JP2000172827A - Human body detector and air conditioner using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner which can make the optimum air conditioning without erroneously detecting a violently moving object as a human body. SOLUTION: An air conditioner is provided with an image picking-up section 101, a reference image storing section 103 which temporarily stores the image picked up by means of the section 101 as a reference image, and a difference computing section 102 which generates a difference image from the image picked up by means of the section 101 and reference image. The air conditioner is also provided with a binarizing section 104 which generates a binary image by binarizing the difference image, an addition computing section 105 which generates an added image by cumulatively adding binary images, and a mask image generating section 107 which generates a mask image by binarizing the added image. In addition, the conditioner is also provided with a mask computing section 108 which computes the mask of the binary image by using the mask image, a human body discriminating section 109 which discriminates the existing location of a human body from the image obtained by means of the section 108, and a control section 110 which controls the operation/non- operation, temperature, wind direction, and wind speed of an air-conditioning section (not shown in the figure) from the information on the existing location of the human body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a human body detecting device and an air conditioner using the same, and more particularly, to a human body detecting device capable of accurately detecting the presence or absence of a person in a room and the position of the person. It relates to an air conditioner using the same.

[0002]

2. Description of the Related Art In a conventional air conditioner, a user operates switches attached to an air conditioner body or a remote control (hereinafter, referred to as "remote control") to turn on / off the operation of the air conditioner. The operation control is performed by setting the temperature, the wind direction, the wind speed, and the like.

[0003] The operation ON / OFF switch is a switch for operating the start and stop of operation of the air conditioner. Normally, when the user needs or no longer needs temperature control by the air conditioner
The / OFF switch is operated.

[0004] The temperature setting switch is a switch for setting a target value of the indoor air temperature automatically adjusted by the air conditioner. Usually, the temperature at which the user feels comfortable is set as the target value.However, if the user warms the room in advance while the user is absent, or if the user leaves the room for a short time,
Alternatively, when the user is sleeping, the target value (set temperature) may be changed from the viewpoint of energy saving or prevention of falling asleep.

[0005] The wind direction switch is a switch for controlling the direction of the wind flowing in the room by adjusting the angle of the louver attached to the outlet of the air conditioner. By operating the wind direction switch, the wind direction can be adjusted so that the temperature of the entire room becomes as uniform as possible, or the wind direction can be adjusted so that the wind is directed in a direction where a person is present or absent.

[0006] The wind speed switch is a switch for adjusting the amount of air blown from the air conditioner to control the intensity of wind flowing in the room. By operating the wind speed switch, the wind will be strong at the start of operation, and the wind will change every moment, such as a weak wind as the set temperature is approached. Or the strength of the light.

However, in such a conventional air conditioner, if the user forgets to stop the operation due to carelessness, the operating state is maintained despite the absence of the user, and energy is wasted. There was a problem of doing it.

Further, when the room is warmed in advance when the user is absent, when the user leaves the room for a short time, or when the user is sleeping, the temperature is reduced from the viewpoint of energy saving or prevention of getting cold. In some cases, it is necessary to reset the wind direction and the wind speed by operating a remote controller or the like.

Further, when the difference between the set temperature and the room temperature is large immediately after the start of the operation, the wind is directed in the direction where a person is present, and a sufficient time elapses after the start of the operation, and the difference between the set temperature and the room temperature disappears. In such a case, it is necessary to reset the wind direction and the wind speed by operating a remote controller or the like each time the user wants to prevent the wind from directly hitting a person.

In order to solve such problems, air conditioners having a human body detecting function have been developed in recent years.

In the air conditioner disclosed in Japanese Patent Application Laid-Open No. Hei 5-187682, two infrared sensors having a fixed infrared detection area are arranged so that the detection areas partially overlap.
The direction of the human body and the distance from the air conditioner to the human body are detected from the output of the infrared sensor, and the set temperature, wind direction, and wind speed are controlled.

