JP2005101904A - Recording method of monitor image, and monitor image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording and reproducing apparatus for a monitor image, by eliminating redundant images in the lapse of a prescribed time after recording image data of a monitor camera to attain long time recording, and interpolating the eliminated images to obtain a reproduce image without a sense of incongruity. <P>SOLUTION: The monitor image-recording and reproducing apparatus 20 is realized, such that the apparatus records an image received from a monitor camera 10 to a medium 29 together with photographing time information, reproduces a recorded image after the lapse of a prescribed time, a image difference discriminating means 33 detects and deletes a recorded image which does not contain motion, the image with less motion than the motion of a reference image stored in an image memory 31 is deleted, the recording medium 29 records the reference image and an image with a large motion, together with time information, the deleted recorded image is reproduced as an information image, by repeating the reference image on the basis of the time information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a monitoring image recording method and a monitoring image recording apparatus in a monitoring camera signal recording / reproducing apparatus that efficiently records an image signal input from a monitoring camera every predetermined image period on a recording medium.

  In a surveillance camera recording apparatus that records an image signal input from a surveillance camera, an apparatus for compressing and encoding the image and recording the image on a recording medium such as a hard disk has been developed. The image input from the surveillance camera is often an image from a fixed point camera, and the image may not change over a long period of time.

  Time-lapse recording is also available for devices that record images input from surveillance cameras as continuous images that are 30 frames per second, depending on the situation, or that record time-intermittent images such that one image is recorded every predetermined number of frames. It has been put into practical use as a device. However, even when an image is recorded intermittently, there is a portion in which the image hardly changes in the recorded image data of the surveillance camera.

Therefore, as a time-lapse encoding system that normally records compression-encoded video signals for a long time and records and plays back high-resolution video in an emergency, it has means for alarm detection, and a high bit when an alarm signal is detected A time lapse recording method has been proposed in which a low bit rate video signal in which a wide range component of the video signal is suppressed is reproduced and reproduced when an alarm signal is not detected (see, for example, Patent Document 1). .)
JP 2002-16877 A

  However, it is difficult for a sensor that detects an alarm signal to reliably grasp the situation in an emergency situation. In other words, an emergency situation may occur in a peaceful environment, in which case the emergency situation will be missed. On the other hand, if the sensitivity of the sensor is increased more than necessary, the video signal from the surveillance camera is recorded with a malfunction such as abnormal detection even when the natural environment changes during normal times. It will be wasted.

  In general, a method of recording a surveillance camera video with increased sensitivity of a sensor is used. In that case, the recording time is limited in a recording medium having a limited capacity. Therefore, it is necessary to perform operations such as securing a recording free space on the medium by, for example, deleting images that are determined to be images in a normal state from images recorded every predetermined time in order from the oldest image. Had the problem of.

  The present invention has been made in view of the above situation, and records image data input from a surveillance camera at a predetermined frame rate. A redundant portion of an image that has passed a predetermined time after recording is determined, and the redundant image is deleted. Then, a monitoring image recording method and a monitoring image for realizing a monitoring camera signal recording / reproducing apparatus that does not feel a sense of incongruity in time with respect to the reproduction of the deleted image portion and has a long apparent recording time. A configuration of a recording apparatus is to be provided.

The present invention comprises the following means 1) or 2) in order to solve the above problems.
That is,

