JP2008131572A - Monitoring camera apparatus and photographing method of same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To economize recording capacitance of a recording medium by changing recording operation of image data onto the recording medium in accordance with a moving amount of a subject monitored by a monitoring camera. <P>SOLUTION: A monitoring camera apparatus of the present invention includes: a photographing means (1) for photographing a subject; a video converting means (2) for converting a photographed image into a video signal; a recording means (3) for recording the photographed image converted into the video signal; a motion detecting means (7) for detecting the motion of the subject from the photographed image; a comparison means (7) for comparing the detected motion of the subject with a predetermined threshold value; and a recording control means (7) which performs control in such a way that when it is judged that the compared motion of the subject is faster than the threshold value, recording intervals of photographed images to be recorded on the recording medium are shortened and when it is judged that the motion of the subject is slower than the threshold value, the photographed images to be recorded on the recording medium are recorded while prolonging recording intervals of the photographed images. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a surveillance camera device. The present invention also relates to a monitoring camera device that changes the recording operation of image data on a recording medium in accordance with the movement of a subject.

Currently, surveillance cameras that monitor moving subjects are in widespread use.
Patent Document 1 discloses an image code that adaptively controls a compression method according to the contents of each multiplexed image that changes every moment when a plurality of input image signals are multiplexed and compressed into one frame. An apparatus is disclosed.

  In Patent Document 1, a motion vector detection unit detects a motion vector, a compression method control unit calculates the sum of the magnitudes of the motion vectors for each of the multiplexed images, and determines the correlation with the previous frame image from that value. A technique for controlling a compression method and compressing and encoding image data in accordance with the control of the compression method in an image compression unit is disclosed. By doing so, it is possible to control a compression method suitable for the contents of each multiplexed image.

However, in the technique disclosed in Patent Document 1, one screen is divided into a plurality of small screens and a plurality of images are displayed simultaneously. For this reason, the recording operation cannot be changed according to the amount of movement of the subject to save the recording capacity of the recording medium.
JP 2001-28755 A

  The present invention has been made in view of the above circumstances, and changes the recording operation of the image data on the recording medium in accordance with the amount of movement of the subject monitored by the monitoring camera, thereby saving the recording capacity of the recording medium. For the purpose.

  The surveillance camera device according to the present invention includes a photographing means for photographing a subject, a video converting means for converting the photographed image into a video signal, a recording means for recording the photographed image converted into the video signal, and the photographing A motion detection means for detecting the motion of the subject from the captured image, a comparison means for comparing the detected motion of the subject with a predetermined threshold, and if the motion of the compared subject is determined to be earlier than the threshold, Recording control means for controlling to shorten the recording interval of the captured image to be recorded on the recording medium and to increase the recording interval of the captured image to be recorded on the recording medium when it is determined that the movement of the subject is slower than the threshold value It comprises so that it may be equipped with.

  The surveillance camera photographing method according to the present invention includes a step of photographing a subject, a step of converting the photographed image into a video signal, a step of recording the photographed image converted into the video signal, and the photographed image A step of detecting the movement of the subject from the image, a step of comparing the detected movement of the subject with a predetermined threshold value, and a shooting that is recorded on a recording medium when it is determined that the compared subject movement is earlier than the threshold value. The image recording interval is shortened, and when it is determined that the movement of the subject is slower than the threshold value, a step of controlling to record with a longer recording interval of the captured image to be recorded on the recording medium is provided.

  According to the configuration described above, the recording operation of the image data on the recording medium or the distribution operation to the network is changed according to the moving amount of the subject monitored by the monitoring camera, and the data amount of the image captured by the monitoring camera is reduced. It becomes possible to do. Further, by reducing the amount of image data, the recording capacity of the recording medium can be saved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a monitoring camera apparatus according to an embodiment of the present invention that controls a time interval for recording image data on a storage medium (or a time interval for distribution to the network 10) in accordance with the moving speed of the subject. FIG.

  In FIGS. 1A and 1B, the movement of a moving subject is detected using a monitoring camera device, and the interval between recorded images is controlled. Here, the captured image of the subject is converted into a video signal and continuously recorded on a recording medium.