Referring to FIG. 22, Japanese Patent Application Laid-Open No. 5-18768
The air conditioner disclosed in Japanese Patent Publication No. 2 has two infrared sensors 1 and 2 arranged so that detection areas overlap each other. If only the infrared sensor 1 detects infrared rays radiated by the human body, it is determined that the person is present in the position detection area 3, and if only the infrared sensor 2 detects infrared rays radiated by the human body, the person is detected. It is determined that it exists in the area 5. When the infrared sensor 1 and the infrared sensor 2 detect a human body at the same time, it is determined that the human body exists in the position detection area 4. Also, by utilizing the fact that the output values of the infrared sensors 1 and 2 change according to the distance to the human body, it is determined whether or not a person has entered a range of a certain distance from the air conditioner.

As described above, in the air conditioner disclosed in Japanese Patent Application Laid-Open No. 5-187682, the set temperature, the wind direction, and the airflow are detected by detecting the area where the human body exists and the distance from the air conditioner to the human body. Controls wind speed.

The spot-following air conditioner disclosed in Japanese Patent Application Laid-Open No. Hei 5-231695 detects the presence of a human body and the distance to the human body with an ultrasonic sensor, thereby turning the air in the direction of the air outlet. Dynamic control.

[0015] In this interpersonal tracking air conditioning system, a pair of left and right ultrasonic sensors are supported forward. The ultrasonic sensor is composed of an ultrasonic vibrator and a horn. The ultrasonic vibrator outputs pulsed ultrasonic waves to the front, and the ultrasonic waves reflected on an obstacle (object to be detected). Received by horn. The detection areas of the two ultrasonic sensors have detection areas overlapping each other,
The direction in which the human body exists is detected depending on which ultrasonic sensor detects the human body, such as when only one ultrasonic sensor detects a human body or when both ultrasonic sensors detect a human body. Further, the distance from the following spot air conditioner to the human body is detected by measuring the time from transmission to reception of the ultrasonic wave.

Further, the air conditioner disclosed in Japanese Patent Application Laid-Open No. 4-13036 takes an image difference between an image photographed at a time when no person is present and a current image, thereby obtaining an area where a human body exists. And controls the wind direction.

This air conditioner has photographing means for photographing the indoor scene, and the output signal of the photographing means is binarized by a binarizing circuit and stored in an image memory. The image memory stores two background images, a background image captured beforehand when no human body is present and a current image captured at predetermined time intervals.
The screen is stored. If there is an area where the image difference between these images is large, it is determined that a human body exists in that direction.

Further, the human body detecting device disclosed in Japanese Patent Application Laid-Open No. 5-118916 uses a difference image between a background image and a current image and an output of an infrared sensor.
Perform human body detection.

This human body detecting device obtains a background image and a current image from signals obtained from the image input means, performs a difference operation between the two images, and calculates a difference image by a predetermined threshold value by two. The moving object is extracted by converting the value into a value. The temperature of the extracted region of the moving body is detected by an infrared sensor, and a human body is extracted.

[0020]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No.
In the air conditioner disclosed in Japanese Patent No. 87682, the infrared sensor uses infrared energy radiated from the human body,
The presence area of the human body is detected based on a difference from infrared energy radiated from the background of the human body such as a room wall, a window, and furniture. For this reason, when the difference between the human body temperature and the room temperature is small, such as when it is hot in summer, there is a problem that the detection accuracy deteriorates. Further, the infrared sensor has a property of reacting only to a moving heat source. For this reason, for example, it is difficult to detect a slightly moving human body sitting on a chair,
Conversely, it reacts to small animals such as moving cats.

Therefore, when the infrared sensor responds, there is a high possibility that a person or a small animal is present. However, when the infrared sensor does not respond, there is a problem that it cannot be determined whether or not a person is absent.

[0022] In the spot-following air conditioner for interpersonal tracking disclosed in Japanese Patent Application Laid-Open No. Hei 5-231595, the ultrasonic sensor detects an ultrasonic wave reflected and returned from an obstacle (object to be detected). And objects other than humans show the same reaction. Therefore, it is difficult to distinguish between them. Also, if there are other obstacles around the person, such as a person sitting in a chair, or another obstacle between the person and the ultrasonic sensor, the person will be confused with another obstacle. And detect it. This makes it even more difficult to determine whether a person is present. Therefore, it was not possible to distinguish between people and things.

