JPH10126766A - Monitoring camera equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain automatic recognition of a mobile body intruded in a monitoring area and to trace automatically the mobile body by selecting an output of an image pickup section in response to a detected motion of the mobile body. SOLUTION: A mobile body detection section is configured by a background image memory 7 that stores a background image being a reference image, a reference image memory 8 that stores a current image supplied from a selection section 2, a correlation arithmetic section 9 that obtains a correlation between the background image and the current image, and a discrimination section 10 that discriminates the presence of a mobile body depending on the quantity between the calculated correlation value by the correlation arithmetic section 9 and the setting value. When the detection section discriminates the presence of a mobile body, a differential arithmetic section 11 obtains a differential image based on the background and the current image and an edge image generating section 12 obtains an edge image and a frame generating section 13 generates a circumscribing frame at the outside of the edge image. The circumscribing frame is moved to attain highest correlation detection between the frame image and the original frame image so as to discriminate the presence of the mobile body. Thus, since the motion is discriminated by a frame, mis-discrimination by noise is reduced and the mobile object is traced at a high speed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance camera device for tracking a moving object by switching a plurality of image pickup units.

[0002]

2. Description of the Related Art Conventionally, when tracking a moving object by switching a plurality of imaging units, a monitoring person has manually switched the imaging units.
FIG. 4 shows such a conventional surveillance camera device.

[0003] In FIG. 4, reference numeral 1 denotes n image pickup units for taking an image by dividing a monitoring area into n parts. A selection unit 2 selects one of the n imaging units based on a switching signal 5 supplied from the outside and outputs the imaging signal. Reference numeral 3 denotes a signal obtained from the selection unit 2 as a video signal, for example, NTSC (Na
(National Television System Committee) is a video signal generation unit that converts the signals into signals and the like. Reference numeral 4 denotes a monitor for displaying an image such as the NTSC signal.

FIG. 5 is a plan view showing a situation where a room is monitored using a monitoring camera device having four image pickup units. With reference to FIG. 5, an operation of the conventional surveillance camera device for tracking a moving object will be described. A monitoring person looking at the monitor unit 4 installed in a monitoring room (not shown) or the like sends a switching signal 5 to switch the selection unit 2 and divides the monitoring area into four to capture images. The corresponding imaging unit 1 is selected from (C1, C2, C3, C4). The video signal generator 3 converts the signal output from the selector 2 into an NTSC signal or the like and displays the signal on the monitor 4. Therefore, by appropriately selecting the imaging unit 1, the angle of view is switched to monitor the entire monitoring area. For example, as shown in FIG. 5, the moving object A is currently in the angle of view of the imaging unit C2. It is assumed that this moving object A eventually moves leftward in the angle of view, goes out of the left corner, and disappears.
The observer selects the screen of the imaging unit C1 for photographing the field of view on the left side, tracks the moving object A, and continues monitoring again.

[0005] However, the above-described manual monitoring requires that the observer always keep track of the moving body by looking at the monitor screen.
There has been a problem that the monitoring cost increases and automation is difficult.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a surveillance camera device that automatically recognizes a moving object that has entered a monitoring area and automatically tracks the moving object. The purpose is to do.

[0007]

In order to achieve the above object, a plurality of imaging units, a selection unit for selectively outputting images from the plurality of imaging units, and an image output by the selection unit are stored in advance. A moving body detecting unit that detects the presence or absence of a moving body from a reference image that is present; a motion detecting unit that detects a movement of the moving body from a plurality of frames of images output by the selecting unit; and a control signal to the selecting unit. And a selection control unit that controls the selection unit so as to select the output of the imaging unit in accordance with the movement of the moving object detected by the movement detection unit.

A moving image detecting section includes a background image memory section for storing a background image serving as a reference image, a reference image memory section for storing a current image supplied by a selecting section, and the background image and the current image. And a determination unit that determines the presence or absence of a moving object based on the magnitude relationship between the correlation value calculated by the correlation calculation unit and a predetermined value.

The motion detecting section includes: a difference calculating section for calculating a difference between the background image and the current frame image when the moving body detecting section determines that there is a moving body; and obtaining an edge of the difference image. An edge image generation unit for obtaining an image, a frame generation unit for storing the edge image and generating a circumscribed frame, and a motion determination unit for determining the motion of the moving object from the edge images of a plurality of frames.

