JP3518175B2 - Motion detection device, motion detection method, and video camera system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion detection device and a motion detection method suitable for application to, for example, a surveillance system using a video camera, and a video constructed based on the motion detection device and the motion detection method. It relates to a camera system.

[0002]

2. Description of the Related Art As a method of detecting the movement of a subject photographed by a photographing device such as a video camera, a difference value at the same address between an image of a current field and an image of a previous field is calculated and made into an absolute value. A general method is to integrate an absolute value over the entire field and detect the presence or absence of movement between fields based on the integrated value.

However, in the motion detecting method as described above,
For example, (1) when the moving object is deformed, rotated, or moved in perspective, (2) when the instantaneous moving amount of the moving object is large,
It has been found that motion detection becomes difficult when (3) the moving object has a repeating pattern, and (4) when the moving object partially overlaps with a fixed object in the surroundings. It was not suitable as a technique for automatically detecting motion in the surveillance system used. Further, since the calculation scale is large, the motion detecting device is expensive.

Therefore, the applicant of the present invention has previously proposed, for example, a motion detecting method adapted to be suitable for application to a surveillance system using a video camera (Japanese Patent Application No. 7-284537). In the present invention, the evaluation value of the image is calculated based on the luminance signal component of the video signal extracted from each predetermined area of the image. And
After obtaining the standard value based on the evaluation value in the normal state,
There is shown a configuration in which the movement of the image is detected by comparing the evaluation value obtained from the currently photographed image and the reference value for each area. As a result, even if the moving object is in the state described in (1) to (4) above, it is possible to detect the motion with high accuracy, and it is possible to perform the motion detection that is more suitable for the monitoring system. .

[0005]

However, in the above-described motion detection method proposed by the present applicant, the evaluation value of the image is obtained based on the luminance signal component. Not only when a moving object has entered the field of view, but also when there is a change in the brightness of a relatively large captured image, it is detected that there is movement. For example, there are various situations in which a monitoring system using a video camera can be used, but when monitoring a place where the degree of change in brightness is relatively large due to changes in sunshine and lighting, The change in the brightness of the photographed image should be no motion. However, when the motion detection is performed based on the change in the luminance signal as described above, the motion may be erroneously detected.

[0006]

In view of the above-mentioned problems, the present invention considers the above-mentioned problems, and a chroma signal extraction means for extracting a chroma signal component from a video signal, and an image which is set by dividing an image into predetermined areas. A chroma phase angle calculation means for calculating the phase angle of the chroma signal component for each area, and a motion detection determination element for each area based on the phase angle of the chroma signal component for each area calculated by the chroma phase angle calculation means. An evaluation value calculation means for calculating an evaluation value, a reference value holding means for obtaining and holding a reference value for motion detection based on the evaluation value under normal image conditions, and the evaluation value calculation means The motion detection device is provided with a motion detection unit that detects the presence or absence of image motion based on the result of comparison between the current evaluation value obtained as a result and the reference value held in the reference value holding unit. It was and.

Further, with respect to the configuration of the motion detecting device,
Other motion detection means capable of performing motion detection based on the luminance signal component of the video signal extracted for each of the predetermined areas, and detection information of both the motion detection means and other motion detection means It is decided to provide a motion detection identifying means for identifying the presence or absence of motion detection of an image by referring to.

As a motion detecting method of the present invention, a chroma signal component is extracted from a video signal, a phase angle of the chroma signal component for each predetermined area set by dividing an image is calculated, and the calculated chroma signal is calculated. Calculates the evaluation value that is the judgment factor for motion detection for each area based on the phase angle of the component, and obtains and holds the reference value for motion detection based on the above evaluation value under normal image conditions To do. Then, the current evaluation value and the held reference value are compared, and the presence or absence of image movement is detected based on the comparison result.

Further, as a video camera system of the present invention, an image pickup device, a data processing means for performing data processing using the output of the image pickup device, a monitor device for displaying the output of the image pickup device, and the image pickup device. And a warning device for recording the output of the. And
The data processing device includes at least the motion detecting device according to the present invention. When the motion detecting device detects that there is a motion in an image, the recording device and the alarm device are operated, and the monitor is operated. It is configured to execute a control for displaying a display indicating the area where the motion is detected for the device.

