JPS6377285A - Video signal processing device - Google Patents

Abstract

PURPOSE:To execute a reference updating without being influenced by a noise and interrupting for the image change detection by comparing a reference signal and a video signal, detecting an image change and forming the data to update the reference signal in parallel to this at a comparing process. CONSTITUTION:Plural television cameras 10 input a video signal to a switcher 12, one of signals is selected, sent to a monitoring device 14 and a signal is sent to a video signal processing device 100 with a prescribed sequence and timing. The device 100 compares the binary image data with the reference data set beforehand, and when both data are not coincident, a change detecting signal is generated and an alarm is generated. At this time point, a recording device 16 records the video signal. Reference data sample and compare the video signal for plural fields, makes the signal area of the reference signal corresponding to the picture element, in which a logical value level is changed between respective fields, into a dead band, the comparison of the reference signal and the video signal is executed at the area and the updating of the reference signal is executed at a comparing process.

Description

[Detailed description of the invention] The present invention will first be described below.

A Industrial application field B Summary of the invention C Prior art n H 1irlA(9'2;h l
& Q l-J-f 日Q l'Jj 7E Means for solving the problem F Effect G Embodiment I Effect of the invention A Industrial application field This invention is applicable to the photographing of television cameras, video cameras, etc. The present invention relates to a video signal processing device for detecting fluctuations in image information of a video signal input from the device.

In particular, the present invention relates to a video signal processing device for automatically detecting changes in image information in a monitoring device such as a so-called security camera device that monitors a predetermined area using a photographing device.

B. Summary of the Invention The present invention detects image fluctuations in a monitoring device using a television camera or the like by comparing a video signal input from an imaging device with a preset basic signal. By updating the reference signal at a predetermined timing in the processing device of the Toeiso Igo, the reference signal is made to adapt to environmental changes in the monitoring area monitored by the monitoring device. Further, in the present invention, the data for updating the reference signal is formed in the image variation detection process in which an image is detected by comparing the reference signal and the video signal, so that image variation detection is continuously performed in the reference signal process as well. It was made so that it could be done.

C. Prior Art Conventionally, a predetermined surveillance area has been photographed using a photographing device such as a television camera or a video camera, and by monitoring the images, abnormalities such as a thief's intrusion into the surveillance area have been detected. Monitoring devices such as so-called security cameras are known.

In conventional monitoring devices, image information output from a photographing device is played back on a monitor screen such as a CRT, or monitored using a VTR (video tape recorder).
The device is configured to record.

In this case, the former method has the inconvenience of requiring a human to monitor the monitor, while recording on a VTR is restricted by the recording time of the VTR tape. In addition, in the latter case, attempts have been made to record by dropping frames in order to lengthen the recording time of VTfl, but in this case, if the thinned out video signal contains image information indicating an abnormality, this is not possible. It had the disadvantage that it could not be detected.

In order to solve these conventional problems, a device has been proposed that automatically detects image changes by processing a video signal output from a photographing device.

This type of device is known, for example, from Utility Model Application Publication No. 53-1120226.
is shown. In this device, a video signal input from a photographing device is compared with a video signal from one field before, and a comparison output indicating the number of pixels whose image information does not match is obtained.
This comparison output is compared with a predetermined threshold, and if the value of the comparison output exceeds the threshold, it is determined that there has been a change in the image.

D. Problems to be Solved by the Invention However, in this type of video signal processing device, prevention of false detection due to the influence of noise superimposed on the video signal has become an important issue. In other words, the video signal is superimposed with noise such as flicker noise caused by the discrepancy between the blinking cycle of the fluorescent lamp and the imaging cycle of the imaging device, and the influence of this noise does not actually cause any abnormality in the monitored area. However, there was a risk that fluctuations in the image due to noise could be detected and the system would conclude that there was an abnormality in the monitored area. In order to prevent false detection due to the influence of this noise, it may be possible to make the threshold value relatively large, but by setting the threshold value large, changes in image information will occur in a relatively small number of pixels below the threshold value. 1) Image fluctuations become undetectable.

