Surveillance camera and surveillance system

Abstract

To provide a monitoring camera and a remote monitoring system capable of detecting the occurrence of abnormality in the monitoring camera, reporting it to a monitoring center and attaining quick restoration relating to the monitoring camera and the remote monitoring system using a far infrared sensor.SOLUTION: A sensor module 11 including a far-infrared sensor and a signal processing unit 12 that performs image processing and outputs video data of a live video are provided, and when an environmental temperature change occurs, the sensor module 11 performs shutter calibration and adjusts the sensor, and the signal processing unit 12 outputs video data acquired immediately before as a freeze video instead of the live video. In the monitoring camera and the monitoring system, a signal processing part 12 determines whether the monitoring camera is in a normal state or an abnormal state according to the state of image processing or the state of a sensor module 11, and outputs an alarm to the outside when the monitoring camera is in the abnormal state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a surveillance camera and a surveillance system using a far-infrared sensor, and more particularly to a surveillance camera and a surveillance system that can detect an abnormality in the surveillance camera, notify a monitoring center, and enable a rapid recovery. [Background technology]

[0002] [Prior art description: Figure 6] In recent years, remote monitoring has become mainstream in large-scale surveillance systems, in which multiple surveillance cameras are installed over a wide area and the area is monitored remotely from a remote monitoring center. An example of a conventional monitoring system will be described with reference to Fig. 6. Fig. 6 is an explanatory diagram showing an example of a conventional monitoring system. As shown in FIG. 6, a conventional monitoring system includes a plurality of cameras (monitoring cameras) 10 (cameras 10-1, ... 10-n), a plurality of transmitters 2 (transmitters 2-1, ... 2-n), a network 3, and a monitoring center 40.

[0003] The cameras 10 are surveillance cameras that are installed scattered over a wide area and take images using visible light and / or far-infrared light. They are connected to an optical fiber line 101, convert the captured sensor data (image data, live footage) into optical signals, and output them to the transmitter 2 via the optical fiber line 101. Furthermore, the camera 10 performs various operations based on control signals input from the monitoring center 40 via the optical fiber line 101 .

[0004] The transmitter 2 transmits and receives signals to and from each camera 10 via an optical fiber line 101 , and transmits and receives signals to and from the monitoring center 40 via a line network 3 . The network 3 is a dedicated line or a general-purpose network based on an IP (Internet Protocol) network.

[0005] The monitoring center 40 includes a transmission device 41, an operation terminal 42, and a monitoring monitor 43, and collectively monitors live images from the multiple cameras 10 and remotely controls the multiple cameras 10. The transmission device 41 performs processes such as sending and receiving IP packets, encoding / decoding, etc., and functions as an interface between the network 3 and the operation terminal 42 and monitoring monitor 43. The operation terminal 42 is a terminal operated by an operator, and control commands for the camera 10 are input thereto. The surveillance monitor 43 displays the received live video.

[0006] In a conventional surveillance system, live video images captured by individual cameras 10 installed at scattered surveillance stations are converted into optical signals and output to a transmitter 2, where an IP header such as a timestamp is added to the live video images, the images are converted into IP packets, and the packets are transmitted to a transmission device 41 in a surveillance center 40 via a line network 3.

[0007] The IP packets received by the transmission device 41 in the monitoring center 40 are converted back into live video and displayed on the monitoring monitor 43. The live video from each monitoring point is displayed, for example, on a large monitoring monitor 43 in picture-in-picture format.

[0008] In addition, control signals for controlling pan (horizontal rotation), tilt (vertical rotation), and zoom (telephoto, wide angle) are output as control commands to each camera 10 from the operation terminal 42 of the monitoring center 40, and when the camera 10 receives the control command, the control unit of the camera 10 performs settings and operations in accordance with the control command. In this way, a monitoring system has been constructed in which a wide area is monitored in an integrated manner from a monitoring center.

[0009] [calibration] Infrastructure and important facilities are often monitored continuously, day and night, and in order to display surveillance images more clearly in the dark, an increasing number of monitoring systems are being equipped with far-infrared sensors that use far-infrared rays that cannot be detected by the human eye, in addition to visible light sensors that use visible light. From here on, we will describe surveillance cameras and surveillance systems that use far-infrared sensors. Far-infrared cameras detect radiant heat from the surface of a subject and create an image, so even a slight change in temperature in the monitored environment can significantly degrade the image output by the camera.

[0010] For this reason, in far-infrared cameras, when the environmental temperature changes, calibration is performed to adapt (adjust) the sensor module to the new environmental temperature in order to obtain an image that accurately represents the radiant heat from an object. Calibration is performed when the environmental temperature has changed by a predetermined temperature (for example, 0.1°C) since the previous calibration, or when a specific time has passed since the previous calibration (periodically) even if the environmental temperature has not changed.

