KR102587499B1 - Image storage apparatus and method capable of extending storage period and making the situation easy to grasp - Google Patents

Abstract

A captured image storage device and method for storing captured images that can extend the storage period and easily understand the situation are disclosed. The captured image storage device according to the present invention is a captured image storage device that stores images captured by a surveillance camera, and has a storage point that records the point in time at which each image frame is stored for each image frame constituting the captured image. register; a period elapse determination unit that determines whether the first set period has elapsed from the time it was recorded in the storage time record; an event occurrence determination unit that determines whether an event has occurred in a video frame for which the first set period is determined to have elapsed by the period elapse determination unit; And the video frames in which the event is determined to have occurred by the event occurrence determination unit are extended and stored for a second set period that is set to be longer than the first set period, along with a set number of before and after video frames, and the remaining video frames before that are stored. Characterized in that it includes a storage unit for deleting captured images.

Description

A storage device and method for storing captured images that can extend the storage period and easily understand the situation {IMAGE STORAGE APPARATUS AND METHOD CAPABLE OF EXTENDING STORAGE PERIOD AND MAKING THE SITUATION EASY TO GRASP}

The present invention relates to a captured image storage device and a method for storing the same. More specifically, the storage period of images captured by a surveillance camera can be extended, and an administrator can easily identify important situations regarding captured images in a surveillance area. It relates to a storage device for captured images and a method for storing the same.

In general, surveillance cameras such as CCTV (Closed Circuit Television) are fixedly installed at a specific location indoors or outdoors, and constantly photograph the surrounding area within a set range from that location.

At this time, the surveillance camera stores the captured video in a storage medium installed integrally with the surveillance camera, allowing the administrator to check the stored video at any time.

On the other hand, surveillance cameras are installed in remote areas where people do not visit often but are predicted to have potential, and constantly film the surveillance area, and the captured images are also stored and stored.

However, it is difficult for administrators to regularly visit and check videos shot in such remote areas, and even if they visit periodically to check the stored videos, the stored videos are large in size, so videos in which events occurred are overlooked during the video check process. There is a problem that it may be lost.

In addition, surveillance cameras constantly capture and store surveillance areas, and the better the quality of the captured images, the larger the capacity, so there is a problem in that there is a limit to storing and storing the images captured by the surveillance cameras.

Public Patent Publication No. 10-2018-0065660 (Publication date: 2018.06.18)

The present invention was created to solve the above-mentioned problems. It can extend the storage period of images captured by surveillance cameras, and allows administrators to easily identify important situations regarding captured images in the surveillance area. The purpose is to provide a storage device and its storage method.

A captured image storage device according to an aspect of the present invention for achieving the above-described object is a captured image storage device that stores images captured by a surveillance camera, each image frame constituting the captured images. a storage time recording unit that records the time when the video frame is saved; a period elapse determination unit that determines whether a first set period has elapsed from the time recorded in the storage time record; an event occurrence determination unit that determines whether an event has occurred in a video frame for which the first set period is determined to have elapsed by the period elapse determination unit; and a captured image storage unit that extends and stores video frames in which the event occurrence determination unit determines that an event has occurred, along with a set number of before and after video frames, for a second set period that is longer than the first set period. and a captured image deletion unit that deletes remaining image frames before the image frame extended and stored by the captured image storage unit.

The above-described captured image storage device includes a motion detection unit that detects movement based on an image frame of an image captured by the surveillance camera; When motion is detected by the motion detection unit, a motion comparison unit that sequentially compares the detected movement per unit time; and a motion change calculation unit that calculates the amount of change in motion based on the motion per unit time compared by the motion comparison unit. In this case, the event occurrence determination unit determines that an event has occurred in the corresponding video frame when the amount of change in motion calculated by the motion change calculation unit increases or decreases beyond a set range.

The above-described captured image storage device includes an ambient sound collecting unit that collects ambient sounds corresponding to images captured by the surveillance camera; a sound comparison unit that sequentially compares sounds per unit time with respect to the ambient sound collected by the ambient sound collection unit; and a sound change calculation unit that calculates the amount of change in sound based on the sound per unit time compared by the sound comparison unit. In this case, the event occurrence determination unit determines that an event has occurred in the corresponding video frame when the change in sound calculated by the sound change calculation unit increases or decreases beyond a set range.

A method of storing a captured image according to an aspect of the present invention for achieving the above-described object is a method of storing a captured image performed by a captured image storage device, wherein each image frame constituting the captured image is Recording the point in time at which it is saved; determining whether a first set period has elapsed from the time of recording; determining whether an event has occurred in a video frame for which it is determined that the first set period has elapsed; extending and storing the video frame in which it is determined that the event has occurred, along with a set number of before and after video frames, for a second set period that is longer than the first set period; and deleting video frames previous to video frames extended and stored during the second set period.