In the air conditioner disclosed in Japanese Patent Application Laid-Open No. 4-13036, the brightness of the room changes after the reference image is created due to a change in the amount of sunlight, insertion of direct sunlight, or turning on / off the indoor lighting. When the furniture is moved, or when furniture such as a chair or an object in the room is moved, an image difference is generated from the reference image even in a region where no human body exists.
For this reason, erroneous detection occurs.

As a method of solving this problem, a method is considered in which, when an environmental change such as room brightness occurs, the reference image is taken again.
However, it is difficult to detect an environmental change itself, and automation cannot be performed. On the other hand, it is difficult and impractical to require such judgment and work from a person who uses the air conditioner in an ordinary household.

Further, when an object such as a television screen which does not move but an object whose brightness is fluctuating, or an object which actually moves such as a rotating electric fan is present in the room, the reference image and the If the image difference is taken, it is difficult to determine whether or not the portion is detected and extracted as a person.

Compared to the above conventional example, Japanese Patent Application Laid-Open No. 5-118
In the human body detection device disclosed in Japanese Patent No. 916, human body recognition is performed on a portion extracted from a difference image between a background image and a current image based on the presence or absence of an output of an infrared sensor. For this reason, there is an advantage that it is possible to distinguish an object that does not move itself but moves visually, such as a television, or an object that actually moves, such as a rotating electric fan, from a person.

However, in the case of a person who is slightly moving while sitting on a chair, there is almost no difference between the background image and the current image.
It is difficult to extract the human body from the difference image.

This human body detecting device has a mechanism for extracting a human body from a difference image between a background image and a current image, and a mechanism for extracting whether or not a person is an infrared sensor. For this reason, there is a problem that the size becomes larger and the cost becomes higher than a human body detecting device constituted by only one of the mechanisms.

Further, in order to point the infrared sensor at a portion extracted by the difference image between the background image and the current image, the infrared sensor must be rotated by a motor or the like. By attaching such a mechanism, there is a problem that the size of the human body detection device increases and the cost increases.

Further, in order to detect the temperature with the infrared sensor, a mechanism for interrupting infrared rays, generally called a chopper, is required. In order to drive the chopper, a motor or the like is required, and there is a problem that the size of the human body detection device increases and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a human body detecting device which does not erroneously detect a rapidly moving object as a human.

Another object is to provide a human body detecting device capable of accurately detecting a stationary person.

Still another object is to provide an air conditioner capable of performing optimal air conditioning using a human body detecting device capable of accurately detecting a human body.

[0034]

According to a first aspect of the present invention, there is provided a human body detecting apparatus for capturing an image, and connected to the image capturing means for storing an image obtained by the image capturing means. Difference calculation for creating a difference image by performing a difference between an image obtained by the imaging means and an image held in the reference image storage means, which is connected to the reference image storage means, the imaging means and the reference image storage means. And a binarizing unit connected to the difference calculating unit for binarizing the differential image to create a binary image, and connected to the binarizing unit and accumulating a predetermined number of binary images. Addition operation means for creating an addition image by means of
A mask image generating means for binarizing the added image to generate a mask image, and a mask connected to the binarizing means and the mask image generating means for performing a mask operation between the binary image and the mask image A calculation unit; and a human body recognition unit connected to the mask calculation unit and configured to recognize the presence or absence of a human body and the position of the human body based on an image obtained by the mask calculation unit.

According to the first aspect of the present invention, the difference image between the image obtained by the imaging means and the image held in the reference image storage means is binarized, and the results are cumulatively added. As a result, it is possible to extract, from the image, only an image portion other than the human body, such as a television screen, where the movement is severe. The image obtained in this way is defined as a mask image. On the other hand, a difference is made between the image held in the reference image storage means and the image obtained by the imaging means, and a difference image is obtained. The difference image is binarized to obtain a binary image. By performing a mask operation between the binary image and the mask image, an area of the human body is detected in an area excluding a portion where movement is sharp. For this reason, the presence or absence of a human body and its location can be accurately detected.