Therefore, the detection sensitivity of the monitoring device to abnormalities in the monitoring area is reduced.

Therefore, in order to solve these problems, the applicant processes the video signal to form a reference signal as comparison data.
We proposed a device by comparing this reference signal with the video signal.

The present invention aims to efficiently form a reference signal in a video signal processing device proposed by the applicant, and is a video processing method that does not interrupt image fluctuation detection processing of a video signal due to the reference signal formation processing. The purpose is to provide 4 bags.

E. Means for Solving the Problems In order to achieve the above and other objects, the video signal processing device according to the present invention compares the video signal input from the imaging device Z such as a television camera with a reference signal, and calculates the video signal. In a video signal processing device that detects fluctuations in image information, 11τ Create update data to update the base signal, and update the base signal at a predetermined timing.
It is characterized in that it is updated using Fj update data.

F Function According to the present invention, in the process of comparing the reference signal and the video signal to detect image fluctuations, data for updating the reference signal is formed in parallel with this process, so that the image fluctuations are detected. The reference signal can be updated without interrupting the detection process.

In particular, since the video processing device of the present invention can update the reference signal as described above without interrupting the image fluctuation detection process, it is possible to update the reference signal without interrupting the image fluctuation detection process, so that the video signal processing device can be will be able to be carried out smoothly.

G. Embodiment Hereinafter, an example in which a video signal processing device according to a preferred embodiment of the present invention is used as an image variation detection device of a monitoring device using a television camera or the like will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram schematically showing a monitoring device including a video processing device of the present invention. As shown in FIG. 1, the monitoring device has a plurality of television cameras 10. Each camera 10 outputs image information of a predetermined monitoring area as a video signal. The video signal output from the camera 10 is transmitted to the switcher 1
Please enter 2. The switcher 12 includes a monitor device 14 configured with a CRT or the like. A video signal processing device 100 according to a preferred embodiment of the present invention is connected to a recording device such as a video printer and a video signal processing device 100 for processing video signals and detecting image variations. Control panel 1 that controls the monitoring device by
8 are connected.

The switcher 12 receives video signals input continuously from each camera 10, selects one of the input video signals, and outputs the selected video signal to the monitor device 14. The monitor device 14 reproduces image information included in the video signal input from the switcher 12 on a monitor screen. The switcher 12 normally selects video signals by connecting the video signal inputs to the monitor device 14 in a predetermined order and timing, but if a camera is designated from the control panel 18, the video signals are selected from the designated camera 10. The input video signal is sent to the monitor device 14. The switcher 12 further switches the video signals from each camera input to the video signal processing device 100 in a predetermined order and timing. In the illustrated embodiment, the switcher I2 is configured to switch the video signal to the monitor device 14 and to switch the video signal to the video signal processing device 100, respectively, independently. 14 and the video signal processing device 100 are configured to be performed independently. This is the second problem in which visual monitoring of the monitor device is virtually impossible when the image on the monitor is switched by changing the signal processing speed of the video signal processing device. Therefore, in the switch 12, the video signal to the monitor device 14 is switched by visual monitoring or at possible time intervals, while the video signal to the video signal processing device is switched by processing the video signal from each camera or continuously. It will be done at a convenient time.

The video signal processing device 100 converts the video signal into a logical value “1”,
It has a binarization circuit that converts it into digital data of 0" and 0" in a tree-like manner.The threshold level used in the binarization of the video signal in the binarization circuit can be automatically adjusted. However, in the illustrated example, this can be done by manual operation of the control panel 18.The video signal processing device 100 compares the binarized image data with preset reference data and detects that the two data do not match. A variation detection signal indicating a variation in the image is generated when the image changes.This variation detection signal excites the alarm generation device 20 provided in the switcher 12 to generate an alarm.In the illustrated example, the alarm generation device 20 is connected to the switcher 12. However, it is naturally possible to connect this as an external device to the switcher 12 or the video signal processing device.Furthermore, when the fluctuation detection signal is input, the switcher 12 sends the control signal and fluctuation to the recording device. The image data at the time when is detected is output.This control signal causes the recording device 1 to
6 is also activated and records the image information at the time of detection of the fluctuation. As a recording device, it is possible to use a VTR device 9°L to drive the VTR for a predetermined period of time to record the video signal when a change in the image is detected, or in this example, a video printer is used. The apparatus is configured to print an image based on the video signal at the time when the fluctuation is detected.

