JP2000258700A - Device and method for monitoring door and information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for monitoring a door and an information recording medium. SOLUTION: An image gaining means of a door motoring device gains the image of the situation of the side opposite to the door 111 from one side of the door 111 through the peephole 112 of the door 111, and a hold means 103 holds the image gaining means to one side of the door 111, and an image like- ness judging means judges whether or not the image similar to the prescribed image is incorporated in the images gained by the image gaining means, and a storage means 106 stores the image gained by the image gaining means when the image similar to the prescribed image is incorporated, and records a program controlling the door monitoring device on the information recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a door monitoring device, a monitoring method, and an information recording medium. In particular, the present invention relates to a door monitoring device that can be attached to a door such as an entrance and monitors a visitor by appropriately photographing the outside through a peephole of the door, a monitoring method using the monitoring device, and an information recording medium.

[0002]

2. Description of the Related Art Today, from the viewpoint of maintaining safety, monitoring devices have been installed not only in company buildings and buildings, but also in general houses at entrances and the like.
This is because, for example, damage caused by a stalker tracking a specific person, deterioration of public security due to a recession, frequent occurrence of theft, and the like have become serious social problems.

[0003] Some of such monitoring devices are provided with a camera outside of the entrance for taking a picture of the outdoors, and those embedded in a peephole of the entrance door. In these monitoring devices, an outdoor situation is photographed by a camera, and the photographed image is recorded on a medium such as a video tape or transmitted to a security monitoring center or the like using a dedicated line or a computer communication network.

[0004] Recorded images and transmitted images are usually erased from a video tape or the like after a certain period of time (for example, several hours to several days) due to problems such as limitations on recording capacity.

As described above, in the conventional monitoring device, it is necessary to install a camera in advance outside or on the door itself. The only outdoor video shot was before and after the time when the damage actually occurred.

[0006]

However, it has been found that perpetrators of stalking or theft tend to visit the victim's home frequently for the purpose of the visit itself or for the preliminary investigation. There is a great demand to be able to record outdoor situations in the past few weeks.

[0007] In addition, simply recording an outdoor scene does not require most of the recorded video. There is a great demand for recording only videos that are useful for stalking and theft resolution.

In the case of a single-family house, a dedicated camera can be installed outdoors or on the door itself. However, in a rental house such as an apartment or an apartment, such a camera is newly installed. It is difficult to install.
On the other hand, it is known that women who are most susceptible to stalking are women who live alone in rental housing. Therefore, there is a great demand for monitoring the outside of a rental house such as an apartment or an apartment without remodeling existing entrance equipment and doors.

Further, there is also a problem that the peephole of the door is generally small, and it is difficult to see the outside. For elderly people,
Even when the relationship between the height of the place where the peephole is installed and the height does not match, there is a great demand to be able to easily see the outdoors.

[0010] The present invention has been made to solve the above problems, and has as its object to provide a door monitoring device, a monitoring method, and an information recording medium. In particular, the present invention can be mounted on a door such as a door, and by appropriately photographing the outside through a peephole of the door, a door monitoring device that monitors a visitor, a monitoring method using the monitoring device, and An object of the present invention is to provide an information recording medium in which a program for realizing the door monitoring device and the monitoring method of the present invention is recorded.

[0011]

In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.

The door monitoring device of the present invention includes an image acquisition unit and a holding unit, and the image acquisition unit is configured to display an image on a side opposite to the door from one side of the door through a peephole of the door. And the holding unit holds the image obtaining unit on one side of the door.

Further, the door monitoring device of the present invention further includes a display unit, and the display unit displays an image obtained by the image obtaining unit.

Further, the holding means of the door monitoring device of the present invention can also hold the display means on one side of the door.

Further, the holding means of the door monitoring device of the present invention can hold the image acquiring means on one side of the door by using a magnetic force.

