JPS6252683A - Monitor device - Google Patents

Abstract

PURPOSE:To attain the quick processing at high reliability by comparing a currently fetched picture with the averaged one of three pictures fetched in past. CONSTITUTION:A video caught by a camera 1 is digitized by an A/D converter 2 and is stored as an initial picture in a memory 32. Its contents are added to those in a memory 31, and written in the memory 31. An arithmetic processing circuit 7 repeats said processing four times, and this iteration is divided by four and is written in the memory 31. A picture checking a change is fetched into the 2nd memory 32, and a comparator circuit 5 compares said picture with the contents in the memory 31. If the compared result has a difference over a certain value, a buzzer 6 is rung to stop processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a monitoring device that uses image processing to monitor captured image data.

[Conventional technology]

FIG. 3 is a configuration diagram showing a conventional monitoring device, where l is a camera, and 2 is an A/V connected to the video output terminal of the camera 1.
A D converter, 31 to 3n are first to nth memories, 4 is a memory selection circuit, 5 is a comparison processing circuit, 6 is a buzzer, and 7 is an arithmetic processing circuit.

Next, the operation will be explained.

The video signal captured by the camera 1 is digitized by an A/D converter 2 for storage in each memory. First, in order to compare whether there is an initial change, the original images to be compared are stored in the first memory +731 and the second memory 3.
2. ...store in the (n-1)th memory (3n-1) one after another. The next image to be compared is stored in the nth memory 3.
Store in n. At this time, the memory selection circuit 4 selects the nth memory 3n. Here, in order to remove image noise, the arithmetic processing circuit 7 processes, for example, the contents from the first memory 31 to the (n-1)th memory (3n-1).
1) Add up the numbers, divide it by (n-1), and average it. The comparison processing circuit 5 compares this with the contents of the n-th memory 3n, and if a change of more than a certain value is detected, the buzzer 6 sounds and the process ends.

When there is no change, the memory selection circuit 4 selects the first memory 31, and then selects the averaged value of the second memory 32 to the n-th memory 3n, which is then taken into the first memory 31 at this time. 2 and detect changes. If there is no change at this time, the memory selection circuit 4 selects the second memory 32.

Thereafter, similar processing is performed, but the memory selected by the memory selection circuit 4 is the third. 4th. ...5th n-1, nth, 1st
．． Second. Third. ... n-1st, nth, 1st, 2nd. Third. ... and changes into Like Link. This process is continued until a change greater than a certain level is detected.

[Problem that the invention seeks to solve]

In this way, in the conventional monitoring device, images are taken several times and the images are added together in order to remove noise, which requires a corresponding number of memory circuits. That is, the past n average images and the current image are compared, and if there is a change, the buzzer sounds and the process ends; however, in other cases, the past n average images including the current image, In other words, recent n
- Since the average image of one image and the current image is compared with the next image to be taken, (n+1) memory circuits are required in the end. For this reason, the memory capacity must be increased, which increases the cost, and if the number of memory circuits to be referenced increases, the time required for one monitoring process increases, resulting in problems such as poor reliability.

This invention was made to solve the above-mentioned problems, and it can be configured with only two memory circuits, and
The processing time is short (the purpose is to obtain a highly reliable monitoring device).

[Means for solving problems]

The monitoring device according to the present invention includes two storage circuits that store image data, a calculation processing means that performs predetermined calculation processing on the contents of the storage circuits to obtain average image data for a predetermined period in the past, and The apparatus is provided with comparison processing means for comparing the contents of one storage circuit storing image data with the contents of the other storage circuit storing image data to be compared.

[Effect]

In the present invention, the arithmetic processing circuit applies a weight of 1.0 to the image to be compared, for example. A weight of 3 is given to the images to be compared, and the average image data is obtained by adding these and dividing by 4, and this is compared with the image data to be compared.
The currently captured image will be compared with the average image of the three previously captured images.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a monitoring device according to an embodiment of the present invention.
/D converter 31.32 is the first. 2nd memory, 5 these memories 3
1. A comparison processing circuit for comparing the outputs of 32, 6 a buzzer driven according to the output of the comparison processing circuit 5, and 7 weighting each of the first and second memory circuits 31 and 32. This is an arithmetic processing circuit that performs arithmetic processing to obtain past average image data.

Next, the operation will be explained. FIG. 2 shows a flowchart 1 of image processing in this embodiment.

First, in step 20, the content M of the first memory circuit 31 is
l (I) and the number of repetitions N are initialized.

Here, ■ is 0.1, 2. . . . It changes from I to END and represents the number of pixels. The video signals captured by camera 1 are transferred to an A/D converter to store them in memory.
It is digitized by converter 2. Then, in order to check whether there is any change in the image, these are taken into the second memory 32 as an initial image (background image) (step 21).Next, in steps 22 and 23, the contents of the second memory 32 are transferred to the second memory 32. 1 to the contents of the first memo 1J31 and newly writes it to the first memo IJ31.These processes are repeated four times in the arithmetic processing circuit 7 (steps 21 to 26), and each data is added to the cumulative addition. Then divide it by 4 and save it to the first memory 3.
1 (step 29).

Next, an image to be compared, that is, an image to be examined for changes, is taken into the second memory 32 (step 27), and this and the image to be compared with the first memory 3 are taken into the second memory 32.
1 background image is compared in the comparison processing circuit 5 (step 3
0), and when the comparison result TH detects a change THO of a certain level or more, a buzzer sounds and the process ends (steps 31 to 32). Otherwise, the arithmetic processing circuit 7 stores, for example, the first memory 31. Multiply the contents by 3 and write the second memory 3
The contents of step 2 are added and written in the first memory 31 to be used as a background image again (steps 33 to 35), and the same operation is repeated thereafter.

In this embodiment, only two memories are required (therefore, the device is inexpensive, and the number of times the memory is referenced is reduced compared to the conventional device, so high-speed processing is possible and reliability is improved. I can do it.

Although the above embodiment describes the case where this method is applied to a monitoring device, the basic principle of the present invention can also be applied to a people counting device or a general image processing device that performs general calculations (comparisons) between images. It is.

〔Effect of the invention〕

As described above, according to the monitoring device according to the present invention, two memory circuits for storing image data are provided, and the contents of each memory circuit are subjected to predetermined arithmetic processing to obtain an average image, which is stored in one memory. Write this in the circuit. Since the image to be compared is compared with the image in the other memory circuit, the apparatus can be made inexpensive, and it is also possible to obtain a high-reliability device capable of high-speed processing.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a monitoring device according to an embodiment of the present invention;
FIG. 2 is a flowchart for explaining the operation of the device, and FIG. 3 is a configuration diagram of a conventional monitoring device. 31.32...Memory, 5...Comparison processing circuit, 7.
...Arithmetic processing circuit. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A monitoring device that outputs a detection result when a change is detected in input image data, comprising two memory circuits that store the input image data, and arithmetic processing on the contents of the two memory circuits. an arithmetic processing means for calculating the average data of the image data inputted during a predetermined period of time and writing it into one of the memory circuits; 1. A monitoring device comprising: comparison processing means for comparing the image data with normal image data and outputting a detection signal when a change in the image data is equal to or higher than a predetermined level.