JP2003259339A - Image monitoring method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image monitoring method and apparatus for recognizing and discriminating a change in an object such as a vehicle in a monitor area in a parking place or the like through simple and efficient image data recognition processing and efficiently videorecording a monitored image. <P>SOLUTION: The image monitoring apparatus receives a monitor image at a prescribed time interval, compares a newest input image with an image precedingly received, detects a change depending on the presence of the difference, and detects and decides a place in the monitor area from the position of the change. Further, the image monitoring apparatus starts video-recording by detecting the change in the monitor image and stops the video-recording by detecting restoration of the monitor image to a steady-state. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an electronic camera such as a CCD camera to pick up an image of the presence or absence of an object in a predetermined area, such as parking lot management, on-street parking, or monitoring of people or objects in a specific place. And a method and device for monitoring by.

[0002]

2. Description of the Related Art Various types of vehicle detection methods have been proposed in conventional devices and systems for monitoring the parking conditions of vehicles in a parking lot, vehicle parking on a road, and specific places. For example, in parking lot monitoring, an optical sensor is installed in each of a plurality of parking sections of a parking lot, a method of detecting the presence of a vehicle by a change in the amount of received light, a mechanical sensor is arranged in each parking section, and this sensor is set by parking. There are a method of physically operating and detecting parking, and a method of scanning and moving a surveillance camera by a rail or the like to image a plurality of parking sections and detecting a vehicle by image recognition processing. However, all of these parking lot monitoring systems have special detection equipment and special structures in the parking lot, so there is a problem that construction work such as structural improvement of the parking lot and installation of equipment is large and costly. It was

On the other hand, with the progress of image recognition processing technology, in order to cope with the above-mentioned problems, a plurality of parking sections are imaged by a TV camera installed at one place, the images are converted into digital information, and the image data is processed by a computer. A monitoring method for recognizing and discriminating the presence / absence of a vehicle for each parking section is being implemented. In this method, a captured image when a vehicle is not present is used as a reference image, and each time a monitoring image is input, the reference image and the monitoring image are compared, and the difference between the images is detected to detect the presence of the vehicle. The density of the image around the outside of the area is compared with the image density of a specific parking area and the presence of the vehicle is recognized based on the size of the density, or the digital data of the image is filtered by a computer and the contour of the vehicle is monitored from the monitoring image. There is known one that detects the presence or absence of a vehicle by extracting edge data indicating In addition, some surveillance systems that monitor a specific place record the above-mentioned surveillance image, but among them, one that activates the recording device by detecting a change in the surveillance image in order to efficiently use the recording member for recording. is there.

[0004]

However, in the monitoring to which these image recognition processings are applied, for example, in the case of monitoring the parking lot, the presence / absence of the vehicle is recognized and discriminated in each parking section every time the monitoring image is input. In addition, the complicated image data processing at the time of monitoring image input must be performed at high speed, increasing the processing load on the computer, and identifying the presence / absence of a vehicle every time a monitoring image is input even in a parking lot where the state does not change, which is inefficient. There was a problem. In addition, the system for recording the above-mentioned surveillance image records while the change continues, that is, while the subject in the image is moving. There is a problem that recording is not started or stopped unless it is done. The present invention focuses on these problems, and it is an object to efficiently and simply recognize and discriminate a change in an image and its position, and to enable recording during an abnormal state different from a steady state even if the monitoring image does not move. And

[0005]

According to a first aspect of the present invention, there is provided an image monitoring method, wherein images captured by an electronic camera in a predetermined monitoring area are input at predetermined time intervals. By comparing with the one at the time of input, the difference between the two images is detected and the image position where the difference exists is determined, the position in the predetermined region corresponding to the image position is determined, and the position in the predetermined region is determined. Outputs information indicating the location where the presence or absence of an object has changed.

According to another aspect of the present invention, there is provided an image monitoring apparatus, wherein an electronic camera for picking up an image of a predetermined monitoring area, image input control means for inputting an image of the electronic camera at predetermined time intervals, and an image pickup signal of the electronic camera. Image processing means for converting to a digital signal, image storage means for storing the latest input image and the previous input image of the digital image obtained by imaging the monitoring area, and comparing the latest input image and the previous input image, A difference detecting means for detecting a difference and, when there is a difference between the two images, an image position where the difference exists is discriminated, and a change position determination for deciding a place in the predetermined region where the presence or absence of an object has changed from the discrimination position. And a means for outputting the position information determined by the changed position determining means.