1) Record a photographic image output from the surveillance camera on a medium, reproduce the medium after this recording, and erase the recorded photographic image that does not include a moving photographic object from the reproduced photographic images. A monitoring image recording method,
A first step (31) of storing in a first image memory a captured image of a predetermined frame obtained by reproduction after recording the captured image;
A second step (32) for storing the next captured image for a predetermined frame obtained by reproduction after the first step in a second image memory;
The captured image stored in the first image memory and the captured image stored in the second image memory are compared (33). If the images match, the image is stored in the second image memory. If the captured image recorded on the medium is erased and the two images do not match, the captured image stored in the second image memory is determined as an image necessary for monitoring. A third step (21) of overwriting the captured image stored in the second image memory in the first image memory;
After the third step, a fourth step (32) for storing the next photographed image for a predetermined period of time in the second image memory;
A fifth step (recording only the photographed image determined to be necessary for the monitoring on the medium is repeated by repeating the third and fourth steps in accordance with the presence or absence of movement of the photographed image output from the monitoring camera. 21 and 29),
A method for recording a surveillance image, comprising:
2) Record the photographic image output from the surveillance camera on the medium, play back the medium after this recording, and erase the recorded photographic image that does not include the moving photographic object from the reproduced photographic images. A surveillance image recording device,
First image storage means (31) for storing a predetermined number of frames of a captured image obtained by reproduction after recording the captured image;
Second image storage means (32) for storing a next photographed image for a predetermined frame obtained by reproduction after storage of the photographed image in the first image storage means;
The captured image stored in the first image storage means and the captured image stored in the second image storage means are compared (33), and if the two images match, the second image storage means If the captured image recorded on the medium is erased and the two images do not match, the image stored in the second image storage means is an image necessary for monitoring. And a recording control means (21) for overwriting the captured image stored in the second image storage means in the first image storage means,
An image updating means (32) for storing a next photographed image for a predetermined period of time in the second image storage means after the overwriting to the first image storage means in the recording control means;
Medium recording means (21, 29) for recording, on the medium, only a photographed image having a movement determined to be necessary for the monitoring according to the presence or absence of a movement of the photographed image output from the monitoring camera;
A surveillance image recording apparatus comprising:

The monitoring image recording method and monitoring image recording apparatus of the present invention have the following effects.
That is,

1) A captured image input from a surveillance camera is recorded on a medium, the recorded medium is reproduced after a predetermined time has elapsed since the recording, and the captured image obtained by reproducing the captured image does not include a moving target. Therefore, all the captured images can be reproduced before a predetermined time has elapsed, and a captured image with a subject to be detected whose motion is detected even after the predetermined time has elapsed. The recording method and the configuration of the monitoring image recording apparatus can be provided.

  Hereinafter, preferred embodiments of the monitoring image recording method and monitoring image recording apparatus according to the present invention will be described.

  FIG. 1 shows a schematic configuration of a monitoring camera apparatus according to the first embodiment, and the operation thereof will be described with reference to the drawings.

  The monitoring camera apparatus shown in FIG. 1 includes a monitoring camera 10, a recording / playback control unit 21, a hard disk drive (hereinafter also abbreviated as HDD) 29, an image memory A31, an image memory B32, and a difference determination unit 33. The monitor camera signal recording / reproducing apparatus 20 and the video monitor 40 are configured.

  First, an image signal of 30 frames per second is input from the monitoring camera 10 to the recording / playback control means 21 of the monitoring camera signal recording / playback apparatus 20. The recording / reproduction control means 21 is constituted by a microcomputer, and obtains an image signal by thinning out a video signal as necessary, compresses and encodes the obtained image signal, and formats the compression-encoded signal. For example, recording the recorded signal on the hard disk, unformatting the signal read from the hard disk, and decompressing the signal obtained by unformatting to obtain an image signal.

  The above compression coding is performed using a compression coding method defined by JPEG (Joint Photographic Coding Experts Group), for example. Further, the thinning of the image signal can be set by the user's operation. For example, if one image is recorded every three frames, an image of 10 frames can be recorded per second, and if one frame is thinned out every 30 frames, the image signal is thinned. A JPEG-encoded image can be recorded on the HDD 29 at a rate of one frame per second.

  Further, the above formatted signal is configured by adding a header to a JPEG compression-encoded signal, and the header portion describes time information related to the time supplied from the monitoring camera 10 in the HDD 29. Record. As the time information, a signal from a timer (not shown) included in the recording / reproduction control means 21 may be recorded.

Next, erasure for removing redundancy of recorded signals will be described.
After the above recording, for example, the signal of the HDD 29 is read out after 24 hours. The read signal of the first frame is decoded, and the image data obtained by decoding is stored in the image memory A31. Next, the signal of the second frame is read, decoded, and stored in the image memory B32.