The above-described method of storing captured images includes detecting movement based on image frames of images captured by the surveillance camera; sequentially comparing the detected movements per unit time; and calculating a change in movement based on the compared movement per unit time. In this case, the step of determining the occurrence of the event determines that an event has occurred in the corresponding video frame when the calculated change in motion increases or decreases more than a set range.

The above-described method of storing captured images includes the steps of collecting ambient sounds corresponding to images captured by the surveillance camera; sequentially comparing sounds per unit time with respect to the collected ambient sounds; and calculating the amount of change in sound based on the compared sound per unit time. In this case, the step of determining the occurrence of the event determines that an event has occurred in the corresponding video frame when the calculated change in sound increases or decreases beyond a set range.

According to the present invention, the storage period of images captured by a surveillance camera can be extended and an administrator can easily identify important situations regarding images captured in a surveillance area.

1 is a diagram showing a system to which a captured image storage device according to an embodiment of the present invention is applied.
FIG. 2 is a diagram schematically showing the configuration of the captured image storage device shown in FIG. 1.
Figure 3 is a diagram showing a captured image captured by a surveillance camera and the video frames that make up the captured image.
Figure 4 is a diagram illustrating an example in which the position of a subject in a subsequent video frame is changed relative to the position of a subject in a previous video frame.
Figure 5 is a diagram showing an example of generating a vector based on the subject of Figure 4.
Figure 6 is a flowchart showing a method for storing captured images according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described through exemplary drawings. When assigning reference numerals to components in each drawing, identical components are indicated with the same reference numerals as much as possible, even if they are shown in different drawings. Additionally, when describing embodiments of the present invention, if detailed descriptions of related known configurations or functions are judged to impede understanding of the embodiments of the present invention, the detailed descriptions will be omitted.

Additionally, when describing the components of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. When a component is described as being "connected," "coupled," or "connected" to another component, that component may be directly connected, coupled, or connected to that other component, but may not be connected to that component or that other component. It should be understood that another component may be “connected,” “coupled,” or “connected” between elements.

1 is a diagram showing a system to which a captured image storage device according to an embodiment of the present invention is applied.

Referring to FIG. 1, a captured image storage device 100 may be connected to a surveillance camera 10. Here, the surveillance camera 10 is fixedly installed facing a specific direction indoors or outdoors, and photographs the surrounding surveillance area. At this time, the captured image storage device 100 is integrated with the surveillance camera 10 or is installed within a set distance range from the surveillance camera 10, and stores images captured by the surveillance camera 10.

In addition, the captured image storage device 100 is connected to an administrator terminal (not shown) through a network (not shown), and the image captured by the surveillance camera 10 can be transmitted to the administrator terminal through the network. .

However, the configuration and function of the captured image storage device 100 transmitting the image captured by the surveillance camera 10 to the manager terminal through the network is beyond the gist of the present invention, and therefore its description is omitted here.

FIG. 2 is a diagram schematically showing the configuration of the captured image storage device shown in FIG. 1.

Referring to FIG. 2, the captured image storage device 100 includes a storage point recording unit 102, a period elapse judgment unit 104, an event occurrence determination unit 106, a captured image storage unit 108, and a captured image deletion unit ( 110), a motion detection unit 112, a motion comparison unit 114, a motion change calculation unit 116, an ambient sound collection unit 118, a sound comparison unit 120, and a sound change calculation unit 122. You can.

The storage time recording unit 102 records the time at which each video frame is stored for each video frame constituting the video captured by the surveillance camera 10.

A video is made up of multiple video frames, and a video frame can be said to be a simple still image. For example, the video of the NTSC (National Television System Committee) system of Korea, the United States, Japan, etc. consists of 30 video frames per second. Additionally, a movie usually consists of 24 video frames per second. Likewise, as shown in FIG. 3, the surveillance camera 10 continuously displays a plurality of still images corresponding to the surveillance area, that is, a plurality of video frames 40, during a unit time (for example, 1 second). A captured image 50 is formed by shooting. At this time, the storage time recording unit 102 records the storage time for each captured video frame.

The period elapse determination unit 104 determines whether the first set period has elapsed from the time it was recorded in the storage time record unit 102. At this time, the period elapse determination unit 104 may determine whether the first set period has elapsed in units of 1/100 second for each video frame. For example, the elapse of time determination unit 104 can determine whether 24 hours have elapsed accurately to the nearest 1/100 second for each video frame.