[0011] When performing calibration, the imaging surface of the far-infrared camera is covered with a shutter with a uniform temperature surface, and no image is captured (shutter calibration). As a result, the output of the image sensor temporarily goes black (outputs a black image) during shutter calibration, so some far-infrared cameras have a function (freeze function) that freezes and outputs the live video captured just before.

[0012] [Conventional camera configuration: Figure 7] Next, the configuration of a conventional surveillance camera will be described with reference to Fig. 7. Fig. 7 is a block diagram showing the configuration of a conventional camera. As shown in Figure 7, a conventional surveillance camera (hereinafter sometimes simply referred to as "camera") 10 is a far-infrared camera equivalent to the camera 10 in Figure 6, and is equipped with a sensor module 11, a signal processing unit 12, and a frame memory 13.

[0013] The sensor module 11 is a commercially available module that integrates a lens and a far-infrared imaging element (sensor), and irradiates infrared rays from the module body, converts the detected radiant heat into an image, and outputs it as sensor data. The sensor module 11 performs shutter calibration in response to an instruction from the signal processing unit 12. Furthermore, the sensor module 11 is reset when a reset signal is input from the signal processing unit 13.

[0014] The signal processing unit 12 performs various corrections and signal processing on the received sensor data, and also controls shutter calibration. The frame memory 13 is an external memory that stores sensor data.

[0015] The configuration of the signal processing unit 12 will now be described in detail. The signal processing unit 12 includes a memory IF (Interface) 21, a CPU (Central Processing Unit) 22, an image processing unit 23, an output unit 24, and a reset control unit 25. The memory IF 21 writes to and reads from the frame memory 13 . The CPU 22 is a control unit that controls the sensor module 11 and the signal processing unit 12, and is provided with a temperature sensor and controls shutter calibration. The operation during calibration will be described later.

[0016] The image processing unit 23 corrects and processes the sensor data output from the memory IF 21, and generates a freeze image during calibration. In addition, if the image processing unit 23 detects an abnormality within the image processing unit 23 or if the input sensor data is abnormal (for example, if there is a blackout), it outputs an error detection signal to the reset control unit 25, which will be described later. Furthermore, the image processing unit 23 is reset when a reset signal is input.

[0017] The output unit 24 converts the video data output from the image processing unit 23 into an optical signal and outputs it to the optical line. The reset control unit 25 manages the reset of the entire camera 10. Specifically, when an error detection signal is input from the image processing unit 23, the reset control unit 25 outputs a reset signal to the sensor module 11 and the image processing unit 23.

[0018] [Operation of conventional surveillance cameras] Next, the operation of the conventional camera 10 will be described with reference to FIG. First, normal operation will be briefly described. The sensor data captured by the sensor module 11 is temporarily written into the frame memory 13 by the memory IF 21 of the signal processing unit 12, and is then read out and input to the image processing unit 23. In the image processing unit 23 , the sensor data is corrected and subjected to image processing, and in the output unit 24 , it is converted into an optical signal and sent to the transmitting unit 2 via the optical line 101 . In this way, normal operation is carried out.

[0019] Next, the operation when shutter calibration is performed will be described. The CPU 22 has an internal temperature sensor function to monitor the temperature, and when the temperature exceeds a specific threshold value (for example, ±0.1°C from the temperature at the time of the previous calibration) or when a specific time has passed since the previous shutter calibration, it sends a command (referred to as a send command in the figure) to the sensor module 11 instructing it to perform shutter calibration. Command communication between the CPU 22 and the sensor module 11 is performed using asynchronous serial communication such as UART (Universal Asynchronous Receiver Transmitter), I2C (Inter-Integrated Circuit), or SPI (Serial Peripheral Interface).

[0020] When the sensor module 11 receives the command from the CPU 22 normally, it returns a response command and starts shutter calibration. During the calibration, the output sensor data of the sensor module 11 is temporarily blacked out or stopped.

[0021] After transmitting the command to execute the calibration, the CPU 22 subsequently outputs an instruction to the memory IF 21 to stop writing to the frame memory 13 (write stop instruction), thereby stopping the writing of the sensor data to the frame memory 13. In other words, even if sensor data is output from the sensor module 11 during the shutter calibration, it is not written to the frame memory 13.

[0022] Meanwhile, reading from the frame memory 13 continues without stopping, and the frame data immediately before the shutter calibration stored in the frame memory 13 is read out. While writing to the frame memory 13 is stopped, the frame data immediately before the shutter calibration is repeatedly read out, thereby realizing a video freeze function during the shutter calibration.

[0023] In this way, during shutter calibration, the immediately preceding frame data stored in the frame memory 13 is output to the downstream image processing unit 23, sent as a frozen image to the output unit 24, and sent to the center side.

[0024] Furthermore, when shutter calibration is completed, for example, the sensor module 11 notifies the CPU 22 of the completion, and the CPU 22 cancels the write stop to the memory IF 21 (outputs a write resume instruction), thereby resuming writing of sensor data to the frame memory 13, and the camera 10 outputs video data from the sensor module 11 instead of the frozen video.