An image monitoring method according to a third aspect of the present invention is an image monitoring method in which a predetermined area is imaged by an electronic camera and the captured image is reproducibly recorded. In the image monitoring method, the steady-state imaged image of the predetermined area is used as a reference image. The monitor image that is stored and input at a predetermined time interval during monitoring of the predetermined area is compared with the reference image, and as a result of the comparison, the recording operation is stopped while there is no difference between the two images, The recording is started by the detection, and the recording is stopped again by detecting that there is no difference between the two images.

According to the image monitoring method of the invention of claim 4, date and time information is recorded together with the captured image.

[0009]

By comparing the latest captured image input at every predetermined time interval with the captured image at the previous input, if the images change during the above time, this change can be detected by detecting the difference between the two images. It is possible to determine the place in the corresponding monitoring area from the image position of this difference detection and output the information indicating the place where the presence or absence of the object has changed.

Further, in an image monitoring method for picking up a predetermined area with an electronic camera and replayably recording the picked-up image,
During monitoring, the latest monitoring image input at a predetermined time interval is compared with the steady reference image and the difference between the two images is detected to start recording the monitoring image from the occurrence of a change that is not in a steady state, and the difference disappears. By detecting that, recording can be continued until it returns to a steady state.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the functions of a control configuration of an embodiment in which the present invention is applied to parking lot management, and FIG.
FIG. 3 is a diagram showing a monitoring aspect of an embodiment. In the figure, 1
Is an electronic camera having an imaging field of view of the entire monitoring target section of the parking lot 3 including a plurality of parking sections 2, such as a support post 4
Is installed at a high position, that is, at a position where the entire monitored area can be included in the field of view from diagonally above. 5a and 5b are parked cars. The image captured by the electronic camera 1 is as shown in FIG. 3 or FIG. 4, for example.

Reference numeral 6 denotes a shutter control section for controlling opening / closing of a shutter of the electronic camera, which causes an image to be taken at predetermined time intervals. Reference numeral 7 is an A / D converter that converts an analog captured image signal into a digital signal, and 8 is a memory switching unit that alternately stores the captured digital image information in the first image memory 9 and the second image memory 10. , 11 read the image data stored in the first and second image memories 9 and 10,
A comparison and recognition unit that compares both data to detect the presence or absence of a difference, and if there is a difference, recognizes and discriminates the position of the difference, 12 is installed near the entrance of the parking lot and displays the availability of each parking section of the parking lot. A guide display plate for guiding the user, 13 is a comparative recognition unit 11
The guidance display control unit that controls the display of the parking status of the parking lot 3 based on the information indicating the position and the change from the vehicle, and 14 exits the parking lot based on the information indicating the position and the change from the comparative recognition unit 11. It is a charge calculation unit that calculates a parking charge for a car.

Next, the operation of the above configuration will be described with reference to FIG. The electronic camera 1 puts all the parking sections of the parking lot 3 in its field of view, inputs an image as shown in FIG. 3 or FIG. 4 (step S1), and digitizes this input image signal by the A / D conversion unit 7. , Are alternately stored in the first image memory 9 and the second image memory 10 for each image pickup (step S2). For example, when the image captured at the previous time is stored in the first image memory 9, the image captured this time is stored in the second image memory 10, and the image captured next time is overwritten and stored in the first image memory 9 again. . That is, one of the first image memory 9 and the second image memory 10 stores the image data input last time, and the other stores the latest image data input this time.

The comparison and recognition section 11 reads out the stored data from the two image memories in synchronization with the image input by the electronic camera 1 and compares them (step S3). If there is no difference between the two image data, then there is no change (step S
4) When a predetermined time has passed since the previous image capture (step S
5) The shutter controller 6 drives the shutter of the electronic camera 1 (step S6) to input the next image. The predetermined time is set to a time suitable for the parking cycle monitoring cycle. This operation is repeated every time a predetermined time elapses until a difference between the two image data is detected.

