Imaging device and surveillance system

Abstract

To provide an imaging device that can transmit captured video as video data with image quality appropriate for a monitoring target, thereby reducing the amount of video data transmitted over a network.SOLUTION: A representative imaging device according to the present invention includes an object detection unit that detects a monitoring target from a first image captured by an imaging unit, a calculation unit that calculates a recommended image quality for the monitoring target, an encoding unit that outputs a second image that is encoded from the first image to have the recommended image quality, and an image processing unit that has a communication unit that transmits the second image.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an imaging device and a surveillance system. [Background technology]

[0002] Surveillance systems are used in a wide range of fields, such as crime prevention in public places and management of stores and facilities, but in these surveillance systems, there are cases where high-definition images are required and cases where low-quality images are sufficient depending on the surveillance situation. For example, when the surveillance target is a small or fast-moving object, high-quality images are required, whereas when the surveillance target is a large or slow-moving object, low-quality images may be sufficient. For this reason, in conventional surveillance systems, surveillance cameras transmit images of two different image qualities, high-quality images and low-quality images, allowing the receiving terminal to select either the high-quality image or the low-quality image as needed. However, as camera performance improves, the amount of image information transmitted from a single camera has increased rapidly, and the number of cameras connected to a single network has also increased, making preventing congestion in surveillance camera networks a major technical challenge.

[0003] For this reason, methods are being considered for preventing the load on surveillance cameras and congestion in the network by changing the image quality of images captured by surveillance cameras depending on the surveillance situation. For example, Patent Document 1 discloses a technology that "is a monitoring system mounted on a vehicle and monitors the interior of the vehicle, comprising a first communication unit that communicates with a base station device, a camera that photographs the interior of the vehicle, an acquisition unit that acquires headcount information indicating the number of passengers in the vehicle, a communication control unit that causes the first communication unit to transmit photographed data provided by the camera to the base station device, and a camera control unit that controls the amount of photographed data based on the headcount information." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-80490 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the invention described in Patent Document 1, image quality is changed according to information on the number of people using a human presence sensor, and the amount of video data transmitted over a network is controlled, but the required image quality is not necessarily determined by the number of people included in the image. Therefore, the technology in Patent Document 1 has a problem in that it is difficult to respond to cases where image quality needs to be selected according to features other than the number of people for the monitored object.

[0006] In view of the above problems, the present invention aims to provide an imaging device that can transmit captured video as video data with image quality appropriate to the target of monitoring, thereby reducing the amount of video data transmitted over a network. [Means for solving the problem]

[0007] In order to solve the above problems, one representative imaging device of the present invention includes an object detection unit that detects a surveillance target from a first image captured by an imaging unit, a calculation unit that calculates a recommended image quality for the surveillance target, an encoding unit that outputs a second image that is encoded from the first image to have the recommended image quality, and an image processing unit that has a communication unit that transmits the second image. Effect of the Invention

[0008] According to the present invention, it is possible to provide an imaging device that can transmit captured video as video data with image quality appropriate to the monitoring target, thereby reducing the amount of video data transmitted over a network.

[0009] Problems, configurations and effects other than those described above will become apparent from the following description of the preferred embodiment of the invention. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an imaging device according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing the communication unit. [Diagram 3] FIG. 3 is a diagram showing the setting values ​​of the image quality of the monitoring target. [Figure 4] FIG. 4 is a diagram showing the structure of the database unit. [Diagram 5] FIG. 5 is a flowchart showing a moving image encoding process of the imaging device according to the first embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a monitoring system according to the second embodiment. [Figure 7] FIG. 7 is a flowchart showing a video encoding process of the surveillance system according to the third embodiment. [Figure 8] FIG. 8 is a schematic diagram showing an example of the configuration of an imaging device according to the first modification. [Figure 9] FIG. 9 is a schematic diagram showing an example of the configuration of an imaging device according to the second modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment. In addition, in the description of the drawings, the same parts are denoted by the same reference numerals. When there are multiple components having the same or similar functions, they may be described by using the same reference numerals with different subscripts, or when there is no need to distinguish between these multiple components, the subscripts may be omitted. In addition, although terms such as "first," "second," and "third" may be used in the present disclosure to describe various elements or components, it will be understood that these elements or components should not be limited by these terms. These terms are used only to distinguish one element or component from another element or component. Thus, a first element or component discussed below can also be referred to as a second element or component without departing from the teachings of the inventive concept. In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0012] [First embodiment] First, an imaging device according to the present disclosure will be described with reference to FIG. FIG. 1 is a schematic diagram showing an imaging device 100 according to the first embodiment.

[0013] <Imaging device 100> The imaging device 100 includes an imaging section 10 and an image processing section 20, and encodes a captured first video into a second video of a recommended image quality and transmits the second video.