For this purpose, the recording device is provided with a video memory 22 and a video printer 24. The video memory 22 receives image information from the switcher 12 at the time when an image change in the video signal is detected. Video printer 24 prints images based on the contents stored in video memory.

FIG. 2 shows details of a video signal processing apparatus according to a preferred embodiment of the present invention. In addition, as mentioned above, in the above embodiment, an example is shown in which the video processing device of the present invention is applied to a multi-channel monitoring device having a plurality of camera IOs, but in the following description, for the sake of clarity, This will be explained as single-channel video signal processing. The video signal processing bag 5too of the present invention is constituted by a digital circuit including a microprocessor. As is well known, the microprocessor 102 is a CPU 104. ROMI O6 and R
It is composed of AM108. A coordinate comparator 110 is further connected to the CPU 104 via a path line 112. The coordinate comparator 110 receives the vertical synchronization signal V5sync separated from the video signal output from the switcher 12 by the synchronization separation circuit 119 and further separated by the vertical synchronization separation circuit 114, and synchronizes the horizontal synchronization signal Hsync. It is directly input from the separation circuit 119. Further, the coordinate comparator 110 is connected to a clock generation circuit 116 that generates a clock signal of, for example, 4M1lz in synchronization with the horizontal synchronization signal. In the coordinate comparator 110, the vertical synchronization signal V5y
NC and horizontal synchronization signal! (The address of each image data is specified by sync and the clock input from the clock generation circuit 116 mentioned above.The image data component of the video signal from which the synchronization signal has been separated by the switcher 12
The data is binarized at 18, input to a serial/parallel conversion circuit (hereinafter abbreviated as S/P conversion circuit) 120, and converted into parallel data. The image data converted into parallel data is written to the S/P conversion circuit 120 at the address RMEM of 1'' (AM) assigned to the coordinate position specified by the coordinate comparator 110. Of course, it is possible to write one field's worth of image data into the RMEM area of 06 and detect image fluctuations for all pixels, but this slows down the processing speed and requires a large capacity memory to store it. On the other hand, when considering the function of the monitoring device, it is unnecessary to detect image fluctuations for all pixels of the video signal sent from the camera 10. Therefore, in a preferred embodiment of the present invention, , 1 as shown by the shaded area in Figure 3.
A predetermined region within the image of the field is defined as a variation detection region, and the variation of the image is monitored for this variation detection region. As a result, the RA that stores the image data
The capacity 51 of the RMEM area of M106 can be made relatively small, and the capacity of the S/P conversion circuit 120 can also be made small. Furthermore, in the embodiment of the present invention, the j dimension convex is set to Kanayama 401 Tan Honjiku JIVI:,-
Divided into columns of -4 bytes,
The capacity of the S/P conversion circuit 120 is set to 4 bytes, and the S/P conversion circuit 120 is set to 4 bytes.
The image data latched in the P conversion circuit 120 is
The configuration is such that the capacity shown by the arrow in FIG. 4 is written to MEM.

To detect a variation detection area in a video signal, the CPU 104 outputs base q coordinate data indicating the coordinate position of the variation detection area, and compares this with the coordinate position of input image data detected by a coordinate comparator IO. Figure 3 A1. A
2... is detected, and the image data corresponding to the pixels corresponding to the width of the variation detection area is stored in nM of RAM 10G from this starting point position.
It is designed to write to the E\4 area.

Note that when detecting image fluctuations only in the predetermined fluctuation detection area of each video signal for multi-channel video signals, since the six channels of video signals are not synchronized with each other, the fluctuation detection area of each channel It is necessary to accurately detect the coordinate position of For this reason,
In the video signal processing device according to the preferred embodiment of the present invention, the coordinate comparator 110 is reset when a channel switching command is generated from the CPU 104, and then coordinate detection is started in synchronization with the vertical synchronization signal. The variation detection area at the time of channel switching can be accurately detected for each channel.