[0025] [Freeze video output and error detection] As described above, conventional far-infrared cameras output a frozen image during calibration, so the monitoring center 40 does not detect the frozen image from the camera 10 as an error. On the other hand, there may be cases where the sensor module 11 hangs up during the calibration operation for some reason, preventing normal operation and resulting in the output of a frozen image. Furthermore, a freeze image may continue to be output due to an abnormality in the image processing in the image processing unit 23 of the signal processing unit 12.

[0026] However, in conventional cameras 10, frozen images during operation did not trigger an alarm to the monitoring center 40, and the reset control unit 25 did not output a reset signal to the sensor module 11 or image processing unit 23 for recovery purposes due to frozen images during operation.

[0027] [Related Technology] In addition, conventional technologies related to surveillance cameras and image processing include Patent Publication No. 2023-45713 "Surveillance camera and imaging device," Patent Publication No. 2021-162795 "Liquid crystal display device and image freeze detection method," and Patent Publication No. 2004-64440 "Image capture display system."

[0028] Patent Document 1 describes a surveillance camera and imaging device that uses a far-infrared sensor to suppress the influence of virtual images caused by radiant heat, thereby preventing erroneous recognition and false detection. Patent Document 2 describes a method for detecting whether or not the screen freezes based on a difference in current consumption. Furthermore, Patent Document 3 describes that if no difference is detected between adjacent frame images in the time axis direction, it is reported that the image is frozen. [Prior art documents] [Patent documents]

[0029] [Patent Document 1] Japanese Patent Publication No. 2023-45713 [Patent Document 2] Patent Publication No. 2021-162795 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-64440 Summary of the Invention [Problem to be solved by the invention]

[0030] However, when conventional surveillance cameras output frozen images during operation, the monitoring center is unable to distinguish whether the frozen images are due to shutter calibration, a sensor module hang-up, or a malfunction in image processing, resulting in delayed detection of the abnormality and lengthy recovery times.

[0031] Furthermore, Patent Documents 1 to 3 do not mention notifying the monitoring center of a camera abnormality when outputting a frozen image to enable the monitoring center to distinguish whether the frozen image is due to shutter calibration or a camera abnormality.

[0032] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a surveillance camera and surveillance system that can detect an abnormality in a surveillance camera, notify a monitoring center, respond quickly to the abnormality, and enable a rapid recovery, and in particular, when a frozen image is output during operation, can determine at the monitoring center whether the frozen image is due to normal operation of the surveillance camera or an abnormality. [Means for solving the problem]

[0033] The present invention, which aims to solve the problems of the above-mentioned conventional examples, is a far-infrared surveillance camera that captures images with a sensor and outputs live image data, and when a change in environmental temperature occurs, performs shutter calibration to adjust the sensor, performs image processing to output the image data acquired immediately before as a frozen image instead of the live image, and determines whether the image processing state or the sensor state is normal or abnormal, and outputs an alarm if an abnormal state is found.

[0034] Furthermore, the present invention is characterized in that in the above-mentioned surveillance camera, metadata of the video data from the sensor is analyzed, and if the analyzed metadata is abnormal, the sensor is determined to be in an abnormal state, an alarm is generated, and the sensor is reset.

[0035] The present invention is also characterized in that in the above-mentioned surveillance camera, a response command to a command sent to the sensor is monitored, and if a response command is not received after a specific time has elapsed, the sensor is determined to be in an abnormal state, an alarm is generated, and the sensor is reset.

[0036] Furthermore, the present invention is characterized in that, in the above-mentioned surveillance camera, an image processing unit is provided that processes image data from the sensor, and when shutter calibration is not being performed, the image processing data from the image processing unit is compared with delayed image data to determine whether the image processing data is a frozen image, and if it is determined to be a frozen image, the image processing unit is determined to be in an abnormal state, an alarm is generated, and the image processing unit is reset.

[0037] The present invention is also characterized in that the surveillance system comprises a surveillance camera as described above, a transmission unit that transmits video data from the surveillance camera, and a surveillance center device that receives the video data from the transmission unit and displays it on a surveillance monitor.

[0038] Furthermore, the present invention is characterized in that, in the above-mentioned surveillance system, the surveillance camera outputs an alarm as an alarm signal in addition to the video data, the transmitting unit transmits the alarm signal in addition to the video data, the surveillance monitor device receives the alarm signal in addition to the video data, and issues and displays an alarm based on the alarm signal on the surveillance monitor. [Effects of the Invention]

[0039] According to the present invention, a far-infrared surveillance camera captures images with a sensor and outputs live video data; when a change in environmental temperature occurs, shutter calibration is performed to adjust the sensor, and image processing is performed to output the most recently acquired video data as a frozen image instead of the live video; the camera determines whether the image processing state or the sensor state is normal or abnormal, and outputs an alarm if an abnormal state is found. This has the effect of alerting the camera of any abnormalities during operation, enabling a prompt response and rapid recovery.

