JP2001249008A - Monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce erroneous alarms from a monitor. SOLUTION: Illumination quantity of total field of photograph is varied to clarify the field limit of photographing object and the distance from the filed limit to the object is estimated. The actual size of the object is estimated based on the distance and the size of the object in a screen and a human being and a small animal are properly discriminated. At this moment, it is desired that constant effects of environmental light and the color of the object be avoided by obtaining the brightness variation of the object by flashing the illumination light and obtaining the distance to the object using the brightness variation. Meanwhile, the pattern variation on a moving body surface may be sharply and surely detected by illuminating the field of photograph with a specific projection patten.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device for detecting an abnormality in a scene and outputting alarm information.

[0002]

2. Description of the Related Art Conventionally, as a monitoring system for a building, a store or the like, a system for transmitting a captured image of a security camera to a security center in a remote place is known. In such a surveillance system, a person at the security center must constantly monitor the monitor image, which is a heavy burden on humans.

As an unmanned monitoring device, a device that detects infrared rays emitted by an intruder using a pyroelectric sensor or the like is known. However, such a monitoring device operates similarly for small animals such as rats, and thus has a problem that false alarms are likely to occur.

[0004] There have been several attempts to automate the discrimination between humans and small animals. For example, JP-A-5-6
Japanese Patent No. 4198 (hereinafter referred to as “Conventional Example 1”) discloses an apparatus that obtains the distance of an object by applying the lower end position of the object in an imaging screen to a perspective method, and discriminates a human or a small animal from the distance of the object. Has been described. Further, Japanese Unexamined Patent Publication No.
Japanese Patent Application Publication No. 55 (hereinafter referred to as “Conventional Example 2”) describes an apparatus that detects the position of the center of gravity of an object from a captured image and discriminates a human or a small animal from the height of the position of the center of gravity.

[0005]

By the way, a monitoring device for security use is often installed in a place such as a common passage including stairs or steps, mainly from the viewpoint of privacy protection. Since such a place has a height difference, the position of the lower end and the position of the center of gravity of the object are locally increased. It is also expected that flying objects (for example, insects such as moths and cockroaches) cross the front of the security camera. In such cases,
The lower end position and the position of the center of gravity of the object are relatively high.

In the case where the lower end position of the object is relatively high as described above, in the first conventional example, it is determined that the object is located farther than it is. Therefore, even a small animal such as a moth is erroneously determined to be as large as a human, and a false alarm is generated. Also in the second conventional example, when the position of the center of gravity of the object is raised as described above, a small animal such as a moth is erroneously determined to be as tall as a human. For this reason, false alarms frequently occur.

[0007] Therefore, an object of the present invention is to improve the accuracy of automatic discrimination in a monitoring device and reduce false alarms as described above.

[0008]

According to a first aspect of the present invention, there is provided an illumination unit for varying the amount of illumination light with respect to a field, an imaging unit for capturing an image of the field, and a lighting unit. A distance measuring unit for estimating a distance to an object in an object scene based on an illumination light amount and an imaging luminance of an imaging unit, and outputting warning information based on the distance to the object estimated by the distance measuring unit. And a monitoring unit that performs the monitoring.

In the above configuration, the illuminating section varies the amount of illumination for the entire object scene. At this time, in order to obtain a predetermined imaging brightness in the imaging unit, the illumination light amount of the illumination unit must be increased as the distance to the object increases.
The distance measuring unit estimates the distance to the object by applying the “imaging luminance of the imaging unit” and the “illumination light amount of the illumination unit” to the relationship between the physical quantities. The monitoring unit detects an abnormal approach of the object from the object distance and outputs alarm information. Such an alarm operation is performed irrespective of the lower end position or the center of gravity of the object. Therefore, unlike the conventional case,
There is no possibility that a false alarm is caused by a step or a flying object.

In the above configuration, the illumination section may illuminate light in a specific wavelength range or a specific polarization plane, and the imaging section may discriminate and image the illumination light with a filter or the like. In this case, it is possible to more accurately estimate the distance to the object by reducing the influence of ambient light or the like. In the above configuration, the illumination unit may illuminate infrared light or other invisible light. In this case, the fact that the amount of illumination light is variable is inconspicuous to the intruder, and there is no risk of the intruder being careful and avoiding the illumination area.

In the above configuration, a plurality of illumination units may be provided so as to be gradually separated from the imaging unit. In this case, a distant object can be illuminated by the distant illumination unit, and the range in which the distance can be estimated can be extended. Further, in this case, a plurality of illumination units may be individually controlled, and conditions such as an illumination light amount and an illumination angle may be combined in a complicated manner. In this case, it is possible to obtain imaging data under various lighting conditions, and thus it is possible to further improve the above-described distance estimation accuracy.

