JP2016158205A - Video monitoring system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video monitoring system in which an image focused only to a specific range can be displayed, and missing of a specified point or a moving subject and invasion of privacy of an independent subject can be prevented.SOLUTION: A ideo monitoring system includes shooting means 200 for acquiring the light field information, and a management terminal 100 having shooting information acquisition means 110 for acquiring the light field information acquired by the shooting means, image generation means 111 for controlling the focusing distance and the depth of field from the shooting information acquired by the shooting information acquisition means, and generating an image focused at a specific position, and image display means 113 for displaying the image generated by the image generation means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a video monitoring system that uses a captured video to monitor a subject within a shooting range.

  In video surveillance systems, surveillance camera images are often taken with pan focus settings that focus on as wide a range as possible. As a result, when an abnormality such as an accident occurs within the photographing range, it is possible to confirm a portion to be viewed with an image without so-called “blur”. However, by focusing on the entire image, there is a possibility that it may fall into a state in which the observer looks at the point at the time of monitoring, and the occurrence of an abnormality may be missed. In addition, since the subject other than the portion that the user wants to see is focused, there is a risk that the privacy of the subject is unintentionally impaired.

For example, Patent Document 1 discloses a technique that makes it easy to find a moving object in an image by correcting and displaying the photographed image so that a part other than a specific part is blurred.
On the other hand, a light field camera that can generate an image in which the focal distance and depth of field of an image are arbitrarily changed after shooting by acquiring light bundles of various incident angles as light field information during shooting There is.

JP 2005-303983 A

  In imaging with a video surveillance system, shooting conditions change every moment depending on the shooting location and shooting environment. In the method of Patent Document 1 which is a conventional example, it is easy to find a specific subject or prevent unintentional loss of privacy. However, in order to apply this method, at least the target The subject to be taken must be taken with a clear image. However, when there are a plurality of subjects having different shooting distances due to the shooting distance, shooting angle of view, lens performance, and the like, there are cases where it is impossible to capture all of them clearly. In this case, the method of Patent Document 1 cannot be used.

  The present invention solves the above-described problems. A light field camera is applied as a surveillance camera of a video surveillance system, and the in-focus distance and depth of field of a photographed image are controlled using photographing information of the camera. Then, it is intended to make it easy to find a specific subject or to realize privacy protection by displaying it as a monitoring video.

The video surveillance system according to the present invention includes:
Photographing means for acquiring light field information;
Shooting information acquisition means for acquiring light field information acquired by the shooting means;
An image generating means for controlling the in-focus distance and the depth of field from the shooting information acquired by the shooting information acquiring means, and generating an image focused on a specific position;
Image display means for displaying the image generated by the image generation means;
A management terminal having
It is equipped with.

  According to the present invention, by using the light field information in the video monitoring system, an image focused on a specific range can be displayed, and video monitoring that prevents oversight of a designated place or a moving subject or privacy violation of an irrelevant subject is prevented. It becomes possible to obtain a system.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the image | video monitoring system by Embodiment 1 of this invention. It is a flowchart which shows an example of the process sequence of the video surveillance system by Embodiment 1 of this invention. It is a block diagram which shows the video surveillance system by Embodiment 2 of this invention. It is a flowchart which shows an example of the process sequence of the video surveillance system by Embodiment 2 of this invention.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described with reference to the drawings.
In the first embodiment, an example in which an image focused on a position designated by a user operation is displayed in the video monitoring system will be described. FIG. 1 is a block diagram showing an example of a configuration according to the video surveillance system in Embodiment 1 of the present invention. FIG. 2 is a flowchart showing an example of a processing procedure in the first embodiment of the present invention.

First, the block configuration of FIG. 1 will be described.
In FIG. 1, a management terminal 100 is a management terminal in the video surveillance system. The storage device 101 is a device that can read and write information in the management terminal 100. The photographing unit 200 is a light field camera that can acquire light field information. The display 300 is a display that displays the screen of the management terminal. The photographing information acquisition unit 110, the image generation unit 111, the input analysis unit 112, and the image display unit 113 are functions that the management terminal 100 has. The management terminal 100 may be a general-purpose PC (Personal Computer) or a mobile terminal such as a smartphone or a tablet. The storage device 101 may be a built-in drive such as a hard disk or SSD (Solid State Drive), an external recording medium such as an SD card (Secure Digital Card), or a temporary storage memory (RAM). In addition, a device such as a video recorder, which is different from the management terminal 100, may be used. The photographing unit 200 and the display 300 may be integrated with the management terminal 100.

Next, the operation shown in the processing steps of FIG. 2 will be described.
The imaging information acquisition unit 110 acquires the light field information acquired by the imaging unit 200 (step ST101). The light field information has a lot of light ray information in a three-dimensional space, and after acquiring the light field information, it is possible to obtain an image focused on a position arbitrarily determined based on this information. it can. That is, if the light field information is used, an image in which the in-focus distance and the depth of field are arbitrarily adjusted can be obtained. The input analysis unit 112 recognizes a position specified by a user operation. That is, the specific range in the photographing information designated by the user's operation is analyzed and acquired as designated range information (step ST102).

  The image generation unit 111 generates an image from the light field information obtained in step ST101. At this time, based on the light field information obtained in step ST101, focusing is performed so that only the designated range obtained in step ST102 becomes a clear image, and the other range is blurred. That is, an image in which the in-focus distance and the depth of field are adjusted so as to obtain an image focused on a specific position is generated (step ST103). The image display means 113 displays the image generated in step ST103 on the display 300 (step ST104).