[0040] Furthermore, according to the present invention, the surveillance camera analyzes the metadata of the video data from the sensor, and if the analyzed metadata is abnormal, determines that the sensor is in an abnormal state, generates an alarm, and resets the sensor. This has the effect of enabling the sensor abnormality to be detected through simple processing and the sensor to be reset autonomously, thereby enabling rapid recovery.

[0041] Furthermore, according to the present invention, the surveillance camera monitors the response command to the command sent to the sensor, and if no response command is received after a specific time has elapsed, determines that the sensor is in an abnormal state, generates an alarm, and resets the sensor. This has the effect of detecting sensor abnormalities through simple processing and autonomously resetting the sensor, enabling rapid recovery.

[0042] Furthermore, according to the present invention, the surveillance camera is provided with an image processing unit that performs image processing on the video data from the sensor, and when shutter calibration is not being performed, the image processed data from the image processing unit is compared with delayed video data to determine whether the image processed data is a frozen video or not, and if it is determined to be a frozen video, it determines that the image processing unit is in an abnormal state, generates an alarm, and resets the image processing unit.Therefore, it is possible to detect an abnormality in image processing from a frozen video that is not the result of shutter calibration and to notify the abnormality, and when a frozen video is output during operation, it is possible at the destination of the video data to determine whether the frozen video is a normal frozen video caused by shutter calibration or a frozen video caused by a camera abnormality, enabling a rapid response in the event of an abnormality and achieving a rapid recovery. [Brief explanation of the drawings]

[0043] [Figure 1] FIG. 1 is an explanatory diagram showing the configuration of the present system. [Figure 2] FIG. 1 is a block diagram of the camera. [Figure 3] 10 is a flowchart of a metadata analysis process. [Figure 4] 10 is a flowchart of a process in a hang-up detection timer. [Figure 5] 10 is a flowchart of a freeze image determination process. [Figure 6] FIG. 1 is an explanatory diagram illustrating an example of a conventional monitoring system. [Figure 7] FIG. 1 is a block diagram showing the configuration of a conventional camera. DETAILED DESCRIPTION OF THE INVENTION

[0044] An embodiment of the present invention will be described with reference to the drawings. [Outline of the embodiment] The surveillance camera (the camera) and surveillance system (the system) according to an embodiment of the present invention are a surveillance camera and a surveillance system using the same that captures video using a far-infrared sensor and outputs video data of live video; when a change in environmental temperature occurs, shutter calibration is performed to correct the far-infrared sensor, and image processing is performed to output the video data acquired immediately before as a frozen video instead of the live video; the state of the image processing or the state of the far-infrared sensor is determined to be normal or abnormal; if an abnormality is detected, an alarm is output externally; if an abnormality occurs in the camera during operation, the abnormality is notified to the monitoring center, allowing a prompt response and rapid recovery; in particular, when the camera outputs a frozen video, the monitoring center can determine whether the frozen video is normal due to shutter calibration or a frozen video caused by a camera abnormality, making it possible to respond to the abnormality.

[0045] Furthermore, this camera is capable of detecting multiple types of abnormalities individually, and when an abnormal condition is detected, a specific part of the camera is reset internally depending on the type of abnormality, allowing for a rapid autonomous recovery.

[0046] [System configuration: Figure 1] The configuration of this system will be explained using Figure 1. Figure 1 is an explanatory diagram showing the configuration of this system. As shown in Figure 1, this system has the same basic configuration as the conventional surveillance system shown in Figure 6, and is equipped with multiple cameras (surveillance cameras) 1 (cameras 1-1, ... 1-n), multiple transmission units 2 (transmission units 2-1, ... 2-n), a line network 3, and a monitoring center 4. Of these, the configuration and operation of the camera 1 and the monitoring center 4 are partially different from the conventional ones. The transmitting unit 2 and the network 3 are the same as the conventional ones, and therefore a description thereof will be omitted.

[0047] Camera 1 is a far-infrared camera, and the system is characterized by having an abnormality detection function that detects malfunctions in the sensor module or signal processing unit, and an alarm issuance function that issues an alarm when a malfunction is detected. These functions will be described later. A feature of the camera 1 of this system is that when it detects an abnormality, it outputs an alarm flag to notify the monitoring center 4 of the occurrence of the abnormality, and resets the internal part that is presumed to be the cause of the abnormality.

[0048] Furthermore, the operation terminal 421 of the monitoring center 4 has an alarm issuing function that, upon receiving an alarm flag from the camera 1, causes the monitoring monitor 43 to display an alarm notifying that an abnormality has occurred in the camera 1. The combined configuration of the transmission device 41 and operation terminal 421 of the monitoring center 4 corresponds to the monitoring center device described in the claims.