If a difference between the two image data is detected, it is assumed that the parking situation in the monitoring area has changed (step S
4) The position where the difference occurs in the input image data is determined, and the corresponding parking section is recognized and determined from the position (steps S7 and S8), and the mode of change, that is, from no object to an object or from an object to an object It is determined from the both image data at the difference occurrence position whether the change has occurred (step S9). For example, in the case where the image captured last time is the one shown in FIG. 3 and the latest image captured this time is the image in which the car 5b is parked in the empty parking section 2a as shown in FIG.
A change occurs in the image at the position corresponding to the parking section 2a in the entire input image, and a difference occurs in this portion when comparing the previous input image data with the current input image data. And this difference becomes data showing a change from the absence of an object to the presence of an object. In addition, the position of the image data corresponding to each parking section in the entire input image is uniquely determined as long as the imaging visual field of the electronic camera 1 is fixed, and the position on the image where the difference occurs is the parking section information corresponding to this. Can be converted to. Thus, the car 5 is placed in the parking area 2a.
The comparative recognition unit 11 recognizes and discriminates that b is parked, and outputs information indicating the parking section 2a and information indicating parking.
On the contrary, the previous input image is shown in FIG. 4, and the current input image is shown in FIG.
If the two images are compared by the comparing and recognizing unit 11, a difference occurs between the images at the positions corresponding to the parking section 2a, indicating that the information indicating the parking section 2a and that this parking section has changed from being used to being empty. Output information.

The parking section information and the parking presence / absence information are
It is sent to the guidance display control unit 13 and the charge calculation unit 14. The charge calculation unit 14 measures and stores the time when the information indicating that parking is changed is stored for each parking section, and the time when the information indicating that parking is changed is measured again to calculate the parking time of the parking section. , The parking fee is converted and the time, time and fee are printed out on a receipt. Further, the guidance display control unit 13 switches the display of the corresponding parking section on the guidance display plate 12 to indicate "parking" or "vacant" according to the information parking section information.

In this embodiment, depending on the image capturing timing of the electronic camera 1, the image may be captured when a vehicle is in the process of entering or leaving a certain parking section. In addition, a person present in the parking lot may be imaged. Therefore, only when the difference between the previous input image and the current input image is equal to or higher than the level, the change in the parking situation is recognized. The image data may also consist of pixel shades or brightness, or may be edge data obtained by detecting the contour of the vehicle. Further, when applied to an outdoor parking lot, the brightness of the image changes depending on the time of day and the weather. Prepare

Although one embodiment of the present invention has been described above, various embodiments are possible without being limited to this. For example, in the above-described embodiment, the shutter of the electronic camera is controlled at a timing of a predetermined time interval and the monitoring image is input as a still image.
A continuous moving image is acquired by a moving image camera such as a television camera, the moving image is sampled at a timing of a predetermined time interval, and the sampled image is used as the A / D of the embodiment.
You may make it input into the conversion part 7.

Next, an application example of monitoring for detecting a change in an input image as in the above embodiment will be described. As an example, FIG.
When the inside of the room including the entrance / exit 15 is monitored, the change detection of the input image is used for starting and ending the recording of the monitoring image.

FIG. 7 is a block diagram showing the control configuration of this embodiment. First, an input image of the electronic camera 20 that captures a state in which no one is in the room (hereinafter referred to as “steady state”) is captured as a reference image, converted into a digital signal by the A / D conversion unit 21, and stored in the reference image memory 23. The control unit 22
When a monitoring command is received from the remote monitoring center 24, the monitoring operation is started and the image captured by the electronic camera 20 is input. This image input is performed at appropriate time intervals for monitoring according to the shutter operation by the shutter control unit 25. The input monitoring image is converted into a digital signal like the reference image and stored in the monitoring image memory 26. The control unit 25 compares the reference image data of the reference memory 23 and the image data of the monitoring image memory 26 in synchronization with the shutter operation of the electronic camera 20 and detects a difference. When no difference is detected, this operation is repeated every predetermined time.

When a person enters this room, the surveillance image naturally changes to an image including this person, and a difference is detected as a result of the comparison between the reference image data and the surveillance image data. When this difference is detected, the control unit 25 outputs a recording start command to the recording device 27 and sends the monitor image data in the monitor image memory 26 for recording. Thereafter, every time a new monitoring image is input in synchronization with the shutter operation, this monitoring image data is recorded. At this time, the control unit 25 sends the date and time data obtained from the internal electronic calendar and the electronic timer together with the monitor image data, and reproducibly records the monitor image and the corresponding date and time.