Further, the door monitoring device of the present invention further comprises an image similarity determining means and a storage means, wherein the image similarity determining means displays an image similar to a predetermined image to the image acquired by the image acquiring means. It is determined whether or not it is included, and the storage means
If it is determined that the image is included by the image similarity determination unit, the image acquired by the image acquisition unit is stored.

The door monitoring device of the present invention further comprises:
Detecting means for detecting that the door has moved, and whether or not a difference between a time at which an image is acquired by the image acquiring means and a time at which the door has been moved by the detecting means exceeds a predetermined time; Time range determining means for determining whether the image is acquired by the image acquiring means when it is determined by the time range determining means that the time is exceeded and when the image similarity determining means determines that the image is included. Remember.

The monitoring method according to the present invention includes an image acquiring step of acquiring an image representing a situation on the other side of the door from one side of the door through a peephole of the door, and displaying the image acquired by the image acquiring means. And a displaying step.

Further, the monitoring method of the present invention includes an image acquiring step of acquiring an image representing a state on the opposite side of the door from one side of the door through a peephole of the door, and an image acquired in the image acquiring step. An image similarity determining step of determining whether an image similar to a predetermined image is included in the image, and a storing step of storing the image acquired by the image acquiring means when it is determined that the image is included in the image similarity determining step. Prepare.

Further, the monitoring method of the present invention further includes a detecting step of detecting that the door moves, a time at which an image is obtained in the image obtaining step, and detecting that the door has moved in the detecting step. A time range determining step of determining whether or not the difference from the time exceeds a predetermined time, wherein the storing step is determined to exceed the time range determining step and is determined to be included in the image similarity determining step. If so, the image obtained in the image obtaining step is stored.

Further, a program for realizing the door monitoring device and the monitoring method of the present invention is stored in an information recording medium such as a compact disk, a floppy disk, a hard disk, a magneto-optical disk, a digital video disk, a magnetic tape, and a semiconductor memory. Can be.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. The embodiments described below are for explanation, and do not limit the scope of the present invention. Therefore, those skilled in the art can adopt embodiments in which each of these elements or all elements are replaced with equivalents, but these embodiments are also included in the scope of the present invention.

(First Embodiment) FIG. 1 shows a camera section of a door monitoring apparatus according to the present invention mounted on a door, and the camera section on the opposite side (typically outside) from the side mounted through a peephole of the door. It is explanatory drawing which shows a mode that the state image is image | photographed. This figure is a sectional view.

In the door monitoring apparatus 101 of the present invention, the camera section 102 is held in a form in which it is in close contact with one of the peep holes 112 of the door 111. In many cases, a lens 113 is incorporated in the peephole 112 of the door 111 in advance. Lens 1
When 13 is a fisheye lens, it is possible to see an image of a wide outdoor area. The camera unit 102 also incorporates a lens (not shown) and a focusing mechanism (not shown) so that the outside can be photographed through the viewing hole 112.

As shown in FIG. 1, the camera section 102 is held by the holding section 103 near the peephole 112 of the door 111. It is desirable that the optical axis of the lens 113 incorporated in the viewing hole 112 and the optical axis of the camera unit 102 match.

In this embodiment, the holding portion 103 is a magnet 104
The camera unit 102 can be held by a door made of a ferromagnetic or paramagnetic material such as iron by a magnet 104. If the door can be held by the magnet 104, holes and holes such as screws do not remain on the door itself. Therefore, even in the case of a rental house such as a rental apartment, the monitoring device 101 can be easily attached to the door 111. Also,
Since the camera unit 102 is mounted by the magnet 104,
The camera unit 102 can be detached and the peep hole 112 can be directly viewed as needed.

As will be described later, the holding portion 103 is provided with an adhesive tape or a wood screw, and
2 can also be held. Further, as described later, a hinge is provided on the holding unit 103, and the hinge is used by the hinge.
2 can be moved, and if necessary, the sight hole 11
You can also look into 2.

In this embodiment, a display unit 105 having a display device such as a liquid crystal display and a storage unit 106 having a storage device such as a flash memory card are integrally formed in one housing 108, and a camera unit 102 And a cable 107.