The frame generation unit generates and stores a rectangular circumscribed frame based on the horizontal and vertical directions of the stored edge image.

Further, the motion judging section moves the generated frame in the edge image generated from the difference image of the current frame while sequentially moving the frame within the frame and the frame image stored in the frame generating section. Correlation calculation is performed to detect the circumscribed frame position of the moving body in the current frame, and to detect a motion vector from the distance and direction determined by the frame position of the previous frame and this frame position.

If the position of the circumscribing frame of the moving object cannot be detected within the current angle of view of the imaging unit, the motion determination unit selects an imaging unit that captures an adjacent angle of view via the selection control unit. I made it.

Further, the selection control section generates a control signal for selecting an imaging section for photographing an adjacent angle of view when the end point position of the motion vector is in the designated area.

Further, a clock section is provided, and when the moving body detecting section determines that there is no moving body, the imaging section is sequentially selected at a predetermined time.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With the above-described configuration, when a monitoring area is divided and photographed by a plurality of image pickup units, the moving object detection unit uses the image of one image pickup unit selected by the selection unit and the image pickup of the image. The presence / absence of the moving object is detected from the reference image of the unit, and the motion detecting unit detects the motion of the moving object based on the images of a plurality of frames. The selection control unit controls the selection unit so as to select a corresponding imaging unit according to the movement of the moving body.

Further, the moving object detecting section is configured to calculate a correlation based on a background image serving as a reference image stored in the background image memory section and a current image supplied from the selecting section stored in the reference image memory section. When the calculated correlation is smaller than a predetermined value, the determination unit determines the presence of the moving object.

In the motion detecting section, the difference calculating section calculates a difference between the background image and the current frame image based on the result of the determination of the presence of the moving body by the moving body detecting section to obtain a difference image. Obtains an edge image of the difference image, the frame generation unit stores the edge image and generates a circumscribed frame, and the motion determination unit determines the motion of the moving object from the edge images of the plurality of frames.

Further, in the configuration including the clock section, when the moving body detecting section determines that there is no moving body, the selection control section sequentially selects the imaging sections at a predetermined time measured by the clock section.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a surveillance camera device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a surveillance camera device according to the present invention. The same parts as those in the conventional example (FIG. 3) are denoted by the same reference numerals. Reference numeral 1 denotes a plurality of imaging units that divide the monitoring area to take an image. A selection unit 2 selects one of the plurality of imaging units based on a control signal and outputs an image signal from the imaging unit. 3 converts the image signal obtained from the selection unit 2 into a video signal, for example, NTS.
It is a video signal generator for converting into a C (National Television System Committee) signal or the like. Reference numeral 6 denotes an A / D converter for converting the video signal into a digital signal. Reference numeral 7 denotes a background image memory unit for storing a background image serving as a reference image. Reference numeral 8 denotes a reference image memory unit that stores the current image supplied by the selection unit 2. 9 is the background image,
A correlation operation unit for obtaining a correlation with the current image. Reference numeral 10 denotes a determination unit that determines the presence or absence of a moving object based on the magnitude relationship between the correlation value calculated by the correlation operation unit 9 and a predetermined value set in advance. Configure.

Reference numeral 11 denotes a difference calculation unit that obtains a difference image by calculating a difference between the background image and the current frame image when the moving object detection unit (each of the units 7 to 10) determines that there is a moving object. Reference numeral 12 denotes an edge image generation unit that obtains an edge image of the difference image. Reference numeral 13 denotes a frame generation unit that stores the edge image and generates a circumscribed frame. Reference numeral 14 denotes a motion determination unit that determines the motion of the moving object from the edge images of a plurality of frames. Each of the units 11 to 14 constitutes a motion detection unit. Reference numeral 15 denotes a selection control unit that generates a control signal to the selection unit 2. Reference numeral 16 denotes a control unit that controls each unit. Reference numeral 17 denotes a clock unit for measuring time.