According to a second aspect of the present invention, there is provided a human body detecting apparatus, comprising: an image pickup means for picking up an image; a reference image storage means connected to the image pickup means for storing an image obtained by the image pickup means; A difference calculation unit connected to the imaging unit and the reference image storage unit for performing a difference between the image obtained by the imaging unit and the image held in the reference image storage unit to create a difference image; And a binarizing unit for binarizing the difference image to generate a binary image, and a binarizing unit connected to the binarizing unit for cumulatively adding a predetermined number of binary images to generate an added image Calculating means connected to the adding calculating means for binarizing the added image to generate a mask image;
Mask operation means connected to the addition operation means and the mask image generation means for performing a mask operation between the addition image and the mask image; and a mask operation means connected to the mask operation means and based on the image obtained by the mask operation means. And a human body recognizing means for recognizing the presence or absence of a human body and the position of the human body.

According to the second aspect of the present invention, a mask image is created using the added image. For this reason, it is possible to detect a human body in an area other than the human body, such as a television screen, where the movement is severe. In the mask calculating means, a human body is detected based on the added image. Therefore, even a slight movement of a person can be detected. Therefore, even if a stationary person is present in the room, the presence / absence of the person and the position of the person can be accurately detected.

According to a third aspect of the present invention, there is provided a human body detecting apparatus, comprising: an image pickup means for picking up an image; a reference image storage means connected to the image pickup means for storing an image obtained by the image pickup means; A difference calculation unit connected to the imaging unit and the reference image storage unit for performing a difference between the image obtained by the imaging unit and the image held in the reference image storage unit to create a difference image; And a binarizing unit for binarizing the difference image to generate a binary image, and a binarizing unit connected to the binarizing unit for cumulatively adding a predetermined number of binary images to generate an added image Calculation means for calculating the difference between the two images after binarizing the added image with the first and second threshold values, and performing a difference calculation between the two images after the binarization. Generating means and a mask image generating means. It is, and a human recognition means for, based on the image obtained from the mask image generation unit, to recognize the existence and location of human body.

According to the third aspect of the present invention, the added image is binarized by the first and second threshold values, and a difference image is performed between the two images after the binarization to thereby obtain a human body. Detection is performed. Since the added image is used, even a slight motion of a person can be detected. In addition, the first and second
By properly determining the threshold of, when the difference operation is performed between the two images after the binarization, the part of the TV screen or the like that moves rapidly is erased, and only the person who moves slightly is detected. can do. Therefore, even if a stationary person is present in the room, the presence / absence of the person and the position of the person can be accurately detected.

An air conditioner according to a fourth aspect of the present invention is a human body detecting device according to the first, second or third aspect, an air conditioner for performing air conditioning in a room, and a human body of the human body detecting device. Control means connected to the recognition means for controlling the air conditioning means according to the presence or absence of the human body and the position of the human body.

According to the fourth aspect of the present invention, the air conditioner is controlled based on the accurate information on the presence or absence of a human body and the position of the human body obtained from the human body detecting device according to the first, second or third aspect. Control is performed. For this reason, an air conditioner that can perform optimal air conditioning can be provided.

[0042]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] An air conditioner according to one embodiment of the present invention will be described below with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Since their names and functions are the same, repetition of the description will be appropriately omitted.

Referring to FIG. 1, an air conditioner according to the first embodiment has an image pickup section 101 for picking up an image of an indoor state.
And a reference image storage unit 103 that is connected to the imaging unit 101 and temporarily stores an image obtained by the imaging unit 101 as a reference image, and is connected to the imaging unit 101 and the reference image storage unit 103 and obtains an image from the imaging unit 101. Image and
A difference calculation unit 102 for calculating a difference between corresponding pixels with the image stored in the reference image storage unit 103, and a binarization unit connected to the difference calculation unit 102 for binarizing the image obtained by the difference calculation unit 102 Binarization unit 104 and binarization unit 10
4 and an addition image storage unit 106 to be described later, which is added between corresponding pixels between the binary image output from the binarization unit 104 and the addition image temporarily stored in the addition image storage unit 106. An addition operation unit 105 for performing an operation, an addition image storage unit 106 for temporarily storing an addition image obtained by the addition operation unit 105, and an addition image connected to the addition operation unit 105 and output from the addition operation unit 105. Mask image generator 10 for binarizing and generating a mask image
7, a mask operation unit 108 connected to the binarization unit 104 and the mask image generation unit 107 for performing a mask operation of the binary image using the mask image, and a mask operation unit 10
8, a human body recognizing unit 109 for recognizing the presence / absence of a human body and the position of the human body from the image obtained by the mask calculating unit 108, and connected to the output of the human body recognizing unit 109 to provide the human presence position information And a control unit 110 for controlling the operation / non-operation of the air conditioning unit (not shown), the temperature, the wind direction, and the wind speed, and a processing control unit (not shown) for controlling the processing of each unit.