As shown in FIGS. 5 and 6, the binarization circuit 118
and the synchronous separation circuit 119 each have a comparator 118
a and 119a.

A negative input terminal of a comparator 118a constituting the binarization circuit 118 is connected to a video signal output terminal of the switcher 12. On the other hand, the comparator 11 of the binarization circuit 118
A variable resistor 118b is connected to the positive input terminal of 8a. The resistance value of this variable resistor ll8b is made variable by operating the control panel 18, and by changing this resistance value, the binarization threshold Vl shown in FIG.
change. As is well known, the brightness level of the digital image data binarized by the binarization circuit 118 is equal to or higher than the threshold "1".
In the second signal region, the logical value level is "1", and on the other hand, in the signal region where the luminance level is lower than the threshold value, the logical value level is "0".

Therefore, the digital image data becomes a signal indicating the brightness level at each pixel position as "1" or "0".

On the other hand, the video signal from the switcher 12 is input to the negative input terminal of the comparator 119a, and the synchronization reference signal indicating the synchronization reference value 0 is input to the positive input terminal. As shown in FIG. 6, the comparator 19a detects a synchronizing signal by comparing the levels of both input terminals, and generates a pulse signal indicating the synchronizing signal. As mentioned above, the synchronous separation circuit 11
The synchronization pulse signal outputted from the coordinate comparator 110 is separated into a vertical synchronization signal and a horizontal synchronization signal, and is input to the coordinate comparator 110.

7 to 11 show the process of forming a reference signal in the video signal processing device 100 and this reference signal. FIG. 9 is stored in the ROM 106 and the CPU 104
A video processing program executed in is shown. Also, FIG. 7 shows the configuration of the RAM 108, and
In the figure, each address GMEM I of RAL・1108,
GMEM2...GMEM8 configurations are shown. These addresses store image data and reference signal data input from the 8-channel camera 10, respectively. Therefore, when performing short channel video signal processing, a single address is used.

Each address corresponds to a first area 106a and a second area 106b.
The first area 106a stores data used for updating reference data, which will be described later, and the second area 106b stores base data currently in use. As shown in FIG. 8, the data stored in the first area 106a to update the basic data is the logical sum (OR) data (01 signal) and the logical product (01 signal) corresponding to each pixel.
AND) data (consisting of AI multiplied signals. Also, the reference data is the exclusive OR (
EXOR) data (X1 signal), and the 01 signal and the X1 signal are stored as a pair of base data at the address corresponding to the fS pixel.

As mentioned above, the reference data is obtained by sampling video signals for multiple fields (n fields), comparing the video signals for the sampled n fields, and detecting pixels whose logical value level changes between each field. The signal area of the reference signal corresponding to the pixel whose logical value level fluctuates is set as a dead area, and the content is such that the reference signal and the video signal are compared in this dead area.

The reference signal is used in initialization step 1 of the video signal processing program.
It is formed in steps 1002 to 1012 following 000. In the initialization step 1000, the above-mentioned R4
First region 106a of G M E M region of M2O3
is initialized. In this initial setting, each pixel's 0
All 1 signals are set to logic level "0", and all AI signals are set to logic level "1".

Next, in step 1002, the image data of the first field is read, and in step 1001, the logical value level of each pixel of the read image data and RAM+0
GME of 6 to 1' of 1:) The 01 signal of each address is updated by calculating the OR with the 01 signal of the 18 corresponding addresses stored in the area 106a.

Next, in step 1006, G of RAM l 06
The logical value level of each corresponding pixel is ANDed with the Al signal of the corresponding address stored in the first area 106a of MEM, thereby updating the Al signal of each corresponding address.

At the end of the process in step +006, 1 is added to the count value of the counter shown in the figure.

In step 1008, it is checked whether the count value of the counter has reached a predetermined field loss (n).