[0014] <<Imaging unit>> The imaging unit 10 is typically a camera that uses visible light, infrared light, or the like. For example, by disposing such a camera as a surveillance camera at a surveillance location, a surveillance system that monitors for intrusion of a person, etc., can be constructed. As will be described with reference to FIG. 6 and other figures, in the surveillance system 1, the imaging unit 10 captures an image of a surveillance range and transmits the captured image to the image processing unit 20 as a first image. Furthermore, the imaging unit 10 can capture images of sufficiently high quality for use in a surveillance system, and can adequately identify the surveillance target and confirm its movements even if the surveillance target is a small or fast-moving object, for example.

[0015] In addition, the imaging unit 10 may be equipped with a digital zoom function. In that case, the imaging unit 10 may, for example, enlarge a portion of an image captured by an optical lens using the digital zoom function and transmit the enlarged image to the image processing unit 20 as a first image.

[0016] <<Image processing section>> The image processing unit 20 includes an object detection unit 21 , a calculation unit 22 , an encoding unit 23 , a communication unit 24 , and a storage unit 25 .

[0017] <<<Object detection section>>> The object detection unit 21 can detect a preset monitoring target from within the first video image and extract detection information of an image relating to the monitoring target. Here, the detection information is, for example, information such as the coordinates, size, brightness, etc. of the monitored object. Note that the object detection unit 21 may use any method as long as it can identify and extract the surveillance target from the first video. For example, the target of surveillance may be detected by digital image processing such as template matching, or the first video may be subjected to image analysis based on a learning model of AI (artificial intelligence) using a neural network to determine whether or not a target of surveillance is present and to obtain coordinate information, etc., for images relating to the target of surveillance.

[0018] In addition, targets of surveillance, such as people and vehicles, may be extracted from static shape characteristics, or from human movement, for example, behavior such as wandering, or dynamic, incidental characteristics such as carrying a knife or the like. In addition, when extracting an object based on characteristics such as its shape or movement, it is also possible to refer to not only one frame image but multiple frame images to calculate the moving speed, etc., and extract the target of monitoring. In either case, it is sufficient for the object detection unit 21 to detect a monitoring target based on the contents preset in the database unit 221 described later.

[0019] <<<Calculation section>>> The calculation unit 22 is a functional unit that calculates, for each monitoring target, the optimal recommended image quality for displaying the monitoring target. The calculation unit 22 can also include a database unit 221 that stores a setting value of the recommended image quality for each monitoring target. The calculation unit 22 also refers to the database unit 221 for a monitoring target detected by the object detection unit 21, and acquires a setting value of the recommended image quality in consideration of detection information related to the detected object, calculates the recommended image quality, and outputs it to the encoding unit 23. At this time, the calculated recommended image quality may be expressed, for example, using a setting value in the database unit 221, or may be expressed using an index of a general image quality level such as 4K resolution. The database unit 221 will be described in detail later.

[0020] <<<Encoding section>>> Encoding unit 23 is a functional unit that encodes the first video into the second video so as to have the recommended image quality calculated by calculation unit 22. By encoding, the data capacity of the second video is reduced compared to the first video, making it possible to reduce the amount of information transmitted over the network, and thus making it possible to avoid congestion of network 200, which will be described later. If the object detection unit 21 does not detect a monitoring target, encoding may be performed at a low image quality standard that is set in advance, as in the prior art, or encoding may be stopped.

[0021] <<<Communications Department>>> The communication unit 24 is a communication device that enables the imaging device 100 to communicate with the outside via a network 200, which will be described later. Details will be described later with reference to FIG.

[0022] <<<Storage section>>> The accumulation unit 25 is a storage unit that accumulates the second video encoded by the encoding unit 23. The second video accumulated in the accumulation unit 25 is transmitted, for example, via the communication unit 24 to a video distribution server 500, which will be described later.

[0023] Furthermore, the storage unit 25 may store a video other than the second video, for example, the first video before encoding. If the first video before encoding is stored in the storage unit 25 or the like, the video monitoring terminal 300 described later will be able to check the first video when it becomes necessary.

[0024] <Communications Department> Next, the communication unit 24 will be described with reference to FIG. FIG. 2 is a schematic diagram showing an example of the configuration of the communication unit 24. As shown in FIG. The communication unit 24 may be composed of a first communication unit 241, a second communication unit 242, a third communication unit 243, and a fourth communication unit 244, and these may enable communication between the imaging device 100 and other devices included in the surveillance system 1 described below.

[0025] <<First communication section>> 1 to a video monitoring terminal 300 (to be described later) via a network 200 (to be described later). The transmission method used by the first communication unit 241 utilizes, for example, the Internet Protocol, but may be another transmission method.