The display unit 105 can display not only an outdoor image taken by the camera unit 102 but also a past outdoor image stored in the storage unit 106. For this reason, monitoring can be performed easily on a wider screen than when looking outside through the peep hole 112.

The storage unit 106 records an outdoor image taken by the camera unit 102. The image similarity discrimination mechanism provided in the storage unit 106 selects only an image that includes an image similar to a human figure and selects an image. Since the information is stored, it is possible to store only the image information necessary for stalking and theft prevention for a long period of time.

As will be described later, one or both of the display unit 105 and the storage unit 106 are connected to the camera unit 10.
2 and can be held on the door 111 side by the holding unit 103.

Further, as will be described later, it is possible to transmit information of images picked up and selected via a telephone line or the like to the security headquarters.

FIG. 2 shows the camera unit 10 of the embodiment shown in FIG.
FIG. 3 is an explanatory view showing the shape of a holding unit 103 and a holding unit 103. FIG. 2A shows a front view of the camera unit 102 and the holding unit 103, FIG. 2B shows a right side view thereof, and FIG. 2C shows a left side view thereof.

The position of a lens (not shown) of the camera unit 102 can be changed by rotating the knob 109. Thereby, the camera unit 102 can be focused.

In this embodiment, the camera unit 102 is arranged at the center and four magnets 104 are arranged around the camera unit 102. However, the number and arrangement of the magnets 104 are arbitrary. Magnet 10
By making the number of fours plural, the holding can be ensured. By arranging the magnets 104 at symmetrical positions with respect to the camera unit 102, the holding can be balanced.

When the camera unit 102 is held by a material that cannot be held by the magnetic force of the magnet 104, for example, a wooden door, the wood screw hole 20 provided in the holding unit 103 is provided.
1 and can be fixed to the door with wood screws. Alternatively, a double-sided adhesive tape may be attached to the surface of the magnet 104, and the magnet 104 may be fixed to the door with the adhesive tape.

However, when the holding portion 103 having the shape of the present embodiment is employed and is held using a wood screw or an adhesive tape, the camera portion 102 is detached from the viewing hole 112 as necessary, and the viewing hole 112 is removed. Is difficult to see directly. The measures in such a case will be described later.

In this embodiment, the power for driving the camera unit 102 is supplied by a cable 107, and the outdoor state photographed by the camera unit 102 is transmitted to the display unit 105 and the storage unit 106 via the cable 107. .

Note that an embodiment in which a battery or the like is incorporated in the camera unit 102 itself may be adopted. Further, an embodiment in which a power generator is incorporated in a hinge of the door itself or the like and the camera unit 102 is driven by the power generated by the power generator may be adopted. These embodiments are also included in the scope of the present invention.

FIG. 3 is a block diagram showing the configuration of the door monitoring device shown in FIG.

The camera unit 102 held on the door by the holding unit 103 is connected to the storage unit 10 by a cable 107.
6 is connected. The storage unit 106 and the display unit 105 are also connected. The storage unit 106 supplies power to the camera unit 102 via the cable 107, and receives outdoor image information to be captured and transmitted by the camera unit 102.

The storage unit 106 includes an interface unit 301 connected to the cable 107 and an R for temporarily expanding image information received by the interface unit 301.
An AM (Random Access Memory) 302, a non-volatile storage device 303 such as a flash memory card for storing image information, and a CPU (Central)
A processing unit (central processing unit) 304 and a receiving unit 305 such as a keyboard, a button, and a switch for receiving a user's instruction are provided. The power supply is not shown because a known technique can be used.

The CPU 304 monitors whether the interface unit 301 has received the image information transmitted by the camera unit 102 and expands the received image information in the RAM 302. Further, the image information developed in the RAM 302 is checked to determine whether the image includes an image similar to a human figure. If it is included, the image information expanded in the RAM 302 is stored in the nonvolatile storage device 303 together with information on the date and time when the image information was captured.