[0012] According to a second aspect of the present invention, in the monitoring device according to the first aspect, the distance measuring unit includes "a change in the amount of illumination light in the illumination unit" and a change in the amount of light. The method is characterized in that a distance to an object in an object scene is estimated based on “a change in luminance of an image captured by an imaging unit”.

In the above configuration, the imaging brightness of the imaging unit also changes according to the change in the illumination light amount of the illumination unit. At this time,
In order to obtain a predetermined change in luminance in the imaging unit, the farther the object, the greater the range of change in the amount of illumination. The distance measuring unit estimates the distance to the object by applying the “amount of change in the amount of illumination light” and the “amount of change in luminance” to such a relationship. In such an operation, distance estimation is performed based on the change. Therefore, it is possible to reduce the stationary effects such as the color of the object and the ambient light to some extent, and it is possible to further increase the accuracy of distance estimation. As an extreme example, the illumination unit may blink the illumination light.
In this case, it is possible to estimate the distance to the object in the scene based on the amount of change in the amount of light due to the blinking and the amount of change in luminance associated with the change.

According to a third aspect of the present invention, in the monitoring device according to the first or second aspect, the monitoring unit includes: a distance to the object estimated by the distance measuring unit; Is used to estimate the actual size of the object based on the size of the object imaged in the screen and output alarm information according to the actual size of the object.

In the above configuration, the monitoring unit estimates the actual size of the object based on the estimated distance to the object and the size of the object in the screen. Therefore, it is possible to output accurate warning information to a distant person or the like based on the size estimation.

According to a fourth aspect of the present invention, in the monitoring device according to any one of the first to third aspects, the distance measuring unit is configured to detect a stationary body area from a captured image of the imaging unit. It has a mask means for removing (non-moving object region), and estimates a distance to a moving object in the object scene based on the illumination light amount of the illumination unit and the imaging luminance after masking.

In the above configuration, the mask means in the distance measuring section is
The stationary body region is removed in advance from the image captured by the imaging unit. As a result, the distance measuring unit is less likely to measure the distance of a stationary object such as a background, and can narrow the distance measurement target to a moving object (such as an intruder).

In a fifth aspect of the present invention, an illuminating unit for illuminating the object scene with a predetermined projection pattern, an image of the object scene, and a moving object are obtained based on the movement of the projection pattern in the object scene. An imaging unit that generates an image, a moving body detection unit that determines the shape or size of a moving body in a subject based on a moving body image generated by the imaging unit, and a moving body detection unit that detects the shape or size of the moving body detected by the moving body detection unit. And a monitoring unit that outputs alarm information.

In the above configuration, the illumination section illuminates the scene with a predetermined projection pattern. At this time, if there is a moving object in the object scene, the projection pattern moves little by little on the undulating surface of the moving object. The imaging unit generates a moving object image from the movement of the projection pattern.

Conventionally, when a difference image is simply generated under uniform illumination light, only the outline of a moving object is extracted. In order to determine the shape and dimensions of a moving object from such a difference image,
Paint processing such as painting the inside of the contour is required separately. At this time, if there is a break or noise in the outline,
It is very difficult to accurately determine the shape and dimensions of the moving body. In addition, for a slowly moving moving object, the extracted contour line becomes very thin. Therefore, there is a problem that it is difficult to detect a slowly moving moving object.

However, in the configuration of the fifth aspect,
The motion of the projection pattern generated on the surface of the moving object is extracted. Therefore, not only the contour information of the moving object but also the surface information of the moving object can be extracted as the movement of the projection pattern. Therefore, it is possible to appropriately detect the shape and size of the moving object based on the extracted surface information of the moving object.

Also, a moving object that moves slowly causes a remarkable movement of the projection pattern depending on the surface angle of the moving object surface. Therefore, with the configuration of the fifth aspect, a slowly moving moving object can be detected sensitively. Furthermore, since the projection pattern by the illumination unit is blocked by the moving object, the shadow portion behind it is crushed black, and no pattern is generated.
Therefore, the moving body surface and the shadow portion can be easily determined based on the presence or absence of the pattern. As a result, the shadow behind the moving object is rarely erroneously determined to be a part of the moving object, and the original shape and size of the moving object can be accurately determined. The monitoring unit detects an abnormal situation such as the entry of a vertically long moving body (bipedal walking human!) And outputs alarm information based on the shape and dimensions of the moving body reliably and sharply detected in this way. . The above-mentioned alarm operation is performed irrespective of the lower end position or the center of gravity of the object. Therefore, unlike the case of the conventional example, there is no possibility that a false alarm is caused by a step or a flying object.