[0026] <<Second communication section>> The second communication unit 242 is a communication unit for transmitting, to the video monitoring terminal 300, advance notice information when the image quality of the second video encoded by the encoding unit 23 is to be changed. Here, the image quality of the second video generated by the encoding unit 23 may be changed in response to detection of a monitoring target or an instruction from a monitoring system server 400, which will be described later.

[0027] <<Third Communication Department>> The third communication unit 243 is a communication unit for transmitting advance notice information to the monitoring system server 400 described later when the image quality is changed by the encoding unit 23 as described later. When a large number of image capturing devices 100 are present, it is desirable for the monitoring system server 400 to control the image quality of the encoded second video for each image capturing device 100 so as to prevent congestion in the network 200. For this reason, it is desirable for the image capturing device 100 to be provided with the third communication unit 243 for communicating with the monitoring system server 400.

[0028] <<Fourth Communication Department>> The fourth communication unit 244 is a communication unit for transmitting the second video stored in the storage unit 25 to a video distribution server 500, which will be described later. Furthermore, the fourth communication unit 244 may transmit the first video stored in the storage unit 25 to the video distribution server 500.

[0029] <Recommended image quality> Next, the setting value of the recommended image quality will be described with reference to Fig. 3. As mentioned above, the recommended image quality indicates an image quality suitable for displaying the monitored object. Specifically, it is set by the number of pixels, the recommended amount of movement (the number of pixels that a moving object moves for each frame), the compression rate, etc., as will be described later.

[0030] As described later, in the surveillance system 1, the user watches the video surveillance terminal 300 to monitor the surveillance target, so when the first video is converted into the second video by the encoding unit 23, the second video needs to meet the image quality desired by the user. The image quality desired by the user differs depending on the surveillance purpose and the surveillance target, and the recommended image quality can be determined, for example, by the recommended number of pixels, which is the required number of pixels, the recommended movement amount, which is the required amount of pixel movement, and the recommended compression rate, which is the compression rate of the video. Note that the setting value of the recommended image quality may be a setting value other than the above. Below, various examples of setting values ​​for setting the recommended image quality will be described.

[0031] <Recommended pixel count> The recommended number of pixels is the number of pixels or more that should be used to represent the monitored object. Pixels are the smallest unit that makes up an image, and the greater the number of pixels, the more precise and clear the image will be. Conversely, a lower number of pixels will result in a coarse and blurry image. For this reason, the recommended number of pixels is an important setting value that determines the recommended image quality. If the recommended number of pixels is not sufficiently secured in the second image, the object of surveillance will be displayed as coarse and blurry, making it difficult to accurately determine the object of surveillance.

[0032] FIG. 3A is a diagram showing the recommended number of pixels for a person 310 who is the monitoring target. For example, as shown in FIG. 3(A), if the monitored object is a person 310 and a setting of 150 pixels vertically and 50 pixels horizontally can achieve the monitoring objective of the monitoring system 1 described below, then the recommended number of pixels can be set to 7,500 pixels, which is the product of the number of vertical pixels and the number of horizontal pixels.

[0033] The recommended number of pixels can be appropriately set to different values ​​even for each imaging device 100. The recommended number of pixels can also be changed for each type of monitoring target. For example, even if the recommended number of pixels for people is set to 7,500 pixels, the recommended number of pixels for animals can be set to 2,500 pixels, and the recommended number of pixels for automobiles can be set to 5,000 pixels, etc.

[0034] <Recommended travel distance> The recommended movement amount is a setting value for displaying the movement status of the monitoring target on the video monitoring terminal 300 to an extent that the monitoring purpose of the monitoring system 1 is achieved. For a monitoring target that involves movement, the smaller the movement amount of the corresponding pixels per frame, the smoother the image that the movement can be displayed. In other words, by switching frames at short intervals and increasing the number of frames per unit time, the visibility of a fast-moving monitoring target is improved. In other words, the recommended amount of movement is a value that indicates within how many pixels the monitored object needs to move per frame for appropriate monitoring. The smaller the recommended amount of movement, the more finely the movement is sampled, improving the visibility of fast-moving objects, but the amount of video data transmitted will increase. The recommended frame rate is then calculated based on the recommended amount of movement and the coordinates that the monitored object has moved per unit time (frame interval).

[0035] FIG. 3B is a diagram showing the recommended movement amounts of a person 310 who is the monitoring target. 3B, for example, person 310 has moved 200 pixels from the image of the previous frame. In this case, if the movement of person 310, who is the monitoring target, is an amount that achieves the monitoring purpose of image capture device 100, the recommended amount of movement can be set to 200 pixels per frame (200 pixels / frame).

