JPH0514792A - Monitoring device - Google Patents

Abstract

PURPOSE:To detect or set the visual field of a camera, that is, the angle of view, and the attitude of the camera, that is, the surrounding angles of vertical and horizontal axes with an extremely high accuracy, in a monitoring device equipped with an image pickup device such as a television camera or the like by which a remote control can be attained. CONSTITUTION:An analog video signal obtained by an image pickup device 1 is converted into a digital signal by an A/D converting part 7. An obtained picture is picture-processed by a characteristic extracting part 8, the information of a characteristic is extracted, and stored in a characteristic storing part 9. On the other hand, the characteristic obtained by the characteristic extracting part 8 is compared with the information preliminarily stored in the characteristic storing part 9 by a characteristic comparing part 10, so that the information concerned with the visual field and attribute of the present image pickup device 1 can be calculated. Moreover, a focus distance detecting and setting part 4 and a frame angle detecting and setting part 5 are controlled by giving a command to a visual field and attribute control part 6, based on the pertinent information, so that the attribute visual field and attribute can be set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of changing the field of view of an image pickup device such as a television camera installed on a movable base, that is, the angle of view and posture of the image pickup device, that is, the angle around each axis, and setting to an arbitrary state. It is a thing.

[0002]

2. Description of the Related Art FIG. 4 shows a monitoring device for obtaining camera attitude information and angle-of-view information in an image pickup device such as a remotely controllable television camera mounted on a movable mount which has been generally used. It is a block diagram which shows a structure. 1
Is an image pickup device for obtaining an image, 2 is a monitor device for monitoring an image signal obtained from the image pickup device 1,
3 is a movable mount for holding the image pickup apparatus 1 and setting an arbitrary angle of view, 4 is a focal length detection setting unit for changing the field of view by changing the focal length of the lens of the image pickup apparatus 1,
Reference numeral 5 is a pedestal angle detection setting unit for changing the angles of the movable pedestal 3 around the horizontal axis and the vertical axis to set a desired angle, 6
Is a visual field posture control unit that remotely controls the visual field and posture of the image pickup apparatus 1 from the place where the monitor device 2 is installed through the focal length detection setting unit 4 and the mount angle detection setting unit 5.

The operation of a conventional surveillance device having a remotely controllable television camera will be described below. The image pickup apparatus 1 is installed in a position where it is held on a movable base 3 and overlooks a place to be monitored. At this time, the video signal output from the image pickup device 1 is sent to the monitor device 2 using a transmission means such as a video signal cable or an optical fiber to display an image on a television display or record it with a video tape recorder. To be done. On the other hand, when a part of the field of view of the image pickup apparatus 1 is enlarged, or conversely, when a wider range is desired to be viewed, the field-of-view posture control unit 6 is operated to operate the focal length detection setting unit 4.
Can be remotely controlled to change the focal length of the lens of the image pickup apparatus 1. Alternatively, when it is desired to change the posture of the TV camera to see the surroundings, the view posture control unit 6 can be operated to remotely control the mount angle detection setting unit 5 to change the angle of the movable mount. It is possible.

[0004]

In the conventional monitoring apparatus equipped with the remotely controllable television camera as described above, a potentiometer, a stepping motor or the like is used for the focal length detection setting unit 4 and the mount angle setting unit 5. There is. Therefore, its detection accuracy is often subject to mechanical restrictions,
Further, the setting accuracy of the field of view and the posture at that time is not sufficient for A / D converting the image of the television camera to perform image processing. Therefore, it is necessary to correct the position and size of the image before the image processing.

The present invention has been made in order to solve the above-mentioned problems, and in the past, since the detection was mainly made by a mechanical sensor, the visual field of an image pickup device such as a television camera which lacked accuracy, That is, it is an object of the present invention to obtain a monitoring device capable of accurately detecting the angle of view and the attitude of the television camera, that is, the angle information based on the image obtained from the television camera.