According to a sixth aspect of the present invention, there is provided the monitoring apparatus according to the fifth aspect, further comprising a noise removing unit for removing a noise image other than the projection pattern from the moving object image of the imaging unit. Features.

In the above configuration, the pattern of the moving body surface extracted by the imaging unit strongly reflects the characteristic of the projection pattern. Therefore, the noise removing unit removes noise images other than the projection pattern based on the two-dimensional characteristics of the projection pattern. For example, in the projection pattern of vertical stripes, the pattern on the surface of the moving object extracted by the imaging unit is also a pattern centered on the vertical stripes. In this case, by adding weights to the images in the vertical direction, noise images other than vertical stripes can be accurately reduced. By such noise removal, the shape or size of the moving object can be accurately determined, and more accurate alarm information can be output.

<Seventh Aspect> According to a seventh aspect of the present invention, there is provided an illumination section for illuminating an object scene with a predetermined projection pattern and varying the amount of illumination light, and for imaging the object scene, and An imaging unit that generates a moving object image from the movement of the projection pattern of the imaging unit; a distance measurement unit that estimates a distance to a moving object in an object scene based on an illumination light amount of an illumination unit and imaging luminance of the imaging unit; Based on the moving object image generated by the moving object detection unit that calculates the shape or size of the moving object in the subject, the distance to the moving object obtained by the distance measurement unit, and the shape or size of the moving object obtained by the moving object detection unit A monitoring unit that estimates an actual shape or size of the moving object based on the estimated shape or size and outputs alarm information according to the estimated actual shape or size.

In the above configuration, by combining the constituent features of claim 1 and claim 5, it is possible to further enhance the automatic determination accuracy of the monitoring device.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

<< First Embodiment >> The first embodiment is an embodiment corresponding to the first to fourth aspects of the present invention. FIG. 1 is a diagram illustrating a configuration of the monitoring device 11 according to the first embodiment. In FIG. 1, a monitoring unit 11 is provided with an illumination unit 12 for illuminating a scene. The illumination unit 12 varies the illumination light amount according to a light amount control signal given from the control unit 13. Further, the monitoring device 11 is provided with a motion detection image sensor 14. As the motion detection image sensor 14, for example, one described in Japanese Patent Application Laid-Open No. H11-225287 is used. The motion detection image sensor 14 captures an image of an object scene in accordance with an imaging control signal provided from the control unit 13. The motion detection image sensor 14
The imaging result is output as an image signal and a difference signal. Among them, the difference signal is a binary image signal representing a difference between image frames. This difference signal is transmitted to the control unit 13
And the monitoring unit 16. The image signal is provided to the monitoring unit 16. The control unit 13 generates distance information and transmits it to the monitoring unit 16. The monitoring unit 16 generates alarm information and transmits it to the remote security center together with the image signal.

[Correspondence between the present invention and the first embodiment]
Hereinafter, the correspondence between the respective constituent features described in claims 1 to 3 and the present embodiment will be described. Regarding the correspondence between the inventions described in claims 1 to 4 and the first embodiment, the illumination unit corresponds to the illumination unit 12, and the imaging unit is the motion detection imaging device 1.
4, the distance measurement unit corresponds to the "function for estimating the distance" of the control unit 13, the monitoring unit corresponds to the monitoring unit 16, and the mask unit removes the stationary body region from the captured image of the control unit 13. Function ".

[Explanation of Operation of First Embodiment] FIG. 2 is a diagram for explaining the blinking timing of the illumination unit 12. FIG.
FIG. 3 is a diagram showing an example of a field. FIG. 4 shows the monitoring device 1
3 is a flowchart for explaining the operation of FIG. FIG. 5 is a diagram illustrating an imaging result of the motion detection imaging element 14. Hereinafter, the operation of the monitoring device 11 will be described according to the step numbers shown in FIG.

Step S1: In normal times, the illumination unit 12 illuminates the object scene with a constant light amount. Note that the distance estimation range (A to G shown in FIG.
In an environment where the zone is constantly illuminated, the illumination unit 12 may be turned off. Motion detection image sensor 14
Captures the object scene in such a state and generates an image signal and a difference signal. This difference signal is a signal obtained by extracting the outline of the moving object.

Step S2: Based on the difference signal, the control section 13 determines whether or not a moving object exists in the object scene. This operation is repeatedly performed until a moving object is detected. When a moving object is detected in such a repeated operation, the control unit 13 shifts the operation to Step S3 in order to obtain more detailed information on the object scene.

