JPH07115587A - Video memory device - Google Patents

Abstract

PURPOSE:To easily specify an occurrence location of a sudden event corresponding to a state of a natural phenomenon by mixing a video image of a fixed pattern and a video image in a video memory and observing the mixed images even when discrimination of a status is difficult only with the video image of the video memory. CONSTITUTION:When a fault takes place at night, a video image of a light by explosion in darkness such as a video image 400 is stored in a sudden occurrence memory. When plural chimneys are in existence, it is unable to discriminate in which chimney an explosion takes place. A video image such as a video image 200 of a fixed pattern displaying a usual state of chimneys is stored in a fixed pattern memory, then a system control section mixes the fixed pattern and the video image of a sudden occurrence memory to give the mixed video image to the video memory and the video image is outputted to a monitor. Thus, a supervisor can discriminate momentarily in which chimney the explosion takes place and activate an alarm device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surveillance camera system for monitoring a situation with a surveillance camera.

[0002]

2. Description of the Related Art FIG. 11 is a block diagram showing a configuration of a video recording system of a conventional video memory. FIG. 12 shows a monitor screen of a conventional memory image display example, particularly an image taken by a surveillance camera at night. FIG. 13 is a daytime image of the image in FIG. In FIG. 11, 1 is an A / D converter, 2 is a video memory, and 3 is a D / A.
A converter, 5 is a system control unit, and 11 is an external signal input unit.

Next, the operation will be described. In FIG. 11, for example, a video input of a chimney of a night factory photographed by a surveillance camera is converted from analog to digital by the A / D converter 1, and continuous images are recorded in the video memory 2 as digital signals. It should be noted that the video to be recorded is cyclically recorded at a maximum of five images in consideration of the capacity of the video memory 2. The external signal input unit 11 inputs an external signal indicating a change in the monitoring state from the sensor or an image change signal indicating a change in the state of the image displayed on the surveillance camera to notify the system control unit 5 of the change in the monitoring state. Tell. The system control unit 5 which has been notified of the change in the monitoring state controls the video memory 2 to convert an analog-converted image from the image input into an arbitrary video recording pattern, for example, immediately after the change in the monitoring state is notified. Three seconds' worth of video is recorded for one second, and then the writing operation of the video memory 2 is stopped. Then, the D / A converter 3 converts this image from a digital signal into an analog signal and outputs the image to a monitor or the like. Since the five images are cyclically recorded in the video memory 2, the images projected on the monitor are the five images continuously projected as shown in FIG. In the daytime image, the chimney stands out with three smokes as shown in FIG. 13, but since the image in FIG. 12 is taken at night, the background of the first two sheets and the latter three sheets is dark. Therefore, it is not possible to identify in which chimney the explosion occurred.

[0004]

In a conventional video memory device, an image taken by a surveillance camera is recorded in a video memory and output to a monitor or the like, irrespective of the state of a natural phenomenon such as daytime or nighttime. Therefore, in the case of nighttime, it is difficult to identify the location of the unexpected event only with the video image captured by the surveillance camera.

The present invention has been made to solve the above-mentioned problems, and facilitates the identification of the occurrence location of an unexpected event corresponding to the situation of a natural phenomenon.

[0006]

A video memory device according to the first invention has the following elements. (A) Fixed pattern memory for storing fixed patterns,
(B) A video memory for inputting and storing an image, (c) System control means for mixing and outputting the fixed pattern stored in the fixed pattern memory and the image stored in the video memory.

A video memory device according to a second aspect of the present invention is the same as the video memory device according to the first aspect of the present invention, in which an image of a specified time is stored in the sudden memory, and an external signal input means is provided in the sudden memory. It is characterized in that a signal for designating a time for storing an image is inputted from the outside, and the system control means mixes and outputs the image stored in the sudden memory and the fixed pattern stored in the fixed pattern memory. .