[0006]

According to another aspect of the present invention, there is provided a monitoring device according to the present invention, wherein a visual field posture control section holds a visual field and a desired posture via a focal length detection setting section and a pedestal angle detection setting section held by a movable gantry. A monitor device is used to monitor an image obtained from an imaging device that can be set to a remote state and remotely controlled, and an A / D conversion unit that converts an analog video signal output from the imaging device into a digital signal, a converted digital image A feature extraction unit for processing image features to extract image features, a feature storage unit for storing the extracted image features, and an image captured by comparing the previously stored image features with the current image features. A feature comparison unit for calculating information about the field of view and posture of the apparatus, that is, the angle of view of the image pickup apparatus or the focal length of the lens, the angle about the horizontal axis and the angle about the vertical axis of the image pickup apparatus is provided.

Further, it has a function of changing the field of view and the posture of the image pickup device to an arbitrary state by using the information on the posture of the image pickup device obtained by the feature comparison section.

[0008]

The field of view and the posture of the image pickup apparatus, for example, a television camera according to the present invention is detected as follows. That is,
The analog signal obtained from the television camera is converted into a digital signal, and the image is processed by the feature extraction unit to extract various features of the image, and the extracted features are stored in the feature storage unit. Then, when the field of view or posture of the television camera changes, the process up to the extraction of image features is performed again, and the differences are compared with the features stored in the feature comparison unit, that is, the size of the features on the image. This is done by detecting the difference in pod position. At this time, it is possible to detect these differences pixel by pixel on the image, and therefore it is possible to detect the field of view and the posture of the television camera with extremely high accuracy.

Further, if a signal is sent to the visual field posture control unit based on the state detected above, the focal length detection setting unit and the gantry angle detection setting unit respectively detect the focal length of the lens and the horizontal and vertical axes of the gantry. The angle can be changed to any state.

[0010]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the monitoring device of this embodiment. In FIG. 1, 1 is an image pickup device for acquiring an image, a TV camera in this case, 2 is a monitor device for monitoring a video signal obtained from the image pickup device 1, and 3 is an arbitrary device holding the image pickup device 1. A movable mount 4 for setting the angle of view of the movable mount 3, a focal length detection setting unit 4 for changing the field of view by changing the focal length of the lens of the image pickup apparatus 1, and 5 for the horizontal axis and the vertical axis of the movable base 3. A gantry angle detection setting unit for changing the angle and setting it to a desired angle, a reference numeral 6 denotes a visual field and a posture of the image pickup apparatus 1 from a place where the monitor device 2 is installed, through a focal length detection setting unit 4 and a gantry angle detection setting unit 5. A field-of-view posture control unit 7 that controls the focal length detection setting unit 4 and the gantry angle detection setting unit 5 based on a signal from a feature comparison unit described later, and 7 is an analog obtained from the imaging device 1. A / D converter for converting an image signal into a digital signal, 8 is A / D
A feature extraction unit for processing the digital signalized image obtained from the conversion unit 7 to obtain the feature of the image, 9
Is a feature storage unit for storing various features obtained by the feature extraction unit 8, and 10 is a feature comparison unit for comparing the feature of the image previously stored with the feature of the current image. Figure 2
FIG. 3 is a schematic diagram showing an example of an image obtained from the image pickup apparatus 1. Reference numeral 11 is a box shown in the image of FIG. 12 is the first feature point obtained from the image of FIG. 2, 13 is the second feature point, 14 is the third feature point, and 15 is the fourth feature point.
Is the characteristic point of. Further, FIG. 3 is a schematic explanatory view showing another example of an image acquired in a camera attitude slightly different from that in FIG. Reference numeral 11 in the figure is the same as the box 11 in FIG. 1
Reference numerals 6, 17, and 18 are first, second, and third characteristic points obtained from the image of FIG. 3, respectively.

The operation of this embodiment will be described below. The image obtained from the image pickup device 1 is sent to the monitor device 2 by a transmission means such as a video signal cable or an optical fiber, and is used for monitoring work. On the other hand, the video signal output from the image pickup apparatus 1 is subjected to image processing by the feature extraction unit 8 via the A / D conversion unit 7, and the feature is extracted. 12, 1 in FIG.
3, 14, and 15 are examples of this. An edge, an intersection point of the edges, an end point, or the like in the image may be selected as a characteristic of the image. In the embodiment shown in FIG. 2, the intersection of edges is selected. These features store the position in the image, the positional relationship between the features, and the distance in the feature storage unit 9.