If the count value has not reached n, step 100
Returning to step 2, the image data of the next field is fetched, and the processes of steps 1004 and 1006 described above are executed for this data. Therefore, the processing from steps 1002 to 1006 is repeated once, and the 01 signal and the A1 signal at the end of the nth processing are n field 1.
This means that it was formed from minute image data. In the OR data obtained by sampling the image data for one n field, only the addresses corresponding to the logic value level of the image data for one n field or pixels having all "0" have "0". On the other hand, in the l signal obtained by sampling the image data of n fields, only the address corresponding to the pixel whose logical value level of the image data of one field of n fields is always "l" has a logical value level "1". become the 10th
(E) and FIG. 10(B)).

When it is detected in step 1008 that sampling of image data for 1 minute of n fields has been completed, step 1
At step 010, the 01 signal obtained in the processing of steps 1004 and 1006 above is EXORed with the Al signal.
Let it be the l signal.

At this time, the X1 signal obtained in step 1010 indicates that the logical value level of the image data for one field of n fields is "1" or "0".
”, the address corresponding to the pixel that does not change is “0”, and the address corresponding to the pixel where the image data changes is “0”.
l”.

In step 1012, 01 obtained in step 1004
The signal and the X1 signal obtained in step 1010 are respectively stored as the 02 signal and the X2 signal at each address in the second area +06b as reference data. 02 signal and x
When the formation of the reference data consisting of 22 signals is completed, in step 1013, all the 01 signals in the first area 106a of the GME and ■ areas are initialized to "0", and 1. Al
All signals are initialized to "l". Next, step 1
Image data (
■ Signal) and start processing to monitor image fluctuations.

In step 1016, the 2 signal taken in at step +014 is stored in the corresponding address and is ORed and EXORed with the 02 signal and the x22 signal. (See Figures 11.(A), 11(B) and (C)). That is,
In step 1016, when X2 is received, the corresponding ■signal signals are ORed (11th (D), II (IE)
, II (G) and + 1 (H) (0, 4), then EXOR this OR data with the 02 signal (11th
(F) and II (I) At this time, if there is no change in the image data, 11 (D), 11 (E) and 11
(F) As shown in the figure, EXO of OR data and 02 signal
The level of the logical value of R is "0" for all pixels. On the other hand, if there are fluctuations in the image data, the 11th (G
), 11(H), and 11(I), the logic value level of the OR data and the OR of the 02 signal becomes "1" for the pixel where the image data has changed.

By the way, in the monitoring device to which the present invention is applied, it is impossible for a single pixel to undergo an image change, so even if a logical value level "1" is detected for a single pixel in the process of step 1016 above, Therefore, it cannot be determined that there is an abnormality in the monitoring area. Therefore,
In step +018, find f in step 1016 above.
For a pixel whose EXOR logical value level is "l", check the EXOR of the adjacent pixel, and if all the EXOR logical value levels of the adjacent pixel are "0", the logical value of the concerned pixel is Adjust the level to "0".

Next, in step 1020, EX
The presence or absence of an OR is checked, and if an EXOR with a logical value level of "1" does not exist, the process returns to step I OI li and the processes of steps 1016 to 1020 are executed for the image data of the next field.

On the other hand, if EXOR of logical value level "1" is detected in step 1020, a fluctuation detection signal is outputted in step 1022, the alarm 20 is excited, and the recording device 16 is activated.

At step 1022, a fluctuation detection signal is output, and
The base yarn data stored in the second area 106b of the RAM is reset. After this, the standby state is maintained for a predetermined time in step 1024, and after the predetermined time has passed, step 1000 is performed.
to resume video signal processing.

Note that the reference data used in the above processing needs to be updated in accordance with environmental changes in the monitoring area over time, such as changes in shadows due to changes in solar radiation. Therefore, it is necessary to update the reference data by executing the processes of steps 1002 to 1008 described above at predetermined intervals. As long as a single-channel video signal is being processed, will there be any major problems even if the processing of steps 1000 to 1008 is executed for a predetermined time fi as described in 1?This is shown in Figure 1. When applied to a multi-channel monitoring device, a non-negligible amount of time is required to create the base data for each channel, resulting in the problem that images cannot be monitored while this base data is being updated. .

