JP5106452B2 - Monitoring and recording system - Google Patents

Description

  The present invention relates to a monitoring and recording system that stores video data of a certain period or longer with good quality and without reducing the load on the system.

  Conventionally, in a monitoring (recording) recording system for capturing and recording peripheral images, the recording device is periodically overwritten in order to realize continuous operation even with a limited recording device capacity. The method of recording is often used.

  On the other hand, when such a monitoring and recording system is used, it is desired to extend the recording period since video data of the case is taken out and reproduced for a while after the occurrence of the case. For this reason, various methods have been devised for reducing the amount of video data to be recorded and extending the recordable period.

  As described above, video data is digitized and compressed, external signals that indicate an abnormality are input, recording is performed only when there is an abnormality, or recording is performed only when motion of the video data is detected and it is determined that there is movement Techniques such as performing an operation are considered. For example, Patent Document 1 discloses a method of using cue information indicating where video data such as the moment when a motion detection unit detects a moving object is recorded in order to facilitate playback confirmation. . Patent Document 2 discloses a method for determining the presence or absence of a specific abnormal action from video data and changing the recording operation content.

Japanese Patent Laid-Open No. 10-174056 International Publication No. 2006/092854 Pamphlet

  In such a conventional monitoring system, it can be expected that there is an effect of reducing the amount of video data to be recorded. However, when a motion is detected and a recording operation is performed, recording can be performed according to the content of the video data to be captured. Since the period is increased or decreased, there is a problem that it is not possible to specify a recordable period.

  For this reason, it is necessary to provide an unnecessarily large-capacity recording device in order to secure video data for a period longer than necessary, and there is a problem that the cost of the system increases. In addition, since the compression rate of the video data is set lower than a reasonable value, the video data at the time of the incident is deteriorated and it is difficult to distinguish features such as a face.

  The present invention has been made to solve the above-mentioned problems, and records video data for a certain period or more while minimizing deterioration in quality of recorded (compressed) video data and reducing the load on the system. The purpose is to obtain a monitoring and recording system that can do this.

According to a first aspect of the present invention, there is provided a monitoring and recording system comprising: an imaging unit that captures an imaging target to obtain video data; a motion detection unit that detects video motion based on the video data; and the video data is set and compressed. Data compression means for performing compression processing for compression at a rate to obtain compressed video data, recording means for recording processing for recording the compressed video data on a predetermined recording medium, and clock means for generating time information defining the current time And a recording period setting means for providing setting recording information defining a set recording period, and controlling the imaging means, the motion detection means, the data compression means, the recording means, the clock means 1 and the pre-recording period setting means A control device that performs the compression processing by the data compression means when the motion detection means detects that there is a motion of the video, The recording process is executed by recording means video data, and the setting recording is performed within the remaining capacity recordable on the predetermined recording medium based on the time information, the setting recording information and the storage capacity of the predetermined recording medium. A compression rate calculation value that can record the compressed video data for a period is calculated, and a compression rate calculation / update process for updating the set compression rate to the compression rate calculation value is executed at a predetermined timing; Includes a combination of minimum and maximum periods.

  According to a first aspect of the present invention, there is provided a monitoring recording system comprising: a control unit that controls the imaging unit, the motion detection unit, the data compression unit, the recording unit, the clock unit, and the previous recording period setting unit; The compression rate calculation value that can record the compressed video data for the set recording period is calculated, and the compression rate calculation / update process for updating the set compression rate to the compression rate calculation value is repeatedly executed at a predetermined timing.

  Therefore, even if the data recording amount of the compressed video data on the predetermined recording medium fluctuates from the initial assumption, the monitoring recording system according to claim 1 obtains the compression ratio calculation value so as to adapt to the fluctuation amount. Therefore, the optimum compression rate calculated value can always be set as the set compression rate within the recordable range of the set recording period.

  Further, since the compression rate calculation / update process is executed in consideration of the storage capacity of the predetermined recording medium, it is not necessary to unnecessarily increase the storage capacity of the predetermined recording medium, and the system includes the predetermined recording medium. The overall load will not increase.

  As a result, the present invention according to claim 1 can reliably record the compressed video data within the set recording period while minimizing the deterioration of the quality of the compressed video data to be recorded and reducing the load on the system. There is an effect that can be done.

It is a block diagram which shows the structure of the monitoring recording system which is Embodiment 1 of this invention. 3 is a flowchart illustrating a video data recording method according to the first embodiment. 3 is a flowchart showing the processing content of a compression rate changing process according to the first embodiment. 3 is a graph showing the relationship between the amount of video data recorded by the recording method of Embodiment 1 and time. 6 is a graph showing the relationship between the amount of video data recorded by the recording method of Embodiment 2 and time. 14 is a graph showing the relationship between the amount of video data recorded by the prerequisite technology of Embodiment 3 and time. 12 is a graph showing the relationship between the amount of recorded video data and time according to the third embodiment. It is a block diagram which shows the structure of the monitoring recording system which is Embodiment 4 of this invention.

<Embodiment 1>
FIG. 1 is a block diagram showing a configuration of a monitoring recording system according to Embodiment 1 of the present invention.

  As shown in the figure, the monitoring recording system 1 according to the first embodiment includes an imaging means 11, a motion detection means 12, a data compression means 13, a recording means 14, a recording medium 15, a clock means 16, a recording period setting means 17, and The controller 18 is configured. The recording medium 15 can be provided outside the monitoring recording system 1.