  FIG. 1A shows how the subject moves quickly during the photographing by the surveillance camera device. For example, when a moving object moves in front of a stationary subject, a conventional surveillance camera device that does not change the recording operation according to the amount of movement of the subject captures an image at a constant speed and performs image compression at a constant speed. It was recorded on a recording medium. For this reason, in the case of a subject that moves quickly as shown in FIG. 1A, the CPU performs output control at a constant speed. At this time, for example, even if there is an ability to output an image of three frames in a certain image output period, the number of frames in which the subject is photographed is two.

  In the embodiment of the present invention, as will be described later, the CPU acquires the motion (movement amount) of the subject detected by the motion detection unit and reflects it in the output control. For example, when the movement (movement amount) of the subject increases, the number of output frames per unit time is doubled in conjunction therewith. As a result, the number of frames in which the subject is photographed becomes four, and the movement of the subject can be recorded in more detail.

FIG. 1B shows how the subject slowly moves during shooting by the surveillance camera device.
For a slowly moving subject, the CPU determines that the amount of movement of the subject is small, and reduces the number of output frames per unit time to, for example, one half. In this case, since the subject is moving slowly, it is possible to record an image within a range where the movement of the subject can be sufficiently grasped, and to save the recording capacity of the recording medium.

FIG. 2 is a block diagram illustrating the configuration of the surveillance camera device according to the embodiment of the present invention.
Reference numeral 1 is a photographing unit, reference numeral 2 is a signal processing unit, reference numeral 3 is a memory 1, reference numeral 4 is a calculation unit, reference numeral 5 is a compression unit, reference numeral 6 is a memory 2, reference numeral 7 is a CPU, reference numeral 8 is a control unit 1, reference numeral Reference numeral 9 denotes a control unit 2, reference numeral 10 denotes a NIC (network interface card), and reference numeral 11 denotes a recording medium (HDD, DVD, video tape, etc.).

  The photographing unit 1 constitutes a lens and an image sensor that are not shown. The surveillance camera device according to the embodiment of the present invention includes a pan / tilt mechanism (not shown), and can photograph the subject by moving the photographing unit 1 in the pan / tilt direction.

  The light reflected from the subject is imaged by the image sensor through the lens. The lens is driven back and forth by a focus motor (not shown), thereby adjusting the focus of the image formed on the image sensor.

  The imaging element inputs an electrical signal obtained by converting the captured light into an electrical signal to the signal processing unit 2. The signal processing unit 2 extracts a video signal by sampling and holding for each pixel using a clamp pulse from an electric signal for each pixel generated by photoelectric conversion in the image sensor. The video signal obtained in this way is amplified with a predetermined gain and then converted from an analog video signal to a digital video signal. Thereafter, signal processing such as gamma and detail is performed and output to the memory 1 (3). The memory 1 (3) is composed of a semiconductor memory such as a DRAM and stores the video signal.

  The calculation unit 4 is controlled by the CPU 7 and has a motion detection function for detecting the motion vector from the difference between the frames of the video signal and recognizing the motion of the subject. Then, the motion vector is detected from the difference between the frames of the video signal (image data) stored in the memory 1 (3) to recognize the motion of the subject. The video signal (image data) stored in the memory 1 (3) is compressed by the compression unit 5 and stored in the memory 2 (6).

  At this time, the information is distributed from the NIC (network interface card) 10 to the network via the control unit 1 (8). In addition, a video signal (image data) is recorded on the recording medium 11 via the control unit 2 (9). The signal processing unit 2, the calculation unit 4, the compression unit 5, the control unit 1 (8), and the control unit 2 (9) are controlled by the CPU 7.

  In addition, the surveillance camera device according to the embodiment of the present invention has a function of acquiring the magnitude of a motion vector for each frame by a motion detection function. That is, the digitized image data is stored in the memory 1 (3) for each time series, and the calculation unit 4 detects a motion vector from the difference of the image data of each frame, and is proportional to the motion of the photographed subject. It has a function that can be replaced with a quantified numerical value.

  In addition, the surveillance camera device according to the embodiment of the present invention digitizes the magnitude of the motion vector and determines the storage interval (time) of the captured image based on the information. Specifically, the detected movement of the subject is compared with a predetermined threshold value.

  The CPU 7 manages the frame rate of the image data output from the memory 2 (6). Then, the time interval for distributing the image data stored in the memory 2 (6) via the NIC (10) and the time interval for storing in the recording medium 11 are controlled.