  Differences between the images stored in the two image memories are detected by the difference determination means 33. The determination result indicating that there is no difference or there is a difference is supplied to the recording / reproduction control means 21. The recording / playback control means 21 erases the recorded portion of the HDD 29 related to the image stored in the image memory B32 determined to have no difference, and erases the recorded portion related to the image determined to have the difference. Do not do. That is, the image is recorded together with the time information, but the time information is not erased but only the image is erased.

  By performing the above operation on all the image data recorded, for example, after 24 hours, only the image data determined to have a difference in the HDD 29 by the difference determination unit 33 and the time recorded for each image Information is not erased and is recorded on the medium.

Next, reproduction of image data recorded on the HDD 29 will be described.
First, when a playback button (not shown) of the surveillance camera signal recording / playback apparatus 20 is operated, the signal recorded in the HDD 29 is read out by the recording / playback control means 21 together with the header describing the time information as described above. . The compressed encoded data is decoded to obtain image data.

  Based on the time information, the decoded image data is reproduced as an interpolated image by repeating the previous image to be deleted if there is deleted image data. As a result, it is reproduced as a signal on the same time axis as at the time of recording. The image signal obtained by reproduction is supplied to the video monitor 40 and displayed.

The reproduction operation of the surveillance camera signal recording / reproduction device 20 has been described above.
Next, the recording and erasing operations will be further described.
FIG. 2 shows an image recorded on the medium, which will be described with reference to the drawings.

  In the figure, an example of an image after 24 hours has passed since the above recording is shown. Here, the image output from the monitoring camera 10 is recorded as an intermittent image obtained by thinning out one image per second.

  That is, the image 301 is the first image that has passed 24 hours after recording, and this image is stored in the image memory A31 as a reference image. The next image 302 is a second image after one second has passed, and this image is stored as an inspection image in the image memory B32.

  Difference data between the reference image 301 and the inspection image 302 is obtained by the difference determination means 33. Here, when there is no difference data between the two images, that is, when there is no shooting target whose motion vector is detected in the shot shooting target, the image portion recorded in relation to the inspection image 1 is erased.

Next, the third image is stored as an inspection image in the image memory B32, the reference image 301 and the inspection image 303 are compared, and difference data is obtained.
Here, the detection of the motion vector is not obtained for each adjacent image data, but is obtained as an amount of motion for an image recorded on the medium and not erased.

  Therefore, even if the amount of motion between adjacent images is small, the reference image to be compared is an image that is recorded on the medium and is not erased. Therefore, when the accumulated motion amount reaches a predetermined magnitude, the image can be detected as an image with motion, so that detection failure is unlikely to occur.

Further, it is possible to prevent the inconvenience that all the images taken by the subject to be photographed are erased even for the subject having a minute movement.
Next, image data that is erased because the amount of motion is small will be further described.

FIG. 3 shows the format of an image recorded on the medium, which will be described with reference to the drawing.
In the figure, data recorded on the medium is composed of a header and an image data portion. Time information is described in the header, and image data for one screen compressed and encoded by JPEG or the like is stored in the image data portion.

  Here, the image 301 is a reference image, and reference image data is described in the image data description area. The images 302 and 303 are deleted, that is, deleted, because the difference determination means 33 does not include motion information.

  For inspection images in which no motion is detected, a method of transcribes the recording time information relating to the image to be erased into the header of the reference image in addition to erasing the data portion of the image data portion only and not erasing the header portion as it is There is also.

  In the case of the method of transferring the time information related to the image data to be erased, all data including the header can be erased, so that the amount of data recorded on the medium after the erase operation can be further reduced.

  Furthermore, if the recording time information to be recorded on the reference image is recorded before the reference image to be recorded next, the last time information of the image data portion to be erased is recorded, the header area can be further reduced. it can. In the time information B shown in the figure, the time data of the inspection image 1 is transferred at the first deletion, and the time data of the inspection image 2 is overwritten when the next inspection image 2 is deleted.