  The imaging unit 11 receives the imaging target data SD1 that is an imaging target, captures the imaging target data SD1, and obtains video data VD1.

  The motion detector 12 detects the motion of the video (presence / absence) based on the video data VD1. The data compression means 13 compresses the video data VD1 at a set compression rate to obtain compressed video data CVD1. The recording unit 14 records the compressed video data CVD1 on the recording medium 15.

  The clock means 16 has a clock function, acquires the current time, and generates time information that defines the current time. The recording period setting means 17 sets and stores a set recording period, and gives setting recording information defining this set recording period to the control device 18. The control device 18 controls these means 11 to 17 (excluding the recording medium 15).

  In FIG. 1, a solid black arrow represents a flow of video data (video data VD1, compressed video data CVD1) in the monitoring recording system 1. As indicated by the black arrow, the video data VD1 acquired by the imaging unit 11 is transferred to the motion detection unit 12 and the data compression unit 103, and the compressed video data CVD1 compressed by the data compression unit 13 is further recorded by the recording unit 14. It is recorded on the recording medium 15. Also, the white arrow indicates data transmission / reception of a portion that is not necessary as internal processing. That is, since the imaging target data SD1 is data obtained from the outside, and the recording medium 15 can be provided outside, it is indicated by a white arrow.

  On the other hand, the broken line in FIG. 1 represents the connection of the control system, and the entire monitoring recording system 1 is controlled by controlling the means 11 to 17 (excluding the recording medium 15) by the control device 18. Note that the control includes transmission / reception of control data such as provision of setting record information of the recording period setting means 17 to the control device 18.

  The motion detection means 12 is shown separately from the data compression means 13 for the sake of simplifying the description of the functional configuration of the monitoring recording system 1, but the functions necessary for the operations of the motion detection means 12 and the data compression means 13. Of these, the same function may be shared.

  For example, when the video data VD1 is compressed in the MPEG format, it has screen information at a plurality of times, the difference information is extracted, and the compressed data of the video data is composed of a combination of standard screen information and difference information. In this case, the function of the data compression means 13 is detected by performing a determination that there is no movement when the amount of difference information is smaller than a certain amount, and vice versa. It can be used as a function of the means 12.

  In the surveillance recording system 1, audio data may be recorded together with video data. However, in the first embodiment, only video data will be described. Note that even when audio data is recorded together with video data, the video data is in the same form, and the audio data can be configured in almost the same form as the handling of the video data. Of course.

  Further, depending on the configuration of the monitoring recording system, the recording unit 14 and the recording medium 15 may be configured by the same unit, or the recording medium 15 may be replaced and configured separately from the recording unit 14. In the monitoring recording system 1 according to the first embodiment, a recording unit 14 as a unit for performing a recording process and a recording medium 15 as a medium in which actual video data (compressed video data CVD1) is stored are shown separately.

  FIG. 2 is a flowchart showing a video data recording method by the monitoring recording system 1 according to the first embodiment. Hereinafter, the video data recording procedure by the monitoring recording system 1 will be described with reference to FIG.

  First, in step S1, the imaging means 11 acquires video data VD1 by imaging the imaging target data SD1.

  Next, in step S <b> 2, the imaging unit 11 passes the video data VD <b> 1 to the motion detection unit 12.

  Thereafter, in step S3, the motion detection means 12 determines the presence or absence of video motion based on the video data VD1, and returns to step S4 if there is motion (YES), or returns to step S1 if there is no motion (NO). .

  As described above, in step S3, when it is determined that the video data VD1 is in motion compared with the previous video data VD1 (obtained from the imaging unit 11) (YES), the processing after step S4 is performed. If the previous video data VD1 does not exist in the initial operation, it is determined that there is a motion, and the processes after step S4 are performed.

  On the other hand, if it is determined that the difference from the previous video data VD1 is not significant and there is no movement (NO), the process returns to step S1 again, and the video data VD1 acquisition process of step S1 is executed. Thereafter, the processes in steps S1 to S3 are repeated until YES is determined in step S3.

  By this processing of the motion detection means 12, for example, when there is continuous background data that does not move as the imaging target data SD1, video data VD1 that does not need to be recorded for monitoring is not recorded (as compressed video data CVD1). Therefore, the capacity of the recording medium 15 can be used effectively.

  In step S <b> 4 that is executed when YES in step S <b> 3, the imaging unit 11 passes the video data VD <b> 1 to the data compression unit 13.

  Thereafter, in step S5, the data compression means 13 compresses the video data VD1 to obtain compressed video data CVD1. The compression process is performed using a preset compression rate. Note that, in the algorithms for moving image compression such as MPEG2 format and MPEG4 format, even if the same set compression rate is set, the amount of the compressed video data CVD1 varies depending on the contents of the original video data VD1, and does not become a constant value. Therefore, the set compression rate does not generally indicate the ratio (VD1 / CVD1) of the video data amount before and after compression.

  Next, in step S6, the recording unit 14 records the compressed video data CVD1 on the recording medium 15.

  Thereafter, in step S7, it is determined whether to end under the control of the control device 18 (YES) or not (NO). If YES, the process ends. If NO, the process from step S1 is performed again. repeat.

  Since the monitoring recording system 1 needs to continuously monitor, normally, the processing from step S1 is repeated under the control of the control device 18. That is, NO is obtained in step S7.