The processing executed by the CPU 304 is performed by a ROM
(Read Only Memory) 306. When the power of the storage unit 106 is turned on, the CPU 304
The program stored in 306 is read from a predetermined address and executed. When the nonvolatile storage device 303 is realized by a flash memory card or a floppy disk, the program stored in the ROM 306 is
It is also possible to update with a program stored in these information storage media.

In accordance with the instruction given by the user to the receiving unit 305, the CPU 304
03 is displayed on the display unit 105 such as a liquid crystal display, the camera unit 102 captures and transmits the image information, and the interface unit 301 receives and transmits the image information.
The image information developed in 02 can be displayed on the display unit 105 as it is. In the latter case, the outdoor state currently being photographed by the camera unit 102 can be easily seen on a screen larger than the peephole 112. It should be noted that a method of giving an instruction by the user using the reception unit 305 or the display unit 105 can use a known technique, and thus a description thereof is omitted in the present application.

It is also possible to provide a center connection unit (not shown) in the storage unit 106 and transmit necessary image information to the security headquarters via a telephone line or a computer communication network. In this case, the nonvolatile storage device 303 is a hard disk or a videotape recorder provided in the security headquarters. Further, in this case, the update program transmitted by the security headquarters can be received by the center connection unit, and the program stored in the ROM 306 can be updated.

The nonvolatile storage device 303 includes:
In addition to a flash memory card, an information recording medium such as a hard disk, a floppy disk, and a magnetic tape can be used, and these embodiments are also included in the scope of the present invention. At present, flash memory cards and floppy disks are widely used as image storage media for digital cameras. When used as a videotape image recording medium, images can be viewed on a home television device or the like.

In this embodiment, the storage unit 106 and the display unit 10
5 are integrally formed in one housing 108, but a home television device is adopted as the display unit 105, and an image output unit (not shown) for the television device is provided in the storage unit 106. A form can also be adopted. In this case, there is no need to prepare a dedicated display unit 105, which can contribute to cost reduction.

Here, the camera unit 102 functions as an image acquiring unit, the holding unit 103 functions as a holding unit, the display unit 105 functions as a display unit, the CPU 304 functions as an image similarity judging unit, Storage device 30
Reference numeral 3 functions as storage means.

FIG. 4 is a flowchart showing the flow of an image storage process for selectively storing an image in the nonvolatile storage device 303. The image storage process is executed under the control of the CPU 304.

First, the interface unit 301 receives image information transmitted by the camera unit 102 (step S4).
01). The received image information is developed in the RAM 302 (step S402).

Next, the CPU 304 sets the RAM 30
It is determined whether or not an image similar to a human figure is included in the image information developed in Step 2 (Step S40).
3). This judgment is based on "Image Recognition Theory" (written by Makoto Nagao, Corona Publishing Co., 1983, ISBN4-339-02015-
A known method such as the method described in X) can be used.

If not included (step S403;
No), after waiting for a predetermined time (step S404),
Returning to step S401, monitoring is continued. The standby time can be appropriately changed according to the image capturing speed of the camera unit 102, the performance of the interface unit 301, the RAM 302, the CPU 304, and the like. Prolonging the standby time can reduce power consumption. Also,
The waiting time can be shortened, or the waiting time can be set to 0 (no waiting).

On the other hand, if it is included (step S40)
3; Yes), the CPU 304 determines whether or not to store the image information based on whether or not the specific condition is satisfied (step S405). If it is determined that the image information is to be stored (step S405; Yes), The image information is stored in the nonvolatile storage device 303 together with the current time information (step S406).

Here, the types of the specific conditions determined in step S404 will be described below.

When a shape similar to a human figure is recognized, it is always stored. This is great because it captures everything that could be a stalker or thief.