  Further, the CPU 7 acquires the movement amount (change amount) quantified by a motion detection unit (not shown) including the memory 1 (3) and the calculation unit (4). This is reflected in the frame rate output from the memory 2 (6). That is, the time interval for distributing to the network 10 and the time interval for storing in the recording medium 11 are lengthened or shortened according to the magnitude of the motion obtained by motion detection.

  When it is determined that the movement of the compared subject is faster than the threshold, the recording interval of the captured image to be recorded on the recording medium is shortened, and when the subject movement is determined to be slower than the threshold, the recording to be recorded on the recording medium is performed. Control is performed so that the image recording interval is increased.

FIG. 3 is a flowchart for explaining the operation of the surveillance camera apparatus according to the embodiment of the present invention.
Symbol S100 is a start step here (start). Then, it progresses to the step which attached | subjected code | symbol S101.
Reference numeral S101 is a step of detecting the motion of the subject in the image captured by the monitoring camera using the motion vector. Subsequently, the process proceeds to the step denoted by reference numeral S102.
Reference numeral S102 is a step of detecting whether or not there is a motion of the subject using the motion detection method. If it is determined that the movement of the subject has been detected, the process proceeds to the step denoted by S103 (Yes). If it is determined that no movement of the subject is detected, the process proceeds to the step denoted by reference numeral S101 and the above process is repeated (No).

Reference numeral S103 is a step for comparing the movement of the subject with a predetermined value (threshold value) as described above. Subsequently, the process proceeds to the step denoted by reference numeral S104.
Reference numeral S104 denotes a step of comparing the movement of the subject with a threshold and detecting whether the movement of the subject is the same as the threshold, whether the movement of the subject is larger than the threshold (fast), or whether the movement of the subject is smaller than the threshold (slow). is there. If it is determined that the movement of the subject is the same as the threshold, the process proceeds to the step denoted by S105 (same). If it is determined that the movement of the subject is larger (faster) than the threshold value, the process proceeds to the step marked S106 (larger (faster)). If it is determined that the movement of the subject is smaller than the threshold value (slowly), the process proceeds to the step labeled S107, which is small (slowly).

  Reference numeral S <b> 10 <b> 5 is a step of maintaining the time interval for distributing the image data to the network 10 or the time interval for storing the image data in the recording medium 11 as it is without being particularly changed. Subsequently, the process proceeds to the step denoted by reference numeral S101, and the above process is repeated.

  Reference numeral S10 6 denotes a step of shortening the time interval for distributing the image data to the network 10 or the time interval for storing the image data in the recording medium 11. Subsequently, the process proceeds to the step denoted by reference numeral S101, and the above process is repeated.

  Reference numeral S <b> 10 <b> 7 is a step of increasing the time interval for distributing the image data to the network 10 or the time interval for storing the image data in the recording medium 11. Subsequently, the process proceeds to the step denoted by reference numeral S101, and the above process is repeated.

  That is, the surveillance camera device according to the embodiment of the present invention detects the movement of the subject, converts the captured image of the moving subject into a video signal, and continuously records it on the recording medium. Then, a photographing means for photographing the subject, a video converting means for converting the photographed image into a video signal, a recording means for recording the photographed image converted into the video signal, and a motion detection for detecting the motion of the subject from the photographed image Means for comparing the detected movement of the subject with a predetermined threshold; if it is determined that the movement of the compared subject is faster than the threshold, the recording interval of the captured image to be recorded on the recording medium is shortened; When the movement of the image is determined to be slower than the threshold, the recording interval of the captured image to be recorded on the recording medium is set to be long.

  FIG. 4 shows the image quality (compression rate) of a recorded image in which image data is recorded on a storage medium (or distributed to the network 10) according to the moving speed of the subject in a surveillance camera device according to another embodiment of the present invention. It is a figure explaining how to control.

  In the above-described embodiment of the present invention, the recording interval is the control target. However, in another embodiment of the present invention, the amount of motion of the subject is linked to the captured image frame, and the compression rate corresponding to the amount of motion is linked. Apply.

