JPH05167978A - Picture information recording device - Google Patents

Abstract

PURPOSE:To reduce am recording information amount and to make a retrieval at the time of reproduction easy by recording picture data when a change with the reference picture occurs in a recording picture and on and after differential data. CONSTITUTION:When starting operation of detecting recording start, one screen of picture data is written in a RAM 5. Then, the difference between the picture data to be outputted from an A/D converter 4 and the data written in the RAM 5 is obtained by a differential circuit 6. Based on this, an integrating circuit 7 calculates it as a differential total value for each frame. By comparing the total value with the set recording start device, a system control circuit 10 is shifted to the recording operation when the total value exceeds the other and stops the recording when the total value becomes lower than the other. In the case the differential value for each picture element provided by the differential circuit 9 remains 0 for more than the prescribed time, the recording is stopped and the picture recorded on the RAM 5 is replaced by the input picture at that point. The comparison obtaining the difference is performed by the rewriting reference picture.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image information recording apparatus, and more particularly to an image information recording apparatus which reduces the amount of recorded information and is suitable for long-time recording. 2. Description of the Related Art In an image information recording apparatus for monitoring a predetermined space with a surveillance camera and recording the image information in a memory for the purpose of crime prevention and accident prevention, it is necessary to record the image information for a long time. Therefore, the image information is often compressed and recorded. As this kind of compression method, a difference compression method of recording only the difference between image information obtained for each field and a method of reducing the frequency component of the image are generally used. As described above, in the conventional image information recording apparatus, the recording information is compressed by the image information compressing process, but the recording operation is performed during the actual monitoring period. However, the amount of recorded information becomes enormous when recording for a long time. As a result, it takes a lot of time to reproduce and search the image information after recording, and there is a problem that quick search is difficult. Therefore, an object of the present invention is to provide an image information recording apparatus that reduces recorded information and facilitates retrieval during reproduction. In order to solve the above-mentioned problems, the image information recording apparatus according to the present invention provides an image signal corresponding to the entire screen recorded at the time, at the time after the recording time. First monitoring means for sequentially and continuously obtaining first information indicating a time-dependent change of the image signal continuously supplied after the above-mentioned time point as a reference signal in the section, and successively and continuously. Second monitoring means for successively and continuously obtaining second information indicating a difference between a value representing the image at the time point of the supplied image signal and a value representing the image at the time point immediately before the time point; Each time when it is recognized that the change with time exceeds a predetermined value by one piece of information, the original image for recording the image information representing one whole screen supplied at that time on the information recording medium information The recording means, the difference information recording means for successively and continuously recording the second information in the time section following the recording time of the image information by the original image information recording means, and the time-dependent change amount by the first information. When it is recognized that the predetermined value has not been reached and / or the value representing the image at that time point of the image signal successively supplied by the second information and the image at the immediately previous time point are displayed. When it is recognized that the state in which the difference from the indicated value does not reach the predetermined value has continued for the predetermined time or more, the second information is recorded by the difference information recording means.