A method of comparing the time when the image was stored in the nonvolatile storage device 303 immediately before and the current time, and storing the difference when the difference is longer than a predetermined time (for example, one second to several seconds). This is advantageous in that images can be appropriately thinned out, the storage capacity of the nonvolatile storage device 303 can be effectively used, and recording can be performed for a longer period.

A method of storing when the difference between the image information stored immediately before in the nonvolatile storage device 303 and the image information currently expanded in the RAM 302 is equal to or more than a predetermined amount. In this method, the image can be thinned out in the same manner as described above.

An appropriate image can be stored for a long period of time by appropriately combining these methods.

After storing the image information in step S406 and when it is determined not to store the image information (step S405; No), the process waits for a predetermined time (step S404), returns to step S401, and continues monitoring. .

In step S406, if the free space of the non-volatile storage device 303 is insufficient, one or more sets of the most recently stored image information and its recording time are erased, so that The latest image information can be stored by increasing the free space.

When a flash memory card is used as the non-volatile storage device 303, erasing information takes a long time. Therefore, erasing a plurality of old images collectively helps to improve the performance.

As described above, in the present embodiment, the camera unit 102 photographs the outdoor state through the peephole 112 of the door 111, and stores only an image including an image similar to a human figure in the nonvolatile storage device 303 as appropriate. By doing so, it is possible to provide a monitoring device and a monitoring method suitable for stalking and anti-theft measures.

(Second Embodiment) In the first embodiment described above,
The camera unit 102 is moved to the door 1 by the magnet 104 of the holding unit 103.
11 is different from the second embodiment described below in that the holding unit 103 holds the camera unit 102 to the door 111 with a wood screw or an adhesive tape.

As described above, when the holding unit 103 having the shape of the first embodiment holds the camera unit 102 on the door 111 using a wood screw or an adhesive tape, it is extremely difficult to directly view the peep hole 112 of the door 111. It becomes difficult. The second embodiment described below solves this.

FIG. 5 is an explanatory view showing the shapes of the camera section and the holding section of the door monitoring apparatus according to the second embodiment of the present invention.
In FIG. 5, the storage unit and the display unit are not shown.

The camera unit 502 of the door monitoring device 501 includes:
The same configuration as that of the first embodiment can be adopted, but the holding portion 503 has a hinge 504. One side plate 505 of the hinge 504 supports the camera unit 502, and the other side plate 506 is fixed to the door 511 using an adhesive tape or a wood screw.

By opening and closing the hinge 504, the camera section 502 can take a picture of the outside through the peep hole 512 of the door 511, and the user can directly view the outside through the peep hole 512.

A holder (not shown) such as an adhesive tape, a magnet, or a stopper can be provided between one side plate 505 and the other side plate 506 of the hinge 504. This allows
The state in which the hinge 504 is closed, that is, the camera unit 50
The camera unit 502 can be prevented from being shaken in a state in which the outside is photographed through the peep hole 512 of the door 511 in the step 2.

In this embodiment, the camera section 502 is in close contact with the peephole 512 when the hinge 504 is closed (bent), and the peephole 512 is visually observed in the open state. As shown, hinge 504 is approximately 180
It is also possible that the camera unit 502 is in close contact with the peephole 512 in the open state each time, and the peephole 512 is visually observed in a folded state.

According to the present embodiment, even when the camera section of the door monitoring device is held on the door with an adhesive tape or a wood screw, the camera section can be removed and the peephole of the door can be directly viewed. Easy.

(Third Embodiment) In the above embodiment, while the camera unit is held on the door by the holding unit, a housing housing the storage unit and the display unit is separately provided. In the present embodiment, the storage unit and the display unit are integrally formed with the camera unit, and are mounted on the door by the holding unit.

In this embodiment, when the display section is provided on the side mounted on the door, a large screen such as a liquid crystal display is mounted on the door. For this reason, there is an advantage that the outdoors can be easily confirmed on a large screen without looking through a small peephole.