  In this specification, the state in which the operation from step S1 to step S7 in FIG. 2 is continued is defined as “the operation is continued”. That is, if the operation of any of steps S1 to S7 is continued, including the case where steps S1 to S3 are repeated without recording (compressed) video data in step S6, whether or not video data is recorded. Regardless, it is defined as “operation continues”. As described above, the operation may be described as “operation is continuing” in distinction from the operation of recording the video data by the recording unit 14. On the other hand, if YES is determined in step S7 due to some external factor or the like and the control device 18 determines to stop the operation, it is defined as “stop the operation”.

  FIG. 3 is a flowchart showing the processing contents of the compression rate calculation / update processing of the monitoring recording system 1 according to the first embodiment. Note that the processing shown in FIG. 3 is performed by controlling the operation of means 11 to 17 (excluding the recording medium 15) under the control of the control device 18 itself and the control of the control device 18. Hereinafter, the processing procedure of the compression rate calculation / update processing of the monitoring recording system 1 will be described with reference to FIG.

  First, in step S11, the clock unit 16 notifies the control device 18 of a process start notification instructing the start of the compression ratio calculation process. The processing start notification time (predetermined timing) may be set periodically such as every day, or may be arbitrarily set according to the operation status such as the frequency of recording video data.

  Also, when the set compression rate of the data compression unit 13 is reflected, it is necessary to stop the recording of the (compressed) video data. However, if the recording of the video data is continued and cannot be immediately reflected, the motion of the video data is changed. After the recording of the video data is stopped due to a cause such as disappearance, the compression rate calculation processing after step S12 may be started. That is, the processing start notification by the clock means 16 is performed, and when the recording of the video data is stopped, the processing after step S12 may be started.

  Next, in step S <b> 12, the set recording period specified in the set recording information from the recording period setting unit 17 is acquired. The set recording period may be a fixed value in the monitoring recording system 1, or an input means from the user to the monitoring recording system 1 may be separately provided so that the setting recording period can be changed as appropriate.

  In step S13, which is performed in parallel with step S12, the recording unit 14 acquires the start time of recording start. The starting time may be the time when the oldest data of the video data (compressed video data CVD1) recorded on the recording medium 15 is recorded, or recording at a specific location such as the top address of the recording medium 15 It is good also as the time which implemented. The recording time of the data recorded on the recording medium 15 may be recorded on the recording medium 15 or may be held by the control device 18 in a dedicated memory (not shown in FIG. 1).

  In the latter case, the start time is updated when recording on a specific location of the recording medium 15 is executed. In the latter case, the processing of step S13 is simplified, but the amount of recorded video data that is the target of compression rate calculation for a time set later than the original calculation time (oldest data recording time). Therefore, the accuracy of calculating the compression ratio tends to be reduced accordingly.

  Note that the monitoring recording system 1 is required to record the compressed video data CVD1 based on the imaging target data SD1 on the recording medium 15 from the counting time to the setting recording period depending on the counting time and the setting recording period. .

  On the other hand, in step S14 performed in parallel with steps S12 and S13, the current time defined in the current time information provided by the clock means 16 is acquired.

  When step S12 and S13 are completed, in step S15, the amount of video data (recorded video) recorded after the start time from the recording means 14 based on the information (set recording period and start time) acquired in step S12 and step S13. Data amount) and the capacity of the recording medium 15 (recording medium capacity).

  Then, in step S16 executed after step S15, the control device 18 uses the recorded video data amount and the recording medium capacity acquired in step S15 to record an area where video data before the start time is recorded or an unrecorded area. The remaining capacity that can be recorded in the recording medium 15 in the future is calculated.

  On the other hand, when all steps S12 to 14 are completed, in step S17, a necessary recording period that is a period to be recorded in the future is calculated based on the set recording period, the starting time, and the current time acquired in steps S12 to 14. That is, the difference recording period from (the time after the set recording period from the start time) to the current time is the necessary recording period.

  When steps S16 and S17 are completed, in step S18, an appropriate compression rate is calculated as a compression rate calculation value based on the remaining capacity acquired in step S16 and the necessary recording period acquired in step S17.

  When an arbitrary value can be designated as the compression rate calculation value, the compression rate calculation value is simply set to approach the recording rate obtained from the quotient (RV / NT) of the remaining capacity (RV) and the necessary recording period (NT). It only has to be calculated. When selecting from a discrete set value as the compression rate calculation value, the installation value closest to the recording rate obtained in the same manner may be selected as the compression rate calculation value.

  Next, in step S19, whether or not the compression rate calculation value calculated in step S18 is the same as the compression rate calculation value previously reflected (reflected) in step S19, that is, the currently set compression rate (YES) / not Determine (NO).

  If the compression rate calculation value is the same as the set compression rate (YES in step S18), the subsequent processing is not executed and the processing returns to step S11 and waits until the next compression rate calculation processing. On the other hand, if the calculated compression rate is different from the set compression rate (NO in step S18), the process proceeds to step S20.

  In step S20, it is determined whether or not to execute the process of reflecting the set compression rate based on the compression rate calculation value obtained in step S18 (YES) / whether (NO). When changing the set compression rate of the video data compression processing by the data compression means 13, depending on the type of compression method of the data compression means 13, it may be necessary to stop the compression processing. Must stop.

  As shown in FIG. 2, since the monitoring recording system 1 performs recording only when there is motion in the video data by the motion detection means 12, when the compression rate calculated value is to be reflected as the set compression rate Even if the recording process is executed, if the user waits for a while, the motion of the video data is lost and the recording process can be expected to stop. That is, NO is obtained in step S3 in FIG. 2, and a period in which steps S1 and S2 are repeated can be expected.

