JP2009055341A - Picture monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To set a frame rate and the compression rate by inputting significance and picture recording time for every input picture channel. <P>SOLUTION: The picture monitoring device has a picture recording parameter changing means for holding the significance and the picture recording time inputted with every CH, a frame rate calculating means for calculating the frame rate with every CH based on the total storage capacity and residual capacity of a storage device, a frame significance calculating means for calculating significance of a processing frame based on holding significance, the frame rate for every CH and a frame count value to respective picture frames of respective CH, a frame selecting means for selecting only a picture frame larger in the significance of the processing frame than a threshold value, a compression rate calculating means for calculating the compression rate of the picture frame based on the frame rate for every CH and an average frame rate of input CH, and a frame compressing means for compressing the selected picture frame based on the compression rate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a video monitoring apparatus that controls a frame rate of a digitized monitoring video and accumulates it in a storage device.

  In a video surveillance device that digitizes video captured by a surveillance camera and records it on a storage medium, recording all video results in large amounts of data, so there is a limit to the recording medium. Only the video frames of the contents are recorded. Therefore, the remaining capacity of the storage medium, image quality parameters, and image importance are determined from the recording time input by the operator, and the frame rate is controlled according to these parameters, so that the video can be recorded for a predetermined time. . For example, in Patent Document 1, when image data sequentially captured from an imaging unit is stored in a digital data storage medium, the frame rate is calculated according to the recording time of the image data in the digital data storage medium, or A technique for calculating according to the remaining capacity of the digital data storage medium is described.

JP 2002-44609 A

  In the conventional video monitoring apparatus, since the frame rate is individually set for a plurality of input video channels based on the recording time input by the operator, the recording time is set to be long and the frame rate is set to be high. It was difficult. Further, since the bandwidth of the device is not considered when changing the storage device, it is necessary to change the frame rate calculation method every time the device is changed.

  The present invention has been made to solve the above-described problems, and obtains a video monitoring apparatus capable of setting a frame rate and a compression rate by inputting importance and recording time for each input video channel. With the goal.

  The video monitoring apparatus according to the present invention digitally converts and encodes video signals of a plurality of channels received from each monitoring camera installed at a monitoring location, and controls the frame rate of each channel to store the video frames in a storage device. In the video monitoring apparatus, a video signal detecting means for detecting a video signal of each channel and outputting detection information, and a recording parameter changing means for holding importance and recording time inputted for each channel according to the detection information are held. Frame rate calculating means for calculating a frame rate for each channel based on the recording time and the total storage capacity and remaining capacity of the storage device, and the importance level calculated for each video frame of each channel, and the calculated channel Calculate the importance of the current processing frame based on the frame rate and frame count value for each Frame importance calculation means, frame selection means for selecting only video frames whose calculated processing frame importance is greater than a predetermined threshold, calculated frame rate for each channel, and average frame rate of input channels determined in advance A compression rate calculating means for calculating the compression rate of the video frame based on the frame, a frame compression means for compressing the video frame selected by the frame selecting means based on the calculated compression rate, and a compressed video frame A storage means for storing in the storage device is provided.

  According to the present invention, the operator inputs the importance level and the recording time for each video channel, and calculates the frame rate and the compression rate for the video frame to be processed for each channel based on the importance level and the recording time. Therefore, it is possible to save the operator from inputting the frame rate and the compression rate for each input channel. In addition, it is possible to flexibly cope with a change in a device such as a storage device.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a functional configuration of a video monitoring apparatus according to Embodiment 1 of the present invention.
1 includes a video input unit 1, a frame importance calculation unit 2, a frame selection unit 3, a frame compression unit 4, a storage unit 5, a video signal detection unit 6, a recording parameter change unit 7, a frame rate calculation unit. 8 and compression rate calculation means 9 and a storage device 10. Here, the storage device 10 is for accumulating the video frame and its metadata. However, the storage device 10 can detect the total storage capacity and the remaining capacity of the storage medium. Accumulate / read.