[0036] Similarly to the recommended number of pixels, the recommended amount of movement can be set to different values ​​as appropriate even for the same imaging device 100. The recommended amount of movement can also be changed for each type of monitoring target. For example, the amount of movement required to distinguish the movement of a person can be set to 200 pixels / frame, and the recommended amount of movement for a fast-moving vehicle can be set to 100 pixels / frame.

[0037] <Recommended compression ratio> The recommended compression rate is the compression ratio of image data when encoding from a first image to a second image, and is the value of how much data can be deleted from the amount of information in the second image compared to the amount of information in the first image when encoding from the first image to the second image. The lower the compression rate, the less noise there is in the image, improving the visibility of small surveillance targets and surveillance targets in dark conditions, but the amount of video data transmitted increases. Conversely, the higher the compression rate, the more information is lost and the greater the degradation of the image.

[0038] For this reason, the recommended compression rate is set according to the brightness and number of pixels of the object to be monitored. For example, the recommended compression rate can be set to a medium rate when an ordinary person is detected as a surveillance target during the day when visibility is good, and to a low rate when the person is detected at night when visibility is poor.

[0039] Next, the structure of the database unit 221 will be described with reference to FIG. FIG. 4 is a diagram showing the structure of the database unit 221. As shown in FIG. The database unit 221 is a relational database made up of rows and columns, and includes columns 2211 to 2214 and a row 2215, with setting values ​​stored in each field.

[0040] The attributes in columns 2211 to 2214 are items of setting values ​​for calculating the recommended image quality for each defined monitoring target. For example, column 2211 stores the monitoring target as an attribute, and similarly, column 2212 stores the recommended number of pixels for the recommended image quality of the monitoring target as an attribute. Also, column 2213 stores the recommended movement amount for the recommended image quality of the monitoring target as the number of pixels per frame as an attribute, and column 2214 can store the recommended compression ratio for the recommended image quality of the monitoring target as a level such as high, medium, or low as an attribute.

[0041] The setting values ​​stored in the database unit 221 are, for example, representative setting values ​​such as the recommended number of pixels, the recommended movement amount, and the recommended compression ratio, but are not limited to these. In addition, it is preferable that the value of each setting value is determined based on statistical information obtained from past images. For example, the recommended number of pixels may be the average or median of the number of pixels that have been able to determine the type of monitoring target in the past by the image capture device 100. The same applies to the recommended movement amount and the recommended compression rate.

[0042] Furthermore, the values ​​of the settings stored in the database unit 221 may be automatically input based on statistical information of past images, or any value may be input manually. For example, when a specific monitoring target is to be checked in high image quality without based on statistical information of the past, a value that provides a higher image quality than the normal recommended image quality may be input manually. Also, for example, if there is no need to monitor a particular monitoring target and it is desired to capture an image at a lower image quality than the recommended image quality, a value that results in an image quality lower than the normal recommended image quality may be input.

[0043] The set value stored in the database unit 221 may be set as a numerical value or as a degree.

[0044] <Video encoding process> Next, the moving image encoding process in the imaging device 100 will be described with reference to FIG. FIG. 5 is a flowchart showing the moving image encoding process of the imaging device 100.

[0045] (Step S101) In step S101, the object detection unit 21 acquires a first image from the imaging unit 10.

[0046] (Step S102) In step S102, the object detection unit 21 performs image processing on the first video to detect an object. Here, object detection refers to detecting an object, person, or the like that is the target of surveillance in the first video. At this time, the object detection unit 21 may output the monitoring target defined in the database unit 221 based on the learning model. In addition, information such as coordinates, size, and brightness of the detected object may be simultaneously acquired during object detection.

[0047] (Step S103) In step S103, the object detection unit 21 determines whether or not a monitoring target has been detected. If a monitoring target is detected, the process proceeds to step S104, and if not, the process proceeds to step S110.

[0048] (Step S104) In step S104, it is determined whether the detected monitoring target is defined in the database unit 221 or not. If the detected monitoring target is defined, the process proceeds to step S105, and if not, the process proceeds to step S110.

[0049] (Step S105) In step S105, the calculation unit 22 calculates a recommended image quality based on the detected monitoring target. At this time, the calculation unit 22 acquires the recommended number of pixels, the recommended amount of movement, and the recommended compression rate stored in the database unit 221 based on the detected monitoring target, and calculates the recommended image quality based on these values ​​and detection information such as the coordinates, size, and brightness of the object detected during object detection. Furthermore, the calculation unit 22 transmits changeability information about the calculated recommended image quality to the monitoring system server 400 (described later) via the third communication unit.

[0050] (Step S106) In step S106, the calculation unit 22 receives the response of the changeability information transmitted to the monitoring system server 400. If the reply of the change permission information is "OK", which indicates permission, the process proceeds to step S107, and if the reply is "NG", which indicates denial, the process proceeds to step S110.