The image pickup unit 101 is incorporated in a part of the air conditioner for photographing an indoor image. Imaging unit 101
May output an analog video signal like a CCD (Charge Coupled Device) camera,
It may output a digital video signal. If the output of the imaging unit 101 is an analog video signal,
The air conditioner further includes an A / D converter (not shown) for performing A / D conversion on the video signal by quantization and sampling to generate a digital video signal. Digital images obtained from digital video signals
As shown in FIG. 2, each pixel constituting the image is mapped in a two-dimensional coordinate space, and each pixel has a gray scale for representing shading. In FIG. 2, the number of pixels in the x-axis direction and the number of pixels in the y-axis direction are each 512 pixels. However, the number of pixels is not limited thereto, and may be other numbers.

Referring to FIG. 3, each part of the air conditioner operates as follows. The state of the room is imaged by the imaging unit 101 (S201). I output from the imaging unit 101
Let A _i (i = 1, 2,...) Be the image of the th frame,
Let the pixel value of the coordinates (x, y) of the image A _{i be} a _i (x, y).

The reference image A _i stored in the reference image storage unit 103 is fetched into the difference calculation unit 102, and thereafter, S
An image A _{i + 1} captured in 201 is set as a reference image A _i
It is stored in the reference image storage unit 103 (S202). Difference calculation unit 102, the image A _{i + 1} taken by the imaging means at S201, performs difference between ipecac's reference image A _i from the reference image storage unit 103 at S202, to create a difference image B _i ( S203). That is, when the pixel value of the coordinates (x, y) of the difference image B _i is b _i (x, y),
b _i (x, y) is represented by the following equation (1).

B _i (x, y) = | a _{i + 1} (x, y) −a _i (x, y) | (1) The binarization unit 104 converts the difference image into two at a predetermined threshold value. and valued, creating a binary image C _i (S204). As a result, a region having a large motion between frames is extracted. Assuming that the pixel value of the coordinates (x, y) of the binary image C _i is c _i (x, y) and the threshold value is L1, the pixel value c _i (x, y)
Is represented by the following equation (2).

[0048]

(Equation 1)

[0049] For example, obtains a difference image B _i between the image A _{i + 1} shown in the image A _i and 5 shown in FIG. 4, a difference image B
_{When a} binary image C _i is obtained from _i , C _i is as shown in FIG. That is, the part of the hand of the person who moved and the part of the television screen are detected.

The mask operation unit 108 includes a binary image C _i obtained in S204, performs mask operation between the mask image E obtained by the processing of S210 will be described later, the image portions other than the human body is masked F _i is obtained (S205). The pixel value of the coordinates (x, y) of the mask image E is e (x, y), and the pixel value of the coordinates (x, y) of the image F _i is f _i (x, y).
y), f _i (x, y) is represented by the following equation (3). Here, e (x, y) is a value of 0 or 1.

F _i (x, y) = c _i (x, y) −e (x, y) (3) The expression between the mask image E shown in FIG. 7 and the binary image C _i shown in FIG. When performing an operation based on (3), an image F _i, as shown in FIG. 8 is obtained. In the image F _i , it can be seen that only the part of the human hand is detected and the part of the television screen is not detected.