  The medium thus recorded is reproduced by repeating the reproduction of the reference image recorded in the image data area from the time of the time information A to the time of the time information B (repeat), thereby reproducing the deleted image. Interpolated reproduction can be performed, and reproduction on the same time axis as recording can be performed.

The configuration of the image data when it is determined and deleted by the difference determination unit 33 has been described above.
Next, operations for more images will be described.
FIG. 4 shows a large number of inputted and recorded images, and the operation on these images will be described.

  In the figure, images 401 to 418 indicate images that are input and thinned out, for example, by one per second. The first image 401 is an image in which a tree is reflected in the background, and an image without motion continues to an image 405. In the images 406 to 410, the round ball is moving from the bottom to the top, and then the images 411 to 418 are followed by images without movement.

  Here, the image 401 is stored as a reference image in the image memory A31, and the images 402 to 405 are deleted (erased) in order because there is no movement. Therefore, the time information B described in the time information B shown in FIG. 3 is overwritten and updated up to the time information of the image 405 in order.

  Next, the images 406 to 411 are stored as they are up to the image 411 when the round ball is moving and the ball disappears. Thereafter, the images after the image 411 until the image is moved are deleted, and the updated time information is written (overwritten) in the time information B.

  Then, no motion is detected in the images 411 to 418. In addition, it is not preferable that all the images in the meantime are erased when no motion is detected. For example, when it exceeds 10 seconds (described as 7 seconds in the figure), the image is referred to as a reference image. And the record is stored as it is without being erased.

By periodically storing the images, even if the illuminance of the subject gradually changes, the recorded images can be played back at a high speed and a reproduced image without any sense of incongruity can be obtained.
Next, re-recording of an image having redundancy on the HDD 29 and reproduction of the re-recorded image will be described.

  First, in the first image 401, time information 401 (hereinafter also referred to as time 401) related to the image 401 is described in the time information A area of the header portion, and time 405 is described in the time information B area. Recorded. Each of the images 406 to 410 is recorded with a header in which time 406 to time 410 is described in each of the time information A areas, and in which the empty data such as “0” is described in the time information B area. Is done.

Similarly, time 411 and time 417 are described in the header of the image 412.
When the image data is re-recorded in the HDD 29, the images 401, 406 to 411, and the image 418 are continuously recorded. Further, when deleting the images 402 to 405 and the images 412 to 417 recorded on the medium, only the header portions of the images 401 and 411 are rewritten, or only the data in the area of the time information B is rewritten. .

The operation for deleting (erasing) a redundant image having no motion has been described above.
The reproduction of the image data from which those redundant images are deleted is performed in the time information B area while comparing the time information from a timer (not shown) of the surveillance camera signal recording / reproducing apparatus 20 with the data of the header portion of the image data. When the time information is described, the image recorded following the header is repeatedly reproduced during that time.

The relationship between the image to be deleted and the time information described in the header has been described above. Here, how to obtain the difference value will be further described.
First, a difference value obtained by image comparison is obtained as a difference value by a value obtained by subtracting pixels at the same place in a frame image and squared and adding the difference values for each pixel obtained by the subtraction. There is a way. A difference value in the entire frame image is obtained by the first method.

  The second difference value obtained by comparing the images is obtained by calculating the movement of the location of the subject in the image memory B32 with respect to the subject in the image memory A31 using a motion vector, and performing the difference based on the magnitude (movement amount) of the obtained motion vector. It is a method of determining as a value. In the case of the difference value according to the second method, even a small subject can be determined as a large difference value when the amount of movement is large.

  When a large difference value is obtained by either the first difference value or the second difference value obtained by the above method, the image is determined as an image having a target that needs to be monitored. When both of the difference values obtained by the first and second methods are small, it is determined that the image in the image memory B32 is an image that does not need to be monitored and is to be deleted.

  Since the weighting between the first difference value and the second difference value differs depending on the type of monitoring target, the threshold level may be selected by the user.