First, the operation of the recording parameter changing means 7 will be described using the flowchart of FIG.
The recording parameter changing means 7 is activated at the first activation of the video monitoring apparatus after shipment from the factory or when a new video input channel is added. The video input means 1 is input with a plurality of channels of CCD output video and NTSC signals taken by each surveillance camera installed at each surveillance location, while the recording parameter change means 7 receives signal detection. Detection information for detecting the video signal of each channel is given from the means 6 (step ST100).

  The details of the video signal detection operation of each channel in the video signal detection means 6 will be described with reference to the flowchart of FIG. First, the target channel number is initialized with 0 (step ST110), and the presence / absence of a synchronization signal of the target channel number is determined (step ST111). If there is a synchronization signal in the target channel number, this synchronization signal is detected and output to the recording parameter changing means 7 as detection information together with the channel number (step ST112), and the process proceeds to step ST113. On the other hand, if there is no synchronization signal, the process proceeds to step ST113. In step ST113, it is determined whether processing for all the video channels has been completed. If the detection process for the total number of video channels has not been completed, the value of the target channel number is incremented by 1, and the process proceeds to step ST111 (step ST114). On the other hand, when it is completed, the operation of the video signal detecting means 6 is completed.

  Returning to the operation of the recording parameter changing means 7 in FIG. 2, the target channel number is initialized to 0 (step ST101), and based on the detection information of the video signal detecting means 6, whether or not the target channel number has a detection signal. Is determined (step ST102). If there is a detection signal for the target channel number, the operator inputs the recording time for the target channel (step ST103), and further inputs the importance for the target channel (step ST104). These parameters are input using input / output means such as a mouse, a keyboard, and a monitor (not shown). Here, the importance is an integer from 1 to 10, for example. The input recording time and importance of the target channel are stored as recording parameters (step ST105), and the process proceeds to step ST106. The storage method is such that it is stored in its own memory or storage device 9. On the other hand, if there is no detection signal in the target channel in the determination in step ST102, the process directly proceeds to step ST106. In step ST106, it is determined whether the processing has been completed for all video channels. If the processing for all the video channels has not been completed, the value of the current target channel number is incremented by 1 (step ST107), and the process proceeds to step ST102. On the other hand, if it has been completed, the operation of the recording parameter changing means 7 is completed.

Next, a series of operations relating to the accumulation of video of each channel will be described with reference to the flowchart of FIG.
The video input means 1 digitally converts and encodes the input video signal of each channel, and outputs the generated digital signal to the frame importance calculation means 2 for each video frame (step ST120). Here, the digital signal is, for example, a YUV signal, an RGB signal, or the like. Further, the video input unit 1 updates the frame count for each channel (step ST121). For example, the frame count value is incremented by one. Here, the frame count is initialized when the apparatus is activated, for example, 0. The frame count value for each channel is also output to the frame importance calculation means 2.

The frame rate calculation means 8 calculates the frame rate for each channel based on the recording time for each channel input and held by the recording parameter change means 7 and the total storage capacity and remaining capacity of the storage device 10 (step ST122). The frame rate calculation processing method will be described with reference to the flowchart of FIG. 5 and the table of FIG. The table of FIG. 6 is calculated by the input channel number 140 input to the video input means 1, the importance 141 and recording time 142 for each channel input and held by the operator in the recording parameter changing means 7, and the frame rate calculating means 8. The frame rate 143 is associated.
First, the frame rate calculation means 8 acquires the recording time from the recording parameter change means 7 (step ST130). For example, in the setting of FIG. 6, it is assumed that the total recording time for channels 1 to 4 is 700 hours. Next, the total storage capacity and the current free capacity (remaining capacity) are acquired from the storage device 9 (step ST131), and the frame rate is calculated for each channel (step ST132). The frame rate of each channel is calculated according to equation (1).

Frame rate = (free space / number of channels) / (recording time x recording frame size)
(1)

Here, the frame rate is the number of frames processed per second, the free space is the byte size, the number of channels is the number of connected channels obtained by the video signal detection means 6, the recording time is the number of seconds to record, and the recording frame size is This is the byte size of a recording frame at a predetermined encoding time.
For example, when the free space is 700 gigabytes and the recording frame size is 30 kilobytes (default compression ratio 1/20), the frame rate is as shown in FIG.