[0051] (Step S107) In step S107, the setting value of the encoding unit 23 is set based on the recommended image quality calculated by the calculation unit 22.

[0052] (Step S108) In step S108, the encoding unit 23 encodes the first video into a second video based on the set value.

[0053] (Step S109) In step S109, the communication unit 24 transmits the second video to the video monitoring terminal 300.

[0054] (Step S110) In step S110, similarly to step S107, the encoding unit 23 treats the preset image quality as the recommended image quality and encodes the primary video.

[0055] <Actions and Effects> The imaging device 100 according to the first embodiment has been described above. The imaging device 100 of the present disclosure mainly has an object detection unit 21, a calculation unit 22, and an encoding unit 23. The calculation unit 22 calculates a recommended image quality according to the surveillance target contained in the first image captured by the imaging unit 10, and encodes the second image based on the recommended image quality, thereby making it possible to obtain an appropriate image according to the surveillance target and to avoid network congestion since the amount of data transmitted to the network is not unnecessarily increased.

[0056] [Second embodiment] Next, the monitoring system of the present disclosure will be described with reference to FIG. FIG. 6 is a schematic diagram showing a monitoring system 1 according to the second embodiment. The surveillance system 1 according to the second embodiment differs from the first embodiment in that it includes a network 200, a video surveillance terminal 300, a surveillance system server 400, and a video distribution server 500 in addition to the imaging device 100 of the first embodiment.

[0057] The components of the monitoring system 1 will be described below in order. <Network> The network 200 is a computer network that enables mutual communication among the imaging device 100, the video monitoring terminal 300, the monitoring system server 400, and the video distribution server 500. The network 200 is, for example, a VPN, but may be other types of computer networks.

[0058] <Video monitoring terminal> The video monitoring terminal 300 can display the second video transmitted from the image capturing device 100, and can provide the monitoring results to a user of the monitoring system. Furthermore, the video monitoring terminal 300 may be capable of operating devices included in the monitoring system 1, such as the image capturing device 100 and the monitoring system server 400, as an operation terminal of the monitoring system 1. The monitoring system 1 may include a plurality of imaging devices 100, and the video monitoring terminal 300 may display, on a multi-screen, the second video output from each imaging device 100. In this case, the video monitoring terminal 300 may be capable of performing digital zoom on the second video. Furthermore, the imaging device 100 transmits advance notice information to the video monitoring terminal 300 before the image quality of the second video is changed, that is, when the imaging device 100 detects a monitoring target, or when the monitoring target that was detected is no longer detected. By receiving the advance notice information, the video monitoring terminal 300 can perform a preparatory operation, and can suppress display delays and image distortions when the recommended image quality is switched. Furthermore, it is also possible to notify the user of the image quality change.

[0059] <Monitoring system server> The surveillance system server 400 is a control unit that determines whether or not the image quality can be changed to the recommended image quality when the image capturing device 100 encodes the first image into the second image. When the surveillance system 1 includes many imaging devices 100, each imaging device 100 performs encoding based on the recommended image quality set therein. As a result, congestion may occur in the entire network. For this reason, the surveillance system server 400 may determine whether or not to change to the recommended image quality, and may control whether to perform encoding based on a low image quality standard set in advance, based on the recommended image quality, or based on the image quality specified from outside the imaging device 100, taking into account the amount of image information transmitted on the network 200.

[0060] For example, when the surveillance system server 400 replies "OK" to an inquiry from the image capture device 100 about permission to change the image quality, the image capture device 100 can encode the first video into the second video at the recommended image quality. Furthermore, if the surveillance system server 400 replies "NG," the imaging device 100 will not be able to encode the first video into the second video at the recommended image quality, and will instead perform encoding at a preset low image quality standard. This allows the monitoring system 1 to precisely control the amount of data transmitted over the network 200. Furthermore, when the surveillance system server 400 permits a change in image quality of the imaging device 100, the surveillance system server 400 can also transmit advance notice information of the image quality change of the imaging device 100 directly to the video surveillance terminal 300. This enables the video surveillance terminal 300 to perform preparatory operations when the recommended image quality is changed, based on the advance notice information received from the surveillance system server 400.

[0061] <Video distribution server> The surveillance system 1 may include a video distribution server 500 for not only distributing the video generated by the imaging device 100 in real time, but also distributing previously stored video to the video surveillance terminal 300. The video distribution server 500 can obtain the second video stored in the storage unit 25 and distribute it to the video surveillance terminal 300 based on an instruction from the video surveillance terminal 300.

[0062] Furthermore, the video distribution server 500 may distribute the second video to a device other than the video monitoring terminal 300. For example, the second video may be distributed to a system other than the monitoring system 1. This makes it possible to link the monitoring information of the monitoring system 1 with an external system.