A video memory device according to a third aspect of the present invention is the same as the video memory device according to the first aspect, wherein an initial parameter storage section stores an initial parameter serving as a reference for image change with the passage of time, The system control means compares the input image with the fixed pattern based on the initial parameters and outputs the comparison result.

A video memory device according to a fourth aspect of the present invention is the video memory device according to the third aspect of the present invention, in which a correction parameter storage unit stores, as a correction parameter, a state of change that can occur with respect to the initial parameter. The image extraction unit extracts the change of the video from the comparison result from the system control unit and transfers it to the correction parameter storage unit, and the system control unit extracts the image from the correction parameter stored in the correction parameter storage unit. The extraction unit searches for a correction parameter that matches the change in the extracted video, corrects the fixed pattern based on the found correction parameter, compares the corrected fixed pattern with the input video, and outputs a comparison result. I am trying.

[0010]

In the video memory device according to the first aspect of the present invention, the system control means mixes the fixed pattern stored in the fixed pattern memory and the image stored in the video memory and outputs the mixed image. Thus, for example, even when it is not possible to determine what is reflected in the dark night image as in the above-mentioned conventional example, if the fixed pattern memory stores the daytime image, the nighttime image and the daytime image are stored. The images can be overlaid and viewed on a monitor.

The video memory device according to the second invention is
The sudden memory stores an image at a designated time by an external signal such as an accident occurrence signal. Then, the system control means mixes the image stored in the sudden memory with the fixed pattern and outputs the mixed pattern. As a result, for example, even when a night explosion accident occurs as in the above-mentioned conventional example, the daytime image stored in the fixed pattern and the image at the time of the accident can be superimposed and viewed on a monitor or the like.

A video memory device according to the third invention is
The system control means compares the difference between the fixed pattern and the input image, and further compares this difference with the initial parameter. This makes it possible to determine whether or not there is a possible change in the image. For example, it is assumed that a fixed pattern stores an image of a road on which several cars are running, and the input image shows only the road. If it is stored as an initial parameter that there is no road passing, it can be determined that the input image is a possible image change.

The video memory device according to the fourth invention is
The system control means further compares the result determined by the third invention with the correction parameter. As a result, whether or not there is a possible change in the image can be determined for another image pattern. For example, suppose that the input image shows how an animal is passing.
It is assumed that the same parameters as the third invention are stored as the initial parameters. In this case, it is determined that there is no change in the image that can occur, but if it is stored in the correction parameter that there is passage of the animal, it can be determined that there is a change in the image that can occur.

[0014]

【Example】

Example 1. In this embodiment, an example in which an image stored in a fixed pattern memory and an input image are mixed and output will be described.

FIG. 1 is a block diagram showing the configuration of a video memory device in all the embodiments described below.
In FIG. 1, 12 is a video memory device, and 1 is A /
D converter, 2 is a video memory, 3 is a D / A converter, 4 is a video mixing circuit, 5 is a system controller, 6
Is a sudden memory, 7 is a fixed pattern memory, 8 is an initial parameter, 9 is an image extraction unit, 10 is a correction parameter, 11
Is an external signal input section. Reference numerals 4a and 4b are switches for selecting an image to be input to the image mixing circuit 4. The burst memory 6, the initial parameter 8, the image extraction unit 9, the correction parameter 10, and the external signal input unit 11 will be described in detail in the subsequent embodiments.

FIG. 2 is a diagram showing an image output by mixing the input image and the fixed pattern image stored in the fixed pattern memory in this embodiment. Figure 2
In FIG. 1, 100 is a diagram showing an image output to the video memory, 200 is a diagram showing an image stored in a fixed pattern, and 300 is an image 1 in the video memory.
00 is a diagram showing an image in which 00 and a fixed pattern image 200 are mixed. Next, the video mixing operation will be described.