[0052] human body recognition section 109 determines whether or not a person from the image F _i obtained in S205 is present, if the person is present to determine its position (S206).
That is, the area of a region where f _i (x, y) = 1 is obtained from the image F _i , and if the area value is larger than a predetermined value, it is determined that a person exists. If it is determined that a person exists, the center coordinates of the region extracted as the human body are obtained, and the center coordinates are used as the position where the person exists.

The control unit 207 determines a control method of the air conditioner in accordance with the information on the presence or absence of a person and the position of the person, and performs desired control (S207). Specifically, when it is determined that no person is present in the room, the operation of the air conditioner is stopped, the temperature setting, the air volume, and the like are changed. That is, the control is performed such that unnecessary energy consumption is suppressed by changing the temperature setting slightly higher than the room temperature during the cooling operation in summer and changing the temperature setting slightly lower than the room temperature during the heating operation in winter. When it is determined that a person is present, the wind direction is directed to a direction where a person is present or a direction where no person is present, and the flow rate is controlled.

[0054] adder 105 generates the added image D _i by cumulatively adding the binary image C _i obtained by the processing of S204. That is, the adder 105 performs addition processing between corresponding pixels of the binary image C _i obtained the added image D _i-1 stored in the added image storage section 106 in the processing in S204, a new create a Do addition image D _i, and stores the added image D _i in the added image storage section 106 (S20
8). Added image D _i-1 and D _i of the coordinates (x, y) of each pixel value d _i-1 (x, y) and d _i (x,
y), d _i (x, y) is represented by the following equation (4).

D _i (x, y) = d _i−1 (x, y) + c _i (x, y) (4) The processing control unit (not shown) determines a series of processing from S201 to S208. It is determined whether the operation has been performed the number of times (S
209). If these processes have not been performed a predetermined number of times (NO in S209), the processes from S201 onward are repeated again. If these processes have been performed a predetermined number of times (S209
In YES), the mask image generation unit 107 generates a mask image E by binarizing the addition image D _i which is stored in the added image storage unit 106 at a predetermined threshold value (S
210). Then, the process returns to S201. As a result, a portion where the frequency of image change is high, such as a television screen, in which the object itself does not move but the brightness varies, or a rotating fan, is extracted as the mask region. Assuming that the predetermined number of times determined in the process of S209 is n, d _n (x, y) can be expressed by the following equation (5). Assuming that the binarization threshold value in S210 is L2, e (x, y) is represented by the following equation (6).

[0056]

(Equation 2)

The mask image E obtained according to the equation (6)
7 is shown in FIG. It can be seen that the screen portion of the television is extracted as a mask area.

As described above, in the air conditioner according to the present embodiment, the difference image between the current image and the reference image is set to two.
The operation of converting into a value is performed a plurality of times, and the results are cumulatively added. As a result, it is possible to extract only a portion of a moving image other than the human body, such as a television screen, where the movement is severe, from the moving image.The image portion is used as a mask region, and the region is excluded from the detection target of the human body. It is possible to accurately detect the presence / absence of a human body and its location.

Even if the brightness of the room gradually changes due to a change in the amount of sunshine or the like, since the reference image is constantly updated, there is no difference in brightness between the difference image between the reference image and the current image. In addition, an object whose position is shifted only can be effectively detected. [Second Embodiment] Referring to FIG. 9, an air conditioner according to a second embodiment has the same configuration as the air conditioner according to the first embodiment described with reference to FIG. Part 1
In this example, a mask calculation unit 118 is used in place of 08. Other components are the same. Therefore, description thereof will not be repeated.

The mask operation unit 118 is connected to the addition operation unit 105 and the mask image generation unit 107, and
This is for masking the added image obtained from the mask image 05 with the mask image obtained from the mask image generation unit.

Referring to FIG. 10, each part of the air conditioner operates as follows. The processing from S211 to S214 is the same as the processing from S201 to S204 in FIG. Therefore, the description will not be repeated. The process of S215 is the same as the process of S208 in FIG. Therefore, description thereof will not be repeated.