According to the above construction, in the present invention, the motion detection is performed based on at least the chroma signal component extracted from the predetermined area of the image. That is, the motion detection is performed based on the change in the color component of the image. Further, if the motion detection based on the chroma signal component and the motion detection based on the luminance signal component extracted from the predetermined area of the image are used together, the reliability of the motion detection can be further enhanced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. The following description will be given in the following order. 1. 1. Configuration example of video camera system 2. Configuration example of evaluation value calculation block 3. Configuration Example of Motion Detection Unit in Microcomputer 4. Processing operation for motion detection 5. Configuration of other motion detection unit Configuration Example of Motion Detection Device According to Another Embodiment (configuration in which a motion detection device using a luminance signal component is also used)

1. Configuration Example of Video Camera System FIG. 1 shows an overall block configuration of a video camera system as an embodiment of the present invention. The video camera system shown in this figure includes a video camera 1 for capturing an image of a specific surveillance area preset by a user, and a video camera 1
A data processing device 2 for detecting the movement of an object in a surveillance area based on a video signal from the monitor, a monitor device 8 for displaying the output of the video camera 1, and a video tape recorder (hereinafter referred to as VTR) for recording the output of the video camera 1. 4),
An alarm device 5 that performs an alarm operation by the output of the data processing device 2 and a synthesizing circuit 6 that synthesizes the white frame signal generated by the data processing device 2 with the output of the video camera 1 are provided.

The video camera 1 includes a CCD 11 for generating a video signal corresponding to a subject, a sample / hold AGC circuit 12 for performing sample / hold and gain adjustment on the output of the CCD 11, and a sample / hold.
An A / D conversion circuit 13 for converting the output of the AGC circuit 12 into, for example, a 10-bit digital signal, and a camera signal processing circuit 14 for subjecting the output of the A / D conversion circuit 13 to predetermined camera signal processing are provided. ing.

The data processing device 2 uses the digital data sent from the A / D conversion circuit 13 in the video camera 1 to calculate the evaluation value of the subject, and the evaluation value calculation block 1
5 and a microcomputer (hereinafter referred to as a microcomputer) 16 that detects the movement of the subject in the monitoring area based on the evaluation value sent from the evaluation value calculation block 15. When the microcomputer 16 detects the movement of the subject as described later, the microcomputer 16 controls the VTR 4 to start the recording operation of the captured image and controls the alarm device 5 to perform the alarm operation. As a result, when it is determined that the subject in the surveillance area is moving, the alarm device 5 is activated and the video signal captured by the video camera 1 is recorded. Further, the microcomputer 16 gives the evaluation value calculation block 15 a signal for designating a divided area (hereinafter referred to as a frame) in which one screen is divided into a plurality of areas. This "frame"
The designation of will be described later with reference to FIG. The evaluation value calculation block 15 calculates the evaluation value within the designated frame and sends it to the microcomputer 16. When a signal indicating that the subject is moving is received from the microcomputer 16, a white frame signal for designating the frame is created and output to the synthesizing circuit 6. The details of the data processing device 2 described above will be described later.

2. Configuration Example of Evaluation Value Calculation Block The block diagram of FIG. 2 is a block diagram showing a configuration example of the evaluation value calculation block 15 shown in FIG. The evaluation value calculation block 15 shown in this figure includes a Y, I, Q matrix circuit 21 and two systems of chroma phase angle calculation circuits (22, 2).
6), gate circuit (23, 27), integrating circuit (24, 2)
8) and a switch circuit (25, 29).

In the case of the present embodiment, the video signal data supplied from the A / D conversion circuit 13 of the video camera 1 shown in FIG. 1 to the evaluation value calculation block 15 corresponds to, for example, an RGB signal in pixel units. Digital data is supplied. The RGB signal data supplied from the A / D conversion circuit 13 is input to the Y, I, Q matrix circuit 21, and the luminance signal data (Y signal component), the I signal and the Q signal are input from this input signal. Chroma signal data consisting of Then, of the Y signal data and the chroma signal data extracted here, the chroma signal data is branched and output to the chroma phase angle calculation circuits 22 and 26.

Chroma signal data (I signal data and Q signal data) corresponding to each pixel is input to the chroma phase angle calculation circuits 22 and 26. Then, in the chroma phase angle calculation circuits 22 and 26, the value of the I signal data is I and the value of the Q signal data is Q,

[Equation 1] The phase angle of the chroma signal component (hereinafter simply referred to as the chroma phase angle) is calculated for each pixel by performing the calculation process represented by. That is, from the chroma signal component to the hue (Hu
Obtain the information in e). The chroma phase angle calculation circuits 22 and 2
The information signal of the chroma phase angle for each pixel calculated by 6 is supplied to the gate circuits 23 and 27, respectively.

The gate circuit 23 extracts a signal (chroma phase angle information signal) within a predetermined frame in the upper half of one screen, and a gate circuit 27 extracts a signal within a predetermined frame (chroma phase angle) in the lower half of the screen. Information signal of).

Now, the areas extracted by the gate circuits 23 and 27 will be described with reference to FIG. In this figure, the area surrounded by a thick line corresponds to one screen.
Here, one screen is vertically divided into two channels, A channel and B channel, and each is horizontally divided into 15, that is, one screen is divided into 30 frames.

The gate circuit 23 extracts the video data in the frame of the A channel for each field in order from the left end,
The gate circuit 27 sequentially extracts the video data in the frame of the B channel for each field from the left end. Further, the extraction of the video data in the frame of the A channel and the extraction of the video data in the frame of the B channel are performed in parallel or in time series. Here, the frame is set by the frame number output from the microcomputer 16.