For example, assume that there is an accident monitoring system that monitors a factory chimney. There are usually three chimneys in a factory, as shown in the fixed pattern image 200 of FIG. 2, and all three emit smoke. Watchers at night, video memory device 1
Even if the image output from 2 is seen, since it is dark like the image 100 in the video memory of FIG. 2, it is not possible to monitor what the chimney is like. Therefore, the fixed pattern memory 7 stores in advance an image such as the fixed pattern image 200 shown in FIG. If the switch 4b is in the ON state, the input image is converted by the A / D converter 1 even at night, and then the system control unit 5
Is mixed with the image stored in the fixed pattern memory 7. After mixing, it is converted by the D / A converter 3 and then output to a monitor or the like. The switch 4b may be switched ON / OFF by a monitor depending on the situation, or may be automatically switched by the system control unit 5 according to time and weather.

As described above, in this embodiment, the digitally processed video input is mixed with other video (fixed pattern video) to output the video. As a result, it becomes possible to confirm an image that cannot be confirmed by the conventional video memory device.

Example 2. Further, in the above-described first embodiment, it has been described that the image input by the system control unit 5 and the image of the fixed pattern memory are mixed. However, if the switch 4a is ON, the system control unit 5 may pass the video of the fixed pattern memory to the video memory 2. An image mixing circuit (analog adder) mixes the image of the fixed pattern memory passed to the video memory 2 and the input image, and outputs the image to a monitor or the like.

Example 3. Also, if you want to release the monitoring state and always watch the input video live, switch 4
It is sufficient to turn on only a.

Example 4. In this embodiment, an example will be described in which an image stored in a fixed pattern memory when a sudden accident occurs and an input image are mixed and output.

FIG. 3 is a diagram in which the image of the sudden memory and the image of the fixed pattern memory in this embodiment are mixed and output. In FIG. 3, 400 is an image stored in the sudden memory 6, and 200 is a fixed pattern memory 7.
FIG. 3 is a diagram stored in FIG.
It is an image after mixing 0 and a fixed pattern image 200. FIG. 4 is a flow chart showing a procedure for creating a mixing image created when a sudden accident occurs in this embodiment. The procedure for creating a mixing image created when a sudden accident occurs will be described below with reference to the flowchart of FIG.

Also in this embodiment, as in the case of the above-mentioned first embodiment, an accident monitoring system for monitoring a chimney of a factory is taken as an example. Normally, if no accident occurs, in this video memory device, the input image is converted by the A / D converter and stored in the video memory 2. The latest 5 images are stored cyclically. Then, at night, as in the first embodiment, the fixed pattern image and the input image are mixed (S2), and the mixed image is output to a monitor or the like (S3). If the monitoring state is daytime, the state of the chimney can be confirmed, and thus the mixing process of S2 is not necessary. The factory shall have a sensor to detect a chimney explosion. When an explosion accident occurs, this sensor notifies the video memory device 12 of the accident occurrence signal to the external signal input unit 11 as the external input shown in FIG. The external signal input unit 11 notifies the system control unit 5 of the occurrence of an accident. The system control unit 5 immediately stores the video input converted by the A / D converter 1 in the sudden memory 6 (S4).
a). The storage method is, for example, video input for 1 second after receiving an external input. (It is an image 400 of the sudden memory in FIG. 3.) Incidentally, regardless of the occurrence of the accident as shown in FIG.
When the latest five video images are stored cyclically, the video signal is input for one second after receiving the accident occurrence signal, and then the video storage in the emergency memory is stopped (S4b). If the accident occurs at night, the sudden memory 6 will be an image in which the light from the explosion is reflected in the dark like the image 400 of the sudden memory in FIG. With this, if there are multiple chimneys, which chimney caused the explosion,
I can't judge. Fixed pattern image 200 of FIG. 3 showing a normal chimney state in fixed pattern memory 7.
If an image like this is stored, the system controller 5 mixes the fixed pattern and the image in the sudden memory (S5) to pass the mixed image to the video memory 2, and the D / A converter 3 The video converted by is output to the monitor (S6). (This is the image 300 after mixing in FIG. 3.) With this, the observer can instantly determine in which chimney the explosion occurred. In addition to displaying the image on the monitor, the alarm device may be smoothed by the system control unit 5 at the time of receiving the accident occurrence signal. After that, the recovery work of the explosion is performed (S7), and the monitoring is restarted when the recovery work is completed.