Returning to the flow of FIG. 4, the frame importance calculation unit 2 uses the frame rate calculation unit 8 to input and hold the importance of the video frames received from the video input unit 1 by the recording parameter changing unit 7. Based on the calculated frame rate and frame count value, importance Pf of the current processing frame is calculated (step ST123). The importance Pf of the processing frame is calculated according to the equation (2).

Pf = | cos (6 × PI / 180 / (1 / Fps) × Fc) | + | cos (6 × PI / 180 / (1 / Fps / Pc) × Fc) | (2)

Here, PI is the processing frame circumference ratio, Fps is the frame rate (frame / sec) of the current channel calculated by the frame rate calculating means 8, and Pc is the importance of the current channel input and held by the recording parameter changing means 7. The frequency value, Fc, is a frame count value.

  In FIG. 7, the first term of equation (2) is a curve 152 of a cosine function having the frame rate of the processing frame as a period. The second term represents a half-cycle offset from the first term, and when added together, the importance of the curves as shown in FIGS. 8 and 9 is obtained. For example, in the setting of FIG. 6, the importance for each input frame of the camera channels 1, 2, and 4 is 158 shown in FIG. In FIG. 8, 157 represents the plot of the first term of equation (2). Also, the importance level of the camera channel 3 with respect to the input frame is 163 shown in FIG. In FIG. 9, 162 represents a plot of the first term of equation (2). Here, for example, when a video frame is input in 33 ms from each camera channel, it becomes 30 fps (frames per second), and a value that matches the remainder of 30 of the current frame count value from FIGS. Degree.

  The frame sorting unit 3 sorts video frames to be stored based on the importance Pf calculated by the frame importance calculating unit 2. Therefore, the importance Pf of the processing frame is compared with a predetermined threshold Th (step ST124). When the importance Pf is larger than the threshold Th, the corresponding processing frame is sent to the frame compression means 4. On the other hand, when the importance Pf is smaller than the threshold Th, the processing frame is discarded (step ST125), and the process proceeds to step ST120. In this case, the compression rate calculation means 9 is notified that the frame has been discarded.

The compression rate calculation means 9 obtains the compression rate of the processing frame (step ST126). Therefore, the previous average frame rate is calculated in advance in the compression rate calculation means 9. For example, it is obtained from the discard rate of the input channel one second ago. The compression rate Cf when the average frame rate is equal to or higher than the frame rate Fps of the current channel calculated by the frame rate calculation means 8 is obtained according to the equation (3).

Cf = Fps / Fave × C (3)

Here, Fave is the average frame rate, C is a predetermined compression rate, and is 1/20, for example.

  The frame compression unit 4 compresses the video frame of the input channel based on the compression rate Cf calculated by the compression rate calculation unit 9, and outputs the compressed video frame and metadata accompanying the data to the storage unit 5 ( Step ST127). Here, for example, JPEG compression is used as the compression method. The storage unit 5 writes and stores the video frame compressed by the frame compression unit 4 in the storage device 10 (step ST128). This writing is performed by SO on the video monitoring apparatus.

  As described above, according to the first embodiment, the operator simply inputs the importance and the recording time for each video channel, and the video frame to be processed for each channel based on the importance and the recording time. Since the frame rate and compression rate are calculated for the above, it is possible to save the operator from inputting the frame rate and compression rate for each input channel. Therefore, it is possible to flexibly cope with a change in a device such as a storage device.