From Odd of field # 0 to field #
With Odd of 7, that is, 15 fields, the extraction of the video data within the frame of the entire screen is completed. Then field #
After the video data in the leftmost frame of one screen is extracted in Even of 7, the video data in the leftmost frame of the screen is extracted again in Odd of field # 8, and then the above-described operation is repeated. That is, the video data in the leftmost frame of the screen is extracted twice within the 16-field period. This prevents the evaluation value, which will be described later, from changing due to the line difference between the odd field and the even field. The extracted data in the even field # 7 is processed separately from the Odd data in the field # 0 and used for motion detection.

As can be seen from the explanation of FIG. 3 above, the gate circuit 23 outputs 1 in the A channel (upper half of the screen).
An information signal of the chroma phase angle in pixel units is output for each of the five divided frames, and the gate circuit 27 outputs information of the chroma phase angle in pixel units for each of the 15 divided frames in the B channel (lower half of the screen). A signal will be output. The output of the gate circuit 23 is supplied to the integrating circuit 24, and the output of the gate circuit 28 is supplied to the integrating circuit 28.

The integrator circuit 24 integrates the chroma phase angle information signal supplied from the gate circuit 23 for each frame for each frame, and the integrator circuit 28 integrates the chroma phase angle information signal for each frame for each frame supplied from the gate circuit 27. Integration is performed on the phase angle information signal. As a result, the integration circuit 24
And 28, the integrated value of the chroma phase angle of the pixel existing in the frame unit can be obtained. By performing such integration, the average of the chroma phase angle in each frame can be obtained. There is.

The switch circuits 25 and 29 output the outputs of the integrating circuits 24 and 28 to the microcomputer 16 as evaluation values in frame units. The evaluation value output from the switch circuits 25 and 29 is formed of, for example, 2-byte data. Further, the numbers 1 to N attached to the outputs of the switch circuits 25 and 29 are the numbers of the frames described in FIG.
In the case of this embodiment, N = 16.
In the evaluation value calculation block 15 shown in FIG.
The functional blocks after the chroma phase angle calculation circuits 22 and 26 can be configured by software.

3. Configuration Example of Motion Detection Unit in Microcomputer FIG. 4 shows the configuration of one channel of the motion detection unit in the microcomputer 16. Therefore, in actuality, two sets of motion detecting units having the configuration shown in FIG. 4 are provided in response to the frame being divided into two channels, A and B, as shown in FIG. As shown in this figure, the motion detection unit in the microcomputer 16 inputs each evaluation value of the frame 1 to the frame N of the switch circuit 25 (or 29) shown in FIG. Configured to perform motion detection,
N motion detection blocks 41-2 to 41-N are provided. In the present embodiment, when the frame division method of FIG. 3 is used, 16 motion detection blocks are provided for each of the A and B channels. In this figure, a motion detection block 41 for detecting the motion of the frame 1
Although the internal configuration is shown only for −1 and the following description is also given for the motion detection block 41-1, the internal configuration is the same as the other motion detection blocks 41-2 to 41-2.
The same applies to 41-N.

The motion detection block 41-1 includes a maximum value register 51, a minimum value register 52, and a maximum value register 5.
A first comparator 53 that compares the value stored in 1 with the currently input evaluation value, and a first comparator 53 that compares the value stored in the minimum value register 52 with the currently input evaluation value. 2 comparator 54, switch SW1, switch S
W2 and a first sign that stores the sign of the output of the first comparator 53
Code register 55, a second code register 56 that stores the code of the output of the second comparator 54, and an AND gate 57 that performs a logical product of the first and second code registers 55 and 56. ing.

The switches SW1 and SW2 are three-state position switches. Maximum value register 51
And the minimum value register 52 include switches SW1 and SW2.
Stores the evaluation value when is connected to L (low).
The first and second sign registers 55 and 56 are always in the hold state except for storing the outputs of the first and second comparators 58 and 54.

The AND gate 57 determines that the subject within the frame is moving when either one of the outputs of the first and second code registers is L. The outputs of the detection blocks 411 to 41-N are sent to the AND gate 61. When the output of the AND gate 61 is L, it is determined that the subject in the plane is moving, and when the output is H, it is determined that there is no movement. That is, when the subject in at least one frame moves, the subject in the screen moves.

In the structure of the motion detecting section described above, except for the maximum value register 51, the minimum value register 52, and the code registers 55 and 56, the software of the microcomputer 16 is used. It can also be configured.

4. Processing Operation for Motion Detection Next, the processing operation when the microcomputer 16 actually executes the motion detection based on the configuration of the data processing device 2 described above with reference to FIGS. 2 to 4 will be described. Figure 5
3 is a flowchart showing the flow of the entire motion detection process by the microcomputer 16. Of the processing steps shown in this figure, step S1 and step S2 are executed while the user (monitor) monitors the screen of the monitor device 3 while confirming that there is no abnormality in a state where the monitoring area is normal. To do.

