JP2021010051A - Imaging apparatus and method for controlling the same - Google Patents

Abstract

To make it possible, in an imaging apparatus capable of lighting control, to reduce erroneous detection in detecting a moving body.SOLUTION: An imaging apparatus comprises: imaging means; control means that controls lighting with which an area picked up by the imaging means is irradiated; and detection means that detects a moving body by analyzing an image picked up by the imaging means. When the detection means operates, the control means controls at least one of light-on and light-off of the lighting on the basis of a first parameter, and when the detection means does not operate, the control means controls at least one of light-on and light-off of the lighting on the basis of a second parameter different from the first parameter.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image pickup apparatus and a control method thereof.

Conventionally, a network camera capable of remotely controlling a camera and monitoring an image via a network or a dedicated line has been known. Some network cameras have built-in lighting, and in dark places, lighting may be used to supplement the amount of light in the imaging location (imaging area) to capture the subject more clearly. Infrared lighting is used in addition to white lighting.

In addition, some network cameras that do not have built-in lighting have a contact output terminal with an external device, and a switch that controls the lighting device is connected to this contact output terminal so that the camera controls the external lighting device. Sometimes. The number of lighting devices and cameras that support wireless communication such as wireless LAN and Bluetooth (registered trademark) is increasing. By wirelessly connecting the camera and the lighting equipment, the degree of freedom of installation is expanded, and it is expected that the system configuration in which the camera and the lighting equipment are linked will be realized more easily.

In addition, an increasing number of models are equipped with a function called an intelligent function, such as motion detection, which analyzes an image captured by a camera and detects a moving object in the captured image. Some have a function of discriminating not only a moving object but also the type of a subject to detect a human body or detecting the face of a specific person. In the future, in a surveillance system using a network camera, it is desired to save labor and improve efficiency by using such an intelligent function.

As a problem in the configuration in which a camera having such an intelligent function controls the illumination that illuminates the imaging location (imaging area), there is an influence on image analysis when the illumination changes. In the image analysis of the intelligent function, the change in brightness due to the change in illumination of the captured image may be erroneously detected as a moving object. Therefore, in the image analysis, it is preferable that the change in illumination is small. On the other hand, in a situation where the observer monitors while directly checking the image of the camera, the illumination of the imaging location that the observer wants to see is immediately turned on, the imaged object can be captured quickly and clearly, and the illumination is turned on in the situation where the illumination is unnecessary. It is preferable to turn off the light immediately. In addition, if the lighting is intended for warning, it may be preferable to turn it on immediately when necessary.

For example, Patent Document 1 discloses a technique for detecting a moving object in a dark place and for accurately visually confirming the moving object with an image after the detection. Patent Document 1 has near-infrared illumination and visible light illumination, detects moving objects with images captured by near infrared illumination, and irradiates with visible light illumination after detection.

Further, Patent Document 2 discloses a technique for easily detecting a moving object without performing complicated processing of a signal from an image sensor such as moving object detection by an inter-frame difference method or a background subtraction method. In Patent Document 2, even if the driving condition of the image sensor is set to the moving object extraction mode, the normal imaging mode and the moving object extraction mode can be easily switched by changing the illumination condition.

Japanese Unexamined Patent Publication No. 2000-175176 Japanese Unexamined Patent Publication No. 2004-304377

However, the technique disclosed in Patent Document 1 does not mention a configuration having only one illumination, and a motion detection function when the illumination changes (change from lighting to extinguishing, change from extinguishing to lighting). May malfunction (false positive).
Further, the technique disclosed in Patent Document 2 is a method related to motion detection by an image sensor, and cannot be used for a motion detection function using image analysis that malfunctions (erroneous detection) due to a change in lighting.
Therefore, an object of the present invention is to reduce erroneous detection when detecting a moving object in an imaging device capable of controlling illumination.

In order to achieve the above object, the imaging apparatus according to one aspect of the present invention includes an imaging means, a control means for controlling illumination that illuminates a region imaged by the imaging means, and an image captured by the imaging means. When the detection means for detecting a moving object and the detection means are operating, the control means controls at least one of turning on and off the lighting based on the first parameter, and the detection means. When the means are not operating, the control means controls at least one of turning on and off the lighting based on a second parameter different from the first parameter.

According to the present invention, it is possible to reduce erroneous detection when detecting a moving object in an imaging device capable of controlling lighting.

The functional block diagram of the network camera in 1st Embodiment of this invention. The figure which shows the lighting control timing of the network camera of FIG. The flowchart explaining the main processing of the network camera of FIG. The flowchart explaining the lighting control processing of the network camera of FIG. A table showing lighting control conditions of the network camera of FIG. The figure which shows the lighting control timing in the modification of 1st Embodiment. The flowchart explaining the lighting control processing in the modification of 1st Embodiment. A table showing lighting control conditions in a modified example of the first embodiment. The figure which shows the lighting control timing in another modification of 1st Embodiment. The flowchart explaining the lighting control processing in another modification of 1st Embodiment. A table showing lighting control conditions in another modification of the first embodiment. The flowchart explaining the main processing of the network camera in 2nd Embodiment. The flowchart explaining the lighting control processing of the network camera of FIG. A table showing the second lighting control condition of the network camera of FIG. The figure which shows the imaging area and the illumination irradiation range of the network camera in 3rd Embodiment of this invention. The flowchart explaining the main processing of the network camera of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following embodiments do not limit the present invention, and not all combinations of features described in the present embodiment are essential for the means for solving the present invention. The configuration of the embodiment may be appropriately modified or changed depending on the specifications of the apparatus to which the present invention is applied and various conditions (use conditions, use environment, etc.). The technical scope of the present invention is determined by the scope of claims and is not limited by the following individual embodiments. In addition, a part of each embodiment described later may be appropriately combined and configured.