  Therefore, even if the calculation of the compression ratio calculation is performed until this time, it does not matter so much in the system operation of the monitoring recording system 1. Therefore, immediately before the execution of step S20, when the monitoring recording system 1 is executing the recording process of the compressed video data CVD1 on the recording medium 15, the process returns to step S11 without reflecting the compression rate calculation value. This is because, in such a case, it is appropriate to wait for the next opportunity to reflect the compression rate calculation value without reflecting the compression rate calculation value immediately. Note that it is possible to increase the possibility that the recording process is stopped during the period of step S20 by giving a time margin to the determination period of step S20.

  As described above, if NO in step S20, the processes in steps S11 to S19 are performed again. That is, steps S11 to S19 are repeated until YES is executed in step S20.

  On the other hand, when the compression rate calculation value is reflected in the monitoring recording system 1 as the set compression rate in step S20, the monitoring recording system 1 continues to perform this set compression until the compression rate calculation value is newly reflected as the set compression rate. Continue operation at a rate.

  After YES in step S20, in step S21, the presence or absence of termination is checked. Step S21 is normally NO when the operation of the monitoring recording system 1 is continued, and the process returns to step S11. Thereafter, the processes in steps S11 to S21 are repeatedly executed until YES is determined in step S21 (the operation end of the monitoring recording system 1 or the like).

  As described above, the monitoring recording system 1 according to the first embodiment uses the control device 18 that controls the units 11 to 17 (excluding the recording medium 15) to calculate the compression rate that can be recorded in the recording medium 15 within the set recording period. , And the compression rate calculation / update process for updating the set compression rate of the data compression unit 13 to the compression rate calculated value is repeatedly executed at the timing (predetermined timing) when the processing start notification is performed in step S11.

  Therefore, even if the data recording amount of the compressed video data on the recording medium 15 fluctuates from the initial assumption, the control device 18 of the monitoring recording system 1 according to the first embodiment calculates the compression rate so as to adapt to the fluctuation amount. Since the set compression rate can be updated by obtaining the value, it is possible to always set the optimum set compression rate within the recordable range in the set recording period.

  That is, the monitoring recording system 1 of the first embodiment calculates the remaining capacity of the recordable recording medium 15 and the necessary recording period, for example, periodically, and resets the set compression rate based on these information. If implemented, it is possible to always set an appropriate set compression rate regardless of the capacity of the recording medium 15 constituting the system. As a result, the life of the entire monitoring recording system 1 can be extended by the amount that can be appropriately reduced in the amount recorded on the recording medium 15.

  For example, when the amount of compressed video data recorded on the recording medium 15 is larger than originally assumed, the compression rate calculation / update process for increasing the set compression rate from the middle is performed to ensure that the set recording period falls within the set recording period. The recording medium 15 can be adjusted so that it can be recorded. On the other hand, when the amount of compressed video data recorded on the recording medium 15 is smaller than originally assumed, the image quality at the time of reproduction is improved by performing compression ratio calculation / update processing that lowers the set compression ratio from the middle. Since compressed video data can be recorded, it becomes easy to distinguish features such as a face from a video at the time of occurrence of a case based on the compressed video data.

  In addition, since the compression rate calculation / update process is executed in consideration of the storage capacity of the recording medium 15, it is not necessary to unnecessarily increase the storage capacity of the recording medium 15, and the load on the entire system including the recording medium 15 There is an effect that the stem can be constructed at a low cost without increasing.

  As a result, the monitoring recording system 1 according to the first embodiment reliably records the compressed video data within the set recording period while minimizing the deterioration of the quality of the compressed video data to be recorded and reducing the load on the system. There is an effect that can be.

  In addition, since it is not necessary to set the compression rate higher than necessary in advance, the compression rate of the recorded video data is very high and the quality is low, so the problem that the features in the video data at the time of the incident cannot be caught is surely ensured. There is an effect that can be avoided.

  In the first embodiment, the setting target of the compression rate calculation value has been described as the setting compression rate of the data compression unit 13, but the reference for determining whether or not the motion detection unit 12 detects motion is also set as the setting target. It is also possible to configure as described above. The motion detection means 12 compares at least one previous video data with the video data to be processed, and determines the presence or absence of motion depending on whether the difference is a certain amount or not. At this time, by raising and lowering the reference for determining the presence or absence of motion detection, it is possible to exhibit the effect of changing the amount of video data in the same way as changing the set compression rate of the data compression means 13 to high / low. it can. If comprised in this way, there exists an effect which can implement | achieve reducing the quantity of the video data recorded, maintaining the quality of the video data of each required one high.

<Embodiment 2>
The monitoring recording system 2 (not shown) in the second embodiment of the present invention has the same configuration as that of the first embodiment shown in FIG. However, the difference is that the set recording period that can be set by the recording period setting means 17 is not limited to one period but can be specified in the range between the minimum period and the maximum period. That is, the setting record information given from the recording period setting means 17 defines a setting recording period consisting of a combination of a minimum period and a maximum period.

  FIG. 4 shows the recording (compression) when the setting recording period specified by the setting recording information of the recording period setting means 17 is set only at a specific time as in the monitoring recording system 1 of the first embodiment. ) A graph showing the relationship between the amount of video data and time.