The configuration and operation of the monitoring camera signal recording / reproducing apparatus 20 have been described in detail above.
Next, an operation algorithm of the monitoring camera signal recording / reproducing apparatus 20 will be described.
FIG. 5 and FIG. 6 show flowcharts relating to the erasing operation in the surveillance camera signal recording / reproducing apparatus, which will be described with reference to FIG.

  First, in S (step) 61, it is detected whether or not a reference image is stored in the image memory A31. If it is not detected, the reference image is transferred to the image memory A31 in S62. When it is detected that the reference image is stored, and after the operation of S62, the operation of S63 is performed.

  In S63, the inspection image is transferred to the image memory B32. In S64, the difference value between the image in the image memory A and the image in the image memory B is obtained, and whether the obtained difference value exceeds a predetermined threshold value. Whether or not is detected.

  If there is no image change detected in S64 as not exceeding the threshold value, it is detected in S65 whether or not the continuous deletion (erasing) time exceeds a predetermined set value (for example, 10 seconds). . If the predetermined time is exceeded in S65, and if the difference value between images exceeds the threshold value in S64 (the image is changed), the image in the image memory B32 is copied to the image memory A31 in S68. Then, the reference image is replaced and the process proceeds to S69.

  When it is detected in S65 that the continuous deletion time does not exceed the set value, the time information related to the image stored in the image memory B32 is described in the time information B area of the reference image data in S66. After the description, the compressed encoded data recorded on the medium relating to the image stored in the image memory B32 is deleted, and the process proceeds to S69.

  In S69, it is detected whether a series of operations related to erasure of redundant images has been completed. If not, the operations from S63 are repeated, and erasure (deletion) of image data recorded on the medium is completed when the series of operations is completed. ) End the operation.

  Here, for example, it is described that the redundant image erasing operation is performed on an image that has passed 24 hours after recording. As the operation, when the free area of the HDD 29 becomes less than a predetermined value, the redundant image erasing operation may be started at an arbitrary time operated by the user or at a predetermined time interval set.

The configuration and operation of the surveillance camera signal recording / reproducing apparatus 20 according to the first embodiment have been described above. In this example, all images from the surveillance camera are first recorded at a predetermined frame rate, and redundant images are deleted after a predetermined time has elapsed.
Next, an example will be described in which an image inputted from the surveillance camera is recorded in the HDD 29 with redundant images reduced.

  FIG. 7 shows the configuration of the surveillance camera signal recording / reproducing apparatus 20a according to the second embodiment, which will be described with reference to the drawings. Components having the same functions as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the same figure, the monitoring camera signal recording / reproducing apparatus 20a is provided with a recording / reproducing control means 21a instead of the recording / reproducing control means 21 as compared with the monitoring camera signal recording / reproducing apparatus 20 described above, and the connection. The method is different in different ways.

  First, an image output from the monitoring camera 10 is first input as a reference image to the image memory A31. The next image is input to the image memory B32 as an inspection image. The difference determination unit 33 determines whether the difference between the inspection image with respect to the reference image and the amount of movement of the shooting target being shot are below a predetermined level.

  If it is determined that the difference is equal to or lower than a predetermined level, the image in the image memory B32 is deleted, and the next image from the monitoring camera is input as an inspection image. For an image in which no motion is detected, this operation is repeated for 10 seconds, for example.

  Before the 10th second image is input, the time information related to the image is described in the time information B in the header. The reference image with the header describing the time information A and the time information B is supplied from the image memory A 31 to the recording / reproduction control unit 21 a via the difference determination unit 33 and recorded in the HDD 29.

  Next, the image supplied from the monitoring camera 10 is input as a reference image to the image memory A31, and thereafter the same operation is repeated. An image in which the amount of motion of the inspection image is equal to or greater than a predetermined value is also recorded in the HDD 29. The recording is performed in the same manner as shown in FIG.

  The configuration and operation of the surveillance camera signal recording / reproducing apparatus 20a according to the second embodiment have been described above. In the case of the second embodiment, since the image from which the redundant image is deleted is recorded in the HDD 29 from the beginning, it is not necessary to perform the redundancy processing operation while continuing the image recording.

