Limits...
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.


Results of optimal ellipse fitting.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5375716&req=5

sensors-17-00430-f008: Results of optimal ellipse fitting.

Mentions: Figure 8 depicts an optimal ellipse model derived by applying the RANSAC ellipse fitting algorithm to the contour points of the circles in Figure 7e,f. We first obtained a binary image by the Otsu method, then we selected a contour in which a pixel value is 255 and which has a minimum of two pixels with the value of zero in eight neighborhoods. The centers of the ellipse model and outside marker coordinates are highlighted in red. Hence, an optimal ellipse model can be determined by applying the RANSAC algorithm of ellipse fitting. This optimizes the model by excluding invalid data points, an important advantage in situations where a portion of the data may be unreliable due to some area of the circle either closing or showing an unclear edge.


PTZ Camera-Based Displacement Sensor System with Perspective Distortion Correction Unit for Early Detection of Building Destruction
Results of optimal ellipse fitting.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

sensors-17-00430-f008: Results of optimal ellipse fitting.
Mentions: Figure 8 depicts an optimal ellipse model derived by applying the RANSAC ellipse fitting algorithm to the contour points of the circles in Figure 7e,f. We first obtained a binary image by the Otsu method, then we selected a contour in which a pixel value is 255 and which has a minimum of two pixels with the value of zero in eight neighborhoods. The centers of the ellipse model and outside marker coordinates are highlighted in red. Hence, an optimal ellipse model can be determined by applying the RANSAC algorithm of ellipse fitting. This optimizes the model by excluding invalid data points, an important advantage in situations where a portion of the data may be unreliable due to some area of the circle either closing or showing an unclear edge.

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.