  Here, the acquired light field information may be recorded in the storage device 101 in step ST101. In step ST103, the light field information is acquired from the photographing information acquisition unit 110. However, the light field information recorded by the storage device 101 may be acquired from the storage device 101. In step ST103, the generated image may be recorded in the storage device 101, or the light field information that is the basis of the generated image may be deleted.

  As described above, according to the first embodiment of the present invention, in the video surveillance system, an image focused on only the range designated by the user is displayed, making it easier to focus on the designated range, and subjects other than the designated range. It is possible to deter privacy violations. Furthermore, since it is possible to determine the focus range from the entire range being photographed by using the light field information, it is impossible to focus on a plurality of subjects with the conventional surveillance camera. The above effects can also be obtained in a photographing case.

  Because of the characteristics of light field cameras, it is not necessary to narrow the lens during shooting, so the shutter speed can be increased compared to conventional surveillance cameras when shooting in the same environment, and a clear image with less subject blurring can be obtained. Is possible. Further, when an image focused on only a specific range is recorded, the recording capacity can be reduced as compared with the case where all the light field information is recorded.

Embodiment 2. FIG.
Embodiment 2 of the present invention will be described with reference to the drawings. In the second embodiment, an example in which an image focused on a moving subject is displayed in a video monitoring system will be described. FIG. 3 is a block diagram showing an example of a configuration according to the video monitoring system in Embodiment 2 of the present invention. FIG. 4 is a flowchart showing an example of a processing procedure in the second embodiment of the present invention.

First, the block configuration of FIG. 3 will be described.
The configuration of FIG. 3 is the same as the configuration of FIG. 1 of the first embodiment except that the image analysis unit 114 is configured instead of the input analysis unit 112.

Next, the operation shown in the processing steps of FIG. 4 will be described.
The imaging information acquisition unit 110 acquires the light field information acquired by the imaging unit 200 (step ST201). Based on the light field information obtained in step ST201, the image generation unit 111 generates an image in which the focus distance and the depth of field are adjusted so as to focus on the entire shooting range (step ST202). The image analysis unit 114 analyzes the image generated in step ST202, and acquires the position of the subject (step ST203). That is, the image analysis unit 114 recognizes the position of a specific subject from the shooting information acquired by the shooting information acquisition unit 110. From the light field information obtained in step ST201 and the subject position information obtained in step ST203, the image generation unit 111 focuses so that only the subject shooting range is in focus as a specific position and other ranges are blurred. An image in which the focal distance and the depth of field are adjusted is generated (step ST204). Image display means 113 displays the image generated in step ST204 on display 300 (step ST205).

  Here, in step ST201, the acquired light field information may be recorded in the storage device 101. In step ST202, the light field information is acquired from the imaging information acquisition unit 110, but the information recorded in the storage device 101 may be acquired from the storage device 101 as the light field information. As an image analysis method for acquiring the subject position in step ST202, a known technique such as a background difference method, an inter-frame difference method, optical flow detection, or the like can be used.

  In step ST204, the generated image may be recorded in the storage device 101, and the light field information that is the basis thereof may be deleted. In step ST203, a plurality of subjects may be detected simultaneously. When a plurality of subjects are detected, a plurality of images corresponding to each subject may be generated in step ST204, or the plurality of images may be displayed simultaneously in step ST205. In addition, a plurality of these images may be recorded in the storage device 101.

  As described above, according to the second embodiment of the present invention, it is possible to display an image that is always in focus on a moving subject, preventing the subject from being overlooked, and suppressing privacy infringement on subjects outside the specified range. It becomes possible to do. Furthermore, since it is possible to determine the focus range from the entire range being photographed by using the light field information, it is impossible to focus on a plurality of subjects with the conventional surveillance camera. The above effects can also be obtained in a photographing case.

  The light field camera does not need to narrow the lens due to its characteristics, so the shutter speed can be increased compared to conventional surveillance cameras when shooting in the same environment, and it is possible to obtain clear images with less subject blurring It is. Further, by recording an image focused on only a specific range, the recording capacity can be reduced as compared with the case where all the light field information is recorded.

DESCRIPTION OF SYMBOLS 100 Management terminal, 101 Storage device, 110 Shooting information acquisition means, 111 Image generation means, 112 Input analysis means, 113 Image display means, 114 Image analysis means, 200 Shooting means, 300 Display

Claims (6)

Photographing means for acquiring light field information;
Shooting information acquisition means for acquiring light field information acquired by the shooting means;
An image generating means for controlling the in-focus distance and the depth of field from the shooting information acquired by the shooting information acquiring means, and generating an image focused on a specific position;
Image display means for displaying the image generated by the image generation means;
A management terminal having
A video surveillance system comprising:   The video monitoring system according to claim 1, wherein the management terminal includes a storage device that records an image generated by the image generation unit. The management terminal has input analysis means for recognizing a position designated by a user operation,
The video monitoring system according to claim 1, wherein the image generation unit generates an image with the specified position recognized by the input analysis unit as the specific position. The management terminal has image analysis means for recognizing the position of a specific subject from the shooting information acquired by the shooting information acquisition means,
The video monitoring system according to claim 1, wherein the image generation unit generates an image using the position of the specific subject recognized by the image analysis unit as the specific position. The image generation means generates a plurality of images having different focus distances or depths of field,
5. The video monitoring system according to claim 1, wherein the image display unit simultaneously displays the plurality of images generated by the image generation unit. 6. The image generation means generates a plurality of images having different focus distances or depths of field,
The video monitoring system according to claim 2, wherein the storage device records the plurality of images generated by the image generation unit.

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