[0049] [Configuration of this camera: Figure 2] Next, the configuration of the camera 1 will be described with reference to Fig. 2. Fig. 2 is a block diagram of the configuration of the camera. As shown in FIG. 2, the camera 1 basically includes a sensor module 11, a signal processing unit 20, and frame memories 13 and . Of these, the sensor module 11 and the frame memory 13 are the same as those in the conventional camera 10 shown in FIG. 7, and therefore a description thereof will be omitted. As will be described later, the signal processing unit 12 differs from conventional ones in configuration and operation. The frame memory 14 is a newly provided memory.

[0050] [Configuration of signal processing unit 20] The configuration of the signal processing unit 20 will now be described in detail. The signal processing unit 20 of this camera 1 has the same parts as conventional ones, such as a memory IF 21, a CPU 22, and an image processing unit 23, and has the following characteristic parts of this camera 1: a metadata analysis unit 31, a hang-up detection timer 32, a freeze image determination unit 33, a delay circuit 34, an output unit 240, and a reset control unit 250. The output section 240 and the reset control section 250 perform new operations in addition to conventional operations, which will be described later. Description of components and operations that are the same as those of the conventional device will be omitted.

[0051] Before describing the characteristic parts of the signal processing unit 20, the abnormality detection function of the camera 1 will be described. Normally, a frozen image is output during operation only when the sensor module 11 is performing shutter calibration, so the main cause of abnormal freezing is thought to be a hang-up of the sensor module 11.

[0052] Therefore, in order to detect a hang-up of the sensor module 11, the camera 1 is provided with a metadata analysis unit 31 and a hang-up detection timer 32, each of which detects a hang-up.

[0053] Furthermore, even if shutter calibration is not performed in the sensor module 11 and the sensor module 11 is operating normally, a frozen image may be output from the camera 1. In this case, a malfunction in the image processing in the image processing unit 23 is assumed. Therefore, the camera 1 includes a freeze image determination unit 33 to detect abnormalities in the image processing in the image processing unit 23.

[0054] Here, the freeze image determination unit 33 performs the process of freeze image detection only when shutter calibration is not being performed by the sensor module 11, based on an instruction from the CPU 22 (an instruction to stop writing to the memory IF). This will be described later.

[0055] The operations of the metadata analysis unit 31, hang-up detection timer 32, and freeze image determination unit 33 will be described later, but each of them outputs an alarm when it detects an abnormality. Here, it is assumed that the metadata analysis unit 31 outputs an alarm (1), the hang-up detection timer 32 outputs an alarm (2), and the freeze image determination unit 33 outputs an alarm (3).

[0056] Next, the characteristic parts of the signal processing unit 20 will be specifically described. [Metadata Analysis Section 31] The metadata analysis unit 31 analyzes the meta-information included in the sensor data output by the sensor module 11, and detects that the sensor module 11 has hung up if the meta-information is abnormal. The process of detecting a hang-up in the metadata analysis unit 31 is referred to as a metadata analysis process.

[0057] Information about frames, such as frame numbers and frame rates, is usually embedded as metadata in the sensor data output by the sensor module 11. The metadata is often embedded in lines corresponding to blanking periods in the video, and is used by external devices to understand the status of the sensor module.

[0058] The metadata analysis unit 31 extracts the metadata contained in the sensor data from the sensor module 11 and checks whether the metadata has been correctly updated. If the sensor module 11 falls into an abnormal state and hangs up, the metadata that should be updated at frame intervals will no longer be updated, and the metadata analysis unit 31 will determine that a hang-up has occurred in the sensor module 11 and will output an alarm (1) to the reset control unit 250 and the output unit 240.

[0059] Alarm (1) is output as a flag from the metadata analysis unit 31. Under normal circumstances, the status is output as "0", and if a hang-up is detected, the status is changed to "1" and output. Note that changing the status of alarm (1) and alarms (2) and (3) described below from "0" to "1" is synonymous with outputting alarms (1) to (3), and corresponds to generating an alarm in the claims.

[0060] [Hang-up detection timer 32] The hang-up detection timer 32 is a timer that counts the time from when the CPU 22 issues a command to perform shutter calibration to when it receives a response from the sensor module 11, and detects a hang-up of the sensor module 11 if a specific time is exceeded.

[0061] Command exchange between the CPU 22 and the sensor module 11 will be described using the commonly used UART serial communication as an example. UART is an asynchronous serial communication method that transmits multiple bits of information one bit at a time in a time series, and is suitable for communication between one-to-one systems such as the CPU 22 and the sensor module 11.

[0062] During shutter calibration, the CPU 22 sends an execution command (bit string) to the sensor module 11, the sensor module 11 returns a response command, and when a series of communications ends normally, the shutter calibration starts. In UART serial communication, the bit string that makes up the command is sent one bit at a time at regular intervals, and the command length for calibration and the command that returns a response is the same every time, so the access time required for a series of operations is almost constant.