<First Embodiment>
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.
<Network camera configuration>
FIG. 1 is a functional block configuration diagram of the network camera 10 according to the present embodiment. The network camera 10 is connected to a client device (information processing device) (not shown) via the network 20 so as to be able to communicate with each other.
The network camera 10 includes an imaging unit 11, an image processing unit 12, a system control unit 13, an illumination unit 14, an illumination control unit 15, an illuminance acquisition unit 16, and a communication unit 17. The network camera 10 is an example of an imaging device.

The configuration and function of each part of the network camera 10 will be described with reference to FIG.
The image pickup unit 11 is composed of a lens, an image pickup element, and a control element thereof, and performs imaging of a subject and conversion into an electric signal.
The image processing unit 12 performs a predetermined development process, a moving object detection process, and a compression coding process of the signal imaged and photoelectrically converted by the image pickup unit 11, generates image data (captured image), and transmits it to the system control unit 13. To do. The moving object detection process performed by the image processing unit 12 analyzes the image and detects a moving object (moving object) in the captured image. As an image analysis method, for example, a background subtraction method can be used. In the background subtraction method, a stationary portion in a captured image acquired for a certain period of time is extracted to generate a background image, and a moving object is detected by extracting the difference between the background image and the current image. The image processing unit 12 transmits the detected motion detection information to the system control unit 13.

The system control unit 13 distributes the generated image data to the client device via the communication unit 17.
Further, the system control unit 13 receives the camera control command transmitted from the client device via the communication unit 17. The system control unit 13 analyzes the received camera control command and performs processing according to the command. For example, the image processing unit 12 is instructed to adjust the image quality. Further, the system control unit 13 transmits a response to the camera control command to the client device via the communication unit 17.
The system control unit 13 has a clock function using an RTC (Real Time Clock). Therefore, the network camera 10 can acquire the time.

When the system control unit 13 receives the motion detection information from the image processing unit 12, the system control unit 13 transmits the motion detection information to the client device via the communication unit 17. The client device that has received the motion detection information performs processing such as recording an image when motion detection occurs.
Further, the system control unit 13 receives a command transmitted from the client device, sets the position and size of the motion detection frame in the captured image for motion detection, and enables / disables the motion detection function. To do.
When the network camera 10 is using the motion detection function, the system control unit 13 sets the lighting control unit 15 for lighting control when the motion detection is used.

The illumination unit 14 is composed of white illumination using an LED or the like, and irradiates a portion (region) to be imaged by the image pickup unit 11. The illumination unit 14 may be configured by infrared illumination instead of white illumination. Infrared lighting is lighting that prevents people from perceiving it in the dark. Further, although the lighting unit 14 is built in the network camera 10 in FIG. 1, the lighting unit 14 may be provided outside the network camera 10 and connected to the network camera 10.
The illuminance acquisition unit 16 is composed of an illuminance sensor or the like, and acquires an illuminance value in a region to be imaged by the image pickup unit 11. The illuminance acquisition unit 16 transmits the acquired illuminance value to the illumination control unit 15.
The illumination control unit 15 controls the illumination unit 14 by using the illuminance value transmitted from the illuminance acquisition unit 16.

The communication unit 17 receives the camera control command transmitted from the client device and transmits it to the system control unit 13. Further, the communication unit 17 transmits various signals and information from the network camera 10 to the client device.
As described above, the network camera 10 of the present embodiment can control the illumination that illuminates the imaging region, and also has a motion detection function using image analysis.
The network camera 10 may include elements not shown in FIG. For example, the network camera 10 may include a storage unit that stores a program used by the system control unit 13, a program used by the lighting control unit 15, a lighting control condition, and the like.

<Lighting control timing>
FIG. 2 is a diagram showing the lighting control timing. The vertical axis of the graph of FIG. 2 shows the illuminance, and the horizontal axis shows the time. The solid line 21 shows the change in the illuminance of the imaging environment, the first broken line 22 shows the lighting control timing when the moving object detection function is not used, and the second broken line 23 shows the lighting control timing when the moving object detection function is used. The solid line 21 may be referred to as an imaging environment illuminance in the following description.
I1 on the vertical axis is an illuminance threshold for turning on (or turning off) the illumination when the motion detection function is not used. I2 is an illuminance threshold that turns on (or turns off) the light when the motion detection function is used. On the horizontal axis, TA1 indicates the sunset start time, TA2 indicates the sunset completion time, TA3 indicates the sunrise start time, and TA4 indicates the sunrise completion time. TA1 is the time when the leftmost vertical dashed line in FIG. 2 intersects the horizontal axis (time axis). TA4 is the time when the rightmost vertical dashed line in FIG. 2 intersects the horizontal axis (time axis).

The imaging environment in this embodiment is affected by sunlight, and the imaging environment illuminance (solid line) 21 gradually (linearly) increases from the sunset start time TA1 to the sunset completion time TA2, as shown in FIG. It is assumed that the value gradually decreases and gradually increases from the sunrise start time TA3 to the sunrise completion time TA4.
It is assumed that the illuminance threshold I1 is the illuminance limit at which the captured image can be visually recognized in the scene where the observer (for example, the user of the client device) directly visually observes and monitors the captured image. When the imaging environment illuminance 21 gradually decreases at sunset and becomes a visible illuminance threshold I1 or less, the illumination is turned on. Further, when the imaging environment illuminance 21 gradually increases at sunrise and the illuminance threshold value I1 or more is reached, the illumination is turned off. With the visible illuminance limit as the illuminance threshold, the lights are turned on when the illuminance threshold is below the threshold and turned off when the illuminance threshold is exceeded, so that the lights are turned on only when necessary and turned on when not needed. You can avoid it. The value of the illuminance threshold I1 at sunset and the value of the illuminance threshold I1 at sunrise may be different. In the following description, the illuminance threshold value at sunset is referred to as I1a, and may be referred to as the illuminance threshold value I1b at sunrise.