  In FIG. 4, compression rate change times TC1 to TC7 represent times when it is determined that the set compression rate of the data compression means 13 should be changed from the remaining capacity that can be recorded in the future and the required recording period. That is, in the flowchart of FIG. 3, it means the YES execution time of step S20.

  An ideal actual value line L0 indicated by a broken line indicates an ideal actual value line connecting the remaining capacity of the recording medium 15 and the set required recording period TP. In the process of continuing the operation of the system, When the ideal actual value line L0 is deviated, in principle, it is necessary to reset the compression rate. In the example shown in FIG. 4, the compression rate changes when the difference between the actual video data amount line L1 indicating the video data amount recorded on the recording medium 15 after the recording start time TS and the ideal actual value line L0 is relatively large. It is determined that the times are TC1 to TC7, and the set compression rate is changed.

  On the other hand, when changing the set compression rate, the recording process may be stopped as described above.

  In FIG. 5, as in the monitoring recording system 2 of the second embodiment, the setting recording period specified by the setting recording information of the recording period setting unit 17 is specified as the minimum necessary recording period TPA and the maximum necessary recording period TPB (minimum period. And the maximum period) is a graph showing the relationship between the amount of recorded video data and time.

  In FIG. 5, compression rate change times TC11 and TC12 represent times when it is determined that the set compression rate of the data compression unit 13 should be changed from the remaining capacity that can be recorded in the future and the required recording period. That is, in the flowchart of FIG. 3, it means the YES execution time of step S20.

  A minimum ideal actual value line L0A indicated by a broken line indicates an ideal minimum actual value line connecting the remaining capacity of the recording medium 15 and the set minimum required recording period TPA. Similarly, the maximum ideal actual value line indicated by the broken line is shown in FIG. The actual value line L0B indicates an ideal maximum actual value line that connects the remaining capacity of the recording medium 15 and the set maximum required recording period TPB.

  In the monitoring recording system 2 according to the second embodiment, the actual video data amount line L2 indicating the video data amount recorded on the recording medium 15 after the recording start time TS in the process of continuing operation is the maximum ideal actual value. It suffices if it falls within the ideal region R0 sandwiched between the line L0B and the minimum ideal actual value line L0A, and if it deviates from the ideal region R0, in principle, the compression rate needs to be reset.

  In the example shown in FIG. 5, the time when the actual video data amount line L2 indicating the video data amount recorded on the recording medium 15 after the recording start time TS deviates from the ideal region R0 is determined as the compression rate change times TC11 and TC12. It will be.

  As described above, the monitoring recording system 2 according to the second embodiment can specify the set recording period in the range from the minimum period to the maximum period, and therefore can suppress the change frequency of the set compression rate to the minimum necessary.

  That is, in the monitoring recording system 2 of the second embodiment, the operation is continued without changing the set compression rate of the data compression means 13 unless the recording amount of the compressed video data deviates from the designated range (ideal area R0). It becomes possible.

  For this reason, the monitoring recording system 2 of Embodiment 2 has the effect that the compression rate change frequency can be suppressed compared with the monitoring recording system 1 of Embodiment 1. In particular, when the video data is not moved for a while and the video data is suddenly moved from a specific date, the monitoring recording system 1 tends to increase the frequency of changing the set compression rate significantly. However, even in such a case, the monitoring recording system 2 of the second embodiment can minimize the frequency of the operation of changing the set compression rate to the minimum necessary.

  In the operation of changing the set compression rate, for example, a series of operations for stopping the compression operation, changing the set compression rate, and starting the compression operation again is necessary. During this time, the compressed video data cannot be recorded. Since there is a concern about harmful effects, the monitoring recording system 2 of the second embodiment has an effect of improving the performance as the monitoring recording system by reducing the frequency of changing the set compression rate.

<Embodiment 3>
The monitoring recording system 3 (not shown) in the third embodiment of the present invention is the same as the configuration of the first embodiment shown in FIG. Further, the second embodiment is configured such that the set recording period defined as the set recording information of the recording period setting unit 17 can be specified in the range between the minimum period and the maximum period without being set as one period. It is the same.

  The third embodiment is different from the first and second embodiments in that the set compression ratio that can be set in the data compression means 13 is several discrete values (a plurality of discrete compression ratios). .

  In addition, in the third embodiment, one of the minimum required recording period and the maximum required recording period set by the recording period setting unit 17 is automatically set according to a value that can be set as the plurality of discrete compression rates. The difference is the configuration.

  As in the third embodiment of the present invention, when the recording period is specified in the range between the minimum period and the maximum period, as in the second embodiment, there is an effect of reducing the frequency of the operation of changing the set compression rate. Already explained.

  On the other hand, when the set compression rate that can be set in the data compression unit 13 is not an arbitrary value but can be set within a range of a plurality of discrete compression rates, the set compression rate is limited by the variation of the set compression rate. The effect of reducing the frequency of change operations may be reduced.

  Assume that the minimum period set by the recording period setting means 17 is A and the maximum period is B. Also, a plurality of discrete compression ratios that can be set as the set compression ratios are defined as compression ratios Px (x = 1 to n). The compression ratios P1 to Pn satisfy the following expressions (1) and (2). The unit of the compression rate Px is shown as a compression rate as [bytes / second]. That is, in the compression ratios P1 to Pn, the compression ratio P1 indicates the maximum compression ratio, and the compression ratio Pn indicates the minimum compression ratio.