As described above, this embodiment is characterized in that the sudden event is stored in the emergency memory as a starting condition from the external input, and the image is output by mixing with the fixed pattern image. By mixing the images, it becomes easy to identify the event change.

Example 5. Further, in the fourth embodiment, the occurrence of the explosion accident is notified by the external input by the sensor, but it may be notified by the image change signal of FIG. The image change signal is, for example, a signal indicating that there is a change in the amount of light by a device that measures the change in the amount of light of a captured image as an image change signal. Similar to the fourth embodiment, it is assumed that a chimney explosion accident occurs at night. When the light quantity of the image photographed by the above device is measured, it is in the darkness before the explosion accident and the light quantity is zero. When an explosion accident occurs, the amount of light becomes 0 or more due to at least the light from the explosion. As a result, a change in the image is detected, and the video memory device is notified as an image change signal.

As described above, the writing to the sudden memory due to the occurrence of the sudden event may be automatically performed by a device for measuring the digital amount change of the image such as the light amount.

Example 6. In this embodiment, an example will be described in which an event is determined by comparing an input image with a fixed pattern image having an initial parameter and further comparing the comparison result with the initial parameter image.

FIG. 6 is a diagram showing an initial parameter image, a fixed pattern image, and an input image in the present invention. In FIG. 6, 500 is an image of initial parameters, which is a diagram showing a state of a road where there is no traffic of vehicles. Reference numeral 200 is a fixed pattern image, and is a diagram when there are five vehicles per second. Reference numeral 110 is an input image, and is a diagram in the case where the traffic volume of vehicles is three per second. FIG. 7 is a flow chart showing the procedure of the event determination processing in this embodiment. The event determination procedure will be described below with reference to this flowchart.

For example, assume that there is a traffic monitoring system that monitors the traffic volume of a vehicle. In this system, a sensor that measures traffic volume is attached to the road. This sensor is 1
The number of vehicles passing in a second is measured, and if there are less than five vehicles passing in a second, it is determined that there is a risk of congestion or an accident, and external input is performed to the video memory device. In the initial parameter 8, an image when there is no traffic is stored in advance. Fixed pattern memory 7 has 1
The image when there are five units per second is stored in advance.

First, the external signal input unit of the video memory device 12 is notified by an external input that the number of vehicles passing by the sensor has decreased to three per second (S).
1). Then, assuming that the latest five video images are cyclically stored in the normal video memory 2, the system control unit 5 immediately stops the cyclic storage of the video memory (S10). After this, the system controller 5
The image input converted by the D converter 1 (the input image 110 in FIG. 6) and the fixed pattern image (the fixed pattern image 200 in FIG. 6) are compared (S11). If there is no difference between the two images in the comparison of S11, it is determined that the traffic volume of the car does not change,
The video input as it is is output to the monitor (S2
1). If there is a difference in the comparison in S11, the comparison result in S11 and the initial parameter (the image 500 of the initial parameter in FIG. 6) are further compared. S1
In the comparison of No. 2, if there is no difference, it is determined that there is no change in the traffic volume of the vehicle, and the input image is output as it is (S21). If there is a difference in the comparison of S12, that is, the traffic volume of the vehicle is less than 5 per second,
Since it is possible to determine that there is one or more vehicles passing, it is possible that congestion has begun. Therefore, an abnormality is notified to the observer. This abnormality may be a buzzer notification of abnormality. Alternatively, characters such as "traffic jam" may be displayed on the monitor (S20).
After that, the input image is output to the monitor (S2
1). At this time, in S20, when a character such as "traffic jam" is displayed on the monitor, the character and the input image must be mixed and then displayed.