Recording stop means for stopping the recording of information. According to the present invention, the amount of information to be recorded is greatly reduced by recording the image data at the time when the image to be recorded changes from the reference image and the difference data after that. And facilitate search during playback. When the changed state continues for a predetermined time or more, the image is used as the reference image, so that the amount of recorded information can be further reduced. Next, embodiments of the present invention will be described in detail. The present invention stores an image in a memory as a reference image at the start of recording, and thereafter records the difference information only for a period in which the difference from the reference image is equal to or more than a predetermined level for each field (frame), Recorded information has been greatly reduced. Since the image is recorded only when the change occurs in the image, the target image scene can be found very quickly during reproduction and retrieval. The determination of the start of recording of the difference information is performed by detecting that the sum of the difference values with the reference image is equal to or greater than a predetermined threshold value, or that a point where the difference value in the image is large occurs in close proximity. The recording end can be determined by detecting the release of the recording start case. At this time, if the conditions for starting the recording are met and the changes do not return to the original state, the conditions do not end under the above conditions and the amount of recording data becomes large. After doing
When the steady state continues, the reference image at that time is replaced with the one at that time. Also, when actually writing to a magneto-optical disc, etc., by recording the original image to be recorded at the start of each recording and the recording start address of each block in a separate area, the menu display of the scene where the change occurs can be displayed. It is easy to perform, and the search is easier because there is no need to search while looking at the screen with sequential playback. FIG. 1 is a structural block diagram showing an embodiment of an image information recording apparatus according to the present invention, showing an application example to a photographing apparatus. A subject image is formed on the CCD 2, which is an image sensor, via the lens 1. The electric signal obtained from the CCD 2 is subjected to predetermined video signal processing by the imaging process circuit 3 and supplied to the A / D converter 4. The digital image data from the A / D converter 4 is processed as described below under the control of the system control circuit 10. That is, at the start of the recording start detection operation, one screen of the image data is written in the RAM 5. Immediately after the writing, the difference circuit 6 obtains the difference between the image data sequentially output from the A / D converter 4 and the image data written in the RAM 5. This difference is supplied to the integrating circuit 7, and the sum total value of the differences for each frame is calculated. The system control circuit 10 compares the total difference value from the integration circuit 7 with a predetermined recording start value. As a result of the comparison, the recording operation starts when the difference total value becomes larger than a predetermined value. At the start of the recording operation, one screen of information which is the original image information at the start time is written in the RAM 8 and at the same time, the same original image information is written in the magneto-optical disk 13.
Immediately after writing, the difference circuit 9 obtains the difference for each pixel from the image sequentially output from the A / D converter 4,
The data is written to the magneto-optical disk 13 via the RAM 8, the system control circuit 10 and the magneto-optical disk drive 12. Even during this recording operation, the difference summation value is always performed, and the recording is stopped when the summation value becomes smaller than a predetermined value. Further, when the difference value for each pixel obtained by the difference circuit 9 is 0 for a predetermined time or longer, recording is stopped, the image recorded in the RAM 5 is replaced with the input image at that time, and thereafter, Performs a comparison operation for obtaining the difference based on the rewritten reference image. At the time of reproduction, the original image (reference image) reproduced from the magneto-optical disk 13 via the magneto-optical disk drive 12 is written in the RAM 5, and the difference information which is the difference from the next frame is written in the RAM 8. The adder circuit 14
The original image information read from the RAM 5 and the difference information read from the RAM 8 are added. The image data obtained by the addition is subjected to a known reproduction process in the reproduction process circuit 15, and then converted into an analog signal by the D / A converter 16 and output as a monitor. At this time, the added image data obtained by the addition circuit 14 is written in the RAM 5 to be prepared for the same processing as the next difference value. Such processing is repeated by sequentially loading the difference value for each frame to perform reproduction. In FIG. 1, reference numeral 11 denotes an operation unit that gives various operation instructions to the system control circuit 10. As shown in FIG. 2, the difference calculation between the reference image written in the RAM 5 and the input image input for each frame in the above embodiment is an 8-bit difference obtained by subtracting the 8-bit data of each pixel. This is a calculation for obtaining a value (in this example, the luminance signal of the input image has been converted to an 8-bit digital signal). To determine whether to start recording, the difference value is calculated for all pixels, and when the sum of these is equal to or more than the threshold value, it is determined that there is a large change in the input image, and recording is started. FIG. 3 shows a case where a vehicle arrives from the lower right corner of the reference image (with the mountain in the background). When the difference between the images becomes large at the lower right corner and the sum of the difference values exceeds the threshold, recording is performed. Start. The above determination can also be performed by obtaining the difference between the representative pixels in a predetermined block in one image. Further, when the determination is made by the occurrence of the proximity of the pixel having a large difference value in the predetermined block, for example,
As shown in FIG. 4, recording may be started by detecting that the difference value of the 8-bit data between the pixels 41A, 42A, 41B, and 42B in the predetermined block of the reference image and the input image becomes equal to or larger than the predetermined value. Yes, as shown in FIG. 5, a specific area (block) of the shooting screen (scene)
Recording can also be initiated by detecting changes in the. In FIG. 5, recording is started when there is a change in the shaded area of the input image. This is effective, for example, when it is desired to monitor only the petal portion of the flower, or when only the entrance / exit portion of the room is to be monitored. By the way, as the original signal for obtaining the above difference, various signals are used corresponding to the object, that is, according to the purpose. For example, only the luminance signal is used for an object whose change occurs in the form of an object, only the color signal is used for an object whose change occurs in the color of an object, and
Luminance and chrominance signals are used for objects where changes occur in the shape and color of the object. Here, it is possible to recognize a complicated situation change by appropriately changing each judgment condition.