In step S1, various necessary initial settings are made. Then, in the next step S2, the reference value for motion detection is calculated by performing the following operations (1) to (5) for each frame. (1) The switches SW1 and SW2 (FIG. 4) are set to the L position, and the evaluation value of the frame is stored in the maximum value register 51 and the minimum value register 52. At this time, the value of the maximum value register 51 and the value of the minimum value register 52 become equal.

(2) The switches SW1 and SW2 are set to the M position, and the evaluation value is set to the first and second comparators 53.
And 54. (3) When the evaluation value is larger than the value of the maximum value register 51, the output of the first comparator 53 becomes L. At this time, the value of the maximum value register 51 is updated with the evaluation value. Further, when the evaluation value is smaller than the value of the minimum value register 52, the output of the second comparator 54 becomes L. At this time, the value of the minimum value register 52 is updated with the evaluation value. When the evaluation value is between the value in the maximum value register 51 and the value in the minimum value register 52, the values in these registers are not updated. The above operation is performed, for example, tens of times for each frame. The number of times (time) is set to the shortest time during which a normal motion cycle enters within the visual field of the video camera. For example, when there are swaying trees or neon flashes in the image field of view, it is necessary to set the period to be greater than or equal to the cycle of those motions. At this time, the frame 1 is continuously performed tens of times, and then the frame 2 is continuously performed tens of times.
After that, it may be performed several tens of times for each of the frames 3, 4, ... N, or once for each of the frames 1, 2, 3 ,.
You may repeat dozens of times.

(4) When the calculation of the reference value is completed by performing the above operation (3) several tens of times for each frame, the switches SW1 and SW2 are set to L for each frame to set the maximum value register 51 to the value. The value obtained by adding the predetermined value α is the maximum value register 51.
And the reference value θx _(max) (x: frame number (see FIG. 3)) of
A value obtained by subtracting a predetermined β from the value of the minimum value register 52 is set as a reference value θx _(min) (x: frame number) of the minimum value register 52.

The predetermined values α and β are margin values. In other words, the maximum evaluation value is taken into consideration in consideration of the change in state that corresponds to the maximum value and the minimum value of the evaluation value obtained by the procedure of (3) above that may occur during normal monitoring. By giving the margin values α and β to the value and the minimum value, respectively, and setting them as the reference values to be actually stored in the maximum value register 51 and the minimum value register 52, for example, in the normal time of the monitoring area, the evaluation value A relatively small state change that exceeds the maximum value and the minimum value of can be regarded as motion detection. After this, the switches SW1 and SW2 are set to H, and the reference values θx _(max) and θx _(min) are held in the maximum value register 51 and the minimum value register 52, respectively.

(5) In the above (4), when the reference values θx _(max) and θx _{(min )} are held for all the frames, the code registers in all the blocks 41-1 to 41-N in FIG. Set the values of 55 and 56 to H.

Next, in step S3, the motion detection output is obtained by performing the following operations (1) to (5) for each frame. (1) Input an evaluation value for an arbitrary frame. (2) The reference value of the minimum value register 52 is θx _(min) , the reference value of the maximum value register 51 is θx _(max) , and the current evaluation value is θx.

[Equation 2] When the comparison result is obtained, the output of the first comparator 53 becomes L. Also,

[Equation 3] If a comparison result is obtained, the second comparator 54
Output becomes L. In these cases, AND gate 5
Since the output of 7 becomes L, it is determined that there is movement within the frame.

(3) As in the case of (2) above, the reference value of the minimum value register 52 is set to θx _(min) and the maximum value register 5 is set.
With the standard value of 1 as θx _(max) and the current evaluation value as θx,

[Equation 4] When the comparison result is obtained, the detection output of the AND gate 61 becomes H. Then, in this case, it is determined that there is no movement within the screen.

(4) The above operation is performed for each frame, and after one cycle, the process returns to the beginning of step S3, and the same processing is repeated.

(5) When the detection output of the AND gate 61 is L, that is, when a motion is detected in at least one of the frames, the frame in which the motion is detected is reduced by a white frame. Along with the display, the process of operating the alarm device 5 and the process of setting the recording mode for recording the captured image by the VTR 4 are performed in parallel.

5. Configuration of Other Motion Detection Unit FIG. 6 shows another configuration that can be used as a motion detection unit in the microcomputer 16 instead of the configuration shown in FIG. The motion detection unit having the configuration shown in this figure is suitable when the monitoring area is an environment where there are few clear image changes within the field of view of the video camera in normal times, such as when the monitoring area is indoors. It is said that

As shown in FIG. 6, the motion detecting section includes reference value registers 71-1 to 71-for storing reference values for each frame.
N, comparators 72-1 to 72-N for comparing the value stored in the reference value registers 71-1 to 71-N with the currently input evaluation value, and switches SW-1 to SW-N.
, Code registers 73-1 to 73-N for storing the codes of the outputs of the comparators 72-1 to 72-N, and comparators 72-l to
Code register 74-1 for storing the code of the output of 72-N
~ 74-N and code registers 73-1 to 73-N and 7
The AND gate 75 takes the logical product of 4-1 to 74-N.