Further, the control unit 25 continues the comparison of the reference image and the monitoring image in parallel with the recording of the monitoring image in the recording device 27, and when the difference between the monitoring image and the reference image disappears or there is no difference. When a predetermined time has elapsed, a recording stop command is output to the recording device 27, transmission of the monitor image data is stopped, and the recording operation is ended. The comparison between the reference image and the monitoring image continues during the monitoring time, and when a person enters the room again, the above operation is repeated again. As a result, the monitoring image is recorded only while the room is not in a steady state, and the number of recording members can be saved.

In this embodiment, the surveillance image is recorded, but the surveillance image is transmitted to the image display device of the remote surveillance center by using the communication means, and the surveillance image is displayed only while the room is not in the steady state. It may be displayed on a remote display device. In this case, in the monitoring center, it is possible to know the intrusion of a person by displaying the monitoring image and to monitor the person's behavior while the person stays indoors. Further, it can be applied not only to indoor steady state and initial state monitoring, but also to monitoring abnormalities such as fire and smoke generation and indoor monitoring as well as physical quantity observation of stored materials.

[0024]

As described above, according to the present invention, the latest captured image input at every predetermined time interval is compared with the captured image at the previous input, and if the image changes, this change is detected by the difference detection between the two images. Can be detected. By narrowing down the image position of this difference detection, determining the place in the corresponding monitoring area and outputting the information indicating the changing place, complicated data processing of the monitoring image can be performed in a short time and simply. It is possible,
Increases processing efficiency.

Further, in an image monitoring method for reproducibly recording a picked-up image of a predetermined area, the recording of the monitoring image is started from the occurrence of a change other than the steady state or the initial state, and when the state returns to the original state, the recording is stopped, The recording member for recording can be used efficiently.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a control configuration according to an embodiment of the present invention.

FIG. 2 is a diagram showing a monitoring aspect of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of an input image example according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of another input image example according to the embodiment of the present invention.

FIG. 5 is a diagram showing an operation procedure of an embodiment of the present invention.

FIG. 6 is a diagram showing a monitoring aspect of another embodiment of the present invention.

FIG. 7 is a block diagram of control functions of another embodiment of the present invention.

[Explanation of symbols]

1 electronic camera 2 parking areas 3 parking lots 5a car 5b car 6 Shutter controller 7 A / D converter 9 First image memory 10 Second image memory 11 Comparison recognition unit 20 electronic camera 22 Control unit 23 Reference image memory 24 Monitoring Center 26 Monitoring image memory 27 Recording device

Claims (4)

[Claims] 1. An image captured by an electronic camera in a predetermined monitoring area is input at predetermined time intervals, and the captured image is compared between the latest input and the previous input, and the difference between the two images is determined. An image position in which the difference exists is detected, and a position in the predetermined area corresponding to the image position is determined, and information indicating a position where the presence or absence of an object in the predetermined area is changed is output. Image monitoring method. 2. An electronic camera for picking up an image of a predetermined surveillance area, an image input control means for inputting images of the electronic camera at predetermined time intervals, and an image processing means for converting an image pickup signal of the electronic camera into a digital signal. An image storage unit that stores the latest input image and the previous input image of the digital image of the monitoring area, and a difference detection unit that compares the latest input image and the previous input image to detect a difference, When there is a difference between the two images, the change position determining unit that determines the image position where the difference exists and determines the position in the predetermined region where the presence or absence of the object has changed from the determination position, and the change position determining unit An image monitoring apparatus comprising: an output unit that outputs the determined position information. 3. An image monitoring method for capturing a predetermined area with an electronic camera and replayably recording the captured image, wherein a steady-state captured image of the predetermined area is stored as a reference image, and the predetermined area is being monitored. The monitoring image input at a predetermined time interval is compared with the reference image, and as a result of the comparison, the recording operation is stopped while there is no difference between the two images, the recording is started by the difference detection, and the recording is performed again. An image monitoring method characterized by stopping recording by detecting that there is no difference between the two images. 4. The image monitoring method according to claim 3, wherein date and time information is recorded together with the captured image.