On the other hand, in a scene where monitoring is performed using the motion detection function, when the illumination is turned on at the illuminance threshold I1, the illumination is turned on in a situation where the imaging environment illuminance 21 is lowered to some extent, so that the brightness of the captured image changes, and the network camera 10 The motion detection function of is malfunctioning (false positive). Therefore, at sunset, the still bright illuminance at which the imaging environment illuminance 21 begins to decrease is set as the illuminance threshold I2, and the illumination is turned on in the still bright situation where the imaging environment illuminance 21 begins to decrease, so that the brightness of the captured image changes due to the illumination lighting. Operate the motion detection function correctly (reduce false positives). Similarly, by adopting the illuminance threshold value I2 even at sunrise and turning off the illumination when the imaging environment illuminance 21 is sufficiently high, the change in brightness of the captured image due to turning off the illumination is suppressed and the moving object detection function operates correctly ( Reduce false positives). As described above, in the present embodiment, the change in the brightness of the captured image when the motion detection function is used is made smaller than the change in the brightness of the captured image when the motion detection function is not used.
The value of the illuminance threshold value I2 at sunset and the value of the illuminance threshold value I2 at sunrise may be different. In the following description, the illuminance threshold value at sunset is referred to as I2a, and may be referred to as the illuminance threshold value I2b at sunrise.

<Main flowchart of network camera>
FIG. 3 is a flowchart illustrating the main processing of the network camera 10. When the motion detection setting of the network camera 10 is changed, the system control unit 13 executes the processing flow shown in FIG. S is an abbreviation for Step.
In S11, the system control unit 13 determines whether or not the network camera 10 is using the motion detection function. If the motion detection function is used, the process proceeds to S12. If the motion detection function is not used, the process proceeds to S13. Whether or not the network camera 10 uses the motion detection function is determined by, for example, whether or not the motion detection process of the image processing unit 12 is operating.

In S12, the system control unit 13 sets the lighting control for the lighting control unit 15 when the motion detection is used. More specifically, it is set to perform lighting control using the illuminance threshold value I2.
In S13, the system control unit 13 sets the lighting control unit 15 for lighting control when no motion detection is used. More specifically, it is set to perform lighting control using the illuminance threshold value I1. The illuminance threshold I1 and the illuminance threshold I2 are parameters used when controlling the turning on and off of the lighting, respectively.

<Flowchart of lighting control>
FIG. 4 is a flowchart illustrating the lighting control process of FIG. When the network camera 10 starts imaging, the lighting control unit 15 executes the processing flow of FIG. 4 at predetermined time intervals.
In S21, the lighting control unit 15 acquires the lighting control conditions corresponding to the set lighting control. The lighting control unit 15 may acquire the lighting control conditions from the client device 20 or from the storage unit.

FIG. 5 shows a table 50 showing lighting control conditions. In the table 50, the lighting illuminance threshold I2a when using motion detection is 90 lux, and the extinguishing illuminance threshold I2b is also 90 lux. Further, the lighting illuminance threshold I1a when the motion detection is not used is 30 lux, and the extinguishing illuminance threshold I1b is also 30 lux. The illuminance threshold is set in consideration of the degree of influence of the lighting on the motion detection function in the imaging environment, the illuminance that can be visually recognized, and the like. The illuminance thresholds I1a, I1b, I2a, and I2b can be set by a command from the client device (a command input by a user operation of the client device). Note that 90 lux and 30 lux are examples, and the user of the client device can also change the illuminance thresholds I1a, I1b, I2a, and I2b. The lighting illuminance thresholds I2a and I2b are higher than the lighting illuminance thresholds I1a and I1b.

Return to FIG.
In S22, the lighting control unit 15 acquires an illuminance value from the illuminance acquisition unit 16.
In S23, the lighting control unit 15 determines whether or not the lighting unit 14 is currently turned off. If it is off, the process proceeds to S24. If it is not turned off (that is, it is turned on), the process proceeds to S26.
In S24, the lighting control unit 15 compares the acquired illuminance value with the lighting control condition, and determines whether or not the acquired illuminance value exceeds the lighting illuminance threshold value. If the acquired illuminance value exceeds the lighting illuminance threshold, the process proceeds to S25. If the acquired illuminance value does not exceed the threshold value, the process ends.
In S25, the lighting control unit 15 lights the lighting unit 14 and ends the process.

In S26, the lighting control unit 15 compares the acquired illuminance value with the lighting control condition, and determines whether or not the acquired illuminance value exceeds the extinguishing illuminance threshold value. If the acquired illuminance value exceeds the extinguishing illuminance threshold, the process proceeds to S27. If the acquired illuminance value does not exceed the extinguishing illuminance threshold, the process ends.
In S27, the lighting control unit 15 turns off the lighting unit 14 and ends the process.

<Effect of the first embodiment>
As described above, according to the present embodiment, in the network camera 10 capable of controlling lighting, by switching the lighting control method according to the usage status of the motion detection function, the visibility in visual monitoring is improved and the motion is detected. It makes it possible to reduce malfunctions (false positives) of functions.
In the present embodiment, the change in the brightness of the captured image when the motion detection function is used is smaller than the change in the brightness of the captured image when the motion detection function is not used. Therefore, when performing motion detection, it is possible to reduce erroneous detection due to a change in brightness.

<Modification example>
In the present embodiment, the network camera 10 having a moving object detection function for detecting a moving object in the captured image has been described, but the present embodiment is not limited to this. For example, even in a camera that has functions such as take-away detection that detects that valuables have been taken away and abandonment detection that detects that a suspicious object has been left behind and causes false detection due to lighting, the above The same methods and controls as those used for can be applied. As a result, it is possible to improve the visibility in visual monitoring and reduce the malfunction of the motion detection function.