The operation of detecting a moving object of the monitoring camera device according to the present invention will be described. The image signal selected by the selection unit 2 in the imaging unit 1 is converted by the video signal generation unit 3 into, for example, an NTS
The signal is converted into a video signal of the C system, and is converted into a digital signal by the A / D converter 6. The above is the imaging / digital signal generation process of the monitoring camera device. First, before entering the monitoring mode, a background image, which is a reference image and is captured for each of the imaging units 1, is stored in the background image memory unit 7 through the imaging / digital signal generation process in advance. Next, in the monitoring mode, the current image of one imaging unit 1 supplied by the selection unit 2 is stored in the reference image memory unit 8, and
The correlation calculator 9 calculates the correlation between the background image and the current image, and the determiner 10 compares the correlation value calculated by the correlation calculator 9 with a predetermined value set in advance, and determines the correlation. If the value is smaller than the predetermined value, it is determined that there is a moving object, and the moving object is detected.

Next, the operation of the surveillance camera device according to the present invention for detecting the movement of a moving body will be described with reference to FIG. 1, FIG. 2, and FIG. FIG. 2 is a conceptual diagram showing the movement of a moving body of the monitoring camera device according to the present invention. In FIG. 2, reference numeral 21 denotes a currently selected angle of view of the imaging unit 1;
Reference numeral 8 denotes an edge image (solid line portion) generated by, for example, differentiating a difference image obtained from the current image of the imaging unit 1 and the background image. Reference numeral 24 denotes a rectangular circumscribed frame based on the horizontal direction and the vertical direction of the edge image, and the center is 0 point. 22 is the currently selected angle of view 2
1 is the left adjacent angle of view, and 23 is the right adjacent angle of view.
Reference numeral 27 denotes an area (designated area) where the currently selected angle of view 21 and the left adjacent angle of view 22 overlap. 25 is
For example, it is a rectangular circumscribed frame of the image one frame after the current one, and reference numeral 26 is a motion vector starting at the center zero of the current image and ending at the center zero of the one frame later. Note that a motion vector may be obtained from the barycentric position of each of the current frame and the image after one frame.

When the moving body detection section (each of the parts 7 to 10) determines that there is a moving body, the difference calculation section 11 calculates a difference between the background image and the current image (frame) to obtain a difference image. . The edge image generation unit 12 obtains an edge image 28 of the difference image as shown in FIG. The frame generation unit 13 stores the edge image 28 and generates a rectangular circumscribed frame by a method of drawing a horizontal line and a vertical line so as to be in contact with the outermost edge of the edge image 28.

The automatic tracking operation of the surveillance camera device according to the present invention will be described with reference to FIGS. FIG. 3 is a diagram showing a tracking operation of a moving object of the surveillance camera device according to the present invention. In FIG. 3, the motion determination unit 14 determines the entire area of the frame of the edge image obtained from the image one frame after the current image and the background image via the difference image by using the circumscribing frame from the upper left corner a, for example. By moving every predetermined pixel, b, ...
.., M,..., While sequentially moving the image in the same frame and the frame image stored in the frame generation unit, the correlation calculation is performed, and the frame position with the highest correlation is detected. It detects that a moving object is present at the frame position. With the above-described method, the motion vector is detected from the frame position of the moving body, the distance and direction determined by the frame position of the previous frame and this frame position. When the start point of the motion vector is at the currently selected angle of view 21 and the leading end position is in the overlapping area (designated area) 27, the selection control unit 15 selects the imaging unit 1 that captures the left adjacent angle of view 22. The signal is supplied to the selector 2. Further, when the size of the motion vector is equal to or more than a predetermined value, the selection control unit 15 sets an imaging unit that captures an adjacent image in the same motion vector direction even if the tip position is within the currently selected angle of view 21. A control signal for selection may be generated. Further, when the moving body detection unit determines that there is no moving body, the imaging unit 1 may be sequentially selected at a predetermined time measured by the clock unit 17.

[0025]

As described above, the present invention provides a surveillance camera device that automatically recognizes a moving object that has entered a monitoring area and automatically tracks the moving object. Therefore, the problem of the conventional manual monitoring, specifically, in order for the observer to always look at the monitor screen and track the moving object, it is necessary to appropriately transmit a switching signal to the selection unit according to the movement of the moving object. Yes, monitoring personnel require skill, which increases monitoring costs. Further, there is an advantage that it is possible to solve the problem that automation is difficult due to manual monitoring. As a feature of the present invention, since the motion is determined using the frame, erroneous determination due to noise can be reduced. In addition, the automatic recognition is performed by digital image processing, in particular, by a method of tracking a moving object using a circumscribed frame of the moving object, so that tracking can be performed with high accuracy. Furthermore, high-speed tracking that is difficult for human eyes to track is also possible.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram illustrating a movement of a moving body of the monitoring camera device according to the present invention.