Reference value registers 71-1 to 711-N store evaluation values when switches SW-1 to SW-2 are connected to L, respectively. Here, the reason that there is one register for storing the evaluation value for each frame will be described with reference to FIG. 7.

FIG. 7A shows an example of the maximum value of the evaluation value input from the evaluation value detection block 15 in an environment where there is no clear surface image change in the visual field of the video camera in a normal state. 7 (b) is an example of the minimum value. The evaluation value consists of 2 bytes. Then, since the lower 4 bits are fluctuation components due to noise, etc., FIG.
It is common to (b). The 12th to 7th bits are also fixed values common to FIGS. 7A and 7B. That is,
Only the fifth bit and the sixth bit may have different values in FIGS. 7A and 7B. Therefore, in FIG.
As shown in (c), the reference value registers 71-1 to 72-
The evaluation value to be stored in N is one, and it is rounded to 1 byte.

Code registers 73-1 to 73- shown in FIG.
N and 74-1 to 74-N are comparators 72-1 to 7-7, respectively.
It is always in a hold state except that it stores the 2-N output. Sign registers 73-1 to 73-N and 74-1 to 7-7
The contents of the data latched by 4-N will be described later.

Sign registers 73-1 to 73-N and 74
The data stored in -1 to 74-N is the AND gate 75.
Sent to. When the output of the AND gate 75 is L,
It is assumed that the subject on the screen has a motion, and when H, there is no motion. That is, when the subject in at least one frame moves, the subject in the screen moves.

When the motion detecting section is constructed as shown in FIG. 6, the motion detecting process by the microcomputer 16 is slightly different from the case where the motion detecting section is constructed as shown in FIG. Next, the flow of motion detection processing corresponding to the motion detection unit shown in FIG. 6 will be described. Note that the flow of the entire motion processing is the same as the flowchart of FIG. 5 described above. Also in this case, step S1
And S2 are performed under the condition that the monitoring area is normal. That is, the user monitors the screen of the monitor device 8,
Execute it while confirming that there are no abnormalities.

First, in step S1, various initial settings are made. Next, in step S2, a reference value for motion detection is calculated for each frame. This sets switches SW-1 to SW-N to 1
This is executed by sequentially setting the L position for each field period and storing the evaluation value (integrated value of the chroma phase angle) of each frame in the reference value registers 71-1 to 71-N.
After storing, switch each switch SW-1 to SW-N to H level.
Set the position to the reference value register 71-1 to 71-
Hold the value of N.

This completes the calculation of the reference value. That is,
Since the calculation of the reference value in the motion detection unit shown in FIG. 6 is completed 1 times for each frame, when the number of frames is N, it ends in N field periods. On the other hand, in the case of the motion detection unit having the configuration shown in FIG. 4, the maximum value and the minimum value are calculated tens of times for each frame, so that the process ends in N × tens of field periods. Therefore, the time required to obtain the reference value can be shortened when the motion detection unit shown in FIG. 6 is adopted. When the calculation of the reference value is completed, all the values of the code registers 73-1 to 73-N and 74-1 to 74-N are set to H.

Next, in step S3, a motion detection output is obtained by performing the following operations (1) to (4) for each frame. (1) Input an evaluation value for an arbitrary frame. (2) Each value X of the reference value registers 71-1 to 71-N
X1-β to XN- which are values obtained by subtracting the value β from 1 to XN
Let β be the reference values Y1 to YN of each reference value register, and compare it with the current evaluation values Z1 to ZN of each frame. Then, for example, in the case of frame 1, if the relationship of Y1 ≦ Z1 is established, it is assumed that there is no movement in this frame (output H), and Z1
If the relationship of <Y1 is established, it is assumed that there is movement in this frame (output L). This output is stored in the code register 73-1.

The reference value registers 71-1 to 71-N
X1 + which is a value obtained by adding the value α to each value X1 to XN of
α to XN + α are reference values Y1 ′ to Y of the reference value registers
N ′ and compare it with the current evaluation values Z1 to ZN of each frame. Then, for example, in the case of frame 1, Y1 '<
If the relationship of Z1 is established, there is movement in this frame (output L), and if the relationship of Z1≤Y1 'is established, there is no movement in this frame (output H). This output is stored in the code register 74-1.

(3) The above operation is performed for each frame,
After one cycle, the process returns to the beginning of step S3 and the same process is repeated.

(4) When the detection output of the AND gate 75 is L, that is, when the motion is detected in at least one of the frames, the frame in which the motion is detected is displayed as a white frame with a dot reduction. At the same time, the process of operating the alarm device 5 and the process of setting the recording mode for recording the captured image by the VTR 4 are performed in parallel.