Further, in the present embodiment, the illuminance threshold value I2 when the moving object detection function is used is set higher than the illuminance threshold value I1 when the moving object detection function is not used, but the present embodiment is not limited to this. For example, the illuminance threshold when the motion detection function is used may be lower than the illuminance threshold when the motion detection function is not used. When the limit illuminance that can detect a moving object is lower than the illuminance limit that can be visually recognized, the malfunction of the moving object detection function can be reduced by not performing the illumination control up to the illuminance that can detect the moving object.
Further, in the present embodiment, an illuminance sensor is used as a means (element) for acquiring the illuminance, but the present embodiment is not limited to this. For example, the illuminance may be acquired by using the information included in the imaging signal generated by the imaging unit 11.

Further, in the present embodiment, an illuminance threshold for controlling the illumination with respect to the imaging environment illuminance is provided as the illumination control process, and the illuminance threshold is switched between when the motion detection function is used and when it is not used. Not limited to this. For example, the lighting time and the extinguishing time may be set, and the lighting time and the extinguishing time may be switched between when the motion detection function is used and when it is not used. Hereinafter, a case where the lighting time and the extinguishing time are set will be described with reference to FIGS. 6, 7, and 8. The lighting time and the extinguishing time are parameters used when controlling the on and off of the lighting, respectively.

FIG. 6 is a diagram showing the lighting control timing. The same reference numerals are used for the same components as those in FIG. 2, and the description thereof will be omitted. In FIG. 6, TB1 indicates a lighting time when the motion detection function is not used, TB2 indicates a lighting time when the motion detection function is not used, TC1 indicates a lighting time when the motion detection function is used, and TC2 indicates a motion detection function. Indicates the turn-off time during use.

The imaging environment in FIG. 6 is affected by sunlight as in FIG. 2, and the imaging environment illuminance 21 gradually decreases from the sunset start time TA1 to the sunset completion time TA2 as shown in FIG. It is assumed that the temperature gradually increases from the sunrise start time TA3 to the sunrise completion time TA4.
In a scene where the observer directly visually monitors the captured image, the illuminance limit that can visually recognize the captured image is the illuminance threshold I1, and the time when the imaging environment illuminance 21 becomes the illuminance threshold I1 is TB1. To do. In this case, the imaging environment illuminance 21 gradually decreases at sunset, and the illumination is turned on at the time TB1 which is equal to or less than the visible illuminance threshold I1. Similarly, the imaging environment illuminance 21 gradually increases at sunrise, and the illumination is turned off at the time TB2 when the illuminance threshold value I1 or more is reached. By turning on the light only at the time when the illuminance limit is visible, it is possible to turn on the light only when necessary and not to turn on the light when it is not needed.

On the other hand, in a scene where monitoring is performed using the motion detection function, when the illumination is turned on at time TB1, the illumination is turned on in a situation where the imaging environment illuminance 21 is lowered to some extent, so that the brightness of the captured image changes, and the network camera 10 The motion detection function malfunctions (false positive). Therefore, at sunset, the lighting is turned on in a bright situation before the imaging environment illuminance 21 starts to decrease by setting the time TC1 shortly before the imaging environment illuminance 21 starts to decrease as the lighting time. By turning on the illumination at the time TC1, it is possible to suppress the change in the brightness of the captured image due to the lighting of the illumination. By suppressing the change in the brightness of the captured image, it is possible to reduce the malfunction (erroneous detection) of the motion detection function of the network camera 10. Further, by turning off the illumination at the time TC2 when the imaging environment illuminance 21 becomes sufficiently high at sunrise, it is possible to suppress the change in the brightness of the captured image due to the lighting turning off and reduce the malfunction (erroneous detection) of the motion detection function. it can.

FIG. 7 is a flowchart illustrating the lighting control process of FIG. When the network camera 10 starts imaging, the lighting control unit 15 executes the processing flow of FIG. 7 at predetermined intervals.
In S31, the lighting control unit 15 acquires the lighting control conditions corresponding to the set lighting control. FIG. 8 shows a table 60 showing lighting control conditions. In the table 60, the lighting time when the motion detection is used is 16:40, the extinguishing time is 05:20, the lighting time when the motion detection is not used is 17:00, and the extinguishing time is 05:00. .. The lighting on time and the lighting off time may be fixed values or variable values. When the lighting on / off time is set to a variable value, the lighting on / off time is set to an optimum value according to, for example, the sunset time or the sunrise time that changes depending on the season.
As can be seen from FIG. 8, the lighting lighting time when the motion detection function is used is longer than the lighting lighting time when the motion detection function is not used.

In S32, the lighting control unit 15 acquires the current time from the system control unit 13.
In S33, the lighting control unit 15 determines whether or not the lighting unit 14 is currently turned off. If it is off, the process proceeds to S34. If it is not turned off (if it is lit), the process proceeds to S36.
In S34, the lighting control unit 15 compares the acquired current time with the lighting control conditions, and determines whether or not the current time exceeds the lighting time. If the current time exceeds the lighting time, the process proceeds to S35. If the current time does not exceed the lighting time, the process ends.

In S35, the lighting control unit 15 lights the lighting unit 14 and ends the process.
In S36, the lighting control unit 15 compares the acquired current time with the lighting control conditions, and determines whether or not the current time exceeds the extinguishing time. If the current time exceeds the extinguishing time, the process proceeds to S37. If the current time does not exceed the turn-off time, the process ends.
In S37, the lighting control unit 15 turns off the lighting unit 14 and ends the process.

In FIG. 4 and the above-described modified example (including FIG. 7), a method of switching on / off of lighting as a lighting control process is shown, but the present invention is not limited to this. For example, a method may be adopted in which lighting that can control the amount of light is used to switch from turning on to turning off or from turning off to turning on while gradually changing the amount of light over a predetermined time. Illumination control when an illumination capable of controlling the amount of light is used will be described with reference to FIGS. 9, 10 and 11.

