JP2008010963A - Video monitoring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video monitoring apparatus capable of carrying out accurate video monitoring without detecting a motion of a video image by mistake even when the video monitoring apparatus itself is moved due to vibration. <P>SOLUTION: The video monitoring apparatus 10 for encoding a video signal obtained by imaging and thereafter detecting a motion of the video image, and starting recording of the encoded video signal to a recording section 7 when detecting the motion of the video image, is configured such that the video monitoring apparatus 10 discriminates whether or not the video monitoring apparatus 10 itself is vibrated, the video monitoring apparatus 10 instructs recording start of the encoded video signal when the motion of the video image is detected and it is decided that the video monitoring apparatus 10 is not vibrated, and the video monitoring apparatus 10 does not instruct the recording start of the encoded value as its control when the motion of the video image is detected and it is decided that the video monitoring apparatus 10 is vibrated. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video monitoring apparatus that detects a motion from an encoded captured video signal and records encoded data based on the motion detection.

  In recent years, video monitoring devices using moving object detection technology are often used for the purpose of crime prevention and accident prevention. In this moving object detection technology, as a moving object detection device capable of detecting a moving object at a relatively low cost, a device that uses captured moving image information is known (see, for example, Patent Document 1).

In this Patent Document 1, an MPEG encoder compresses moving image data by using intra-frame (or field) coding and inter-frame (or field) coding, and a data amount detection means uses the compressed moving image data. The determination means extracts the data amount at the time of encoding between the frames (or fields) out of the detected data amount, and at the time of encoding between the extracted frames (or fields). A moving object detection device and a moving object detection system that can determine whether or not a moving object exists in a moving image based on a data amount are described.
Utility Model Registration No. 3085003

  However, in the invention described in Patent Document 1, for example, a moving object can be detected when there is a change in the movement of imaged data such as when an intruder is imaged, but the moving object detection device itself has moved. Even in such a case, the subject in the imaging data is regarded as having moved, and there has been a problem that the moving object is erroneously detected. When such a moving object detection device is used in a video monitoring device, there is a problem that an unnecessary alarm is issued due to erroneous detection of a moving object or unnecessary video recording is performed.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to perform accurate video monitoring without erroneously detecting a moving object even when the video monitoring device itself is moved by vibration. It is to provide a video surveillance device.

In order to solve the above problems, the present invention
[1] After the video signal obtained by imaging by the imaging means (1) is encoded by the encoding means (2), the motion detection means (4, 9) detects the motion of the video, In the video monitoring device that starts recording the encoded video signal to the recording means (7) when motion is detected,
Vibration state determination means (5, 9) for determining whether or not the video monitoring device is vibrating;
Instructing the recording means to start recording of the encoded video signal when the motion detection means detects the motion of the video and the vibration state determination means determines that no vibration has occurred. When the motion detection unit detects the motion of the video and the vibration state determination unit determines that the video is moving, the recording unit is instructed to start recording the encoded video signal. Recording control means (8, 9) for controlling so as not to
A video monitoring device (10) characterized by comprising
Provide
[2] After the video signal obtained by imaging by the imaging means (1) is encoded by the encoding means (2), the motion detection means (4, 9) detects the motion of the video, In a video monitoring device that starts transmission of the encoded video signal to a network when motion is detected,
Vibration state determination means (5, 9) for determining whether or not the video monitoring device is vibrating;
When motion of the video is detected by the motion detection means and when it is determined that the vibration state determination means does not vibrate, the start of transmission of the encoded video signal is instructed, while the motion detection means Transmission control means for controlling not to instruct transmission start of the encoded video signal when motion of the video is detected and it is determined that the vibration state determination means vibrates;
An image monitoring apparatus characterized by comprising: is provided.

  According to the present invention, the motion detection means can detect the motion of the video of the encoded video data, and the vibration state determination means can detect the motion due to the vibration of the video monitoring device itself. Based on the detected information, if video motion detection and vibration are detected, recording of the encoded video data to the recording means is prohibited, while recording is started only when video motion detection is performed. By doing so, it is possible to prevent erroneous video motion detection due to vibration of the video monitoring device itself, and to perform accurate video monitoring (video recording).

  Further, according to the present invention, as described above, when video motion detection and vibration are detected, transmission of encoded video data to the network is prohibited, while only video motion detection is performed. In this case, by starting transmission, it is possible to prevent erroneous video motion detection due to vibration of the video monitoring device itself, and to perform accurate video monitoring (video transmission).

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. First, FIG. 1 shows a schematic configuration of a video monitoring apparatus according to an embodiment of the present invention. In the figure, a video monitoring apparatus 10 includes a video acquisition unit 1, a video encoding unit 2, a video temporary recording unit 3, a code difference amount calculation unit 4, a vibration information acquisition unit 5, and a vibration information temporary recording unit. 6, a recording unit 7, a recording control unit 8, and a control unit 9. The control unit 9 includes a CPU 9a and a memory 9b. In the control unit 9, a control program (not shown) is developed in the memory 9b and is executed by the CPU 9a, whereby the entire video monitoring apparatus 10 is controlled.

