the displacement of a target marker in real time including measurement result in case of no target marker movement, as shown in Figure 13b. After the user tries to select the target marker and manually focus on the monitored region, the internal detection algorithm performs the detection of the center position, feature extraction, and perspective distortion correction. As shown in the left of Figure 13a, we first check the amount of error in the case of no displacement to verify the experiment environment, including stable camera installation. Figure 13b shows a result of long-term displacement measurement.


PTZ Camera-Based Displacement Sensor System with Perspective Distortion Correction Unit for Early Detection of Building Destruction
Host interface to monitor displacement in real time.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

sensors-17-00430-f013: Host interface to monitor displacement in real time.
Mentions: The tests were conducted on nine markers with distances from the camera between 5 m and 72 m, by capturing the image using H.264 codec at 1920 × 1080 resolution, as shown in Table 1 and Table 2. Each marker was printed on 210 mm × 297 mm (A4-size) paper, which consisted of five red circles, spaced 69 mm from the center. The results on markers 1–9 are shown below. We measured the trajectory of displacement during a specific amount of time. Figure 13a shows the implemented host interface to monitor the displacement of a target marker in real time including measurement result in case of no target marker movement, as shown in Figure 13b. After the user tries to select the target marker and manually focus on the monitored region, the internal detection algorithm performs the detection of the center position, feature extraction, and perspective distortion correction. As shown in the left of Figure 13a, we first check the amount of error in the case of no displacement to verify the experiment environment, including stable camera installation. Figure 13b shows a result of long-term displacement measurement.

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.