As described above, in the present embodiment, the motion is detected based on the chroma phase angle calculated from the chroma signal component (I signal, Q signal) of the video signal. As a result, even if there is a large change in the brightness (brightness) of the monitoring area due to factors such as lighting and sunshine, such a change will not be detected as movement. So, for example,
A motion detection device suitable for applications such as a surveillance camera system can be obtained.

Also in the motion detecting apparatus of this embodiment, the moving object is deformed, rotated, or
When performing perspective movement, (2) when the instantaneous amount of movement of the moving object is large, (3) when the moving object has a repeating pattern, and (4) when the moving object partially overlaps with surrounding fixed objects. Accordingly, a good motion detection result can be obtained, and the circuit scale of the motion detection device can be small.

6. Configuration Example of Motion Detection Device According to Other Embodiment (Configuration Using Motion Detection Device Using Luminance Signal Component Together) The motion detection device according to the present embodiment described above is
Although a configuration is adopted in which the motion is detected based on the chroma phase angle obtained from the chroma signal component, as described above, the applicant previously moved based on the luminance signal (Y signal) component of the video signal. A configuration for performing detection has been proposed (Japanese Patent Application No. 7-284537). Therefore, as another embodiment of the present invention, a configuration will be described below in which a motion detection device that performs motion detection based on a chroma signal component and a motion detection device that performs motion detection based on a luminance signal component are used together. . That is, in the present embodiment, the motion detection of the image is performed based on the motion detection results of the two motion detection devices. In this way, by configuring the entire motion detecting device by using the two motion detecting devices together, for example, the accuracy of motion detection is improved as compared with the case of using the motion detecting device that detects the motion based on the chroma signal component. It will be possible.

The overall structure of the motion detecting device according to the present embodiment may be the same as that shown in FIG. 1, but the data processing device 2 uses the motion using the chroma signal component. The detection processing unit and the motion detection processing unit using the luminance signal component are provided. Then, the motion detection processing unit using the chroma signal component may perform the process according to the flowchart of FIG. 5 based on the configuration shown in FIG. 2 and FIG. 4 (or FIG. 6) previously. It Therefore, a configuration example of the motion detection processing unit using the luminance signal component in the data processing device 2 of the present embodiment will be described below.

FIG. 8 is a block diagram showing the structure of the evaluation value calculation block 15 in the data processing device 2, which shows the structure of the evaluation value calculation block for detecting the motion based on the luminance signal component. In the brightness signal evaluation value calculation block shown in this figure, first, the A / D conversion circuit 13 (see FIG.
Is provided with a low pass filter 101 for separating a luminance signal component from digital data output from
The luminance signal data separated by the low pass filter 101 is input to the clamp circuit 102. In the case of the present embodiment, as the brightness signal data input to the clamp circuit 102, the brightness signal data extracted by the Y, I, Q matrix 21 shown in FIG. 2 is input. The low pass filter 101 can be omitted in such a configuration. The luminance signal data input to the clamp circuit 102 is data in pixel units.

The clamp circuit 102 clamps the input luminance signal data, and the high pass filter 1
Output to 03. The high pass filter 103 detects the edge component of the clamped luminance signal data. The cutoff frequency of the high-pass filter 103 is, for example, 100 in consideration of extracting an edge of a low-luminance subject.
Set to about KHz.

The output of the high pass filter 103 is branched and supplied to the gate circuits 104 and 108. The gate circuit 104 extracts the signal in the upper half frame of the screen in the area shown in FIG. 3 by the control signal for designating the frame number output from the microcomputer 16. On the other hand, the gate circuit 108 extracts the signal within the frame in the lower half of the screen by the control signal that specifies the frame number output from the microcomputer 16. The extraction method is the same as the method described above with reference to FIG. In addition, the extraction order and extraction timing of the frames are set so as to be synchronized with the operation of the evaluation value calculation block corresponding to the chroma signal.

The signals extracted in frame units by the gate circuits 104 and 108 are respectively held by the peak hold circuit 10.
5, 109 are supplied. Peak hold circuit 105,
At 109, the peak value in the horizontal direction of the input signal is held. At this time, instead of one peak value, two or three peak values may be held and output. Then, the peak hold circuit 10
The outputs of 5 and 109 are V integration circuits 106 and 1 respectively.
09, where the peak value held for each horizontal line is vertically integrated. For example, assuming that the number of effective lines in one field is about 240, about 120 peak values are integrated for each.

In the switch circuit 107, the V integration circuit 106
The integrated value input from is used as the evaluation value and is switched and output for each frame number previously designated by the gate circuit 104. Similarly, in the switch circuit 111, the integrated value input from the V integration circuit 110 is used as an evaluation value, and the gate circuit 108 is used first.
The frame numbers specified by are switched and output. Also in this case, the evaluation value may be formed of, for example, 2-byte data, as in the case of the motion detection system based on the chroma signal. The configuration of the evaluation value calculation block based on the luminance signal shown in FIG. 8 is an example, and various other configurations are possible.