FIG. 9 is a diagram showing the lighting control timing. The same reference numerals are used for the same components as those in FIG. 2, and the description thereof will be omitted. TB1 is the lighting time when the motion detection function is not used, and TB2 is the extinguishing time when the motion detection function is not used. TC1 is the lighting start time when the motion detection function is used, TC2 is the lighting completion time when the motion detection function is used, TC3 is the extinguishing start time when the motion detection function is used, and TC4 is the lighting start time when the motion detection function is used. It is the turn-off completion time.

The imaging environment in the examples of FIGS. 9 to 11 is affected by sunlight as in FIG. 2, and the imaging environment illuminance 21 gradually increases from the sunset start time TA1 to the sunset completion time TA2 as shown in FIG. It is assumed that the value gradually decreases and gradually increases from the sunrise start time TA3 to the sunrise completion time TA4.
In the scene where the observer directly visually observes the captured image and monitors it, the illumination is turned on only when necessary by turning on the illumination on the condition that the visible illuminance limit is reached, as described in FIG. Can be turned on so that the light is not turned on when it is not needed.

On the other hand, in the scene of monitoring using the motion detection function, the lighting is started at the same time TC1 as the sunset start time TA1. After that, the amount of illumination light is gradually increased so that the required amount of light (maximum set amount of light) is reached at the same time TC2 as the sunset completion time TA2. At the time of sunrise, the lights are turned off at the same time TC3 as the sunrise start time TA3. After that, the amount of illumination light is gradually reduced, and the illumination is completely turned off at the same time TC4 as the sunrise completion time TA4. In this way, by gradually changing the amount of illumination light according to the gradually changing imaging environment illuminance 21, it is possible to suppress the change in the brightness of the captured image and further reduce the malfunction (erroneous detection) of the motion detection function. .. In FIG. 9, it is assumed that the change (increase, decrease) in the amount of illumination light is linear.

FIG. 10 is a flowchart illustrating the lighting control process of FIG. When the network camera 10 starts imaging, the lighting control unit 15 executes the processing flow of FIG. 10 at predetermined intervals.

In S41, the lighting control unit 15 acquires the lighting control conditions corresponding to the set lighting control. FIG. 11 shows a table 70 showing lighting control conditions. In the table 70, the lighting start time when the motion detection is used is 16:55, the lighting change time when lighting is 00:10, the lighting start time when turning off is 04:55, and the lighting change time when turning off is 00. : 10. That is, the lighting control condition is that the time TC1 in FIG. 9 is 16:55, the time TC2 is reached after 10 minutes, the time TC3 is 04:55, and the time TC4 is 10 minutes. The fact that the illumination change time is 00:10 means that the amount of light of the illumination changes over a predetermined time of 10 minutes.
The lighting start time when the motion detection is not used is 17:00, the lighting change time at the time of lighting is 00:00, the lighting start time at the time of turning off is 05:00, and the lighting change time at the time of turning off is 00:00. The lighting change time of 00:00 when the motion detection is not used means that the lighting is immediately switched from the lighting to the extinguishing and the lighting is immediately switched from the lighting to the lighting.
Since the change in the amount of illumination light when the motion detection is used takes 10 minutes, it takes a longer time than the change in the amount of illumination light when the motion detection is not used.

In S42, the lighting control unit 15 acquires the current time from the system control unit 13.
In S43, the lighting control unit 15 determines whether or not the lighting unit 14 is currently turned off. If the light is off, or if the light is being changed from off to on, the process proceeds to S44. If it is lit, or if it is changing from lit to extinguished, the process proceeds to S47. Here, "changing from extinguished to lit" means that the amount of light increases from extinguishing (zero amount of light) and is in the middle of the change to reach the maximum set amount of light. "During the change from lighting to extinguishing" means that the amount of light is decreasing from the maximum set amount of light and is in the middle of the change to zero amount of light.

In S44, the lighting control unit 15 compares the acquired current time with the lighting control conditions, and determines whether or not the current time exceeds the lighting start time. If the current time exceeds the lighting start time, the process proceeds to S45. If the current time does not exceed the lighting start time, the process ends.
In S45, the illumination control unit 15 calculates the amount of illumination light according to the acquired illumination change time at the time of lighting. For example, it is assumed that the illumination light amount can be controlled from 0 lux to 100 lux, the lighting state (maximum set light amount) is 100 lux, the extinguishing state is 0 lux, and the current time has passed 1 minute from the lighting start time. Since the illumination change time is 10 minutes, the amount of illumination light after 1 minute is as follows.
100 x 1/10 = 10
That is, when 1 minute has passed, the amount of illumination light becomes 10 lux.

In S46, the illumination control unit 15 lights the illumination unit 14 with the illumination light amount calculated in S45, and ends the process. After that, the amount of illumination light is gradually increased according to the elapsed time. In addition, when the illumination change time is 00:00, the illumination is turned on immediately (the amount of illumination light is immediately changed from 0 lux to 100 lux).
In S47, the lighting control unit 15 compares the acquired current time with the lighting control conditions, and determines whether or not the current time exceeds the extinguishing start time. If the current time exceeds the turn-off start time, the process proceeds to S48. If the current time does not exceed the turn-off start time, the process ends.

In S48, the illumination control unit 15 calculates the amount of illumination light according to the acquired illumination change time at the time of lighting. For example, if the current time is 1 minute after the lighting start time, the lighting change time is 10 minutes.
100- (100 x 1/10) = 90
Therefore, the amount of illumination light when 1 minute has passed from the lighting start time is 90 lux.