Step S3: According to the light amount control signal,
The illumination unit 12 turns on / off the illumination every other frame with a weak illumination light amount that reaches the A zone (see FIG. 3). Note that the motion detection image sensor 14 performs XY address type pixel reading. Therefore, for each read row,
The accumulation period of the signal charges is slightly shifted. If the flashing illumination is performed asynchronously with respect to such an accumulation period, the illumination conditions of the readout row are not uniform, and thus a problem such as a part of the screen being darkened occurs. Therefore, as shown in FIG. 2, the illumination unit 12 performs lighting only during the vertical retrace period of the even-numbered frame (the period from the completion of reading of the last row to the start of reading of the first row). This vertical blanking period is the only period common to all readout rows in the accumulation period of the even-numbered frame. As a result, an image signal with uniform illumination conditions for each row is obtained. (Note that the vertical flyback period in this case is N
It is preferable to set a sufficient period for illumination without complying with the TSC standard or the like.) On the other hand, the illumination unit 12 is completely turned off during the accumulation period of the odd-numbered frames. Therefore, an image signal in an unlit state is obtained as an odd frame. The motion detection image sensor 14 determines whether or not there is a difference equal to or larger than the allowable difference between successive frames, and outputs a determination result as a difference signal.

If the object is located in the A zone, the object undergoes a change in luminance due to blinking illumination (a change in the amount of light). Since this luminance change is determined as a difference between frames, the difference signal here shows an object in the A zone. On the other hand, when the object is located in the B to G zones, the blinking illumination hardly reaches the object. Therefore, the brightness change of the object due to the blinking illumination is less than the above tolerance,
It is not determined as a difference between frames. Therefore,
The difference signal here does not show any objects in the B to G zones. The control unit 13 reads a difference signal (difference signal of the stationary body region) related to the A zone that is captured in advance without a moving object from a memory or the like, and masks the current difference signal;
Only the difference signal of the part suspected of moving is extracted. The control unit 13 counts the number of pixels in the difference portion with respect to the difference signal, and sets the number as the area of the moving object in the A zone on the screen.

Step S4: The control section 13 determines the number of pixels counted in step S3 (the area of the moving object in the A zone on the screen).
And the proportional constant S corresponding to the square value of the distance to the zone A
Multiplying by a, the actual size of the moving object in the A zone is estimated.

Step S5: Next, the illumination unit 12
The lighting is turned on and off every other frame with the amount of illumination that reaches the zone. If the object is located in the zones A and B, the object undergoes a luminance change due to the blinking illumination (a change in the amount of light). Since this change in luminance is determined to be a difference between frames, the difference signal here indicates objects in zones A and B. On the other hand, when the object is located in the C to G zones, the blinking illumination hardly reaches the object. Therefore, the change in luminance of the object due to the blinking illumination is less than the above-described tolerance, and is not determined as a difference between frames. Therefore, the objects in the C to G zones do not appear at all in the difference signal here (see FIG. 5α). The control unit 13
The difference signals for the A and B zones imaged beforehand in a state where there is no moving object are read from a memory or the like, the current difference signal is masked, and a difference signal of a portion suspected to be a moving object is extracted.
The control unit 13 counts the number of pixels in the difference portion with respect to the difference signal, and sets the number of pixels in the screen of the moving object in the A to B zones.

Step S6: The control unit 13 calculates the number of pixels (the area of the moving object in the A zone on the screen) counted in step S3 from the number of pixels (the area in the screen of the moving object in the AB zone) counted in step S5. The area in the screen of the moving object in the B zone is obtained by subtraction. In the area within the screen of the moving object in this B zone,
The actual size of the moving object in the B zone is estimated by multiplying the square constant of the distance to the B zone by the proportionality constant Sb.

Step S7: Next, the illumination unit 12
The lighting is turned on and off every other frame with the amount of illumination that reaches the zone. If the object is located in the zones A to C, the brightness of the object changes due to the blinking illumination (light amount change). Since this change in luminance is determined to be a difference between frames, objects in zones A to C appear in the difference signal here (see FIG. 5B). On the other hand, when the object is located in the zone D to G, the blinking illumination hardly reaches the object. Therefore, the change in luminance of the object due to the blinking illumination is less than the above-described tolerance, and is not determined as a difference between frames. Therefore, the difference signal here
Objects in the D to G zones do not appear at all. The control unit 13 reads a difference signal related to the A to C zones imaged in advance without a moving object from a memory or the like, masks the current difference signal, and extracts a difference signal of a portion suspected to be a moving object. The control unit 13 counts the number of pixels of the difference portion with respect to the difference signal, and sets the number of pixels in the screen of the moving object in the A to C zones.