For example, it is assumed that a person passes and motion is detected while the surveillance camera is monitoring a motionless video.
First, a process before a person passes will be described. At this time, since the video does not move before a person passes, the CPU 7 controls the compression unit 5 so that the image data remains at low image quality (high compression). Then, the image data subjected to the low image quality (high compression) compression is output to the memory 2 (6). As described above, this image data is distributed to the network 10 or stored in the recording medium 11.

  Next, processing when a passage of a person is detected will be described. When the passage of a person (that is, a moving subject) is detected, the CPU 7 controls the compression unit 5 and changes the compression rate so as to achieve high image quality (low compression). The image data is compressed with high image quality (low compression) and output to the memory 2 (6). The image data is distributed to the network 10 or stored in the recording medium 11.

  Next, processing when a person's passage is no longer detected will be described. When the passage of a person (a moving subject) is no longer detected, the process returns to the same process as before the person passed. That is, when the passage of a person (a moving subject) is no longer detected, the CPU 7 controls the compression unit 5 to change the compression rate so that the image quality is low (high compression). Then, the image data subjected to the low image quality (high compression) compression is output to the memory 2 (6). As described above, this image data is distributed to the network 10 or stored in the recording medium 11.

FIG. 5 is a diagram for explaining how to control the image quality (resolution) of a recorded image with respect to the moving speed of a subject in a surveillance camera device according to another embodiment of the present invention.
In another embodiment of the present invention, the amount of motion of the subject and the captured image frame are linked, and image quality (resolution) corresponding to the amount of motion is applied.
For example, it is assumed that a person passes and motion is detected while the surveillance camera is monitoring a motionless video.
First, a process before a person passes will be described. At this time, since the video does not move before the person passes, the CPU 7 controls the compression unit 5 so that the image data remains at a low resolution. The low-resolution compressed image data is output to the memory 2 (6). As described above, this image data is distributed to the network 10 or stored in the recording medium 11.

  Next, processing when a passage of a person is detected will be described. When the passage of a person (that is, a moving subject) is detected, the CPU 7 controls the compression unit 5 to change the reduction ratio so that the image data has a high resolution. Then, the image data is compressed at a high resolution and output to the memory 2 (6). The image data is distributed to the network 10 or stored in the recording medium 11.

  Next, processing when a person's passage is no longer detected will be described. When the passage of a person (a moving subject) is no longer detected, the process returns to the same process as before the person passed. That is, when the passage of a person (a moving subject) is no longer detected, the CPU 7 controls the compression unit 5 and changes the compression rate so that the resolution becomes low. The low-resolution compressed image data is output to the memory 2 (6). As described above, this image data is distributed to the network 10 or stored in the recording medium 11.

  By configuring as described above, in the embodiment of the present invention, the recording operation of the image data to the recording medium or the distribution operation to the network is changed according to the movement amount of the subject monitored by the monitoring camera, There is an effect that it is possible to reduce the amount of data of an image captured by the surveillance camera. Further, there is an effect that the recording capacity of the recording medium can be saved by reducing the amount of image data.

  Note that the present invention is not limited to the above-described embodiment as it is, and various modifications can be made to the constituent elements without departing from the spirit of the invention at the implementation stage.

FIG. 6 is a diagram for explaining how to control the interval of recorded images with respect to the moving speed of a subject in the monitoring camera device according to the embodiment of the present invention. The block diagram explaining the structure of the surveillance camera apparatus which concerns on embodiment of this invention. The flowchart explaining operation | movement of the surveillance camera apparatus which concerns on embodiment of this invention. The figure explaining how to control the image quality (compression rate) of the recorded image with respect to the moving speed of the subject in the surveillance camera device according to another embodiment of the present invention. The figure explaining how to control the image quality (resolution) of the recorded image with respect to the moving speed of the subject in the surveillance camera device according to another embodiment of the present invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Imaging | photography part (a lens, an image pick-up element), 2 ... Signal processing part, 3 ... Memory 1, 4 ... Calculation part, 5 ... Compression part, 6 ... Memory 2, 7 ... CPU, 8 ... control unit 1, 9 ... control unit 2, 10 ... NIC (network interface card), 11 ... recording medium (HDD, DVD, video tape, etc.).