Embodiment 2. FIG.
In the first embodiment, the frame rate and the compression rate can be calculated and controlled based on the recording time and importance set for each input channel. However, in the second embodiment, the presence / absence of an alarm signal is also determined. Considering control of the frame rate and compression rate in consideration. Here, the alarm signal is a signal indicating the occurrence of an abnormal state for each monitoring place. For example, when the monitoring place is assumed to be unattended, it is detected when opening or closing of a door or window or movement of a person is detected. It is sent from a sensor or the like.
FIG. 10 is a block diagram showing a functional configuration of a video monitoring apparatus according to Embodiment 2 of the present invention. In the figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted in principle. In the second embodiment, an alarm input unit 11 is added to the configuration of the first embodiment.
The alarm input unit 11 is a unit that receives an alarm signal from a contact interface (not shown) of the video input channel when an abnormality occurs in the monitoring target, and transmits the alarm signal to the frame importance level calculation unit 2 and the storage unit 5. . Further, the frame importance calculation means 2 in the second embodiment performs a process of biasing the importance of the processing frame calculated in the first embodiment when there is an alarm signal of a channel corresponding to the video frame.

The operation of the frame importance calculation means 2 will be described with reference to the flowchart of FIG.
In the frame importance calculation means 2, first, as in the first embodiment, the importance Pf of the current processing frame is calculated according to the above equation (2) (step ST200). Next, it is checked whether there is an alarm signal in the channel corresponding to the processing frame (step ST201). If there is an alarm signal, the variable Bias is set to a predetermined value Bin (step ST203). Here, Bin is an integer value greater than zero. On the other hand, if there is no alarm signal, the variable Bias is set to 0 (step ST202). Next, the variable Bias value is added to the importance Pf of the processing frame calculated previously to update the importance of the processing frame and output it to the frame selection means 3 (step ST204). Therefore, the frame sorting means 3 sorts video frames based on the importance updated in consideration of the alarm.
In addition, the storage unit 5 stores the compressed video frame in association with the alarm signal when writing the compressed video frame in the storage device 10 when there is an alarm signal. This allows the supervisor to identify what kind of alarm the accumulated video is due to.

As described above, according to the second embodiment, since the importance level of the video frame including the presence / absence of the alarm signal is calculated, a larger frame is used for an important video in an emergency situation where an alarm occurs. The rate can be secured.
In the above example, the default value is uniformly set for the alarm signal. However, the importance may be updated by setting a bias value Bin specified for each type of the alarm signal. It is possible to secure a frame rate according to the above.

Embodiment 3 FIG.
In the third embodiment, for example, in the configuration of FIG. 1, the writing speed of the storage device 10 and the processing speed of the frame compression means 4 are stored in the storage device 10 in advance, and the maximum writing of the storage device 10 from these processing speeds. A description will be given of determining a frame rate by using a predetermined frame rate.
The operation of the frame rate calculation means 8 in this case will be described using the flowchart of FIG.
The frame rate calculation means 8 first acquires the recording time that is input and held from the recording parameter change means 7 (step ST300). Next, the total storage capacity and the current free capacity are acquired from the storage device 10 (step ST301), and the frame rate is calculated for each channel according to the above equation (1) (step ST302). Next, the calculated frame rate of each channel is compared with a predetermined maximum write frame rate of the storage device (step ST304). If the calculated frame rate is larger than the maximum write frame rate of the storage device, the maximum write frame rate is output instead of the frame rate (step ST305). In other cases, the channel frame rate is left as it is. Output.

As described above, according to the third embodiment, since the processing frame rate is limited by the maximum writing frame rate of the storage device 10, the entire system can be processed smoothly.
In the third embodiment, the frame rate is calculated in consideration of the information on the writing speed of the storage device 10 and the processing speed of the frame compression means 4, but the processing speed in the video input means 1 and the frame selection means 3 is calculated. The frame rate may be calculated in consideration of the above.

Embodiment 4 FIG.
In the fourth embodiment, it will be described that a bias is applied to the importance of a predetermined time zone in which time changes periodically at a monitoring place, for example, every day, every month, or every year. The operation of the frame importance calculation means 2 in such a case will be described using the flowchart of FIG.
In the frame importance calculation means 2, first, the importance Pf of the processing frame is calculated in the same manner as in the first embodiment (step ST400). Next, for example, the importance level Bnow corresponding to the processing frame, for example, in a predetermined time zone every day is acquired from the recording parameter changing means 7 (step ST401), and the importance level Bnow is added to the importance level Pf of the processing frame calculated previously. Then, the added importance is output to the frame selection means 3 (step ST402).