  That is, it becomes easy to manage a sequence for simultaneously performing recording, reading, and erasing with respect to the HDD 29. On the other hand, since an image erased as having no motion cannot be restored, it is necessary to increase the detection accuracy of the difference determination means 33.

The configuration and operation of the surveillance camera signal recording / reproducing apparatus according to the first and second embodiments have been described above. According to these embodiments, when recording a monitoring image output from the monitoring camera on a recording medium such as an HDD, data with high redundancy can be determined, deleted, and recorded.
The recording method can be described as follows.

A photographed image input from a surveillance camera is recorded on a medium together with photographing time information, the recorded medium is reproduced after a lapse of a predetermined time from the recording, and does not include a moving photographing object among the photographed images obtained by reproduction. A monitoring image recording method for erasing a recorded image,
A first step of storing a first captured image obtained by reproduction after the predetermined time has elapsed in a reference image memory;
A second step of storing a photographed image obtained by reproduction after the first step in an inspection image memory;
The captured image stored in the reference image memory and the captured image stored in the inspection image memory are compared to detect the amount of motion for each subject captured in each image, and the amount of motion is determined. When the photographing object having the amount of motion is detected, the photographing image having the amount of motion is deleted when only the photographed image is deleted from the photographed image and the photographing time information related to the inspection image memory. A third step of copying a captured image stored in the inspection image memory to the reference image memory;
After the third step, a fourth step of storing a next captured image obtained by reproducing the medium in the inspection image memory;
A monitoring image recording method comprising: repeating the third and fourth steps to delete redundant captured images.

According to the recording method, the following can be realized.
That is, a captured image input from a surveillance camera is recorded on a medium together with shooting time information, the recorded medium is played back after a predetermined time has elapsed from the recording, and a moving shooting target among the captured images obtained by playback is selected. Since the shooting time information is not deleted for captured images that are not included, only the captured images are deleted, so the captured image where the subject whose motion is detected is captured even after a predetermined time has passed. A monitoring image recording method for reproduction as a time-axis signal can be realized.

The recorded signal is reproduced as follows.
That is, a captured image input from a surveillance camera is recorded on a medium together with shooting time information, the recorded medium is played back after a predetermined time has elapsed from the recording, and a moving shooting target among the captured images obtained by playback is selected. When erasing recorded images that do not include
The first captured image obtained by the reproduction after the predetermined time has elapsed is stored in the reference image memory, the next captured image is stored in the inspection image memory, and the captured image stored in the reference image memory And the captured image stored in the inspection image memory, and the captured image and the captured time recorded on the medium are detected only when the amount of motion for each captured object captured in each image is not detected. A monitoring image reproduction method for reproducing a medium recorded so as to erase only a captured image of information,
A first step of outputting the captured image obtained by reproducing the recording medium;
When the medium is played back and the photographed image cannot be obtained and only the photographing time information is obtained, the currently output photographed image is continuously output, while when the photographed image is obtained, a new image is obtained. A second step of outputting the obtained captured image;
A method for reproducing a monitoring image, wherein the captured image recorded on the medium is reproduced by repeating the second step.

  In addition, according to the reproduction method, the captured image input from the surveillance camera is recorded on the medium together with the captured time information, and the captured time information is not deleted for a captured image that does not move after a predetermined time has elapsed, and only the captured image is recorded A monitoring image reproduction method capable of reproducing a medium recorded in an erased manner as a signal on the same time axis as that at the time of photographing a photographed image on which a subject whose motion is detected is detected even after a predetermined time has elapsed. realizable.

  Furthermore, at the time of reproduction, the image immediately before the deleted image is repeated based on the time information and reproduced as an interpolated image. Therefore, the apparent recording time can be extended with a recording medium having the same capacity without affecting the reproduced image.