Now, it is assumed that the visual field posture control section 6 is operated so that the image pickup apparatus 1 faces slightly to the upper right. At this time, the visual field posture control unit 6 instructs the gantry angle detection setting unit 5 to change the angle around the vertical axis (called pan) and the angle around the horizontal axis (called tilt). An image obtained from the image pickup apparatus 1 at that time is shown in FIG.
Is. Compared to FIG. 2, the box 11 moves in the lower left direction on the image by the amount that the imaging device 1 faces the upper right. According to the same procedure as above, the first, second, and third characteristic points 16, 17, and 18 are obtained from FIG. 3, respectively. In the feature comparison unit 10, these feature points 12, 13, 14, 15, 16, 17, 18
Identity is determined.

This determination may be performed as follows, for example. It is assumed that the feature storage unit 9 stores the coordinates of each of the feature points 12, 13, 14, and 15. At this time, first, pay attention to the highest feature point 12 on the screen.
Then, 16 is selected as the highest feature point on the screen for each of the feature points of the images for which the identity is to be determined. Now, these characteristic points 12 and characteristic points 1
Assuming that 6 are the same, there should be characteristic points below the characteristic point 16, lower right, and lower left from the information stored in the characteristic storage unit 9. Actually, the characteristic point 17 exists below the characteristic point 16 and the characteristic point 18 also exists at the lower right side, and the distance relationship between the characteristic points also matches the content stored in the characteristic storage unit 9. Therefore, the feature comparison unit 10 determines that the feature points 12, 13, and 14 are the same as the feature points 16, 17, and 18, respectively. This means that the change in the camera posture is as large as the change in the coordinates of the corresponding feature points. This change amount has a corresponding relationship with the change in the posture of the camera and can be easily converted. Therefore, the feature comparison unit 10 can know the change in the posture of the camera in pixel units.

Further, based on this information, the visual field posture control unit 6
By controlling, it becomes possible to set the camera posture extremely accurately.

[0015]

As described above, according to the present invention, the monitoring device capable of remotely controlling the visual field and the posture of the image pickup device is provided.
An A / D converter that converts the output of the imaging device into a digital signal, a feature extractor that processes the converted digital image to extract image features, and a comparison between the extracted image features and the stored features Since the feature comparison unit that calculates information on the visual field and orientation of the imaging device is provided, there is an effect that the visual field and orientation of the imaging device can be detected with extremely high accuracy.

Further, since it has a function of changing the visual field and the posture of the image pickup apparatus to an arbitrary state by using the information on the posture of the image pickup apparatus obtained by the feature comparison unit, the visual field and the posture can be accurately measured. The effect is that it can be changed to any state.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a monitoring device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of an image obtained from the image pickup apparatus according to the embodiment of the present invention.

FIG. 3 is a schematic diagram showing an example of an image obtained from the image pickup apparatus according to the embodiment of the present invention.

FIG. 4 is a block diagram showing the configuration of a conventional monitoring device capable of remotely controlling the field of view and posture of a television camera.

[Explanation of symbols]

1 Imaging device 2 monitor 3 movable mounts 4 Focal length detection setting section 5 Mounting angle detection setting section 6 Vision posture control unit 7 A / D converter 8 Feature extraction unit 9 Feature storage 10 Feature comparison section

Claims (2)

[Claims] 1. A field-of-view attitude control unit, which is held by a movable base, sets a field of view and attitude to a desired state via a focal length detection setting unit and a base angle detection setting unit, and is obtained from a remotely controllable imaging device. In a monitoring device for monitoring an image captured by a monitor device, an A / D conversion unit for converting an analog image signal output from the image capturing device into a digital signal, and processing the converted digital image to extract characteristics of the image. A feature extraction unit, a feature storage unit that stores the features of the extracted image, and information relating to the field of view and orientation of the imaging device by comparing the previously stored image features with the current image features, that is, the imaging A monitoring device comprising a feature comparison unit for calculating an angle of view of the device, a focal length of a lens, an angle about a horizontal axis and an angle about a vertical axis of the imaging device. 2. The apparatus according to claim 1, further comprising a function of changing the field of view and the posture of the image pickup device to an arbitrary state by using the information on the posture of the image pickup device obtained by the feature comparison unit. Monitoring equipment.