Claims (8)

In a monitoring camera device that detects the movement of a subject, converts a captured image of the moving subject into a video signal, and continuously records it on a recording medium.
Photographing means for photographing the subject;
Video conversion means for converting the captured image into a video signal;
Recording means for recording a photographed image converted into a video signal;
Movement detection means for detecting movement of a subject from the photographed image;
A comparison means for comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the movement of the compared subject is faster than the threshold, the recording interval of the captured image to be recorded on the recording medium is shortened, and when the movement of the subject is determined to be slower than the threshold, the captured image to be recorded on the recording medium. A surveillance camera device comprising recording control means for controlling the recording to be performed with a longer recording interval. In a monitoring camera device that detects the movement of a subject, converts a captured image of the moving subject into a video signal, and continuously records it on a recording medium.
Photographing means for photographing the subject;
Video conversion means for converting the captured image into a video signal;
Recording means for compressing and recording the captured image converted into the video signal;
Movement detection means for detecting movement of a subject from the photographed image;
A comparison means for comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the movement of the compared subject is faster than a threshold value, the compression rate of the photographed image to be recorded on the recording medium is lowered, and when the subject motion is judged to be slower than the threshold value, the photographed image to be recorded on the recording medium. A surveillance camera device comprising recording control means for controlling so as to record at a high compression ratio. In a monitoring camera device that detects the movement of a subject, converts a captured image of the moving subject into a video signal, and continuously records it on a recording medium.
Photographing means for photographing the subject;
Video conversion means for converting the captured image into a video signal;
Recording means for recording a photographed image converted into a video signal;
Movement detection means for detecting movement of a subject from the photographed image;
A comparison means for comparing the detected movement of the subject with a predetermined threshold;
If it is determined that the movement of the compared subject is faster than the threshold, the resolution of the captured image to be recorded on the recording medium is increased, and if it is determined that the movement of the subject is slower than the threshold, the captured image to be recorded on the recording medium is increased. A surveillance camera device comprising recording control means for controlling to record at a reduced resolution. Shooting a subject,
Converting the captured image into a video signal;
Recording a captured image converted into a video signal;
Detecting a movement of a subject from the captured image;
Comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the movement of the compared subject is faster than the threshold value, the recording interval of the captured image to be recorded on the recording medium is shortened, and when it is determined that the subject movement is slower than the threshold value, the recording of the captured image to be recorded on the recording medium is performed. A method for photographing a surveillance camera, comprising the step of controlling to record at a longer interval. Shooting a subject,
Converting the captured image into a video signal;
A step of compressing and recording a captured image converted into a video signal;
Detecting a movement of a subject from the captured image;
Comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the compared movement of the subject is faster than the threshold, the compression rate of the captured image to be recorded on the recording medium is lowered, and when the movement of the subject is determined to be slower than the threshold, the captured image to be recorded on the recording medium is compressed. A method of photographing a surveillance camera, comprising a step of controlling to record at a high rate. Shooting a subject,
Converting the captured image into a video signal;
Recording a captured image converted into a video signal;
Detecting a movement of a subject from the captured image;
Comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the movement of the compared subject is faster than the threshold, the resolution of the captured image to be recorded on the recording medium is increased, and when the movement of the subject is determined to be slower than the threshold, the resolution of the captured image to be recorded on the recording medium is increased. A method for photographing a surveillance camera, comprising the step of controlling to record at a low level. In a monitoring camera device that detects the movement of a subject, converts a captured image of a moving subject into a video signal, and continuously outputs the video signal.
Photographing means for photographing the subject;
Video conversion means for converting the captured image into a video signal;
Output means for outputting a captured image converted into a video signal;
Movement detection means for detecting movement of a subject from the photographed image;
A comparison means for comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the compared subject movement is earlier than the threshold, the output interval of the output captured image is shortened, and when the subject movement is determined slower than the threshold, the output interval of the output captured image is increased. A surveillance camera device comprising a recording control means for controlling as described above. Shooting a subject,
Converting the captured image into a video signal;
Outputting a captured image converted into a video signal;
Detecting a movement of a subject from the captured image;
Comparing the detected movement of the subject with a predetermined threshold;
When it is determined that the movement of the compared subject is earlier than the threshold, the output interval of the captured image to be output is shortened, and when the movement of the subject is determined to be slower than the threshold, the output interval of the captured image to be output is increased. A monitoring camera photographing method comprising a step of controlling.

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