  Here, it is assumed that the remaining capacity of the recording medium 15 is Z. The unit of A and B is [second], the unit of Px is [byte / second] as described above, and the unit of Z is [byte]. Then, it is assumed that Z, A, B, P1, and Pn satisfy the following expression (3).

  In this case, if the compression rate Px is continuously set to the minimum compression rate Pn, there is a possibility that it will be shorter than the minimum period A. Conversely, if the compression rate is continuously set to the maximum compression rate P1, the maximum period B is set. Suppose there is a possibility of exceeding.

  A case where the following expression (4) is satisfied is considered. In this case, the ratio of the numerical values that can be set for the set compression rate is larger than the ratio (B / A) between the maximum period B and the minimum period A.

  Therefore, in the worst case, there is a concern that the following formula (5) cannot be satisfied for any y (y = 1 to n).

  Hereinafter, a case where a plurality of discrete compression ratios and minimum and maximum (necessary recording) periods that do not satisfy Expression (5) are set will be described as a prerequisite technique of the third embodiment.

  FIG. 6 shows, as a prerequisite technology of the third embodiment, the setting recording period specified by the setting recording information by the recording period setting unit 17 is set in a range by a combination of the minimum necessary recording period TPA and the maximum necessary recording period TPB. 6 is a graph showing the relationship between the amount of recorded video data and time.

  In FIG. 6, compression rate change times TC21 to TC25 represent times when it is determined that the set compression rate of the data compression unit 13 should be changed from the remaining capacity that can be recorded in the future and the required recording period. That is, in the flowchart of FIG. 3, it means the YES execution time of step S20.

  Further, the minimum ideal actual value line L0A indicated by a broken line indicates an ideal minimum actual value line as in the second embodiment, and the maximum ideal actual value line L0B indicated by a broken line is similar to that in the second embodiment. The ideal maximum actual value line is shown.

  In the base technology of the third embodiment, in the process of continuing the system operation, the actual video data amount line L30 indicating the video data amount recorded on the recording medium 15 after the recording start time TS is the maximum ideal actual value. It suffices if it falls within the ideal region R0 sandwiched between the line L0B and the minimum ideal actual value line L0A, and if it deviates from the ideal region R0, in principle, the compression rate needs to be reset.

  In the example shown in FIG. 6, the time when the actual video data amount line L2 indicating the video data amount recorded on the recording medium 15 after the recording start time TS deviates from the ideal region R0 is determined as the compression rate change times TC21 to TC25. It will be.

  As shown in FIG. 6, since the actual video data amount line L30 is not stable regardless of any of the plurality of discrete compression ratios and tends to frequently deviate from the ideal region R0, the set compression ratio is inevitably set. The frequency of changes increases.

  For example, when the compression rate Py is set, the actual video data amount line L30 exceeds the minimum ideal actual value line L0A, and the compression rate Py is increased by one rank at the compression rate change time TC22 to be changed to the compression rate P (y-1). . Then, the compression rate P (y−1) is too high, and this time falls below the maximum ideal actual value line L0B, and at the compression rate change time TC23, the compression rate P (y−1) is lowered by one rank and the compression rate is restored. Py needs to be changed. Thereafter, similarly, it is necessary to change to the compression rate P (y−1) and the compression rate Py at the compression rate change times TC24 and TC25.

  Thus, in the base technology of the third embodiment, there is a concern that the compression rate Py that satisfies the above formula (5) does not exist and the process of resetting the compression rate Py is repeated.

  The monitoring and recording system 3 according to the third embodiment is intended to eliminate the material of concern for the base technology. That is, the compression ratios P1 to Pn, the minimum necessary recording period TPA (A), and the maximum necessary recording period TPB (B) by the monitoring recording system 3 satisfy the following formula (6). Equation (6) is premised on satisfying Equation (2).

  If setting is made so as to satisfy the above equation (6), there is a compression rate Py that can always satisfy the equation (5) at a certain y (y = 1 to n). Therefore, for example, in the recording period setting means 17, only the minimum necessary recording period TPA (A) of the recording period is set in advance, and the maximum necessary recording period TPB (B) is obtained by the following equation (7). A variable setting is conceivable.

  In the monitoring and recording system 3 according to the third embodiment, the primary purpose is to be configured so that a period longer than the set period can be recorded, and only the minimum period A (minimum required recording period TPA) is fixed. There is no problem even if configured.

  In the above example (formula (7)), the minimum period A is specified in advance and the maximum period B (maximum required recording period TPB) is calculated. However, depending on the conditions that the system should satisfy, the maximum period B is specified in advance. However, the minimum period A may be calculated.

  FIG. 7 shows that the compression ratios P1 to Pn, the minimum required recording period TPA (A), and the maximum required recording period TPB (B) satisfy the above formula (7), as in the monitoring recording system 3 of the third embodiment. The period setting means 17 follows the formula (7), and the minimum necessary recording period TPA is fixed, but the maximum necessary recording period TPB is automatically set by the recording period setting means 17 according to the situation (contents of the compression ratios P1 to Pn). It is a graph showing the relationship between the amount of recorded video data and time when variably setting.

  In FIG. 7, compression rate change times TC31 and TC32 represent times when it is determined that the set compression rate of the data compression unit 13 should be changed from the remaining capacity that can be recorded in the future and the required recording period. That is, in the flowchart of FIG. 3, it means the YES execution time of step S20.

  Further, the minimum ideal actual value line L0A and the maximum ideal actual value line L0B indicated by broken lines are the same as those in the base technology of FIG.