In the comparison of S12, if there is one or more cars passing but the movement is completely stopped, it can be determined that an accident has occurred, and therefore, in the abnormality notification process of S20, " It is also possible to output a character such as "occurrence" to the monitor.

As described above, in this embodiment, the input image is compared with the fixed pattern image, and the comparison result is also compared with the initial parameter image.
It is characterized by checking changes in video in multiple stages.

Example 7. In this embodiment, an image extractor and a correction parameter are provided, and after the comparison with the initial parameters performed in the sixth embodiment (the process of S12 in FIG. 7),
The process of comparing the comparison result and the image of the correction parameter and correcting the image of the fixed pattern as necessary will be described below.

FIG. 8 is a diagram showing an initial parameter image, a fixed pattern image, an input image, and a correction parameter image in this embodiment. In FIG. 8, 50
0 is a diagram showing an image of the initial parameter, which shows a state where there is no traffic of the vehicle. Reference numeral 200 is a diagram showing an image of a fixed pattern, which is a diagram when there are five vehicles per second. Reference numeral 110 is a diagram showing the input image, and is a diagram in the case where there are three vehicles per second. 6
10 is a diagram showing an image of the correction parameter, and is a diagram when there are three vehicles passing in one second. Reference numeral 620 is an image of the correction parameter, and is a diagram in the case where there are five vehicles per second. FIG. 9 is a flowchart showing the procedure of the event determination processing in this embodiment. The event determination process will be described below with reference to the flowchart of FIG.

Also in this embodiment, a traffic monitoring system for monitoring the traffic volume of a vehicle is taken as an example as in the case of the sixth embodiment. Figure 9
In the above, since the process from the confirmation process with external input in S1 to the comparison process between the video of the initial parameter in S12 and the comparison result in S11 is the same process, it is omitted here. S
After the processing of step 12, if there is a difference, the image extraction unit 9 extracts the change of the image from the image of the initial parameter and the comparison result in S11. Based on the change in the extracted video, the image extraction unit 9 searches the video stored in the correction parameter (S13), and checks whether or not a matching video exists in the stored video of the correction parameters. (S14). The initial parameter image, the fixed pattern image, and the input image in this embodiment are as shown in FIG. The change in the video image extracted by the image extraction unit 9 in S13 is the difference between the number of vehicles passing through the vehicle per second being three or five. Therefore, when the video stored in the correction parameter in (A) of FIG. A is searched in 14 above, the video matches the video 610 of the correction parameter. As a result, there is a possibility of congestion, but the degree of mixing is not constant depending on the road being monitored, the day of the week, and the time of day, so it is not judged to be congestion. And the fixed pattern image 2
00 is corrected by the system controller 5 based on the correction parameter image 610 (S15). In the process of S14, if there is no matching correction parameter,
The observer is notified of the abnormality (S20). This abnormality notification may give an alarm as in the sixth embodiment,
You may display the words "in traffic" on the monitor. Next, the input video is output to the monitor (S2
1). In the process of S20, when the character "congested" is displayed on the monitor, the character and the input image are mixed and then displayed on the monitor. In this way, if the correction parameters are used, even if the situation of the monitoring target changes every moment like in a traffic monitoring system, the desired situation should be investigated in advance and stored as an image of the correction parameters. If so, the situation that can occur can be changed according to the change of the situation.
As described above, in this embodiment, the image set by the initial parameter is compared with the image from the image input, and when there is a change, the image extraction unit detects and changes the fixed pattern image with the correction parameter. It is characterized by that.

Example 8. Further, in the above-described seventh embodiment, there is only one image of the correction parameter as shown in FIG. 8 (A). It does not matter if there is more than one. For example, in FIG.
As shown in (B), the image in the case of "the traffic volume of the vehicle is 5 vehicles per second" is stored in the correction parameter 10. As a result, when the traffic volume of the vehicle is smaller than that of the seventh embodiment, the fixed pattern image is corrected by the correction parameter image 620 of FIG. 8B so as to match the current traffic amount. It

Example 9. Furthermore, in this embodiment, the intrusion monitoring system will be taken as an example to describe the event determination processing with reference to the flowchart of FIG.