[0063] <Actions and Effects> The monitoring system 1 according to the second embodiment has been described above. In the surveillance system 1 of the present disclosure, the imaging device 100 equipped with a calculation unit 22 can transmit images with an appropriate amount of information in line with the surveillance purpose to the network, and the surveillance system server 400 monitors the amount of information transmitted to the network from the multiple imaging devices 100 connected to the surveillance system 1 and determines for each imaging device 100 whether or not to encode at the recommended image quality to prevent network congestion, thereby making it possible to effectively suppress congestion in the network 200.

[0064] [Third embodiment] Next, the video encoding process in the third embodiment will be described with reference to FIG. The video encoding process of the third embodiment differs from the video encoding process described in the first and second embodiments in that, in addition to returning "OK" as information on whether the recommended image quality can be changed, if the surveillance system server 400 denies the change information by returning "NG", the surveillance system server 400 calculates and instructs each imaging device 100 on the designated image quality to be encoded. When the calculation unit 22 of the imaging device 100 receives an instructed image quality from the surveillance system server 400, the calculation unit 22 treats the received instructed image quality as the recommended image quality.

[0065] <Video encoding process> FIG. 7 is a flowchart showing the video encoding process of the surveillance system 2. (Steps S101 to S110) Steps S101 to S110 are similar to the video encoding process according to the first embodiment, and therefore a description thereof will be omitted.

[0066] (Step S201) Step S201 is a response to the case where the surveillance system server 400 responds with "NG" to the change information to the recommended image quality from a specific imaging device 100. In this case, the surveillance system server 400 calculates the designated image quality for the imaging device 100 that responded with "NG". In addition, the calculated designated image quality is transmitted to the calculation unit 22 together with the response of the changeability information, and is treated as the recommended image quality.

[0067] <Actions and Effects> The monitoring system 1 according to the third embodiment has been described above. The monitoring system 1 of the present disclosure mainly includes a monitoring system server 400, and the monitoring system server 400 that receives the changeability information of the recommended image quality can calculate the designated image quality. This allows the monitoring system server 400 in the monitoring system 3 to closely control the amount of data transmitted over the network 200 throughout the entire system.

[0068] [Variation 1] Next, a monitoring system according to the first modification will be described with reference to FIG. FIG. 8 is a schematic diagram showing an example of an imaging device included in the surveillance system 1 according to the first modification. The surveillance system 1 according to the first modification differs from the imaging device 100 according to the first embodiment in that the imaging device 100 is an analog imaging device 110. In the following description, components that are the same as or equivalent to those in the above-described imaging device 100 are given the same reference numerals, and descriptions thereof will be simplified or omitted.

[0069] <Analog imaging device> The analog imaging device 110 includes an analog imaging section 11, an image processing section 20, and an analog-to-digital conversion section 30, and digitally converts an image captured on film into a first image, and encodes and transmits the converted first image into a second image of recommended image quality.

[0070] <<Analog imaging section>> The analog imaging unit 11 is a functional unit that continuously exposes images onto a film and shoots moving images. The images shot on the film are moving images constructed by advancing each frame one by one, and are read into the analog-to-digital conversion unit 30. Furthermore, the analog imaging unit 11 is, for example, a film camera, but may also be a tape camera that captures images on a medium other than film, for example, on tape.

[0071] <<Analog-to-digital conversion section>> The analog-digital conversion section 30 reads the image captured by the analog imaging section 11 , converts it into a first image, which is digital data, and transmits it to the image processing section 20 . This allows the image processor 20 to encode the video captured by the analog imaging unit 11, making it possible to reduce the amount of video data transmitted over the network 200.

[0072] <Actions and Effects> The monitoring system 1 according to the first modification has been described above. The surveillance system 1 of the present disclosure mainly comprises an analog imaging device 110 and an analog-digital conversion section 30, and can encode an image of a surveillance target captured by the analog imaging device 110 into a recommended image quality. As a result, in the surveillance system 1, video can be encoded to the recommended image quality regardless of the type of imaging device, and the amount of video data transmitted over the network 200 can be reduced.

[0073] [Variation 2] Next, a monitoring system 1 according to a second modification will be described with reference to FIG. FIG. 9 is a schematic diagram showing an example of an imaging device included in the surveillance system 1 according to the second modification. The surveillance system 1 according to the second modification differs from the surveillance system 1 according to the first embodiment in that the imaging device 120 is separated into an imaging device 120A which is an imaging portion and an imaging device 120B which is an image processing portion. In the following description, components that are the same as or equivalent to those in the above-described monitoring system 1 are given the same reference numerals, and descriptions thereof will be simplified or omitted.