The invention includes a program for realizing the above-described surveillance camera signal recording / reproducing apparatus by a computer. The program for executing the computer, for example, records a captured image input from a surveillance camera on a medium, reproduces the recorded medium after a predetermined time has elapsed from the recording, and reproduces the captured image obtained by the reproduction. A program for a monitoring camera signal recording / playback apparatus that is executed with a function of erasing a recorded image that does not include a moving shooting target,
A first step of storing, in a first image memory, a first photographed image obtained by reproduction after the predetermined time has elapsed;
A second step of storing, in a second image memory, a captured image obtained by reproduction after the first step;
The photographed image stored in the first image memory and the photographed image stored in the second image memory are compared, and if they match, the second image memory is recorded on the medium. A third step of erasing the captured image and copying the captured image stored in the second image memory to the first image memory if they do not match;
After the third step, a fourth step of storing a next photographed image obtained by reproducing the medium in the second image memory;
A monitor camera signal recording / reproducing apparatus program for controlling the apparatus.

  The present invention can be used to realize a monitoring camera device that can efficiently record image data for monitoring purposes on a limited recording medium.

It is a figure which shows schematic structure of the surveillance camera apparatus based on the Example of this invention. (Example 1) It is a figure which shows the order of the image recorded on the recording medium based on the Example of this invention. (Example 1) It is a figure which shows the format of the image recorded based on the Example of this invention. (Example 1) It is a figure which shows the example of the image input and recorded based on the Example of this invention. (Example 1) It is the first half part of the flowchart which shows operation | movement of the signal recording / reproducing apparatus based on the Example of this invention. (Example 1) It is the latter half part of the flowchart which shows operation | movement of the signal recording / reproducing apparatus based on the Example of this invention. (Example 1) It is a figure which shows schematic structure of the surveillance camera apparatus based on the Example of this invention. (Example 2)

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Surveillance camera 20, 20a Surveillance camera signal recording / reproducing apparatus 21 Recording / reproduction control means 29 Hard disk drive 31 Image memory A
32 Image memory B
33 Difference determination means 40 Video monitor 301-303 Image 401-418 Image S61-S69 Operation step

Claims (2)

A recorded image that is output from the surveillance camera is recorded on a medium, the medium is reproduced after the recording, and a recorded image that does not include a moving object is deleted from the captured image obtained by the reproduction. Recording method,
A first step of storing, in a first image memory, a captured image for a predetermined frame obtained by reproduction after recording the captured image;
A second step of storing a next captured image for a predetermined frame obtained by reproduction after the first step in a second image memory;
The photographed image stored in the first image memory is compared with the photographed image stored in the second image memory. If the two images match, the photographed image stored in the second image memory is stored. When the captured image recorded on the medium relating to the image is erased and the two images do not match, the captured image stored in the second image memory is determined as an image necessary for monitoring and the second A third step of overwriting the captured image stored in the image memory in the first image memory;
After the third step, a fourth step of storing a next captured image for a predetermined period of time in the second image memory;
A fifth step in which the third and fourth steps are repeated in accordance with the presence or absence of movement of the captured image output from the monitoring camera, and only the captured image determined to be necessary for the monitoring is recorded on the medium; ,
A method for recording a surveillance image, comprising: A recorded image that is output from the surveillance camera is recorded on a medium, the medium is reproduced after the recording, and a recorded image that does not include a moving object is deleted from the captured image obtained by the reproduction. A recording device,
First image storage means for storing a predetermined number of frames of a captured image obtained by reproduction after recording the captured image;
Second image storage means for storing a next captured image of a predetermined frame obtained by reproduction after storage of the captured image in the first image storage means;
The photographed image stored in the first image storage means is compared with the photographed image stored in the second image storage means. If the two images match, the image is stored in the second image storage means. If the captured image recorded on the medium is erased and the two images do not match, the captured image stored in the second image storage means is determined as an image necessary for monitoring. And a recording control means for overwriting the photographed image stored in the second image storage means in the first image storage means,
An image updating means for storing the next photographed image for a predetermined period of time in the second image storage means after the overwriting to the first image storage means in the recording control means;
Medium recording means for recording, on the medium, only a photographed image having a movement determined to be necessary for the monitoring according to the presence or absence of a movement of the photographed image output from the monitoring camera;
A surveillance image recording apparatus comprising:

Images