FIG. 10 is a diagram showing an initial parameter image, a fixed pattern image, an input image, and a correction parameter image in this embodiment. In FIG. 10, 5
00 is an image of the initial parameter, which is an image showing that human intrusion is permitted. A fixed pattern image 200 is an image showing that there is no intruder. Reference numeral 110 is a diagram showing an input image, which is an image showing that a cat has entered. Reference numeral 610 is an image of the correction parameter, which is an image showing permission of human intrusion. 620 is an image of the correction parameter,
It is a video showing permission of cat invasion. Next in FIG.
The procedure of the event determination process will be described with reference to the flowchart of FIG.

In the intrusion monitoring system in this embodiment, a sensor is installed in front of the door. This sensor makes an external input to the video memory device 12 when there is an intruder. It is assumed that an image for allowing human intrusion is previously stored in the initial parameter 8 (the image 500 of the initial parameter in FIG. 10). It is assumed that the fixed pattern memory 7 stores in advance an image when there is no intruding object (the fixed pattern image 200 in FIG. 10).

First, as shown in the input image 110 of FIG. 10, it is assumed that a cat has entered. Then, the sensor detects an intruder and inputs the external input to the video memory device 1.
It does to 2 (S1). When external input is performed, cyclic storage of the video memory is stopped by the system controller 5 (S10). After the storage of the video memory is stopped, the input image 110 shown in FIG. 10 and the fixed pattern image 200 are compared (S11). In this case, since the image in which the cat has entered is the input image, the image 500 of the initial parameter is compared with the comparison result in S11 (S12). The initial parameter image 500 in FIG. 10 is an image permitting human intrusion, and the input image 11
0 indicates a video that a cat has entered, so there is a difference between a human and a cat in the two videos. The image extraction unit 9 extracts the invasion of the cat as a change in the image. Then, from among the images stored in the correction parameter 10, it is searched whether or not there is an image showing the invasion of the cat (S1).
3). Since the video 620 of the correction parameter of FIG. 10 matches the video allowing the cat to enter (S14), the system controller 5 corrects the video of the fixed pattern using the video 620 of the correction parameter (S15). After the fixed pattern correction, the input image is output to the monitor (S21).

As described above, the intrusion monitoring system in this embodiment permits the intrusion of humans and the intrusion of cats at the same time. For this reason, an image permitting human intrusion in a normal state is stored as the initial parameter, and an image permitting cat intrusion is stored as the image of the correction parameter. As a result, even if a cat invades, the intrusion monitoring system can continue normal monitoring without determining that it is an abnormal situation. Further, if a video allowing human intrusion is also registered as a video of the correction parameter, the video of the fixed pattern will be corrected by the video 610 of the correction parameter when the human intrusion is monitored next time.

Example 10. In the first embodiment described above, the video mixing circuit 4 mixes the video in an analog manner, but digital addition / subtraction may be performed.

[0043]

According to the first aspect of the present invention, even when it is difficult to judge the situation only with the image in the video memory, the situation can be judged by mixing the fixed pattern image and the image in the video memory. There is an effect that can be easily done.

According to the second aspect of the present invention, the external signal input means gives an instruction to record in the sudden memory, and the system control means mixes the image in the sudden memory with another image. This has the effect of facilitating the identification of the location of the unexpected event.

According to the third aspect of the invention, an image serving as a reference of change is stored in the initial parameter, the fixed pattern image is compared with the input image, and the comparison result is compared with the initial parameter image. As a result, there is an effect that it can be determined whether or not there is a possible change in the image. For example,
When there is no traffic on the road because there are no cars on the road, an image of no cars passing is stored as an initial parameter. By comparing the image of the car stagnant with the image of this initial parameter, it can be recognized that the car exists even if there is no movement. Therefore, it can be determined that the vehicle is stagnant due to an accident.