[0074] <Imaging device> Imaging device 120 includes imaging device 120A and imaging device 120B, imaging device 120A includes imaging section 10 and video transmission section 41, and imaging device 120B can include video reception section . The imaging unit 10 and the video transmission unit 41 are directly connected, and similarly, the video reception unit 42 and the image processing unit 20 are also directly connected. The video transmission unit 41 and the video reception unit 42 are connected by, for example, a LAN cable, and can transmit and receive videos. That is, the video transmission unit 41 transmits the first video captured by the imaging unit 10 to the video reception unit 42, and the video reception unit 42 can transmit the received first video to the image processing unit 20.

[0075] Furthermore, as shown in FIG. 9, at least two or more imaging devices 120A can be connected to one imaging device 120B. This makes it possible to encode the first video captured by a plurality of different imaging devices using one image processing device.

[0076] Also, as long as the first video can be transmitted from video transmitting unit 41 to video receiving unit 42, video transmitting unit 41 and video receiving unit 42 may be connected by a medium other than a LAN cable. Furthermore, the video transmission unit 41 may be integrated with the imaging device 120 , and the video reception unit 42 may be integrated with the image processing unit 20 .

[0077] <Actions and Effects> The monitoring system 1 according to the second modification has been described above. The surveillance system 1 of the present disclosure mainly includes an imaging device 120, and the imaging section and the image processing section are not directly connected, and there is no need for a one-to-one relationship between the imaging section and the image processing section. This allows the surveillance system 1 to have a flexible configuration with regard to the connection and arrangement of the imaging devices.

[0078] The present invention can also take the following forms. (Aspect 1) an object detection unit that detects a surveillance target from a first image captured by the imaging unit; A calculation unit for calculating a recommended image quality of the monitoring target; an encoding unit that outputs a second image obtained by encoding the first image to have the recommended image quality; an image processing unit including a communication unit that transmits the second image, Imaging device. (Aspect 2) The imaging device according to aspect 1, The calculation unit includes a database unit that stores a setting value for setting the recommended image quality for each of the monitoring targets, The calculation unit is The setting value is obtained from the database unit based on the monitoring target detected by the object detection unit, and the recommended image quality is calculated. Imaging device. (Aspect 3) The imaging device according to aspect 2, The database unit includes: Save the recommended number of pixels, the recommended amount of movement, and the recommended compression ratio as the setting values ​​for setting the recommended image quality Imaging device. (Aspect 4) The imaging device according to aspect 3, The calculation unit is The recommended image quality is calculated based on the detection information of the monitoring target detected by the object detection unit and the information stored in the database unit. Imaging device. (Aspect 5) The imaging device according to any one of aspects 1 to 4, The encoding unit is When the object detection unit does not detect a monitoring target, the first image is encoded into the second image at a preset image quality, or the encoding is stopped. Imaging device. (Aspect 6) The imaging device according to any one of aspects 1 to 5, The encoding unit is When a surveillance target is detected by the object detection unit, a setting value of the recommended image quality is obtained from the calculation unit, and the first image is encoded into the second image based on the setting value. Imaging device. (Aspect 7) A surveillance system including the imaging device according to any one of aspects 1 to 6, A video monitoring terminal for displaying a video and a network for connecting the video monitoring terminal are provided. Surveillance system. (Aspect 8) 8. The monitoring system of claim 7, further comprising: The communication unit is a first communication unit that transmits the second video to the video monitoring terminal; a second communication unit that communicates the calculated recommended image quality as advance notice information to the video monitoring terminal; The video surveillance terminal includes: A preparation operation for switching the recommended image quality is performed based on the advance notice information. Surveillance system. (Aspect 9) 9. The monitoring system according to aspect 7 or 8, a monitoring system server that determines whether the recommended image quality calculated by the calculation unit of the imaging device can be changed; The communication unit is a third communication unit that communicates the calculated changeability information of the recommended image quality to the monitoring system server; The monitoring system server includes: It is possible to determine whether or not the first video can be encoded at the recommended image quality included in the changeability information. Surveillance system. (Aspect 10) 10. The monitoring system of claim 9, further comprising: The monitoring system server is When a calculation unit of any of the imaging devices denies encoding the first video at the calculated recommended image quality, a designated image quality is calculated, and the designated image quality is transmitted as the recommended image quality to the imaging device for which encoding at the recommended image quality has been denied. Surveillance system. (Aspect 11) A monitoring system according to any one of aspects 7 to 10, a storage unit that stores the second image encoded by the imaging device at the recommended image quality; Surveillance system. (Aspect 12) 12. The monitoring system according to any one of aspects 7 to 11, a monitoring system server that determines whether or not the first video is to be encoded with the recommended image quality calculated by the calculation unit; The encoding unit encodes the second video in the recommended image quality when permission is given by the surveillance system server. Surveillance system. (Aspect 13) 13. The monitoring system according to claim 11 or 12, a video distribution server that distributes the second video; The communication unit is a fourth communication unit that distributes the second video stored in the storage unit to the video distribution server. Surveillance system. (Aspect 14) A monitoring system according to any one of aspects 7 to 13, The object detection unit is Detecting people and animals as the surveillance targets from the first video; The calculation unit is When the object detection unit detects the person, the recommended image quality is calculated as high image quality, and when the object detection unit detects the animal, the recommended image quality is calculated as low image quality. Surveillance system.