  The video acquisition unit 1 includes an optical system such as a lens and a photoelectric conversion unit such as a CCD, and photoelectrically converts video light incident on the optical system by the photoelectric conversion unit and outputs digital video data based on luminance data and color difference data. To do. The video encoding unit 2 encodes the digital video data supplied from the video acquisition unit 1 and outputs video encoded data.

  In the present embodiment, the video encoding unit 2 executes an encoding process at 30 fps according to the MPEG2 system. In this case, the video encoded data output from the video encoding unit 2 was previously encoded with an intra picture (I picture) that can be decoded independently without using encoded data of other frames. It consists of a predictive coded picture (P picture) that is difference data from the data, and a bi-directional predictive code picture (B picture) using data coded before and after. The data amount of the intra picture changes as the video due to luminance and color difference changes. Further, the data amount of the predictive coded picture changes corresponding to the change from the previously coded data. In addition, the data amount of the bi-directional predictive code picture changes corresponding to the change with the information encoded before and after.

  FIG. 2 shows an example in which the change in the data amount with respect to time of the video encoded data output from the video encoding unit 2 is graphed. The state at time ΔT1 indicates the data amount of the encoded video data when there is no motion in the captured video. Each state of time ΔT2 and ΔT3 indicates a case where the amount of video encoded data is larger than that of time ΔT1, and there is motion in the captured video. In the figure, the total amount of data in each of ΔT1, ΔT2, and ΔT3 is N1, N2, and N3.

  The video temporary recording unit 3 is a ring buffer that temporarily records the video encoded data output from the video encoding unit 2 in a FIFO (First In First Out) format. Note that the video temporary recording unit 3 may be included in the recording unit 7.

  The code difference amount calculation unit 4 is an encoded data difference value that is a difference between the data amount of the latest video encoded data recorded in the video temporary recording unit 3 and the data amount of the previously encoded video encoded data. The motion of the video is detected by calculating ΔN. The data amount of the previously encoded video encoded data is an average value of the data amount before a predetermined time. Also, the previously encoded video encoded data may be a reference data amount measured in advance when there is no motion. For example, when the total data amount N1 of the time ΔT1 in FIG. 2 is used as the reference data amount, the encoded data difference value ΔN2 of the time ΔT2 can be calculated by Equation 1.

  Similarly, the encoded data difference value ΔN3 at the time ΔT3 can be calculated by Equation 2.

  The vibration information acquisition unit 5 has a function of detecting a motion such as vibration of the video monitoring device 10. For example, the vibration information acquisition unit 5 detects acceleration at a predetermined sampling period using an acceleration sensor and outputs it as vibration information G. . The vibration information temporary recording unit 6 is a ring buffer that temporarily records the vibration information G supplied from the vibration information acquisition unit 5. The vibration information recording unit 6 may be included in the recording unit 7.

  FIG. 3 shows an example in which the change in the information amount with respect to time of the vibration information G output from the vibration information acquisition unit 5 is graphed. Each state of time ΔT1 and ΔT2 indicates vibration information when the video monitoring apparatus 10 is not moving. The state at time ΔT3 indicates that the vibration information is greatly changed compared to the vibration information at times ΔT1 and ΔT2, and vibration is generated in the video monitoring apparatus 10.

  The recording unit 7 can use, for example, a hard disk, and records video encoded data recorded in the video temporary recording unit 3 and vibration information G recorded in the vibration information temporary recording unit 6. The recording control unit 8 controls the recording start and stop operations of the recording unit 7.

  Based on the encoded data difference value ΔN and the vibration information G, the control unit 9 determines whether to start recording video encoded data in the recording unit 7. Hereinafter, an example of the determination method by the control unit 9 will be described.

  First, the control unit 9 determines whether or not there is a change in the encoded data difference value ΔN. That is, the memory 9b stores a threshold value MN of a predetermined encoded data difference value set in advance. Then, the CPU 9a compares the encoded data difference value ΔN calculated by the code difference amount calculation unit 4 with the threshold MN. When the encoded data difference value ΔN is greater than or equal to the threshold MN (ΔN ≧ MN), the CPU 9a determines that there is motion in the video.

  Next, the control unit 9 determines whether or not the vibration information G has changed. That is, the threshold value MG of predetermined vibration information set in advance is stored in the memory 9b. Then, the CPU 9a obtains the maximum value GL and the minimum value GS of the vibration information per unit time of the vibration information G recorded in the vibration information temporary recording unit 6, and calculates the vibration difference amount ΔG by Equation 3.

  Then, the CPU 9a compares the vibration difference amount ΔG with the vibration information threshold value MG. When the vibration difference amount ΔG is equal to or greater than the threshold value MG of the vibration information G (ΔG ≧ MG), the CPU 9a determines that the video monitoring device 10 has shaken due to large vibration, and outputs the video encoded data to the recording unit 7. Do not start recording. On the other hand, when the vibration difference amount ΔG is smaller than the threshold value MG of the vibration information G (ΔG <MG), the CPU 9a determines that the captured image has moved but the image monitoring device 10 is not shaken, and the encoded video data The recording control unit 8 is controlled to start recording on the recording unit 7.