As described above, when a large change (for example, the block 60 in FIG. 6) occurs in a predetermined block in the reference image, only the changed block image can be zoomed by the camera unit and enlarged and recorded. Becomes Next, a search for an image recorded on a recording medium such as the optical disk 13 will be described. As the recording data, the original image data at the time when the change occurs and the difference data after that are recorded. Therefore, by displaying only the original image data in the menu format at the same time, it is possible to search for a rough position (coarse position) and shift from the address of the difference data attached to the original image data to a high-speed reproduction operation. FIG. 7 shows an example of a specific operation mode of the above search. The search screen is recorded as original image data # 1 to # 12 corresponding to 12 divided blocks. The reference image data # 1 and each difference data are recorded in the first recording and the original image data # 2 are recorded in the second recording. Original image data # 3 and each differential data are recorded on the magneto-optical disk as a file device in the same manner in the third recording, and the original images # 1, # 2, # 3, ... Are searched. ,
When the original image # 3 matches the request, the original image # 3 is selected and reproduced, and thereafter, the original image # 3 is reproduced using the associated difference data. An example of the recording operation when a car and a bus arrive from the lower right side of a scene with mountains in the background will be described below with reference to FIG. First, as in (A), the data of the reference image is recorded, the difference value between the reference image data and the input image data is obtained, and it is determined whether the difference value is equal to or more than the threshold value. Next, as shown in (B), when the vehicle arrives at the lower right side, the difference value between the reference image data and the input image data becomes large, and when it becomes a threshold value or more, the full screen (reference image) data at this time Difference data from the immediately preceding image data for each field is recorded in a file (magneto-optical disk). As shown in (C), when the vehicle moves to the left side and leaves to the lower left side, the difference value becomes small and the recording operation is stopped. After that, the input image data (D) at the time when a fixed time, which is a relatively short time, has elapsed is recorded as new reference image data, and is compared with the input image data input thereafter. Next, as shown in (E), when the bus arrives from the lower left side, the difference value is equal to or larger than the threshold value, and recording is restarted. When the bus is stopped at the center position (F), the difference value is still equal to or more than the threshold value, so that the recording of the difference data is continued and wasteful data is recorded. Therefore, when there is no change in the difference value for each field during recording for a certain period of time or more, the recording operation is stopped,
The input image data at that time is recorded as new reference image data (G), and compared with the subsequent input image data,
Find the difference value. The above recording operation will be described with reference to FIG. 9. The image (A) is used as the reference image # 1 in the memory (RAM).
5), when the image (B) is reached, the sum of the difference values between the input image and the reference image # 1 becomes equal to or greater than the threshold value DA,
The image (B) is recorded as original image data # 1, and the difference data thereafter is also recorded. In the image (C), the sum of the difference values becomes equal to or less than DA and the recording is stopped, and the image (C) after a lapse of a fixed time is recorded in the RAM 5 as the reference image data # 2. Next, in the state of the image (E) in which the sum of the difference values is equal to or more than the threshold value, the original image data # 2 and the subsequent difference data are recorded in the file. Next, when the state of the image (F) continues for a certain period of time T, that is, when a certain period of time T elapses after there is no change in the difference value itself for each field, recording in the file is stopped, and the image at that time ( G) is recorded in the RAM 5 as reference image data # 3. 10 and 11 are flow charts showing the processing procedure of the recording operation. When the recording start detection is started, first, the reference image data is recorded in the RAM 5 (step S1) and the difference value between the reference image and the complaint image pixel data DM (i, j) and DN (i, j) is recorded by the difference circuit 6. Then, the total sum DS of the two is calculated (step S2). Where i and j
Indicates a pixel address, and in this example, i = 1
˜768 and j = 1 to 525. Next, the required D
It is determined whether S is greater than or equal to the threshold value DA (step S3), and DA
If not, the process returns to step S2, and if DA or more, file recording is started. When the file recording operation is started, as shown in FIG. 11, first, n and m, which are address parameters representing pixels, are initialized to 0 (step S4), and then n is set to 1.