Step S8: The control unit 13 calculates the number of pixels counted in step S5 (the in-screen area of the moving object in zones A and B) from the number of pixels counted in step S7 (the area in the screen of the moving object in zones A to C). ) Is subtracted to obtain the area within the screen of the moving object in the C zone. The proportional constant S corresponding to the square value of the distance to the C zone is added to the area of the moving object in the screen in the C zone.
Multiplying by c, the actual size of the moving object in the C zone is estimated.

Step S9: Next, the illumination unit 12
The lighting is turned on and off every other frame with the amount of illumination that reaches the zone. If the object is located in the zones A to D, the brightness of the object changes due to the blinking illumination (change in the amount of light). Since this change in luminance is determined to be a difference between frames, the difference signal here shows objects in zones A to D. On the other hand, when the object is located in the zones E to G, the blinking illumination hardly reaches the object. Therefore, the change in luminance of the object due to the blinking illumination is less than the above-described tolerance, and is not determined as a difference between frames. Therefore, the objects in the E to G zones do not appear at all in the difference signal here. The control unit 13 reads, from a memory or the like, a difference signal regarding the A to D zones that has been captured in advance without a moving object, masks the current difference signal, and extracts a difference signal of a portion suspected to be a moving object. The control unit 13
The number of pixels in the difference portion of this difference signal is counted, and A to D
The area within the screen of the moving object in the zone.

Step S10: The control unit 13 calculates the number of pixels counted in step S7 (the in-screen area of the moving object in the A to C zones) from the number of pixels counted in step S9 (the in-screen area of the moving object in the A to D zones). ) Is subtracted to determine the area within the screen of the moving object in the D zone. The proportional constant S corresponding to the square value of the distance to the D zone is added to the area in the screen of the moving object in the D zone.
Multiply by d and estimate the actual size of the moving object in the D zone.

Step S11: Next, the illumination unit 12
The illumination is turned on / off every other frame with an illumination light amount that reaches the E zone. If the object is located in the zones A to E, the brightness of the object changes due to the blinking illumination (light amount change). Since this change in luminance is determined to be a difference between frames, the difference signal here shows objects in the A to E zones. On the other hand, when the object is located in the FG zone, the blinking illumination hardly reaches the object.
Therefore, the change in luminance of the object due to the blinking illumination is less than the above-described tolerance, and is not determined as a difference between frames. Therefore, the objects in the FG zones do not appear at all in the difference signal here. The control unit 13 reads a difference signal related to the A to E zones imaged in advance without a moving object from a memory or the like, masks the current difference signal, and extracts a difference signal of a portion suspected to be a moving object. The control unit 13
The difference signal is counted for the difference signal, and A to E
The area within the screen of the moving object in the zone.

Step S12: The control unit 13 calculates the number of pixels counted in step S9 (the in-screen area of the moving object in the A to D zones) from the number of pixels counted in step S11 (the in-screen area of the moving object in the A to E zones). ) Is subtracted to determine the area within the screen of the moving object in the E zone. The actual size of the moving object in the E zone is estimated by multiplying the in-screen area of the moving object in the E zone by a proportional constant Se corresponding to the square value of the distance to the E zone. Step S13: Next, the illumination unit 12 turns on the illumination every other frame with the illumination light amount that reaches the F zone.
Turns off. If the object is located in the AF zone, a change in brightness occurs in the object with the blinking illumination (a change in the amount of light). Since this change in luminance is determined to be a difference between frames, objects in zones A to F appear in the difference signal (see γ in FIG. 5). On the other hand, when the object is located in the G zone, the blinking illumination hardly reaches the object. Therefore, the change in luminance of the object due to the blinking illumination is less than the above-described tolerance, and is not determined as a difference between frames. Therefore, the object in the G zone does not appear at all in the difference signal here. The control unit 13 reads a difference signal related to the A to F zones imaged in advance without a moving object from a memory or the like, masks the current difference signal, and extracts a difference signal of a portion suspected to be a moving object. The control unit 13 counts the number of pixels of the difference portion with respect to the difference signal, and sets the number as the area of the moving object in the A to F zones in the screen.

Step S14: The control unit 13 calculates the number of pixels counted in step S11 (the in-screen area of the moving object in the A to E zones) from the number of pixels counted in step S13 (the in-screen area of the moving object in the A to F zones). ) Is subtracted to determine the area within the screen of the moving object in the F zone. The actual size of the moving object in the F zone is estimated by multiplying the in-screen area of the moving object in the F zone by the proportionality constant Sf corresponding to the square value of the distance to the F zone.

Step S15: The control unit 13 is located in the G zone by removing the difference signal after masking obtained in step S13 from the moving object image obtained in step S2 (for example, an image in which the moving object outline is filled). Extract moving objects.