[0079] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the gist of the present invention. [Explanation of symbols]

[0080] 1, 2 Surveillance system 100, 120 Imaging device 110 Analogue imaging device 10. Imaging unit 20 Image processing section 21 Object detection unit 22 Calculation section 221 Database Department Columns 2211, 2212, 2213, 2214 2215 rows 23 Encoding section 24 Communications Department 241 First Communications Department 242 Second Communication Department 243 Third Communications Department 244 Fourth Communication Department 25 Storage section 30 Analog-to-Digital Conversion Section 41 Video transmission unit 42 Video receiving unit 200 Network 300 Video surveillance terminal 310 People 400 Surveillance System Server 500 Video distribution server

Claims

1. an object detection unit that detects a surveillance target from a first video captured by the imaging unit; A calculation unit for calculating a recommended image quality of the monitoring target; an encoding unit that outputs a second image obtained by encoding the first image to have the recommended image quality; an image processing unit including a communication unit that transmits the second image. Imaging device.

2. 2. The imaging device according to claim 1, The calculation unit includes a database unit that stores a setting value for setting the recommended image quality for each of the monitoring targets, The calculation unit is The setting value is obtained from the database unit based on the monitoring target detected by the object detection unit, and the recommended image quality is calculated. Imaging device.

3. 3. The imaging device according to claim 2, The database unit includes: Save the recommended number of pixels, the recommended amount of movement, and the recommended compression ratio as the setting values ​​for setting the recommended image quality Imaging device.

4. 4. The imaging device according to claim 3, The calculation unit is The recommended image quality is calculated based on the detection information of the monitoring target detected by the object detection unit and the information stored in the database unit. Imaging device.

5. 2. The imaging device according to claim 1, The encoding unit is When the object detection unit does not detect a monitoring target, the first image is encoded into the second image with a preset image quality, or the encoding is stopped. Imaging device.

6. 2. The imaging device according to claim 1, The encoding unit is When a monitoring target is detected by the object detection unit, a setting value of the recommended image quality is obtained from the calculation unit, and the first image is encoded into the second image based on the setting value. Imaging device.

7. A surveillance system including the imaging device according to claim 1, A video monitoring terminal for displaying a video and a network for connecting the video monitoring terminal are provided. Surveillance system.

8. 8. The monitoring system of claim 7, The communication unit is a first communication unit that transmits the second video to the video monitoring terminal; a second communication unit that communicates the calculated recommended image quality as advance notice information to the video monitoring terminal; The video surveillance terminal includes: A preparation operation for switching the recommended image quality is performed based on the advance notice information. Surveillance system.

9. 8. The monitoring system of claim 7, a monitoring system server that determines whether the recommended image quality calculated by the calculation unit of the imaging device can be changed; The communication unit is a third communication unit that communicates the calculated changeability information of the recommended image quality to the monitoring system server; The monitoring system server includes: It is possible to determine whether or not the first video can be encoded at the recommended image quality included in the changeability information. Surveillance system.

10. 10. The monitoring system of claim 9, The monitoring system server is When a calculation unit of any of the imaging devices denies encoding the first video at the calculated recommended image quality, a designated image quality is calculated, and the designated image quality is transmitted as the recommended image quality to the imaging device for which encoding at the recommended image quality has been denied. Surveillance system.

11. 8. The monitoring system of claim 7, The imaging device includes a storage unit for storing a second image encoded with the recommended image quality. Surveillance system.

12. 8. The monitoring system of claim 7, a monitoring system server that determines whether or not the first video is to be encoded with the recommended image quality calculated by the calculation unit; The encoding unit encodes the second video in the recommended image quality when permission is given by the surveillance system server. Surveillance system.

13. 12. The monitoring system of claim 11, a video distribution server that distributes the second video; The communication unit is a fourth communication unit that distributes the second video stored in the storage unit to the video distribution server. Surveillance system.

14. 8. The monitoring system of claim 7, The object detection unit is Detecting a person and an animal as the surveillance target from the first video; The calculation unit is When the object detection unit detects the person, the recommended image quality is calculated as high image quality, and when the object detection unit detects the animal, the recommended image quality is calculated as low image quality. Surveillance system.

Images