Increments only (step S5). Then, the original image data DATn is read (step S6), transferred to the file device (step S7), and whether or not the transfer of the original image data for one frame is completed, that is, n = 403.
It is determined whether the number is 200 (step S8). When it is not the end of one frame, the process returns to step S5, and 1
When the number of frames is completed, m is incremented by 1 as a difference data recording process (step S9),
The difference data DATm is read (step S10),
The difference data is transferred to the file device (step S1)
1). Next, check whether the transfer for one frame is completed.
It is determined by detecting whether or not m = 403200 (step S12), and if not completed, step S9
When the end is determined, the end of the recording operation is detected (step S13), and the difference value is 0 for this end.
It is determined by the fact that the period that becomes When it is determined in step S13 that it is not finished, m = 0 is reset and the process returns to step S9. The detection of the end of recording in step S13 is performed according to FIG.
The procedure is as shown in 2. First, the timer count value T is initialized to 0 (step S15), and it is determined whether the total difference value DS is less than or equal to the threshold value DA (step S1).
6) If not, recording is stopped, and if not, it is determined whether the difference values (DM-DN) for all pixels are 0 (step S18). =
It is cleared to 0 (step S17), the process returns to step S16, the timer is counted when the difference values of all the pixels are 0 (step S19), and it is determined whether the count value T is larger than the predetermined time TE. It is determined (step S20). If T is not larger than TE, step S16
Return to the process of (3), and if it is larger, the recording is stopped. In the above embodiment, the original image data and the difference data are recorded, for example, as follows. FIG.
In, the data is a luminance value that takes a value of 0 to 255,
The original image data DM (shown for one pixel) is set to 128,
1 frame data DN is 130, 2 frame data DN
Difference value D of 1 frame data when +1 is 135
P1 is the difference value D of 2 and 2 frame data as DN-DM
P2 becomes 5 as DN + 1-DN. At the time of reproduction, it suffices to add them in reverse. One frame data is DM + DP11 = 12.
8 + 2 = 130, 2 frame data is DM + DP1 + DP2
= 128 + 2 + 5 = 135. These relationships are shown in FIG. The operation of this embodiment will be briefly described below. (1) At the start of the operation, image information (reference image information) representing one entire screen (reference image) is stored in the RAM 5. (2) The image information supplied at the field rate after the start time is compared with the reference image information by taking the sum of the differences between the pixels for each pixel over the entire screen,
When it is recognized that the total value (first information) exceeds the predetermined value, the image information (original image information # 1) representing one whole screen (original image) supplied at that time is stored in the RAM.
8 and the optical disk. (3) Information indicating the difference between the first information and the value of the image information supplied at the field rate in the field and the value in the immediately preceding field after the original image information is recorded in (2). (Second information) and are continuously monitored. This monitoring will continue as long as the device is in operation. (4) While the monitoring in (3) above is continued, the second information is sequentially recorded at the field rate on the magneto-optical disk. (5) As a result of the monitoring in (3) above, when it is recognized from the first information that the total sum value does not reach the predetermined value, the recording on the magneto-optical disk is stopped. (6) When a relatively short time has elapsed from the stop of recording in (5) above, the image information representing one entire screen supplied at that time is replaced with new reference image information (reference image information # 2). Is updated and stored in the RAM 5. (7) Monitoring of the first information and the second information continues after (6), and as a result of this monitoring, the first information
When it is recognized from the information that the total sum value exceeds the predetermined value, the image information (original image information # 2) representing one entire screen supplied at that time is updated in the RAM 8 as new original image information.・ Store and record on a magneto-optical disk. Such updating / storing of the new original image information in the RAM 8 and recording in the magneto-optical disk are performed by the above first method.