FIG. 3 is a diagram illustrating a tracking operation of a moving object of the surveillance camera device according to the present invention.

FIG. 4 does not show a conventional monitoring camera device.

FIG. 5 is a plan view showing a situation where a room is monitored using a monitoring camera device provided with four imaging units.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image pick-up part 2 Selection part 3 Video signal generation part 4 Monitor part 5 Switching signal 6 A / D conversion part 7 Background image memory part 8 Reference image memory part 9 Correlation calculation part 10 Judgment part 11 Difference calculation part 12 Edge image generation part 13 Frame generation unit 14 Motion determination unit 15 Selection control unit 16 Control unit 17 Clock unit 21 Currently selected angle of view 22 Left adjacent angle of view 23 Right adjacent angle of view 24 Square circumscribed frame 25 Square of image one frame after current Circumscribed frame 26 motion vector 27 overlapping area (designated area) 28 edge image

Claims (11)

[Claims] 1. A plurality of image pickup units, a selection unit that selectively outputs images of the plurality of image pickup units, and a presence / absence of a moving object is detected from an image output by the selection unit and a reference image stored in advance. A moving body detection unit, a movement detection unit that detects movement of a moving body from images of a plurality of frames output by the selection unit, and a selection control unit that generates a control signal to the selection unit; A surveillance camera device that controls the selection unit so as to select an output of the imaging unit in accordance with the movement of the moving object detected by the camera. 2. A moving image detecting unit comprising: a background image memory unit for storing a background image serving as a reference image; a reference image memory unit for storing a current image supplied by a selecting unit; 2. The monitoring system according to claim 1, comprising: a correlation operation unit for obtaining a correlation with an image; and a determination unit for determining the presence or absence of a moving object based on a magnitude relationship between a correlation value calculated by the correlation operation unit and a predetermined value set in advance. Camera device. 3. The motion detecting section comprising: a difference calculating section for calculating a difference between a background image and a current frame image to obtain a difference image when the moving body detecting section determines that there is a moving body; 2. An edge image generating unit for obtaining an edge image, a frame generating unit for generating a circumscribed frame based on the edge image, and a motion determining unit for comparing a plurality of the same edge images to determine a motion of the moving body. The surveillance camera device according to the above. 4. The surveillance camera device according to claim 3, wherein the frame generation unit generates a rectangular circumscribed frame based on a horizontal direction and a vertical direction of the edge image. 5. The motion judging unit according to claim 1, further comprising: moving the frame in the edge image generated from the difference image of the current frame while sequentially moving the frame and the frame image stored in the frame generating unit. 4. The surveillance camera device according to claim 3, wherein an operation is performed to detect a circumscribed frame position of the moving body in the current frame, and a motion vector is detected from a distance and a direction determined by the frame position of the previous frame and the frame position. 6. When the circumscribed frame position of the moving object cannot be detected within the current angle of view of the imaging unit, the motion determination unit selects an imaging unit that captures an adjacent angle of view via the selection control unit. The surveillance camera device according to claim 3, wherein: 7. The surveillance camera device according to claim 3, wherein the tracking calculation unit calculates the motion vector of the moving object based on the position of the center of the circumscribed frame of the edge images of the two frames. 8. The surveillance camera device according to claim 3, wherein the tracking calculation unit calculates a motion vector of the moving body based on the position of the center of gravity of the edge images of the two frames. 9. The surveillance camera device according to claim 1, wherein the selection control unit generates a control signal for selecting an imaging unit that captures an adjacent angle of view when the end point position of the motion vector is in a designated area. . 10. The selection control unit according to claim 1, wherein the selection control unit generates a control signal that selects an imaging unit that captures an adjacent image in the same motion vector direction when the size of the motion vector is equal to or greater than a predetermined value. Surveillance camera device. 11. The surveillance camera device according to claim 1, further comprising a clock section, wherein when the moving body detection section determines that there is no moving body, the imaging section is sequentially selected for a predetermined time.