In the subsequent stage of the switch circuits 107 and 111, apart from the circuit system for motion detection by the chroma signal component,
A motion detector having the same configuration as that shown in FIG. 4 (or FIG. 6) is provided. Then, also in the motion detection processing system based on the luminance signal, as the motion detection processing by the microcomputer 16, the processing according to the description of the flowchart of FIG. 5 may be performed previously. Further, in the case of the present embodiment, the processing operation of motion detection based on the luminance signal is performed in parallel with the processing operation of the chroma signal system.

However, in this case, the motion detection processing system based on the luminance signal and the motion detection processing system based on the chroma signal
The presence or absence of motion detected by the processing of the flowchart of FIG. 5 is assumed to be detected only on the basis of the luminance signal component and only on the chroma signal component. The configuration will be described later. Further, in the case of the motion detection processing system based on the luminance signal, for example, in the initial setting stage of step S1 of the flowchart of FIG. 5, the high pass filter 10 shown in FIG.
3 cutoff frequency, peak hold circuit 105,
When the setting of the number of peaks to be held in 109 can be changed, these settings can be made. When the motion detecting unit shown in FIG. 4 is adopted in the motion detection processing system based on the luminance signal, the maximum value register 51 of each motion detection block stores the calculated maximum value D1 _{(max) in} normal times. A value obtained by adding a predetermined margin value α to DN _(max) D1 + α _{(max) to} DN
_(max) + α is set as the standard value. Further, the minimum value register 52 of each motion detection block has a value D1-β _{(min )} obtained by subtracting a predetermined margin value β from the calculated maximum values D1 _{(min) to} DN _{(min) in} normal times. ₎ ~ DN
_(max) -β is set as the reference value. Then, in step S3, these reference values D1 + α _{(max) to} DN
_(max) + α, and D1-β _{(min) to} DN _(max) -β,
For the current evaluation values D1 to DN of each frame, by performing the processing in accordance with the comparison processing described in the above embodiment,
Motion detection is performed based on the luminance signal component.

In the present embodiment, for example, if the motion detector of FIG. 4 is adopted, the output of the AND gate 61 of the motion detector based on the luminance signal component and the motion detector based on the chroma signal component. Based on the output of the AND gate 61 of
The microcomputer 16 is configured. That is, FIG.
As shown in (a), an OR gate 81 for inputting the outputs of both AND gates 61 is provided, and the final judgment of the motion of the image is made based on the output of the logical sum by the OR gate 81.

As can be seen from the above description, AND
When the output of the gate 61 is H, it is determined that there is no motion detection, and when the output of the gate 61 is L, it is detected that there is motion. Based on this, in this embodiment, the motion detection determination is performed as shown in FIG. 9B. That is, when the output of the AND gate 61 of the motion detection unit based on the luminance signal component and the output of the AND gate 61 of the motion detection unit based on the chroma signal component are both set to L and the output of the OR gate 81 is set to L. It is determined that there is a movement only in. In the present embodiment, when it is determined that there is motion in this way, the microcomputer 16 blinks the frame in which the motion has been detected in a white frame, and
A process for operating the alarm device 5 and a process for starting the recording operation of the VTR 4 will be performed.

On the other hand, one of the output of the AND gate 61 of the motion detector based on the luminance signal component and the output of the AND gate 61 of the motion detector based on the chroma signal component is H, or both of them are H. If the output of the OR gate 81 is H, it is determined that there is no motion.

Specifically, for example, while the output of the AND gate 61 of the motion detecting section based on the luminance signal component is L (moving), the output of the AND gate 61 of the motion detecting section based on the chroma signal component is If it is determined to be H (no movement), there is a high possibility that, for example, the brightness in the monitoring area changes due to some factor, and no abnormality actually occurs. For example, in the case where the motion detection is performed based on only the luminance signal component, the above state is detected as motion and the alarm device 5 or the VTR is detected.
No. 4 is operated, but by combining the motion detection of both as in the present embodiment, the possibility of such malfunctions is reduced, and the reliability of the surveillance camera system is improved. Become.

The motion detecting apparatus of the present invention can be applied not only to the surveillance camera system (which monitors intruders, fires, accidents, etc.) described in the above embodiments, but also to the following system. It is suitable. (1) Product Limitation An inspection system that sets the limiter for motion detection from sample products and inspects the appearance of products. (2) Set the camera body type VTR to the desired angle,
A recording device that realizes power saving and field absence recording by starting recording as soon as a moving object enters the angle. (3) Automatic tracking system for moving objects. (4) Door phone.

The present invention is not limited to the above-described embodiments, but various changes can be made according to actual use conditions. For example, in the present embodiment, the I signal is used as the chroma signal component. The chroma phase angle is obtained based on the Q signal, and the motion is detected based on the chroma phase angle. For example, the color difference signals of RY and BY and the color signal (RGB signal) itself are detected. It may be considered that the motion detection is performed based on the signal obtained.