[0063] Therefore, if the hang-up detection timer 32 does not receive a response from the sensor module 11 even after a preset response time has elapsed, it determines that a hang-up has occurred in the sensor module 11 and outputs an alarm (2).

[0064] Specifically, the hang-up detection timer 32 starts counting up from an initial value of zero upon receiving a command from the CPU 22, and stops counting upon receiving a response command from the sensor module 11. If the response command is received within a predetermined time, it is determined that the operation is normal. Then, when the next command is input from the CPU 22, the count value of the timer is cleared and the timer starts counting up again from zero.

[0065] On the other hand, if the sensor module 11 becomes inoperable due to a malfunction or the like, the output of the response command is delayed, and the response command is not received by the hang-up detection timer 32, the count-up of the hang-up detection timer 32 does not stop, and when the timer expires after a predetermined time has passed, the hang-up detection timer 32 outputs alarm (2) to the output unit 240 and the reset control unit 250.

[0066] [Delay circuit 34] The delay circuit 34 branches and inputs the write stop instruction output from the CPU 22 to the memory IF at the start of shutter calibration, delays it for a predetermined time, and outputs it to the freeze image determination unit 33. The predetermined time is the processing time in the image processing unit 23. As will be described later, when a write stop instruction is input, the freeze image determination unit 33 turns off the freeze image determination process that determines whether the image is frozen, and when the write stop is released (when a write resume instruction is input), the freeze image determination process is turned on. The signal input from the delay circuit 34 to the freeze image determination unit 33 is called a status signal.

[0067] [Freeze Video Judgment Unit 33] The freeze image determination unit 33 determines whether the image data sent from the image processing unit 23 is a freeze image or not, and detects an abnormality in the image processing in the image processing unit 23 . In particular, in this camera 1, freeze image determination unit 33 does not perform freeze image determination processing during shutter calibration, but performs freeze image determination processing when shutter calibration is not being performed, based on instructions from CPU 22. A frozen image during shutter calibration is due to normal operation, and is therefore not subject to freeze image detection.

[0068] The above-mentioned Patent Documents 2 and 3 have been proposed for determining whether a video is a frozen video (freeze image, video freeze, image freeze), and the freeze video determination unit 33 determines whether or not the video is a frozen video using these methods or other existing methods. In the methods of Patent Documents 2 and 3, image freeze detection is performed constantly, but in the freeze image determination unit 33 of this camera 1, the operation of the freeze image determination process is turned off during shutter calibration.

[0069] The freeze image determination is turned on / off by using a write stop instruction from the CPU 22 to the memory IF 21. Specifically, when shutter calibration starts, the write stop instruction sent by the CPU 22 is branched and delayed by a predetermined time in a delay circuit 34, and input to the freeze image determination 33 in synchronization with the image data from the image processing unit 34. When the write stop instruction is input, the freeze image determination unit 33 determines that shutter calibration is in progress and stops the freeze image determination process. Then, when the write stop is released by a signal from the delay circuit 34 (when a write restart instruction is input), the freeze image determination process is turned on.

[0070] When the freeze image determination process is on, freeze image determination unit 33 calculates the difference between the current frame data from image processing unit 23 and the frame data successive in the time axis direction stored in frame memory 14 in the manner described above, and detects whether the image is frozen or not.

[0071] If the difference between the current frame data and the frame data consecutive in the time axis direction stored in the frame memory 14 is smaller than a specific value, the freeze image determination unit 33 determines that the image is frozen and outputs an alarm (3) to the output unit 240 and the reset control unit 250. In this case, it is assumed that the freeze image is being output due to an abnormality occurring in the image processing in the image processing unit 23.

[0072] [Reset control unit 250] The reset control unit 250 monitors the input of alarm (1) from the metadata analysis unit 31, alarm (2) from the hang-up detection timer 32, and alarm (3) from the freeze image determination unit 33, and when an alarm is input, it resets the image processing in the sensor module 11 or the image processing unit 23 accordingly.

[0073] Specifically, the reset control unit 250 is preset with the parts to be reset depending on the type of alarm, and when alarm (1) from the metadata analysis unit 31 and / or alarm (2) from the hang-up detection timer 32 are input, it outputs a reset signal to the sensor module 11 to reset the sensor module 11. Furthermore, when the reset control unit 250 receives an alarm (3) from the freeze image determination unit 33, it outputs a reset signal to the image processing unit 23 to instruct the image processing unit 23 to reset the image processing.

[0074] In this way, the camera 1 changes the type of alarm depending on which part has malfunctioned, so the reset control unit 250 can reset only the part that is estimated to have malfunctioned depending on the type of alarm, providing a fail-safe function that can quickly recover from an abnormal state.