Therefore, in the embodiment of the present invention, step 1014
Following the image monitoring processing of steps 1020 to 1020, step 1100
0 for forming reference data from image data for a predetermined number (+n) of fields by executing the processes from 1104 to 1104.
1 signal and l~l signal to G M E i of RΔ~1106
It is formed in the first region 106a of vl. For this reason, step 1020 and step! Step 110 during 014
0 to 110 = 1 is inserted. This step +
The process of forming the 01 signal and the At signal from 100 to 1104 is basically the steps 1000 to 10 described above.
This is the same as the processing in 06. That is, if no variation in the video signal is detected in step 1020, then in step 1100 the logical value level of each pixel of the V signal of the field read in step 1014 and the RAM are determined.
The 01 signal of each address is updated by calculating the OR with the 1) signal of the corresponding address stored in the first area 106a of GMEM 106. Then step 110
2 in RAM +06 G M E M first area 1
The logical value level of each corresponding pixel is ANDed with the corresponding address A1 signal stored in 06a, thereby updating the At signal of each corresponding address.

At the end of the process in step 1102, 1 is added to the count (A) of the counter. In step 104,
The count value of the counter is a predetermined field Ta (m)
Check whether it has been reached. If the count value has not reached m, the process returns to step 10111 to take in the V signal of the next field, and after this, the processes of r0 steps 1100 and 1102 to 1102 are repeated m times. .

In step 1104, the O1 signal and the A signal for m fields are
When it is detected that sampling of the t signal is completed,
At step 1010, the f20l signal obtained by the processing of steps 1100 and +102 of the upper third party is EXORed with the hel signal, and at step +012, the step 110
The OR data obtained in step 0 and the XIl signal obtained in step 110G are stored at each address in the second area 106b as reference data, that is, the 02 signal and the X2 signal.

Therefore, the reference data will be updated to m field hi.

H Effects of the Invention According to the present invention, the language signal and the video signal are compared once to detect the fluctuations in the image, thereby detecting the fluctuations in the video signal without being affected by noise. 1. At about ω when comparing the video signal and the reference signal, in parallel, the variation detection process of the reference signal Ichite 16j-16 is interrupted. It is possible to update the base signal without any trouble. In particular, since the video processing device of the present invention can update the reference signal without interrupting the image fluctuation detection process as described above, the video signal can be This allows processing to be carried out smoothly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the entirety of a monitoring device including a video signal processing device according to a preferred embodiment of the present invention, FIG. 2 is a block diagram of a video signal processing device according to a preferred embodiment of the present invention, and FIG. 3 is an image An explanatory diagram showing the fluctuation detection area in data, Figure 4 is a diagram showing the data storage procedure of the RM E M area of RA h, 1, and Figure 5 is a diagram showing the binarization circuit and synchronization separation circuit of the video signal processing circuit. The circuit diagram shown in Figure 6 is a waveform diagram showing the operation of the binarization circuit and the synchronous separation circuit, and Figures 7 and 8 are the G of the RAM.
~A diagram showing the configuration of the fErA area, FIG. 9 is a flowchart of the video processing program, 10(A) to 10(2)
The figure shows a waveform diagram explaining the base signal formation process and the 11th (
Figures A) to 11(I) are waveform diagrams used to explain the video signal processing program. IO...Count, 12...Switcher, 14...
- Monitor device, 16... Recording device, 18... Control panel, 20... Alarm, 100... Video signal processing device, +02... Microprocessor, 11
0: Coordinate comparator, 120: S/P conversion circuit. Doji Figure 1 Figure 3 Figure 4 Figure 1I

Claims (1)

[Claims] In a video signal processing device that compares a video signal input from an imaging device such as a television camera with a reference signal to detect variations in image information of the video signal, the video signal input from the imaging device such as a television camera is compared with the video signal input from the imaging device. It is characterized by forming update data for updating the reference signal based on the video signal at the same time as detecting a change in image information, and updating the reference signal with the update data at a predetermined timing. video signal processing equipment.