In S49, the illumination control unit 15 lights the illumination unit 14 with the illumination light amount calculated in S48, and ends the process. After that, the amount of illumination light is gradually reduced according to the elapsed time. In addition, when the lighting change time is 00:00, the lighting is immediately turned off (the amount of illumination light is immediately changed from 100 lux to 0 lux).
In FIG. 9, the amount of illumination light is linearly changed from the illumination start time to the illumination completion time, but this modification is not limited to this. For example, the amount of illumination light may be changed non-linearly according to the change in the imaging environment illuminance 21.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. 1, 12, 13, and 14. In the second embodiment, lighting control is performed in consideration of the difference in the image analysis method used for motion detection. By using the same reference numerals for the same components as in the first embodiment, detailed description thereof will be omitted. Hereinafter, the differences from the first embodiment will be mainly described. The configuration of the network camera 10 of the second embodiment is the same as the configuration described with reference to FIG.

There are multiple image analysis methods for detecting moving objects. For example, there are a method using background subtraction described in the first embodiment and a method using inter-frame subtraction that extracts differences between consecutive frame images and detects moving objects. In the method using background subtraction, it takes a predetermined time to generate a background image.

The imaging unit (camera head unit) of the network camera 10 may be able to pan (horizontally rotate), tilt (vertically rotate), and zoom (change the angle of view). In addition, the network camera 10 may have an automatic tracking function that automatically controls pan, tilt, and zoom so that a moving subject is detected by image analysis and the detected moving object is always captured in the center of the screen. In motion detection when the network camera 10 has an automatic tracking function, it is difficult to use the background subtraction method because the background image changes every moment due to changes in the angle of view due to pan, tilt, and zoom. In such a case, the inter-frame difference method is used. As described above, in motion detection using image analysis, different image analysis methods may be used depending on the function of the network camera 10.

In the case of the background subtraction method using a background image generated over a predetermined time, the entire image changes before and after the lighting change, so it is necessary to generate the background image again. While the background image is being regenerated, motion detection cannot be performed, so the effect of lighting changes is large. On the other hand, in the case of the inter-frame difference method using only a short period image (frame image) of several frames, a false detection occurs in the image at the moment of the illumination change, but the false detection does not occur immediately after that. The effect of lighting changes is small. In this way, since the effect of lighting change differs depending on the image analysis method used, lighting control is performed so that false detection is reduced only when the motion detection function using the image analysis method, which is greatly affected by lighting change, is used. May be good. By doing so, it is possible to further improve the visibility in visual monitoring and reduce the malfunction (erroneous detection) of the motion detection function. Further, the motion detection function may be suspended (temporarily stopped) for a predetermined time before and after the lighting change (when switching from lighting to extinguishing and when switching from extinguishing to lighting).
In the second embodiment, when the motion detection function is used, the content of the lighting control is changed depending on whether the background subtraction method or the inter-frame subtraction method is used.

FIG. 12 is a flowchart illustrating the main processing of the network camera 10 of the second embodiment. When the motion detection setting of the network camera 10 is changed, the system control unit 13 executes the processing flow shown in FIG.

In S51, the system control unit 13 determines whether or not the motion detection function is used. If the motion detection function is used, the process proceeds to S52. If the motion detection function is not used, the process proceeds to S55.
In S52, the system control unit 13 determines whether or not the motion detection function using background subtraction is used. If the motion detection function using background subtraction is used, the process proceeds to S53. If the motion detection function is not used, the process proceeds to S54.

In S53, the system control unit 13 sets the lighting control unit 15 for lighting control when using motion detection using background subtraction.
In S54, the system control unit 13 sets the lighting control unit 15 for lighting control when using motion detection using the difference between frames. In the present embodiment, the lighting control setting when motion detection is used using the difference between frames is the same as the lighting control setting when motion detection is not used, as will be described later with reference to FIG.
In S55, the system control unit 13 sets the lighting control unit 15 for lighting control when no motion detection is used.

FIG. 13 is a flowchart illustrating the lighting control process. When the network camera 10 starts imaging, the lighting control unit 15 executes the process of FIG. 13 at predetermined intervals.
In S61, the lighting control unit 15 acquires the lighting control conditions corresponding to the set lighting control. FIG. 14 shows a table 80 showing lighting control conditions. As shown in Table 80, the lighting time when the motion detection function using background subtraction is used is 16:40, the extinguishing time is 05:20, and the motion detection function is temporarily stopped "none". Motion detection function Temporary stop means to put the motion detection function into a dormant state. The lighting time when the motion detection using the inter-frame difference is used is 17:00, the extinguishing time is 05:00, and the motion detection function is temporarily stopped. The lighting time when the motion detection is not used is 17:00, the extinguishing time is 05:00, and the motion detection function is temporarily stopped "none".

In S62, the lighting control unit 15 acquires the current time from the system control unit 13.
In S63, the lighting control unit 15 determines whether or not the lighting unit 14 is currently turned off. If it is off, the process proceeds to S64. If it is not off (if it is on), the process proceeds to S70.

In S64, the lighting control unit 15 compares the acquired current time with the lighting control conditions, and determines whether or not the current time exceeds the lighting time. If the current time exceeds the lighting time, the process proceeds to S65. If the current time does not exceed the lighting time, the process ends.

In S65, the lighting control unit 15 determines whether the motion detection function temporarily stopped under the lighting control condition is “yes” or “no”. If "Yes", the process proceeds to S66. In the case of "none", the process proceeds to S69.
In S66, the lighting control unit 15 requests the system control unit 13 to stop the motion detection function. When the system control unit 13 receives a request to stop the motion detection function, the system control unit 13 masks (blocks) the motion detection information from the image processing unit 12 and shifts to a stop state in which the motion detection information is uniformly transmitted as a non-detection state. When the state shifts to the stopped state, the system control unit 13 notifies the lighting control unit 13 that the shift has been completed.
In S67, the lighting control unit 15 lights the lighting unit 14.