[0075] [Output section 240] The output unit 240 converts the sensor data into an optical signal and outputs it to the optical line in the same manner as in the past, and in this camera 1, it monitors the status of alarm (1) from the metadata analysis unit 31, alarm (2) from the hang-up detection timer 32, and alarm (3) from the hang-up determination unit 33, and when any of the alarms is input, it turns on an alarm flag that notifies the monitoring center 4 of an abnormality in the camera 1 and outputs it. The alarm flag corresponds to the alarm signal recited in the claims, and is converted into an optical signal and output together with the video data.

[0076] Here, if none of alarms (1) to (3) are input (state "0"), the output unit 240 sets the alarm flag to "0 (off)" to indicate that there is no abnormality, and if at least one of alarms (1) to (3) is input (state "1"), the output unit 240 sets the alarm flag to "1 (on)" to indicate that there is an abnormality. Incidentally, sending the alarm flag as "1" corresponds to outputting an alarm in the claims, and corresponds to the alarm issuing function shown in FIG.

[0077] In the monitoring center 40, the operation terminal 421 monitors the alarm flag, and when it receives "1", it performs an alarm issuing process and displays an alarm on the monitoring monitor 43 to notify that an abnormality has occurred in the camera 1.

[0078] The monitoring center 40 receives the video data from the camera 1 and displays it on the monitoring monitor 43, as in the conventional case, and during the shutter calibration of the camera 1, a frozen video is output, as in the conventional case. At this time, if the alarm flag from camera 1 is "0", no alarm is displayed on the surveillance monitor 43, and it is clear that the frozen image is normal due to shutter calibration.

[0079] On the other hand, when an alarm flag "1" is received from camera 1, an alarm is displayed on the surveillance monitor 43, allowing the surveillance staff to recognize that an abnormality has occurred in camera 1. When a frozen image is output during operation, in the conventional monitoring center 40 it was not possible to determine whether the frozen image was due to shutter calibration or a malfunction of the camera 10. However, in this monitoring system, the monitoring center 4 can easily determine whether the frozen image is a normal image due to shutter calibration or an abnormality in the camera 1, making it possible to respond quickly to any abnormalities.

[0080] Here, the alarms from the output unit 240 are set as alarm flags regardless of the type of alarm, but they may be set as alarm flags (1) to (3) according to the types of alarms (1) to (3).

[0081] Furthermore, the operation terminal 421 of the monitoring center 4 may store the state of the alarm flag ("0" or "1") together with the date and time as a log, which may be used for analyzing the failure. In this case, if the alarm flag is subdivided into alarm flags (1) to (3), the state and date and time are stored for each type of alarm flag.

[0082] [Metadata analysis process: Figure 3] Next, the metadata analysis process in the metadata analysis unit 31 will be described with reference to Fig. 3. Fig. 3 is a flowchart of the metadata analysis process. As shown in FIG. 3, when sensor data is input (S11), the metadata analysis unit 31 extracts and analyzes the metadata (S12).

[0083] Then, the metadata analysis unit 31 determines whether the metadata has been updated normally (S13), and if it has been updated normally (Yes), the process returns to step S11. Also, if it is determined in process S13 that the metadata has not been updated normally (No), the metadata analysis unit 31 outputs alarm (1) to the output unit 240 and the reset unit 250, and returns to process S11 to continue monitoring. In this way, the metadata analysis process is carried out.

[0084] [Hang-up detection timer processing: Figure 4] Next, the processing in the hang-up detection timer 32 will be described with reference to Fig. 4. Fig. 4 is a flowchart of the processing in the hang-up detection timer. As shown in FIG. 4, the hang-up detection timer 32 monitors whether or not a command instructing shutter calibration has been input from the CPU 22 (S21), and if not input (No), repeats the process S21. When a transmission command is input in step S21 (if Yes), the hang-up detection timer 32 resets the timer (S22) and starts counting up (S23).

[0085] Then, the hang-up detection timer 32 determines whether a response has been received from the sensor module 11 (S24), and if not (No), determines whether a predetermined time has passed and the timer has expired (S25), and if not, returns to processing S23 and continues counting up.

[0086] If a response is received from the sensor module 11 in process S24 (Yes), the hang-up detection timer 32 stops the timer (S26), and proceeds to process S21 to wait for a command instructing the next shutter calibration.

[0087] If the timer expires in step S25 (Yes), the hang-up detection timer 32 outputs an alarm (2) to the output unit 240 and the reset unit 250 (S27), and the process proceeds to step S21. In step S24, if the timer expires, the alarm (2) may not be output immediately, but the process may return to step S21 and the CPU 22 may retry sending the command a predetermined number of times. In this manner, the processing of the hang-up detection timer 32 is carried out.

[0088] [Freeze video detection process: Figure 5] Next, the freeze image determination process in freeze image determination section 33 will be described with reference to Fig. 5. Fig. 5 is a flowchart of the freeze image determination process. As shown in FIG. 5, the freeze image determination unit 33 determines whether or not shutter calibration is being performed based on the status signal from the delay circuit 34 (S31), and if shutter calibration is being performed (Yes), repeats the process S31.