  In the monitoring and recording system 3 of the third embodiment, in the process of continuing operation, the actual video data amount line L3 indicating the video data amount recorded on the recording medium 15 after the recording start time TS is the maximum ideal actual value. It suffices if it falls within the ideal region R0 sandwiched between the line L0B and the minimum ideal actual value line L0A, and if it deviates from the ideal region R0, in principle, the compression rate needs to be reset.

  In the example shown in FIG. 7, the time when the actual video data amount line L3 indicating the video data amount recorded on the recording medium 15 after the recording start time TS deviates from the ideal region R0 is determined as the compression rate change times TC31 and TC32. It will be.

  As described above, in the monitoring recording system 3 according to the third embodiment, if the actual video data amount does not deviate from the designated range (ideal region R0), the operation is continued without changing the set compression rate of the data compression unit 13. It becomes possible. For this reason, as in the second embodiment, it is possible to minimize the frequency of the operation of changing the set compression rate and to improve the performance as the monitoring recording system.

  Furthermore, the monitoring recording system 3 according to the third embodiment configures the data compression means 13 and the like relatively inexpensively because the compression rate calculation value includes any one of a plurality of discrete compression values set as discrete values. be able to.

  A value that can set the data compression means 13 as a set compression rate has a compression function (satisfies equation (2)) by a plurality of non-consecutive discrete compression rates, such as 1 / integer of the generated clock timing When implemented as a data compression means, it can be constructed at a relatively low cost.

  Furthermore, the monitoring recording system 3 of the third embodiment records at least one of the minimum required recording period TPA and the maximum required recording period TPB by the recording period setting means 17 based on the compression ratios P1 to Pn by the data compression means 13. By variably setting by the period setting means 17, even if the data compression means 13 exhibits a compression function with a plurality of discrete compression ratios, the effect that the frequency of changing the set compression ratio can be suppressed to the minimum necessary. Play. Therefore, even if the data compression means 13 has an inexpensive configuration, it is possible to appropriately perform the compressed video data recording operation.

  In addition, in the compression ratios P1 to Pn, when the expression (2) is not satisfied, by adopting “(Py) / (Py−1)” which takes the minimum value at y = 1 to (n−1), Instead of equation (8), the following equation (8) may be satisfied.

  That is, the recording period setting means 17 uses a predetermined two discrete compression ratios adjacent to each other among a plurality of discrete compression ratios based on one period that is one of the minimum period and the maximum period, and the minimum period and the maximum period. What is necessary is just to set the other period which is the other among the maximum periods.

<Embodiment 4>
FIG. 8 is a block diagram showing a configuration of a monitoring recording system according to Embodiment 4 of the present invention.

  As shown in the figure, the monitoring and recording system 4 of Embodiment 4 includes imaging means 11A and 11B, motion detection means 12A and 12B, data compression means 13A and 13B, recording means 14, recording medium 15, clock means 16, The recording period setting means 17 and the control device 18 are included.

  The imaging units 11A and 11B receive the imaging target data SD1A and SD1B, and capture the imaging target data SD1A and SD1B to obtain video data VD1.

  The motion detectors 12A and 12B detect video motion based on the video data VD1A and VD1B.

  The data compression means 13A and 13B compress the video data VD1A and VD1B at a set compression rate, respectively, to obtain compressed video data CVD1A and CVD1B. The recording means 14 records the compressed video data CVD1A and CVD1B on a common recording medium 15.

  The clock means 16 has a clock function and acquires the current time. The recording period setting means 17 sets a setting recording period, and stores setting recording information that defines the set recording period. The control device 18 controls these means 11 (11A and 11B) to 17 (excluding the recording medium 15).

  In FIG. 8, solid black arrows represent the flow of video data (video data VD1A and VD1B, compressed video data CVD1A and CVD1B) in the monitoring recording system 4. As indicated by the black arrows, the video data VD1A and VD1B acquired by the imaging units 11A and 11B are transferred to the motion detection units 12A and 12B and the data compression unit 103, and further compressed by the data compression units 13A and 13B. Video data CVD1A and CVD1B are recorded on the recording medium 15 by the recording means 14. Also, the white arrow indicates data transmission / reception of a portion that is not necessary as internal processing.

  On the other hand, the broken line in FIG. 8 represents connection of the control system, and the control device 18 controls the means 11 (11A, 11B) to 18 to control the entire monitoring recording system 4.

  Thus, the combination of the imaging means, motion detection means, and data compression means is divided into two systems (system A by the imaging means 11A, motion detection means 12A and data compression means 13A, imaging means 11B, motion detection means 12B and data compression. The point which gave the system | strain B) by the means 13B differs from Embodiment 1- Embodiment 3. FIG.

  The procedure showing the procedure for recording the video data of the monitoring recording system 4 follows the flowchart shown in FIG. 2 for the system A and the system B as in the first embodiment. The recording unit 14 receives the compressed video data CVD1A and CVD1B from the data compression units 13A and 13B and records them on the recording medium 15. Since the recording request timing from the system A or the system B is not the same, the recording unit 14 is configured to appropriately record these two systems of video data (compressed video data CVD1A and CVD1B).

  The procedure relating to the compression rate calculation / update processing of the monitoring recording system 4 also follows the flowchart shown in FIG. However, in the process which calculates the compression rate calculation value of step S18, it comprises so that the compression rate set to the system A and the system B may be calculated simultaneously. Thereafter, in step S19 and step S20, the system A or system B is configured to be implemented individually.