  Next, the operation of the monitoring apparatus in the present embodiment will be described with reference to the flowchart of FIG. First, the control unit 9 controls the video acquisition unit 1 to execute an operation of acquiring digital video data, and the video encoding unit 2 performs encoding processing on the digital video data. Control is performed to output the digitized data (step S10).

  Next, the video temporary recording unit 3 records video encoded data (step S11). Next, the control unit 9 determines whether or not the recording control unit 8 is recording video encoded data in the recording unit 7 (step S12). If it is determined in step S12 that recording is not currently being performed (No in step S12), the code difference amount calculation unit 4 calculates an encoded data difference value ΔN (step S13).

  Next, the control unit 9 compares the encoded data difference value ΔN and the threshold value MN (step S14), and if the encoded data difference value ΔN exceeds the threshold value MN (step S14 Yes), the vibration information G changes. It is determined whether or not there has been (step S15). If the vibration information G has not changed as a result of the determination in step S15 (No in step S15), the control unit 9 causes the recording control unit 8 to start recording processing of the video encoded data in the recording unit 7. Thus, the recording control unit 8 controls the recording unit 7 to start recording (step S16). Then, the recording control unit 8 controls the recording unit 7 to record the encoded video data (step S17).

  After recording the video encoded data in the recording unit 7, the control unit 9 determines whether or not to continue the recording (step S18). When the recording is to be ended (Yes in step S18), the processing of the video monitoring device 10 is performed. finish. The determination as to whether or not to continue recording is, for example, when a predetermined time has elapsed since the start of recording. On the other hand, if the recording is not finished in step S18 (No in step S18), the process returns to step S10 and the digital video data encoding process is executed.

  If there is a change in the vibration information G as a result of the determination in step S15 (step S16 Yes), the process returns to step S10 to execute the digital video data encoding process. Also, in the comparison process in step S14, when the encoded data difference value ΔN is equal to or less than the threshold (No in step S14), the process returns to step S10 and the digital video data encoding process is executed. On the other hand, if it is determined in the determination process in step S12 that recording is in progress (Yes in step S12), the process proceeds to step S17 to record the encoded video data in the recording unit 7.

  As described in detail above, according to the video monitoring apparatus of the embodiment of the present invention, the code difference amount calculation unit detects the moving object of the subject from the code data amount per unit time of the video encoded data, and vibrates. Since the information acquisition unit can detect the movement of the video monitoring device itself due to vibrations, etc., when there is a moving object detection and vibration detection based on the detected information, the video acquisition data is recorded to the video encoded data recording unit. Recording is prohibited, but when only moving object detection is performed, recording is started, so that erroneous moving object detection is prevented by vibration and movement of the image monitoring apparatus itself, and accurate image monitoring (video recording) is performed. be able to.

  In the present embodiment, the example in which the encoded video data is recorded in the recording unit 7 has been described. However, as another embodiment, an output control unit is provided instead of the recording unit 7 or together with the recording unit 7. The encoded video data may be transmitted to the outside via the output control unit. In this case, when the external transmission path is a network, the output control unit may be configured as a network interface unit so that video encoded data is converted into packet data.

It is a block diagram which shows schematic structure of the video monitoring apparatus which is embodiment of this invention. It is the graph which showed the change of the data amount with respect to time of the video coding data output from a video coding part. It is the graph which showed the change of the information amount with respect to time of the vibration information G output from the vibration information acquisition part 5. FIG. It is a flowchart for demonstrating operation | movement of the video monitoring apparatus which is embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image | video acquisition part 2 Image | video encoding part 3 Image | video temporary recording part 4 Code difference amount calculation part 5 Vibration information acquisition part 6 Vibration information temporary recording part 7 Recording part 8 Recording control part 9 Control part 9a CPU
9b Memory 10 Video monitoring device

Claims (2)

After the video signal obtained by imaging by the imaging means is encoded by the encoding means, the motion detection means detects the motion of the video, and when the motion of the video is detected, the encoded video signal In the video monitoring device that starts recording to the recording means,
Vibration state determination means for determining whether or not the video monitoring device is vibrating;
Instructing the recording means to start recording of the encoded video signal when the motion detection means detects the motion of the video and the vibration state determination means determines that no vibration has occurred. When the motion detection unit detects the motion of the video and the vibration state determination unit determines that the video is moving, the recording unit is instructed to start recording the encoded video signal. Recording control means for controlling so as not to
A video surveillance device comprising: After the video signal obtained by imaging by the imaging means is encoded by the encoding means, the motion detection means detects the motion of the video, and when the motion of the video is detected, the encoded video signal In the video surveillance device that starts transmission to the network,
Vibration state determination means for determining whether or not the video monitoring device is vibrating;
When motion of the video is detected by the motion detection means and when it is determined that the vibration state determination means does not vibrate, the start of transmission of the encoded video signal is instructed, while the motion detection means Transmission control means for controlling not to instruct transmission start of the encoded video signal when motion of the video is detected and it is determined that the vibration state determination means vibrates;
A video surveillance device comprising:

Images