In S68, the lighting control unit 15 requests the system control unit 13 to restart the motion detection function after a lapse of several frames after the lighting unit 14 is completely lit. When the system control unit 13 receives the restart of the motion detection function, the system control unit 13 shifts to a normal state in which the motion detection information from the image processing unit 12 is transmitted as it is to the subsequent stage. When the transition is completed, the system control unit 13 notifies the lighting control unit 15 that the transition to the normal state has been completed, and ends the process.

In S69, the lighting control unit 15 lights the lighting unit 14 and ends the process.
In this way, when using motion detection using inter-frame difference, by masking the detection information of motion object detection for several frames at the time of lighting switching, the malfunction of the motion detection function of the inter-frame difference method due to lighting change is reduced ( Or can be eliminated).

In S70, the lighting control unit 15 compares the acquired current time with the lighting control conditions, and determines whether or not the current time exceeds the extinguishing time. If the current time exceeds the extinguishing time, the process proceeds to S71. If the current time does not exceed the turn-off time, the process ends.
In S71, the lighting control unit 15 determines whether the motion detection function temporarily stopped under the lighting control condition is “yes” or “no”. If "Yes", the process proceeds to S72. In the case of "none", the process proceeds to S75.

In S72, the lighting control unit 15 requests the system control unit 13 to stop the motion detection function. When the system control unit 13 receives a request to stop the motion detection function, the system control unit 13 masks the motion detection information from the image processing unit 12 and transmits the motion detection information uniformly as a non-detection state.
In S73, the lighting control unit 15 turns off the lighting unit 14.
In S74, the lighting control unit 15 requests the system control unit 13 to restart the motion detection function after the time for several frames has elapsed. When the system control unit 13 receives the request to restart the motion detection function, the system control unit 13 transmits the motion detection information from the image processing unit 12 to the subsequent stage as it is (shifts to the normal state), and ends the process.
In S75, the lighting control unit 15 turns off the lighting unit 14 and ends the process.

As described above, in the present embodiment, in the network camera 10 having a plurality of motion detection functions using different image analysis methods, the lighting control is switched according to the difference in the image analysis method used in the motion detection function to be used. .. By switching the lighting control, the lighting control is performed so that false detection is reduced only when the motion detection function using the image analysis method (background subtraction method), which is greatly affected by the lighting change, is used. By doing so, it is possible to perform lighting control more finely, and it is possible to further improve the visibility in visual monitoring and reduce the malfunction of the motion detection function.

In the present embodiment, the case where the background subtraction method and the inter-frame difference method are used as the plurality of image analysis methods has been described, but the present embodiment is not limited to this. For example, an image analysis method other than these may be configured using a method having a different effect on the lighting control.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIGS. 15 and 16. In the third embodiment, the lighting control in consideration of the motion detection region will be described. By using the same reference numerals for the same components as in the first embodiment, detailed description thereof will be omitted. Hereinafter, the differences from the first embodiment will be mainly described. The configuration of the network camera 10 of the third embodiment is the same as the configuration described with reference to FIG. 1 except for the illumination unit 14. In FIG. 1, one lighting unit 14 is built in the network camera 10, but the network camera 10 of the third embodiment does not have the lighting unit 14, and instead, two lighting units A and lighting from the outside. B is connected to the network camera 10.

FIG. 15 shows the imaging range (imaging area) 31 of the network camera 10 in the present embodiment, the irradiation range 33A by the illumination A, and the irradiation range 33B by the illumination B.
In the present embodiment, two illuminations A and B are connected to the network camera 10, and the two illuminations A and B are used to illuminate the imaging range 31 of the network camera 10. The left side of the imaging range 31 is the irradiation range 33A of the illumination A, and the right side of the imaging range 31 is the irradiation range 33B of the illumination B.
In the present embodiment, the motion detection function can be performed on an image in a predetermined region of the captured image, and the predetermined region (moving object detection region) can be set by the client device. Reference numeral 32 in FIG. 15 indicates a set motion detection region. The network camera 10 performs motion detection on the image in the motion detection region 32. The moving object detection region 32 does not overlap the irradiation range 33B.

As shown in FIG. 15, the illumination A illuminates the set moving object detection area 32, and thus affects the moving object detecting area 32. On the other hand, since the illumination B does not irradiate the moving object detection area 32, it does not affect the moving object detecting area 32. Therefore, it is necessary to consider the malfunction (false positive) of the moving object detection function for the illumination A, but it is not necessary to consider the false detection of the moving object for the illumination B. Therefore, lighting control (referred to as detection priority lighting control in this embodiment) is performed only on the lighting that affects the moving object detection area 32 according to the set position of the moving object detection area 32 and the illumination range of the illumination. By this lighting control, it is possible to perform lighting control more finely, and it is possible to further improve the visibility in visual monitoring and reduce the malfunction of the motion detection function.

FIG. 16 is a flowchart illustrating the main processing of the network camera 10 of the present embodiment. When the motion detection setting of the network camera 10 is changed, the system control unit 13 executes the processing flow shown in FIG.
In S81, the system control unit 13 determines whether or not the motion detection function is used. If the motion detection function is used, the process proceeds to S82. If the motion detection function is not used, the process proceeds to S84.
In S82, the system control unit 13 determines whether or not the lighting is lighting that affects the frame (moving object detection area 32) set by the moving object detecting function. If the lighting affects the motion detection area 32, the process proceeds to S83. If the lighting does not affect the motion detection area 32, the process proceeds to S84.

In S83, the system control unit 13 sets the lighting control when the motion detection is used in the lighting control unit 15, and ends the process.
In S84, the system control unit 13 sets the lighting control when the motion detection is not used in the lighting control unit 15, and ends the process.
Since the lighting control when the motion detection is used and the lighting control when the motion detection is not used are the same as the controls described in the first or second embodiment, the description thereof will be omitted.