Step S16: The control unit 13 counts the number of pixels of the extracted moving object and sets the number as the area of the moving object located in the G zone in the screen. The control unit 13 calculates the number of pixels as G
The actual size of the moving object in the G zone is estimated by multiplying the proportionality constant Sg corresponding to the square value of the distance to the zone.

Step S17: The monitoring unit 16 determines whether a moving object having a size equal to or larger than the threshold exists in any of the zones A to G based on the calculation results of steps S3 to S16. If there is no moving object having a size equal to or larger than the threshold, the monitoring unit 16 determines that the moving object in the screen is a small animal, and shifts the operation to step S18. On the other hand, when a moving object having a size equal to or larger than the threshold exists in any zone,
The monitoring unit 16 determines that the moving object in the screen is a human, and
The operation moves to step S19.

Step S18: Since the monitoring unit 16 has determined that the moving object in the screen is a small animal, it does not output any alarm information and returns to step S1 to continue the monitoring operation.

Step S19: Since the monitoring unit 16 has determined that the moving object in the screen is an intruder, it outputs alarm information and returns to step S1 to continue the monitoring operation.

[Effects of First Embodiment] According to the operation described above, in the first embodiment, the distance of the intruder is estimated from the relationship between the illumination light amount and the imaging luminance. Unlike the case, there is no possibility that a false alarm due to a flying object or the like will occur. In particular, in the first embodiment, since the distance to the moving object is estimated from the luminance change due to the blinking illumination, the stationary effect such as the color of the moving object or environmental light is eliminated as much as possible, and the distance to the moving object is accurately determined. Can be estimated. In the above description, the expression “the amount of illumination light reaching the XX zone” is used in order to avoid a complicated description, but quantitatively, “the brightness change exceeding the tolerance in the XX zone is barely exceeded. Means the amount of illumination light to be generated ". Further, in the first embodiment, blinking illumination is performed, but the present invention is not limited to blinking illumination. For example,
Illumination may be performed alternately with “the amount of illumination reaching the zone A” and “the amount of illumination reaching the zone B”. In this case, if the luminance change of the object located in the A zone falls within the tolerance, an image of only the object located in the B zone can be obtained as a difference signal. By gradually changing such a change in the amount of illumination light, it is possible to sequentially detect an object located in an arbitrary distance zone as a difference signal. In the first embodiment, a stationary body (such as a background)
The difference signal of the moving object portion is extracted by masking the difference signal. In this case, there is an advantage that a false alarm by a stationary body can be prevented. Further, in this case, there is an advantage that the distance can be estimated even for an intruder who is stationary due to fear of an alarm after entering the monitoring area. However, the method of the mask processing is not limited to this. For example, a movable range of the moving object (a range obtained by expanding the moving object outline by a predetermined amount or the like) is determined from the result of the moving object detection in step S2, and a mask image indicating a non-moving object region may be created from the movable range. it can. By the mask processing using this mask image, a difference signal of the moving body portion can be extracted. Also in this case, it is possible to prevent a false alarm from a stationary body. Further, in this case, since the mask image is automatically generated from the moving object detection result, there is an advantage that it is not necessary to manually update the background difference signal every time the background of the monitoring location changes. In the above-described operation, it is preferable that the process of creating a mask image from a moving object detection result is performed every time or timely before estimating the distance for each zone. In this case, the time lag between the time of creating the mask image and the time of estimating the distance is shortened, so that it is possible to avoid problems such as erroneous masking of the high-speed moving body. In the first embodiment, the mask processing is executed to estimate the distance only for the moving object, but the present invention is not limited to this. Not only for moving objects,
If you only need to estimate the distance to the object in the scene,
Of course, the mask processing can be omitted. Also, the first
The embodiment may be provided with means for detecting the ambient light and correcting the light quantity of the blinking illumination so that the distance estimation value is constant according to the change of the ambient light. Further, means for detecting ambient light and correcting the distance estimation value according to a change in the ambient light may be provided. Next, another embodiment will be described.

<< Second Embodiment >> A second embodiment is an embodiment corresponding to the inventions of claims 5 to 7. The configuration of the device according to the second embodiment is the same as that of the first embodiment (FIG. 1), and a description thereof will not be repeated.

[Correspondence between the present invention and the second embodiment]
Hereinafter, the correspondence between the respective constituent elements described in claims 5 to 7 and the present embodiment will be described. Regarding the correspondence between the invention described in claim 5 and the second embodiment, the illumination unit corresponds to the illumination unit 12, the imaging unit corresponds to the motion detection imaging element 14, and the moving object detection unit corresponds to the control unit 13. The monitoring unit corresponds to the monitoring unit 16, which corresponds to “a function for obtaining the shape or size of a moving object”. Regarding the correspondence between the invention described in claim 6 and the second embodiment, the noise removing unit corresponds to the “function to remove a noise image” of the control unit 13. Regarding the correspondence between the invention described in claim 7 and the second embodiment, the illumination unit corresponds to the illumination unit 12, and the imaging unit is the motion detection imaging device 1.
4, the distance measuring unit corresponds to the "function for obtaining the distance to the moving object" of the control unit 13, the moving object detection unit corresponds to the "function for obtaining the shape or size of the moving object" of the control unit 13, and the monitoring unit Corresponds to the monitoring unit 16.