  In the procedure relating to the compression rate calculation / update process, each of the system A and the system B may be performed independently. In this case, for example, in calculating the compression ratio of the system A, the set compression ratio between the system A and the system B is added by adding the set compression ratio of the system B and the immediately preceding set compression ratio set immediately before as the input information. In addition to avoiding a problem that the rate is set in a different direction, it is possible to apply resetting of the compression rate at an appropriate timing for each system. Note that the setting compression rate is set differently between the system A and the system B, for example, the system A changes the setting compression rate regardless of whether the system B changes in the direction of increasing the setting compression rate. It means setting in the direction of lowering. This is because the imaging target data SD1A and SD1B of the system A and the system B are often in a positional relationship close to each other, and it is desirable that the direction of the compression rate be common to the systems A and B.

  A system A including the monitoring and recording system 4, the imaging unit 11A (first imaging unit), the motion detection unit 12A (first motion detection unit), and the data compression unit 13 (first data compression unit) according to the fourth embodiment. One independent first video data processing system is used. Further, the system B including the imaging unit 11B (second imaging unit), the motion detection unit 12B (second motion detection unit), and the data compression unit 13 (second data compression unit) is used as one independent second video. It is a data processing system.

  Therefore, even when there are a plurality of shooting targets and the types of compressed video data to be recorded increase, the compressed video data in the video data processing system consisting of the system A and the system B can be reliably recorded within the set recording period. . That is, it is possible to easily add an image pickup unit, a motion detection unit, and a data compression unit while maintaining the purpose of the original monitoring and recording system.

  That is, the monitoring recording system 4 of the fourth embodiment uses the same processing as that of the first embodiment, and the necessary recording periods set for the system A and the system B, respectively, even when capturing video data of a plurality of systems. There is an effect that it is possible to configure a surveillance recording system that reliably records video data and increases the quality of the video data as much as possible.

  In the conventional monitoring and recording system, since the amount of video data to be recorded increases when an imaging means is added, it is more difficult to estimate the period of video data to be recorded and held. However, in the monitoring recording system 4 according to the fourth embodiment, an appropriate compression ratio calculation value is calculated for each of the system A and the system B based on the remaining recordable capacity and the necessary recording period, and therefore, depending on the number of imaging units. Accordingly, it is possible to realize recording of the designated required recording period, and it is possible to easily change the configuration of the monitoring recording system.

  In the fourth embodiment, it is needless to say that the same effects as those of the second embodiment can be obtained by providing a configuration corresponding to the recording period setting means 17 of the second embodiment for each of the system A and the system B.

  Similarly, in the fourth embodiment, the same effects as those of the third embodiment can be obtained by providing a configuration corresponding to the data compression unit 13 and the recording period setting unit 17 of the third embodiment for each of the system A and the system B. Of course.

  In the fourth embodiment, two systems (system A and system B) are shown as a plurality of systems of video data, but it is of course possible to realize a configuration of three systems or more without departing from the scope of the present invention. is there. That is, it includes first to N-th (N ≧ 3) imaging means, first to N-th motion detection means, and first to N-th data compression means, and i-th (i = 1 to N). ) Imaging means, i-th imaging means, and i-th data compression means can be configured to have independent video data processing systems.

  For example, the present invention can be applied to any monitoring recording system in which monitoring recording is performed using video data and a setting unit for setting a compression rate of a recording data compression unit is provided.

  1, 4 Monitoring recording system 11, 11, 11A, 11B Image capturing means 12, 12, 12A, 12B Motion detection means 13, 13, 13A, 13B Data compression means, 14 Recording means, 15 Recording medium, 16 Clock means, 17 Recording period setting means 18 Control device.

Claims (3)

An imaging means for capturing video data to obtain video data;
Motion detection means for detecting the motion of the video based on the video data;
Data compression means for compressing the video data at a set compression rate to obtain compressed video data;
Recording means for performing recording processing for recording the compressed video data in a predetermined recording medium;
A clock means for generating time information defining the current time;
A recording period setting means for giving setting recording information defining a setting recording period;
A controller for controlling the imaging means, the motion detection means, the data compression means, the recording means, the clock means 1 and the previous recording period setting means,
The controller is
When the motion detection means detects that there is a motion of the video, the compression processing by the data compression means, the recording processing by the recording means video data, and
Based on the time information, the set recording information, and the storage capacity of the predetermined recording medium, a compression rate calculation capable of recording the compressed video data for the set recording period within the remaining capacity recordable on the predetermined recording medium. A compression rate calculation / update process for calculating a value and updating the set compression rate to the compression rate calculated value at a predetermined timing ;
The set recording period includes a combination of a minimum period and a maximum period.
Monitoring and recording system. The monitoring and recording system according to claim 1,
The compression rate calculated value includes any one of a plurality of discrete compression values set as discrete values.
The recording period setting means uses the predetermined two discrete compression ratios adjacent to each other among the plurality of discrete compression ratios based on one period that is one of the minimum period and the maximum period, and Set the other period, which is the other of the period and the maximum period,
Monitoring and recording system. The monitoring recording system according to claim 1 or 2,
The imaging means includes first to Nth (N ≧ 2) imaging means,
The motion detection means includes first to Nth motion detection means,
The data compression means includes first to Nth data compression means,
Having an independent video data processing system by the i-th (i = 1 to N) imaging means, the i-th imaging means, and the i-th data compression means,
Monitoring and recording system.

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