The event occurrence determination unit 106 determines whether an event has occurred in a video frame for which the first set period is determined to have elapsed by the period elapse determination unit 104. At this time, the event occurrence determination unit 106 may determine that an event has occurred when it is determined that there is a change in movement greater than a set value or a change in sound greater than a set value between video frames that are continuously stored.

The captured image storage unit 108 extends the video frames in which the event is determined to have occurred by the event occurrence determination unit 106 along with a set number of before and after video frames for a second set period that is longer than the first set period. Save. For example, if the event occurrence determination unit 106 determines that an event occurred between the 10th video frame and the 11th video frame, the captured video storage unit 108 stores the 8th video frame before the second video frame. It can be extended and stored for a second set period from the video frame to the 13th video frame, which is the second video frame behind. Additionally, when the first setting period is set to 24 hours, the captured image storage unit 108 can set the second setting period to 72 hours and store the image frame in which it is determined that an event has occurred.

The captured image deletion unit 110 deletes the remaining video frames before the video frame extended and stored by the captured image storage unit 108. For example, as described above, when the images captured by the surveillance camera 10 are extended and stored for a second set period from the 8th image frame to the 13th image frame, the captured image deletion unit 110 Before the 8th video frame, that is, the 7th video frame is deleted from the first video frame. At this time, the video frame deleted by the captured video deletion unit 110 is assumed to be a video frame in which no event occurred, and if the previous video frame is extended and stored for the second set period, the video frame that was extended and stored is It is desirable to exclude it from deletion.

The motion detection unit 112 detects movement based on the image frame of the image captured by the surveillance camera 10.

Since the surveillance camera 10 is fixed toward a specific direction and photographs a surveillance area within a set range, if there is no movement within the surveillance area, the previous and subsequent image frames are the same. However, as shown in FIG. 4, when a specific subject 60 moves within the surveillance area, the position of the subject 60 in the previous image frame and the position of the subject 60 in the subsequent image frame change. In this way, when the position of the subject 60 in the subsequent image frame is different with respect to the position of the subject 60 in the previous image frame, the subject 60 in the subsequent image frame is based on the position of the subject 60 in the previous image frame. The change in position of (60) can be expressed as a vector, as shown in FIG. 5. The motion detection unit 112 can compare the image frames constituting the captured image in this way and detect movement depending on whether a vector of a set size or more exists in the previous and subsequent image frames. At this time, the motion detection unit 112 may detect that a plurality of subjects 60 are in motion when comparing the previous and subsequent image frames, and at this time, the vector for each subject 60 The sizes may be different.

When the motion comparison unit 114 detects that there is motion between image frames by the motion detection unit 112, the motion comparison unit 114 sequentially compares the detected motion per unit time. That is, the motion comparison unit 114 sequentially compares the movement per unit time between consecutive image frames among the image frames constituting the image. At this time, when a plurality of subjects 60 are detected to be moving, it is preferable that the motion comparison unit 114 sequentially compare the movements of each subject 60 per unit time.

The motion change calculation unit 116 calculates the amount of change in movement based on the movement per unit time compared by the motion comparison unit 114. For example, the motion change calculation unit 116 determines the size of the motion vector of the specific subject 60 between the first and second image frames, and the size of the motion vector of the specific subject 60 between the second and third image frames ( By comparing the sizes of the motion vectors in 60), it is possible to calculate how much the corresponding motion vector has increased or decreased.

In this case, the event occurrence determination unit 106 determines that an event has occurred in the corresponding video frame when the amount of change in motion calculated by the motion change calculation unit 116 increases or decreases beyond a set range.

The ambient sound collecting unit 118 collects ambient sound corresponding to the image captured by the surveillance camera 10. That is, the ambient sound collecting unit 118 collects ambient sounds generated around the surveillance area when the surveillance camera 10 captures a set surveillance area.

The sound comparison unit 120 sequentially compares the sound per unit time with the ambient sound collected by the ambient sound collection unit 118. For example, the sound comparison unit 120 may sequentially compare sounds at intervals of 1 minute with the ambient sound continuously collected by the ambient sound collection unit 118.

The sound change calculation unit 122 calculates the amount of change in sound based on the sound per unit time compared by the sound comparison unit 120. For example, the sound change calculation unit 122 can calculate the amount of change in terms of how much the amplitude and frequency of the sound collected during the second 1 minute change with respect to the amplitude and frequency of the sound collected during the first 1 minute. there is.