[0089] Then, if it is determined in process S31 that shutter calibration is not being performed (No), the freeze image determination unit 33 compares the image data (image processed data) image-processed by the image processing unit 23 with the data from the frame memory 14 and performs frame analysis (S32).

[0090] As a result of the frame analysis, it is determined whether or not the image processing data from the image processing unit 23 is a freeze image (S33), and if it is not a freeze image (No), the process proceeds to step S31. Furthermore, if it is determined in step S33 that the image processing data is a freeze image (Yes), the freeze image determination unit 33 outputs an alarm (3) to the output unit 240 and the reset control unit 250 (S34). In this way, the freeze image determination process is performed.

[0091] [Effects of the embodiment] The surveillance camera and surveillance system according to this embodiment are provided with a sensor module 11 equipped with a far-infrared sensor, and a signal processing unit 12 that performs image processing and outputs video data of live footage, and when a change in environmental temperature occurs, the sensor module 11 performs shutter calibration to adjust the sensor, and the signal processing unit 12 outputs the video data acquired immediately before as a frozen image instead of the live image, and the signal processing unit 12 determines whether the surveillance camera is in a normal state or an abnormal state depending on the state of the image processing or the state of the sensor module 11, and if it is in an abnormal state, outputs an alarm to the outside, so that the surveillance camera and surveillance system can notify the outside of any abnormality in the camera 1 that occurs during operation, and in particular, when a frozen image is output, the monitoring center 4 to which the image data is sent can determine whether the frozen image is a normal frozen image caused by shutter calibration or a frozen image caused by an abnormality in the camera, which has the effect of enabling a quick response in the event of an abnormality and allowing for quick recovery.

[0092] Furthermore, according to this surveillance camera, the signal processing unit 12 is equipped with a metadata analysis unit 31 and a hang-up detection timer 32 that detect a hang-up of the sensor module 11, and a frozen image determination unit 33 that detects an abnormality in the image processing unit 23, and when each of these detects an abnormality, they each output a different alarm to the reset control unit 250, and the reset control unit 250 resets the set locations in accordance with the input alarm, so that even if an abnormality occurs, the camera can autonomously reset the locations where the abnormality is suspected, thereby enabling a quick recovery. [Industrial Applicability]

[0093] The present invention is suitable for a surveillance camera and a surveillance system that can detect an abnormality occurring in a surveillance camera during operation, notify a surveillance center, and respond quickly to the abnormality to enable a rapid recovery. [Explanation of symbols]

[0094] REFERENCE SIGNS LIST 1,10...camera, 2...transmitter, 3...line network, 4,40...monitoring center, 11...sensor module, 12,20...signal processing unit, 13,14...frame memory, 21...memory IF, 22...CPU, 23...image processing unit, 24,240...output unit, 25,250...reset control unit, 31...metadata analysis unit, 32...hang-up detection timer, 33...freeze image determination unit, 34...delay circuit, 41...transmission device, 42,421...operation terminal, 43...monitoring monitor, 101...optical line

Claims

1. A far-infrared surveillance camera that captures images with a sensor and outputs live video data, When a change in the environmental temperature occurs, shutter calibration is performed to adjust the sensor, and image processing is performed to output the image data acquired immediately before as a frozen image instead of the live image. A surveillance camera characterized in that it determines whether the state of the image processing or the state of the sensor is normal or abnormal, and outputs an alarm if the state is abnormal.

2. The surveillance camera according to claim 1, characterized in that it analyzes metadata of the video data from the sensor, and if the analyzed metadata is abnormal, it determines that the sensor is in an abnormal state, generates an alarm, and resets the sensor.

3. The surveillance camera according to claim 1, characterized in that it monitors a response command to a command sent to the sensor, and if the response command is not received after a specific time has passed, it determines that the sensor is in an abnormal state, generates an alarm, and resets the sensor.

4. an image processing unit that processes image data from the sensor; The surveillance camera of claim 1, characterized in that when the shutter calibration is not being performed, the image processing data from the image processing unit is compared with the delayed video data to determine whether the image processing data is a frozen image, and if it is determined to be a frozen image, the image processing unit is determined to be in an abnormal state, an alarm is generated, and the image processing unit is reset.

5. 5. A surveillance system comprising a surveillance camera according to claim 1, a transmission unit that transmits video data from said surveillance camera, and a surveillance center device that receives the video data from said transmission unit and displays it on a surveillance monitor.

6. The surveillance system according to claim 5, characterized in that the surveillance camera outputs an alarm as an alarm signal in addition to the video data, the transmitting unit transmits the alarm signal in addition to the video data, the surveillance monitor device receives the alarm signal in addition to the video data, and issues and displays an alarm based on the alarm signal on the surveillance monitor.

Images