Whenever it is recognized from the information that the total sum value exceeds the predetermined value, it is repeatedly executed every time. (8) As a result of the monitoring in (3) above (thus, the monitoring in (7) above),
When it is recognized that the state in which the difference between the value in the relevant field of the image information supplied at the field rate and the value in the immediately preceding field does not reach the predetermined value has continued for a predetermined time or more, (4) Is stopped, and the image information (reference image information # 3) representing one entire screen supplied at that time is updated and stored in the RAM 5 as new reference image information. (9) Recording of the original image information in the above (2), (6), (7), and (8) is performed collectively in a predetermined area (original image information recording area) on the magneto-optical disk, or the original image information is recorded. Each time the original image information recording area is recorded without necessarily specifying it with sub information indicating that it is original image information, or it indicates where the original image information is recorded in a predetermined area on the magneto-optical disk. The information is collectively recorded, but the corresponding original image information itself is recorded without necessarily specifying the recording area. (10) At the time of reproducing the recorded information, by configuring a search screen (menu display) visually recognizable as an image for each frame based on the original image information recorded in (9) above,
It is possible to efficiently search for an image when a certain amount of motion is recognized on the screen. As described above, the image information recording apparatus according to the present invention records the image data at the time when the image to be recorded changes from the reference image and the difference data after that. Therefore, the amount of information to be recorded can be significantly reduced and the search during reproduction becomes easy. Further, when the changed state continues for a predetermined time or more, the image is used as the reference image, so that the amount of recorded information can be further reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration block diagram showing an embodiment of an image information recording apparatus according to the present invention. FIG. 2 is a diagram for explaining difference calculation between a reference image and an input image in the present embodiment. FIG. 3 is a diagram showing an example of recording start conditions in the present embodiment. FIG. 4 is a diagram showing an example of recording start conditions in the present embodiment. FIG. 5 is a diagram showing an example of recording start conditions in the present embodiment. FIG. 6 is a diagram showing an example of zoom recording of a changed portion in the present embodiment. FIG. 7 is a diagram for explaining a search operation in the present embodiment. FIG. 8 is a diagram for explaining a specific example of the recording operation in the present embodiment. FIG. 9 is a diagram for explaining a specific operation example of a recording operation in the present embodiment. FIG. 10 is a flowchart showing a recording start detection start processing procedure in the present embodiment. FIG. 11 is a flowchart showing a processing procedure for starting a file recording operation in the present embodiment. FIG. 12 is a flowchart showing a processing procedure for detection of recording end in the present embodiment. FIG. 13 is a diagram showing an example of a recording mode of original image data and difference data. FIG. 14 is a diagram showing an example of recording and reproducing modes of original image data and difference data in FIG. [Description of Reference Signs] 1 lens 2 CCD 3 imaging process circuit 4 A / D converter 5, 8 RAM 6, 9 difference circuit 7 integrating circuit 10 system control circuit 11 operation unit 12 magneto-optical disk drive 13 magneto-optical disk 14 adder circuit 15 Reproduction process circuit 16 D / A converter

Claims (1)

What is claimed is: 1. An image signal corresponding to the entire screen recorded at that time point is used as a reference signal in the time section following the recording time point, with respect to the reference signal of the image signal continuously and successively supplied from the above time point. A first monitoring means for successively and continuously obtaining first information indicating a change with time; a value representing an image at the time point of an image signal continuously and continuously supplied; and an image at the time point immediately before the time point. The second monitoring means for successively and continuously obtaining the second information indicating the difference from the indicated value, and the time point when it is recognized by the first information that the temporal change exceeds the predetermined value. Each time, the original image information recording means for recording the image information representing one whole screen supplied at that time on the information recording medium, and the time interval following the time when the original image information recording means records the image information. The differential information recording means for sequentially and continuously recording the second information, and when it is recognized by the first information that the change with time does not reach a predetermined value and / or the second information.
The difference between the value representing the image at the time point and the value representing the image at the time point immediately before of the image signal sequentially and continuously supplied by the information does not reach the predetermined value for a predetermined time or more. An image information recording apparatus comprising: a recording stop unit for stopping the recording of the second information by the difference information recording unit when recognized.