In this case, the event occurrence determination unit 106 determines that an event has occurred in the corresponding video frame when the change in sound calculated by the sound change calculation unit 122 increases or decreases more than a set range. That is, the event occurrence determination unit 106 may determine that an event has occurred in the corresponding movement per unit time when the amount of change in movement increases or decreases more than a set range and the amount of change in sound increases or decreases more than a set range. .

Figure 6 is a flowchart showing a method for storing captured images according to an embodiment of the present invention. The method of storing a captured image according to an embodiment of the present invention can be performed by the captured image storage device 100 shown in FIG. 2.

Referring to FIGS. 1 to 6, the captured image storage device 100 records the time at which each video frame is stored for each video frame constituting the image captured by the surveillance camera 10 (S101).

A video is made up of multiple video frames, and a video frame can be said to be a simple still image. For example, the video of the NTSC (National Television System Committee) system of Korea, the United States, Japan, etc. consists of 30 video frames per second. Additionally, a movie usually consists of 24 video frames per second. Likewise, as shown in FIG. 3, the surveillance camera 10 continuously displays a plurality of still images corresponding to the surveillance area, that is, a plurality of video frames 40, during a unit time (for example, 1 second). A captured image 50 is formed by shooting. At this time, the captured image storage device 100 records the storage time point for each captured image frame.

The captured image storage device 100 determines whether the first set period set from the time of recording has elapsed (S103). At this time, the captured image storage device 100 may determine whether the first set period has elapsed in units of 1/100 second for each image frame. For example, the captured image storage device 100 can determine whether 24 hours have elapsed accurately to the nearest 1/100 second for each image frame.

The captured image storage device 100 detects movement based on the image frame of the image captured by the surveillance camera 10 (S105).

Since the surveillance camera 10 is fixed toward a specific direction and photographs a surveillance area within a set range, if there is no movement within the surveillance area, the previous and subsequent image frames are the same. However, as shown in FIG. 4, when a specific subject 60 moves within the surveillance area, the position of the subject 60 in the previous image frame and the position of the subject 60 in the subsequent image frame change. In this way, when the position of the subject 60 in the subsequent image frame is different with respect to the position of the subject 60 in the previous image frame, the subject 60 in the subsequent image frame is based on the position of the subject 60 in the previous image frame. The change in position of (60) can be expressed as a vector, as shown in FIG. 5. In this way, the captured image storage device 100 compares the image frames constituting the captured image with each other and can detect movement depending on whether a vector of a set size or more exists in the previous and subsequent image frames. , At this time, the captured image storage device 100 may detect that a plurality of subjects 60 are in motion when comparing the previous and subsequent image frames, and at this time, each subject 60 The sizes of the vectors may be different.

When the captured image storage device 100 detects that there is movement between image frames, it sequentially compares the detected movement per unit time (S107). That is, the captured image storage device 100 sequentially compares the movement per unit time between consecutive image frames among the image frames constituting the image. At this time, when it is detected that a plurality of subjects 60 are moving, it is preferable that the captured image storage device 100 sequentially compares the movement of each subject 60 per unit time.

The captured image storage device 100 calculates the amount of change in movement based on the compared movement per unit time (S109). For example, the captured image storage device 100 stores the size of the motion vector of a specific subject 60 between the first and second video frames, and the size of the motion vector of the specific subject 60 between the second and third video frames ( By comparing the sizes of the motion vectors in 60), it is possible to calculate how much the corresponding motion vector has increased or decreased.

The captured image storage device 100 collects ambient sounds corresponding to the image captured by the surveillance camera 10 (S111). That is, when the surveillance camera 10 captures a set surveillance area, the captured image storage device 100 collects ambient sounds generated around the surveillance area.

The captured image storage device 100 sequentially compares the sound per unit time with the collected ambient sound (S113). For example, the captured image storage device 100 can sequentially compare sounds at intervals of 1 minute with ambient sounds collected continuously.

The captured image storage device 100 calculates the amount of change in sound based on the compared sound per unit time (S115). For example, the captured image storage device 100 can calculate the amount of change in terms of how much the amplitude and frequency of the sound collected during the second 1 minute change with respect to the amplitude and frequency of the sound collected during the first 1 minute. there is.

The captured image storage device 100 determines whether an event has occurred in an image frame in which it is determined that the first set period has elapsed (S117). At this time, the captured image storage device 100 may determine that an event has occurred when it is determined that there is a change in movement greater than a set value or a change in sound greater than a set value between video frames that are continuously stored.

The captured image storage device 100 may determine that an event has occurred in the corresponding video frame when the calculated change in motion increases or decreases beyond a set range.