When the camera unit, the storage unit, and the display unit are integrally formed as in this embodiment and are mounted on the door using the holding unit, the size of the entire door monitoring device is reduced. It has the advantage that it can be installed and takes up less space.

(Fourth Embodiment) In the above embodiment, even when a resident of a house equipped with the door monitoring device of the present invention enters and exits through the door, the resident may be photographed. Since it is not necessary to take such an image by nature, it is prevented and the storage area of the non-volatile storage device 303 is saved to enable a longer-time shooting. Sometimes you want to make it easier.

In this embodiment, the opening and closing of the door is detected,
Images taken within a predetermined time (for example, several seconds) before and after the door is opened and closed are not stored in the nonvolatile storage device 303. That is, in the present embodiment, it is assumed that the person who opens and closes the door is mainly the resident of the house.

The opening and closing of the door can be detected by providing an acceleration sensor in the holding section of the above embodiment. When the door is opened and closed, a rotational motion and a reciprocating motion occur, and this is detected by an acceleration sensor.

It is also conceivable to provide a switch near the hinge of the door or near the knob of the door. There has already been provided a device for turning on a light for a predetermined time after opening and closing a door, but the same technology as this device is used.

The detection result of the acceleration sensor is transmitted to the storage unit via a cable. Using the transmitted detection result, C
The PU makes the decision. That is, step S of the first embodiment
As a specific condition determined in 405, a condition that the time when the door was last opened and closed and the current time are compared and the difference is stored when the difference exceeds a predetermined time (for example, several seconds) is added. This embodiment can be realized.

In the above method, an image taken immediately before the door is opened and closed (an image of a resident of the house when he comes home) is stored in the nonvolatile storage device. Therefore, when the opening and closing of the door is detected, the CPU deletes the image information at a time within a predetermined time (for example, several seconds) from the time from the nonvolatile storage device. According to this method, the image of the figure of the resident of the house when returning home is no longer stored in the nonvolatile storage device, and only the figure of the suspicious individual is recorded.

[0081]

As described above, according to the present invention,
The following effects are obtained.

First, it can be attached to a door such as a door, and by taking a picture of the outside through a peephole of the door as appropriate,
It is possible to provide a door monitoring device that monitors a visitor and a monitoring method using the monitoring device.

Also, a door monitoring device capable of recording only necessary images useful for stalking measures and resolving theft in the past several weeks to several months by image recognition technique,
A monitoring method by the monitoring device can be provided.

Further, it is possible to provide a door monitoring apparatus which can be installed without modifying existing entrance equipment and doors, and a monitoring method using the monitoring apparatus.

Further, it is possible to provide a door monitoring device which allows the outside to be easily seen, and a monitoring method by the monitoring device.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state in which a camera unit of a first embodiment of a door monitoring device of the present invention is mounted on a door.

FIG. 2 is an explanatory diagram showing shapes of a camera unit and a holding unit of the door monitoring device shown in FIG.

FIG. 3 is a block diagram showing a configuration of the door monitoring device shown in FIG. 1;

FIG. 4 is a flowchart showing a flow of an image storing process of selectively storing an image in a nonvolatile storage device in the door monitoring device shown in FIG. 1;

FIG. 5 is an explanatory view showing the shapes of a camera section and a holding section of a door monitoring device according to a second embodiment of the present invention.

FIG. 6 is an explanatory view showing another shape of the camera unit and the holding unit of the door monitoring device according to the second embodiment of the present invention.