  As described above, according to the fourth embodiment, bias is applied to the importance of a predetermined period of time, so it is necessary to monitor the importance of entrances and exits where the number of entrances and exits changes with time. It can be changed according to the characteristics, and there is no need to input the frame rate and compression rate designation for each time zone, and important video in that time zone can be automatically stored.

It is a block diagram which shows the function structure of the video monitoring apparatus by Embodiment 1 of this invention. It is a flowchart which shows the operation | movement procedure of the recording parameter change means based on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement procedure of the video signal detection means which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement regarding the image | video accumulation | storage of the image | video monitoring apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement procedure of the frame rate and compression rate calculation means which concerns on Embodiment 1 of this invention. It is explanatory drawing showing the data relationship of the calculation frame rate of the frame rate and compression rate calculation means which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the curve of 1 term of the importance calculation formula of the frame importance calculation means which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the curve example of the importance of a certain channel calculated by the frame importance calculation means which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the example of a curve of the importance of the other channel calculated by the frame importance calculation means concerning Embodiment 1 of this invention. It is a block diagram which shows the function structure of the video monitoring apparatus by Embodiment 2 of this invention. It is a flowchart which shows the operation | movement procedure of the frame importance calculation means which concerns on Embodiment 1 of this invention. It is a flowchart which shows the operation | movement procedure of the frame rate and compression rate calculation means which concerns on Embodiment 3 of this invention. It is a flowchart which shows the operation | movement procedure of the frame importance calculation means which concerns on Embodiment 4 of this invention.

Explanation of symbols

  1 video input means, 2 frame importance calculation means, 3 frame selection means, 4 frame compression means, 5 storage means, 6 video signal detection means, 7 recording parameter change means, 8 frame rate calculation means, 9 compression rate calculation means, 10 storage device, 11 alarm input means.

Claims (5)

In a video monitoring apparatus that digitally converts and encodes video signals of a plurality of channels received from each monitoring camera installed at a monitoring place, and controls the frame rate of each channel to store video frames in a storage device.
Video signal detection means for detecting the video signal of each channel and outputting detection information;
Recording parameter changing means for retaining importance and recording time input for each channel according to the detection information;
Frame rate calculating means for calculating a frame rate for each channel based on the stored recording time and the total storage capacity and remaining capacity of the storage device;
Frame importance calculation means for calculating importance of the current processing frame based on the held importance, the calculated frame rate and frame count value for each channel for each video frame of each channel;
Frame selection means for selecting only video frames in which the calculated importance level of the processing frame is larger than a predetermined threshold;
Compression rate calculation means for calculating a compression rate of a video frame based on the calculated frame rate for each channel and an average frame rate of an input channel determined in advance;
Frame compression means for compressing the video frames selected by the frame selection means based on the calculated compression rate;
A video monitoring apparatus comprising storage means for storing the compressed video frames in the storage device. An alarm input means for transmitting an alarm signal received from a sensor at a monitoring location of the video input channel to a frame importance calculation means;
The frame importance level calculation means biases the calculated importance level of the processing frame and outputs it to the frame selection means when there is an alarm signal in the channel corresponding to the processing frame. Item 1. The video surveillance device according to Item 1.   3. The video monitoring apparatus according to claim 2, wherein the storage means writes and stores the video frame compressed by the frame compression means in association with an alarm signal in a storage device.   The frame rate calculation means compares the calculated frame rate for each channel with a predetermined maximum write frame rate of the storage device, and if the calculated frame rate of the channel is larger, the frame rate of the channel is replaced with the frame rate. 4. The video monitoring apparatus according to claim 1, wherein a maximum writing frame rate of the storage device is output. The recording parameter changing means presets the importance level of a predetermined period of time,
2. The frame importance calculation means, when a predetermined time zone has arrived, adds the importance of the predetermined time zone to the calculated importance of the processing frame and outputs the result. Or the video monitoring apparatus of Claim 2.

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