Additionally, the captured image storage device 100 may determine that an event has occurred in the corresponding video frame when the calculated change in sound increases or decreases beyond a set range. In other words, the captured image storage device 100 may determine that an event has occurred in the corresponding movement per unit time when the amount of change in motion increases or decreases more than a set range and the amount of change in sound increases or decreases more than a set range. .

The captured image storage device 100 stores the image frames in which it is determined that an event has occurred, together with a set number of before and after image frames, for a second set period that is longer than the first set period (S119). For example, if the captured image storage device 100 determines that an event occurred between the 10th video frame and the 11th video frame, it selects the video frame second behind from the 8th video frame, which is the video frame before the second. Up to the 13th video frame can be extended and stored for the second set period. Additionally, when the first setting period is set to 24 hours, the captured image storage device 100 may set the second setting period to 72 hours and store the image frame in which it is determined that an event has occurred.

The captured image storage device 100 deletes the remaining video frames before the extended stored video frame (S121). For example, as described above, when the images captured by the surveillance camera 10 are extended and stored for a second set period from the 8th image frame to the 13th image frame, the captured image storage device 100 Before the 8th video frame, that is, the 7th video frame is deleted from the first video frame. At this time, the video frame to be deleted is assumed to be a video frame in which no event has occurred, and if the previous video frame has been extended and stored for the second set period, it is desirable that the video frame that has been extended and stored is excluded from deletion. .

Although embodiments according to the present invention have been described above, they are merely illustrative, and those skilled in the art will understand that various modifications and equivalent scope of embodiments are possible therefrom. Accordingly, the scope of protection of the present invention should be determined not only by the following claims but also by their equivalents.

Claims (6)

In a captured image storage device that stores images captured by a surveillance camera,
a storage time recording unit that records the time at which each video frame is stored for each video frame constituting the captured video;
a period elapse determination unit that determines whether a first set period has elapsed from the time recorded in the storage time record;
an event occurrence determination unit that determines whether an event has occurred in a video frame for which the first set period is determined to have elapsed by the period elapse determination unit;
a captured image storage unit that extends and stores video frames in which an event is determined to have occurred by the event occurrence determination unit along with a set number of before and after video frames for a second set period that is longer than the first set period;
a captured image deletion unit that deletes remaining video frames before the video frame extended and stored by the captured image storage unit;
a motion detection unit that detects movement based on an image frame of an image captured by the surveillance camera;
When motion is detected by the motion detection unit, a motion comparison unit that sequentially compares the detected movement per unit time; and
a motion change calculation unit that calculates a change in movement based on the movement per unit time compared by the motion comparison unit;
Includes,
The event occurrence determination unit determines that an event has occurred in the corresponding video frame when the amount of change in motion calculated by the motion change calculation unit between consecutive video frames increases or decreases beyond a set range. Storage device. delete According to paragraph 1,
an ambient sound collecting unit that collects ambient sound corresponding to the image captured by the surveillance camera;
a sound comparison unit that sequentially compares sounds per unit time with respect to the ambient sound collected by the ambient sound collection unit; and
a sound change calculation unit that calculates a change in sound based on the sound per unit time compared by the sound comparison unit;
It further includes,
The event occurrence determination unit determines that an event has occurred in the corresponding video frame when the change in sound calculated by the sound change calculation unit increases or decreases beyond a set range. In the method of storing captured images performed by the captured image storage device of claim 1,
Recording the point in time at which each video frame is stored for each video frame constituting the captured video;
determining whether a first set period has elapsed from the time of recording;
Detecting movement based on an image frame of an image captured by a surveillance camera;
sequentially comparing the detected movements per unit time;
calculating a change in movement based on the compared movement per unit time;
determining whether an event has occurred in a video frame for which it is determined that the first set period has elapsed;
extending and storing the video frame in which it is determined that the event has occurred, along with a set number of before and after video frames, for a second set period that is longer than the first set period; and
deleting video frames previous to video frames extended and stored during the second set period;
Includes,
The step of determining the occurrence of the event includes determining that an event has occurred in the corresponding video frame when the amount of change in motion calculated between consecutive video frames increases or decreases beyond a set range. . delete According to paragraph 4,
collecting ambient sounds corresponding to images captured by the surveillance camera;
sequentially comparing sounds per unit time with respect to the collected ambient sounds; and
calculating a change in sound based on the compared sound per unit time;
It further includes,
The step of determining the occurrence of the event includes determining that an event has occurred in the corresponding video frame when the calculated change in sound increases or decreases beyond a set range.