[Explanation of symbols]

 101 monitoring device 102 camera unit 103 holding unit 104 magnet 105 display unit 106 storage unit 107 cable 108 housing 109 knob 111 door 112 peephole 113 lens 301 interface unit 302 RAM 303 nonvolatile storage device 304 CPU 305 reception unit 306 ROM 501 door Monitoring device 502 camera unit 503 holding unit 504 hinge 505 one side plate 506 the other side plate 511 door 512 peephole

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takeshi Fuchi 9-5-2, Akasaka, Minato-ku, Tokyo No. 28, Berlay Ju Nogizaka Room 901 F-term (reference) 2H087 KA25 5C054 CE06 CE11 FC01 GA01 GA02 GA04 GB01 GB12 GD05 GD06 HA22 9A001 BB03 BB04 HH23 HH34 KK62 LL03

Claims (13)

[Claims] 1. A door monitoring device comprising the following means. (A) image acquisition means for acquiring an image representing a state on the opposite side of the door from one side of the door through a peephole of the door; and (b) holding the image acquisition means on one side of the door. Holding means. 2. The door monitoring device according to claim 1, further comprising: (C) display means for displaying the image acquired by the image acquisition means. 3. The door monitoring apparatus according to claim 2, wherein said holding means also holds said display means on one side of said door. 4. The door monitoring device according to claim 1, wherein the holding unit holds the image acquiring unit on one side of the door by using a magnetic force. 5. The door monitoring device according to claim 1, further comprising the following means. (D) image similarity determining means for determining whether or not the image acquired by the image acquiring means includes an image similar to a predetermined image; and (e) when the image similarity determining means determines that the image is included. Storage means for storing an image obtained by the image obtaining means; (F) detecting means for detecting that the door has moved; (g) detecting the time at which the image was obtained by the image obtaining means, and detecting that the door has moved by the detecting means. Time range determining means for determining whether or not the difference from the set time exceeds a predetermined time, wherein the storage means is determined to exceed by the time range determining means, and the image similarity determining means 6. The door monitoring device according to claim 5, wherein when it is determined that the image is included, the image acquired by the image acquiring unit is stored. 7. A monitoring method comprising the following steps. (A) an image acquisition step of acquiring an image representing a state on the opposite side of the door from one side of the door through a peephole of the door; and (b) a display step of displaying an image acquired by the image acquisition means. . 8. A monitoring method comprising the following steps. (A) an image acquisition step of acquiring an image representing a state on the opposite side of the door from one side of the door through a peephole of the door; and (c) converting the image acquired in the image acquisition step into a predetermined image. An image similarity determination step of determining whether or not a similar image is included; and (d) a storage step of storing the image acquired by the image acquisition means when it is determined that the image is included in the image similarity determination step. 9. Further, (e) a detecting step of detecting that the door moves, (f) detecting a time when an image is obtained in the image obtaining step, and detecting that the door has moved in the detecting step. A time range determining step of determining whether a difference from the set time exceeds a predetermined time, wherein the storing step is determined to exceed in the time range determining step, and the image similarity determining step is performed. 9. The monitoring method according to claim 8, wherein when it is determined that the image is included, the image acquired in the image acquiring step is stored. 10. An information recording medium for recording a monitoring program, comprising the following steps. (A) an image acquisition step of acquiring an image representing a state on the opposite side of the door from one side of the door through a peephole of the door; and (b) a display step of displaying an image acquired by the image acquisition means. . 11. An information recording medium for recording a monitoring program, comprising the following steps: (A) an image acquisition step of acquiring an image representing a state on the opposite side of the door from one side of the door through a peephole of the door; and (c) converting the image acquired in the image acquisition step into a predetermined image. An image similarity determination step of determining whether or not a similar image is included; and (d) a storage step of storing the image acquired by the image acquisition means when it is determined that the image is included in the image similarity determination step. And (f) detecting a movement of the door, (f) detecting a time at which an image is obtained in the image obtaining step, and detecting that the door has moved in the detecting step. A time range determining step of determining whether a difference from the set time exceeds a predetermined time, wherein the storing step is determined to exceed in the time range determining step, and the image similarity determining step is performed. The information recording medium for recording a monitoring program according to claim 11, wherein when it is determined that the monitoring program is included, the image acquired in the image acquiring step is stored. 13. The information recording medium according to claim 10, wherein the information recording medium is a compact disk, a floppy disk, a hard disk, a magneto-optical disk, a digital video disk, a magnetic tape, or a semiconductor memory. Information recording medium.