[0070]

As described above, according to the present invention, the motion detection is performed based on the chroma phase angle obtained from the chroma signal component. However, it is possible to detect that there is no movement with respect to a simple change in brightness. Therefore, for example, in a usage environment of the surveillance camera system, there is no movement with respect to a sudden change in brightness. In the case where such an operation is required, a surveillance camera system with higher reliability for the user can be obtained. Then, by combining with a method of performing motion detection based on a luminance signal, the inconvenience (detecting a change in lightness as movement) occurring in the case of a motion detection method using only a luminance signal is compensated for, and more accurate detection is performed. It is possible to obtain a motion detection device that can perform high motion detection.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall block configuration of a video camera system as an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of an evaluation value calculation block according to the present embodiment.

FIG. 3 is a diagram showing an example of division setting of a frame.

FIG. 4 is a block diagram showing a configuration example of one channel of a motion detection unit.

FIG. 5 is a flowchart showing the overall flow of motion detection processing.

FIG. 6 is a block diagram illustrating another configuration example of a motion detection unit.

FIG. 7 is a diagram showing a data structure of reference values stored in the motion detection unit of FIG.

FIG. 8 is a block diagram showing a configuration example of an evaluation value calculation block using a luminance signal component.

9A and 9B are a circuit diagram and an explanatory diagram for explaining a motion detection operation when using each motion detection system based on a chroma signal component and a luminance signal component together.

[Explanation of symbols]

1 video camera, 2 data processing device, 8 monitor device, 4 VTR, 5 alarm device, 21 Y, I, Q matrix, 22, 26 chroma phase arithmetic circuits, 23, 27
Gate circuit, 24, 28 Integration circuit, 25, 29 Switch circuit, 51 Maximum value register, 52 Minimum value register, 53, 54, 72-1 to 72-N comparator, 71
-1-71-N standard value register, 55, 56, 73-
1-73N code register, 57, 61, 75, AN
D gate, 81 OR gate

Claims (6)

(57) [Claims] 1. A chroma signal extraction means for extracting a chroma signal component from a video signal, and a chroma phase angle for dividing and setting an image for each predetermined area and calculating a phase angle of the chroma signal component for each area. Calculation means, based on the phase angle of the chroma signal component for each area calculated by the chroma phase angle calculation means, an evaluation value calculation means for calculating an evaluation value serving as a determination factor for motion detection for each area, Under an image condition that is normally set, a reference value holding unit that obtains and holds a reference value for motion detection based on the evaluation value, and a current evaluation value obtained by the evaluation value calculation unit, Compare with the reference value held in the reference value holding means,
A motion detection device comprising: a motion detection unit that detects the presence or absence of image motion based on the comparison result. 2. The motion detecting apparatus according to claim 1, wherein the evaluation value calculating means includes an integrating means for integrating the phase angle of the chroma signal component. 3. Another motion detecting means capable of performing motion detection based on a luminance signal component of a video signal extracted for each of the predetermined areas, detection information of the motion detecting means, and the other motion. The motion detecting apparatus according to claim 1, further comprising: a motion detecting / identifying unit for identifying presence / absence of motion detection of an image by referring to detection information of the detecting unit. 4. A chroma signal component is extracted from a video signal, a phase angle of the chroma signal component for each predetermined area set by dividing an image is calculated, and based on the calculated phase angle of the chroma signal component. For each area, calculate the evaluation value that is the judgment factor for motion detection, and under normal image conditions, obtain and hold the reference value for motion detection based on the above evaluation value. A motion detecting method comprising: comparing an evaluation value with the held reference value, and detecting the presence or absence of motion of an image based on the comparison result. 5. Detection information for motion detection based on a luminance signal component of a video signal extracted for each of the predetermined areas,
The motion detection method according to claim 4, wherein the motion detection method is used as an identification element for determining whether or not the motion of the image is detected. 6. An imaging device, a data processing means for performing data processing using the output of the imaging device, a monitor device for displaying the output of the imaging device, and a recording device for recording the output of the imaging device. As a video camera system provided with an alarm device, the data processing device comprises at least a chroma signal extraction means for extracting a chroma signal component from a video signal, and an image divided into predetermined areas for setting and a chroma signal for each area. Chroma phase angle calculation means for calculating the phase angle of the component, based on the phase angle of the chroma signal component for each area calculated by the chroma phase angle calculation means, the evaluation as a motion detection determination element for each area An evaluation value calculating means for calculating a value and a standard value for motion detection based on the above evaluation value are obtained and held under normal image conditions. The reference value holding means, the current evaluation value obtained by the evaluation value calculating means, and the reference value held in the reference value holding means are compared, and the movement of the image based on the comparison result is compared. A motion detecting unit for detecting the presence / absence is provided, and when the motion detecting unit detects that the image has a motion, the recording device and the alarm device are operated, and the motion is detected with respect to the monitor device. A video camera system characterized by being configured to execute a control for displaying to show the area.