[Explanation of Operation of Second Embodiment] FIG. 6 is a flowchart showing the operation of the second embodiment. Hereinafter, the operation of the second embodiment will be described with reference to the step numbers shown in FIG. Step S21: First, the illumination unit 12 illuminates the object scene with a predetermined projection pattern as shown in FIG.

Step S22: The control section 13 takes in the difference signal from the motion detection image pickup device 14.

Step S23: The control unit 13 performs two-dimensional image processing based on the characteristics of the projection pattern to remove noise images other than the projection pattern.

Step S24: The control section 13 determines whether there is a moving object in the difference signal from which noise has been removed. If there is no moving object in the object scene, step S
The operation returns to 21. On the other hand, if there is a moving object in the scene, the operation moves to step S25.

Step S25: The control unit 13 performs processing such as filling the gaps in the pattern by thickening the pixels of the difference signal to generate an image of the moving body surface. The control unit 13 obtains the shape or size of the moving object based on the image of the moving object surface.

Step S26: The illuminator 12 gradually reduces the amount of illumination. In this state, the control unit 13 obtains the minimum light amount that can be imaged (or detected) of the moving object.

Step S27: The control unit 13 refers to experimental data obtained in advance based on the minimum light quantity,
Estimate the distance to the moving object.

Step S28: The monitoring unit 16 performs fuzzy inference or database collation based on the “distance to the moving object” and the “shape or size of the moving object” to comprehensively determine whether the moving object is a human. to decide.

Step S29: If the monitoring unit 16 determines that the moving object is not a human, it does not output any alarm information and returns to step S21. On the other hand, if it is determined that the moving object is human, the operation moves to step S30.

Step S30: The monitoring section 16 outputs alarm information. Thereafter, the monitoring unit 16 proceeds to step S21.
And the monitoring of the moving object is further continued.

[Effects of Second Embodiment, etc.] According to the operation described above, in the second embodiment, a predetermined projection pattern is irradiated to detect the movement of a moving object sharply.
In addition, it is possible to easily obtain an image of the moving body surface. As a result, it is possible to accurately detect the shape and size of the moving object, and it is possible to increase the accuracy of the monitoring device. In the second embodiment, since the noise image is removed based on the image characteristics of the projection pattern, it is possible to reliably prevent a false alarm due to noise. Furthermore, in the second embodiment, it is possible to easily distinguish the shadow behind the moving object from the moving object surface for the following reasons. First, in the situation shown in FIG. 7, when the moving body 41 moves, the shadow 42 behind it also moves. However, no projection pattern occurs in the shadow portion. Therefore, the outline of the shadow portion appears in the difference signal (see FIG. 8). The outline of such a shadow portion is clearly different from the difference pattern of the moving object surface appearing in the difference signal, and can be easily removed in the above-described processing such as the noise removal processing and the thinning of the pixels of the difference signal. it can. Therefore, there is no possibility that the shadow 42 is erroneously determined as a part of the moving body 41 or the number of moving bodies is erroneously determined, and the shape, size, size, or number of the moving body 41 is not erroneously determined. Note that the projection pattern of the present invention is not particularly limited to that shown in the second embodiment. However, it is preferable that the projection pattern be a pattern sensitive to the movement of the moving body surface and a characteristic pattern capable of efficiently removing noise.
Examples of such projection patterns include a striped pattern, a lattice pattern, a concentric pattern, a polka dot pattern, and a checkered pattern.

[0064]

According to the first aspect of the present invention, the distance to the object is estimated based on the illumination light amount and the imaging luminance. Therefore, it is possible to output accurate alarm information according to the distance to the object.

According to the second aspect of the present invention, the distance is estimated based on the amount of change instead of the absolute amount. Therefore, it is possible to reduce stationary effects such as the color of the object and the environmental light, and it is possible to further increase the accuracy of distance estimation.

According to the third aspect of the present invention, the actual size of the object is estimated based on the estimated distance to the object and the size of the object in the screen. Therefore, it is possible to output accurate warning information to a distant person or the like based on the size estimation.