According to the fourth invention, the comparison result obtained in the third invention is further compared with the image of the correction parameter. Thus, for example, even if the situation changes with the passage of time, a possible situation is stored in the correction parameter, and it is possible to determine whether or not the change of the image is possible. Further, the fixed pattern can be corrected according to the result of comparison of the correction parameter with the image. Therefore, even if the situation changes with the passage of time, there is an effect that a reference image can be set corresponding to the change.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a video memory device in all embodiments of the present invention.

FIG. 2 is a diagram in which an input image and an image of a fixed pattern memory according to the first embodiment of the present invention are mixed and output.

FIG. 3 is a diagram in which an image of the sudden memory and an image of the fixed pattern memory according to the fourth embodiment of the present invention are mixed and output.

FIG. 4 is a flow chart showing a procedure for creating a mixing image created when a sudden accident occurs in Embodiment 4 of the present invention.

FIG. 5 is a diagram showing a recording method in an unexpected memory according to a fourth embodiment of the present invention.

FIG. 6 is a diagram showing an initial parameter image, a fixed pattern image, and an input image in Example 6 of the present invention.

FIG. 7 is a flow chart showing a procedure of event determination processing in embodiment 6 of the present invention.

FIG. 8 is a diagram showing an initial parameter image, a fixed pattern image, an input image, and a correction parameter image in the seventh and eighth embodiments of the present invention.

FIG. 9 is a flowchart showing a procedure of event determination processing in the seventh and eighth embodiments of the present invention.

FIG. 10 is a diagram showing an initial parameter image, a fixed pattern image, an input image, and a correction parameter image in Example 9 of the present invention.

FIG. 11 is a block diagram showing a configuration of a video recording system of a video memory in a conventional example.

FIG. 12 is a diagram showing an example of a monitor screen of a conventional memory video display example.

FIG. 13 is a diagram showing a daytime image of the image of FIG. 12 in a conventional example.

[Explanation of symbols]

 1 A / D converter 2 Video memory 3 D / A converter 4 Video mixing circuit 4a Switch 4b Switch 5 System control unit 6 Sudden memory 7 Fixed pattern memory 8 Initial parameter 9 Image extraction unit 10 Correction parameter 11 External signal input unit 12 Video memory Device 100 Video memory or input image 200 Fixed pattern image 300 Mixing image 400 Unexpected memory image 610 Correction parameter image 620 Correction parameter image

Claims (4)

[Claims] 1. A video memory device comprising: (a) a fixed pattern memory for storing a fixed pattern,
(B) A video memory for inputting and storing an image, (c) System control means for mixing and outputting the fixed pattern stored in the fixed pattern memory and the image stored in the video memory. 2. The video memory device further comprises an unexpected memory for storing an image at a designated time, and an external signal input means for externally inputting a signal for designating a time for storing the image in the sudden memory. 2. The video memory device according to claim 1, wherein the system control means mixes and outputs the image stored in the burst memory and the fixed pattern stored in the fixed pattern memory. 3. The video memory device further comprises an initial parameter storage section for storing an initial parameter serving as a reference for image change with the passage of time, and the system control means sets a fixed pattern based on the initial parameter. The video memory device according to claim 1, wherein the input images are compared with each other and a comparison result is output. 4. The video memory device further includes a correction parameter storage unit that stores a state of possible change as a correction parameter with respect to the initial parameter, and a video change based on a comparison result from the system control unit. And an image extraction unit that passes the extracted data to a correction parameter storage unit, and the system control unit matches the change in the video extracted by the image extraction unit from the correction parameter stored in the correction parameter storage unit. 4. The video memory device according to claim 3, wherein the correction parameter is searched, the fixed pattern is corrected based on the searched correction parameter, the corrected fixed pattern is compared with the input image, and the comparison result is output. .