11:00 〜 13:00
[MGI35-P05] ONVIFコマンド用いたカメラのパンチルト操作時に生じるズレについての実験結果
キーワード：カメラ画像のズレ、パンチルト操作、ONVIF、画像処理
Experimental results on the deviation in pan tilt camera operation using by ONVIF
Abstract—When a remotely operated PTZ (Pan-Tilt-Zoom) camera set up for disaster monitoring is panned using the ONVIF (Open Network Video Interface Forum) command with the absolute coordinates specified at the desired point, the camera image shifts to the left or right depending on which direction the panning is done from, even though the same absolute coordinates are specified. In this paper we report the results of outdoor and indoor experiments on this deviation.
Index Terms—Camera image deviation, Pan tilt operation, ONVIF, Image processing
Ⅰ. INTRODICTION
NICT has installed remote-controlled PTZ cameras in various locations for disaster monitoring and other purposes. When an anomaly such as fire or smoke is detected in the camera image by visual inspection or AI, it is necessary to zoom in to see the anomaly in more detail, and to do so, it is necessary to operate the camera so that the anomaly is centered on the image. The method using ONVIF command was reported in [1], however, when the camera is panned from the right or left side, a deviation occurs even if the same absolute PTZ coordinates are specified.
In this paper we report the results of outdoor and indoor experiments on this deviation.
Ⅱ. EXPERIMENTS
A. Indoor experiments
In the indoor experiment, a red line is drawn vertically on the wall as the marker, and the same type camera as mentioned in [1] is placed so that it is perpendicular to the wall and adjusted so that the red line is near the center in the camera image. And then the PTZ absolute coordinate (x,y,z) is obtained as the desired point P0.
The operation of moving the camera from the randomly determined x-coordinate to P0 using the ONVIF command and saving the image is repeated 400 times.
B. Outdoor experiments
In the outdoor experiment, we used the camera mentioned in [1] set up at the top of Mt.Tsukuba. Fig.1 shows the image captured when the camera stopped at the desired point P’0(0.22,1.0,0.0) by the absolute move command of ONVIF and Fig. 2 and Fig. 3 show the image zoomed in 25 times in the red frame in the center of the Fig. 1.
Here, Fig. 2 shows the image when the camera is panned from the left side to P0(0.22,1.0,1.0) by the ONVIF command, and Fig. 3 shows the image from the right side. The deviation in the panning direction of both images is about 50 pixels.
Even after dozens of trials, the misalignment between left and right was almost 50 pixels.
Ⅲ. RESULTS
Fig. 4 shows a distribution of the pixel x-coordinate of the marker (vertical red line) in the captured image at P0. From Fig. 4, we can see that when the camera is panned from the right side, the pixel x-coordinates are distributed around an average of 823.5 pixels, and when the camera is panned from the left side, the pixel x-coordinates are distributed around an average of 766.1 pixels, the difference is about 57.4 pixels.
The magnitude of the misalignment is proportional to the zoom factor and varies depending on the distance and angle between the camera and the target.
Similarly, in the case of tilt, although there is a deviation between tilt from above and tilt from below, the magnitude is smaller than in the case of pan because the range of tilt operation is from 0° to 90° while the range of pan operation is 0° to 360°.
Ⅳ. CONCLUSIONS
In the case of panning with the ONVIF command specifying the absolute coordinates of the camera's destination, we found in laboratory and field experiments that the image captured by the camera shifts left or right when panning from the right side or from the left side. And the magnitude of the deviation is proportional to the zoom factor and varies depending on the distance and angle between the camera and the target.
REFERENCES
Yuki Murakami et al., “Techniques in Pan-Tilt-Zoom Operation of IP Network Camera for Visual IoT,” International Symposium on Wireless Personal Multimedia Communications -WPMC-
Abstract—When a remotely operated PTZ (Pan-Tilt-Zoom) camera set up for disaster monitoring is panned using the ONVIF (Open Network Video Interface Forum) command with the absolute coordinates specified at the desired point, the camera image shifts to the left or right depending on which direction the panning is done from, even though the same absolute coordinates are specified. In this paper we report the results of outdoor and indoor experiments on this deviation.
Index Terms—Camera image deviation, Pan tilt operation, ONVIF, Image processing
Ⅰ. INTRODICTION
NICT has installed remote-controlled PTZ cameras in various locations for disaster monitoring and other purposes. When an anomaly such as fire or smoke is detected in the camera image by visual inspection or AI, it is necessary to zoom in to see the anomaly in more detail, and to do so, it is necessary to operate the camera so that the anomaly is centered on the image. The method using ONVIF command was reported in [1], however, when the camera is panned from the right or left side, a deviation occurs even if the same absolute PTZ coordinates are specified.
In this paper we report the results of outdoor and indoor experiments on this deviation.
Ⅱ. EXPERIMENTS
A. Indoor experiments
In the indoor experiment, a red line is drawn vertically on the wall as the marker, and the same type camera as mentioned in [1] is placed so that it is perpendicular to the wall and adjusted so that the red line is near the center in the camera image. And then the PTZ absolute coordinate (x,y,z) is obtained as the desired point P0.
The operation of moving the camera from the randomly determined x-coordinate to P0 using the ONVIF command and saving the image is repeated 400 times.
B. Outdoor experiments
In the outdoor experiment, we used the camera mentioned in [1] set up at the top of Mt.Tsukuba. Fig.1 shows the image captured when the camera stopped at the desired point P’0(0.22,1.0,0.0) by the absolute move command of ONVIF and Fig. 2 and Fig. 3 show the image zoomed in 25 times in the red frame in the center of the Fig. 1.
Here, Fig. 2 shows the image when the camera is panned from the left side to P0(0.22,1.0,1.0) by the ONVIF command, and Fig. 3 shows the image from the right side. The deviation in the panning direction of both images is about 50 pixels.
Even after dozens of trials, the misalignment between left and right was almost 50 pixels.
Ⅲ. RESULTS
Fig. 4 shows a distribution of the pixel x-coordinate of the marker (vertical red line) in the captured image at P0. From Fig. 4, we can see that when the camera is panned from the right side, the pixel x-coordinates are distributed around an average of 823.5 pixels, and when the camera is panned from the left side, the pixel x-coordinates are distributed around an average of 766.1 pixels, the difference is about 57.4 pixels.
The magnitude of the misalignment is proportional to the zoom factor and varies depending on the distance and angle between the camera and the target.
Similarly, in the case of tilt, although there is a deviation between tilt from above and tilt from below, the magnitude is smaller than in the case of pan because the range of tilt operation is from 0° to 90° while the range of pan operation is 0° to 360°.
Ⅳ. CONCLUSIONS
In the case of panning with the ONVIF command specifying the absolute coordinates of the camera's destination, we found in laboratory and field experiments that the image captured by the camera shifts left or right when panning from the right side or from the left side. And the magnitude of the deviation is proportional to the zoom factor and varies depending on the distance and angle between the camera and the target.
REFERENCES
Yuki Murakami et al., “Techniques in Pan-Tilt-Zoom Operation of IP Network Camera for Visual IoT,” International Symposium on Wireless Personal Multimedia Communications -WPMC-