According to the fourth aspect of the present invention, before the distance estimation, the stationary body region is removed from the captured image. As a result, there is little risk that the distance of a stationary body such as a background is measured, and it is possible to output alarm information useful for monitoring a moving body such as an intruder.

According to the fifth aspect of the present invention, the shape and size of the moving body surface are reliably detected based on the sensitive movement of the projection pattern on the moving body surface. Therefore, it is possible to output accurate alarm information according to the shape and size of the moving body surface.

According to the present invention, a noise image other than the projection pattern is reduced based on the image characteristics of the projection pattern. Therefore, false alarms due to noise can be reliably reduced.

According to the seventh aspect of the present invention, the shape and dimensions of the moving body are accurately estimated by combining the constituent features of the first and fifth aspects. Therefore, it is possible to accurately and automatically discriminate between humans and small animals and output more accurate alarm information.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a monitoring device 11;

FIG. 2 is a diagram illustrating a blink timing of an illumination unit 12 according to the first embodiment.

FIG. 3 is a diagram illustrating an example of a field;

FIG. 4 is a flowchart illustrating an operation of the monitoring device 11 according to the first embodiment.

FIG. 5 is a motion detection image sensor 14 according to the first embodiment.
FIG. 9 is a diagram showing an imaging result of FIG.

FIG. 6 is a flowchart showing the operation of the second embodiment.

FIG. 7 is a diagram illustrating an example of a projection pattern according to the second embodiment.

FIG. 8 is a diagram illustrating an example of a difference signal according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Monitoring apparatus 12 Illumination part 13 Control part 14 Motion detection image sensor 16 Monitoring part

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G06T 7/20 G08B 13/196 G08B 13/196 G01B 11/24 K F term (reference) 2F065 AA00 AA06 AA21 AA51 BB05 BB15 CC16 DD00 DD04 FF04 FF42 GG08 HH06 HH07 KK01 KK03 NN02 NN08 QQ00 QQ03 QQ04 QQ23 QQ24 QQ25 QQ28 QQ34 QQ37 QQ51 SS09 5B057 AA19 BA02 BA11 CE02 DA15 DB02 DB09 DC03 DC09 5C084 AA02 BB07 AA02 AA07 AA02 AA12 AA02 AA12 AA12 AA12 AA12 GA28 HA03

Claims (7)

[Claims] An illumination unit configured to vary an amount of illumination light with respect to an object scene; an imaging unit configured to image the object scene; and an illumination unit configured to illuminate the object based on an illumination light amount of the illumination unit and an imaging luminance of the imaging unit. A monitoring device comprising: a distance measurement unit that estimates a distance to an object in a scene; and a monitoring unit that outputs alarm information based on the distance to the object estimated by the distance measurement unit. apparatus. 2. The monitoring device according to claim 1, wherein the distance measurement unit is configured to calculate a light amount of the illumination light in the illumination unit and a luminance change of the imaging unit according to the light amount change. A monitoring device for estimating a distance to an object in an object scene. 3. The monitoring device according to claim 1, wherein the monitoring unit includes: a distance to the object estimated by the distance measurement unit; and a screen of the object imaged by the imaging unit. A monitoring device for estimating an actual size of the object based on the inside size and outputting alarm information according to the actual size of the object. 4. The monitoring device according to claim 1, wherein the distance measuring unit removes a stationary body region (non-moving body region) from an image captured by the imaging unit. A monitoring device for estimating a distance to a moving object in an object scene based on an illumination light amount of the illumination unit and an imaging luminance after masking. 5. An illumination unit for illuminating a scene with a predetermined projection pattern, an imaging unit for imaging the scene, and generating a moving object image from the movement of the projection pattern in the scene, and the imaging unit A moving body detecting unit that calculates a shape or a size of a moving body in a subject based on a moving body image generated by a moving body; and a monitoring unit that outputs alarm information based on the shape or a size of the moving body detected by the moving body detecting unit. A monitoring device comprising: 6. The monitoring device according to claim 5, further comprising a noise removing unit that removes a noise image other than a projection pattern from a moving object image of the imaging unit. 7. An object scene is illuminated with a predetermined projection pattern,
An illumination unit that varies the amount of illumination light; an imaging unit that captures an image of the object field and generates a moving object image from the movement of a projection pattern in the object field; an illumination light amount of the illumination unit and an imaging luminance of the imaging unit A distance measuring unit for estimating a distance to a moving object in an object scene, based on a moving object image generated by the imaging unit, a moving object detecting unit for calculating the shape or size of the moving object in the subject, Based on the distance to the moving body determined by the distance measuring unit and the shape or size of the moving body determined by the moving body detection unit,
A monitoring unit that estimates an actual shape or size of the moving body and outputs alarm information according to the estimated actual shape or size.