As described above, according to the present embodiment, the illumination control is performed only on the illumination that affects the motion detection area 32 depending on the set position of the motion detection area (detection frame) 32 and the illumination range of the illumination. By such lighting control, it is possible to perform lighting control more finely, and it is possible to further improve the visibility in visual monitoring and reduce the malfunction (false detection) of the motion detection function.

In the present embodiment, the two illuminations A and the illumination B are connected to the network camera 10 and used, but the present embodiment is not limited to this. For example, even when the number of connected lights is one or three or more, lighting control for reducing the malfunction of the moving object detecting function may be performed for the lighting affecting the moving object detecting area 32.
Further, in the present embodiment, the case where the motion detection region 32 is one has been described, but the present embodiment is not limited to this. For example, when the motion detection area 32 is set at a plurality of locations and any one of the plurality of motion detection areas 32 affects a predetermined lighting, lighting control may be performed for the lighting so as to reduce the malfunction of the motion detection function. ..

The functional configuration of the network camera 10 shown in FIG. 1 is an example, and a part of the functional modules (for example, 12, 13, 15, 16) may be realized by hardware. When it is realized by hardware, for example, by using a predetermined compiler, a dedicated circuit may be automatically generated on the FPGA from the program for realizing the function of each functional module. FPGA is an abbreviation for Field Programmable Gate Array. Further, a Gate Array circuit may be formed in the same manner as the FPGA and realized as hardware. Further, it may be realized by ASIC (Application Specific Integrated Circuit). Further, the configuration of the functional module shown in FIG. 1 is an example, and a plurality of functional modules may constitute one functional module, or any functional module may be divided into modules that perform a plurality of functions. May be good.
Although the network camera 10 has been described in the above description, the present invention can be applied to an imaging device other than the network camera.

<Other Embodiments>
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

10 ... Network camera, 11 ... Imaging unit, 12 ... Image processing unit, 13 ... System control unit, 14 ... Lighting unit, 15 ... Lighting control unit, 16 ... Illuminance acquisition unit

Claims (18)

Imaging means and
A control means for controlling illumination that illuminates an area imaged by the image pickup means,
A detection means that analyzes an image captured by the image pickup means to detect a moving object,
When the detection means is operating, the control means controls at least one of turning on and off of the lighting based on the first parameter.
When the detection means is not operating, the control means controls at least one of turning on and off of the lighting based on a second parameter different from the first parameter. .. When the detection means is operating, the control means controls the illumination so that the change in the brightness of the captured image is smaller than that when the detection means is not operating. Item 1. The imaging apparatus according to item 1. An illuminance acquisition means for acquiring the illuminance of the region imaged by the imaging means is further provided.
The imaging device according to claim 1 or 2, wherein the control means controls at least one of turning on and off of the lighting based on the illuminance acquired by the illuminance acquiring means. Claims 1 to 3, wherein the first parameter and the second parameter each include a first illuminance threshold for turning on the illumination and a second illuminance threshold for turning off the illumination, respectively. The imaging apparatus according to any one of the above items. The first illuminance threshold of the first parameter is higher than the first illuminance threshold of the second parameter.
The imaging device according to claim 4, wherein the second illuminance threshold value of the first parameter is higher than the second illuminance threshold value of the second parameter. The first illuminance threshold of the first parameter is lower than the first illuminance threshold of the second parameter.
The imaging apparatus according to claim 4, wherein the second illuminance threshold value of the first parameter is lower than the second illuminance threshold value of the second parameter. Further equipped with a time acquisition means for acquiring the current time,
The imaging device according to claim 1 or 2, wherein the control means controls at least one of turning on and off the lighting based on the current time acquired by the time acquiring means. The imaging device according to claim 7, wherein the first parameter and the second parameter each include information on timing for turning on and off the illumination. In each of the first parameter and the second parameter, the lighting time of the lighting when the detecting means is operating is longer than the lighting time of the lighting when the detecting means is not operating. The imaging device according to claim 8, wherein the imaging device is set as follows. The control means can turn on the lighting while changing the amount of light of the lighting, and can turn off the lighting while changing the amount of light of the lighting.
The imaging apparatus according to any one of claims 1 to 9, wherein the first parameter and the second parameter each include information regarding a change in the amount of light of the illumination. The imaging device according to claim 10, wherein the first parameter changes the amount of light of the illumination over a longer period of time as compared with the second parameter. The imaging device according to any one of claims 1 to 11, wherein the first parameter changes depending on an image analysis method used when the detection means analyzes the image. The image pickup apparatus according to claim 12, wherein the image analysis method is a method of detecting a moving object by a difference between a background image and a current image, and a method of detecting a moving object by a difference between continuous frame images. When the image analysis method is a method of detecting a moving object by a difference between continuous frame images, the control means controls the illumination based on the second parameter even if the detection means is operating. 13. The image pickup apparatus according to claim 13. Claims 1 to 14 are characterized in that the control unit puts the detection means into a hibernation state for a predetermined time before and after the switching when the lighting is switched from turning on to off and when the lighting is switched from turning off to turning on. The imaging apparatus according to any one of the above. The detection means can set a detection region for detecting a moving object in the captured image of the image pickup means.
When the detection region does not overlap the range illuminated by the illumination in the captured image, the control means controls the illumination based on the second parameter even if the detection means is operating. The imaging apparatus according to any one of claims 1 to 15. It is a control method of the image pickup device.
The step of illuminating the area imaged by the imaging means with illumination,
A step of analyzing an image captured by the imaging means to detect a moving object,
When the image pickup apparatus executes the detection step, at least one of turning on and off of the lighting is controlled based on the first parameter, and
When the image pickup apparatus does not perform the detection step, at least one of the lighting is turned on and off is controlled based on a second parameter different from the first parameter.
A control method characterized by having. A program for causing a computer to function as each means of the imaging apparatus according to any one of claims 1 to 16.

Images