The processing control unit (not shown) determines whether a series of processing from S211 to S215 has been performed a predetermined number of times (S216). If these processes have not been performed a predetermined number of times (NO in S216), the processes after S211 are repeated again. If these processes have been performed a predetermined number of times (YES in S216), mask image generating section 107 receives the output of addition calculating section 105 and generates a mask image (S217). The process of S217 is the same as the process of S210 in FIG. Therefore, description will not be repeated.

After generating the mask image, the mask operation unit 1
In step S218, a mask operation is performed between the added image output from the addition operation unit 105 and the mask image. Coordinates addition image (x, y) the pixel value of a d _i (x, y), the coordinates of the mask image (x, y) the pixel values e (x in,
y), and the pixel value of the image obtained as a result of the mask operation is g
_{Assuming that i} (x, y), the pixel value g _i (x, y) is represented by the following equation (7).

G _i (x, y) = d _i (x, y) −e (x, y) (7) It is determined from the image obtained as a result of the processing of S218 whether or not a person exists, If a person exists, its position is determined (S219). Thereafter, control of an air conditioner (not shown) is performed according to the processing result of S219 (S220). The processing in S219 and S220 is the same as that in FIG.
This is the same as the processing of S206 and S207. Therefore, description will not be repeated.

For example, it is assumed that the image of the person and the television shown in FIG. 11 is stored in the reference image storage unit 103 in advance, and the image shown in FIG. The image shown in FIG. 12 is an image taken immediately after the image in FIG.
The TV screen is changing.

By the processing of S213 and S214, a difference image between the image shown in FIG. 11 and the image shown in FIG. 12 is obtained, and the difference image is binarized. FIG. 13 shows an example of a binary image. The part where the person slightly moved and the changed part of the television screen are detected. FIG. 14 shows an example of an added image obtained by cumulatively adding binary images as shown in FIG. In FIG. 14, a human body and a television screen are extracted. Normally, a person moves slightly even when stationary. Therefore, by accumulating the binary images, it is possible to extract a part where a person is slightly moving with a certain large area.

FIG. 15 is a mask image generated by binarizing the image of FIG. 14 in the process of S217.
A part of a part where a person is slightly moving and a television screen are extracted.

FIG. 16 is a diagram showing the addition image shown in FIG.
Are images obtained by performing a mask operation with the mask image shown in FIG. 7 (images obtained in the process of S218). In this image, only a part of the part where the person is slightly moving is extracted.

As described above, in the air conditioner according to the present embodiment, the difference image of the reference image and the current image
By accumulating the value images, even a slight motion of a person can be detected. Therefore, even when a stationary person is present in the room, the position of that person can be accurately detected.

Further, even when the brightness of the room is rapidly changed due to turning on / off the lighting, insertion of sunlight, and the like, and a difference in brightness occurs between the reference image and the current image, the difference is not changed. The effect is mitigated by accumulating images.
For this reason, erroneous detection can be prevented. Third Embodiment Referring to FIG. 17, an air conditioner according to a third embodiment has the same structure as the air conditioner according to the first embodiment described with reference to FIG. In this configuration, the generation unit 107 and the mask calculation unit 108 are deleted, and a mask image generation unit 111 is newly provided. The mask image generation unit 111 is connected to the output of the addition operation unit 105, and the human body recognition unit 109 is connected to the mask image generation unit 111.
Connected to the output. The mask image generation unit 111
The addition image output from the addition operation unit 105 is binarized by two threshold values, and a difference operation is performed between the obtained two images. Other components are the same as in the first embodiment. Therefore, description thereof will not be repeated.

Referring to FIG. 18, the air conditioner according to the third embodiment operates as follows. S221 to S
The processing up to 226 is the same as the processing from S211 to S216 in FIG. Therefore, description thereof will not be repeated. The mask image generation unit 111 includes an addition operation unit 105
The output image is binarized by the first and second threshold values to obtain two binary images. The first threshold is
It is assumed that it is smaller than the second threshold value. By obtaining a difference between the two binary images, an image in which only the human region is extracted is obtained (S227).

It is determined from the image obtained in S227 whether or not a person exists, and if a person exists, its position is determined (S228). Then, control of the air conditioner is performed according to the processing result of S228 (S22).
9). The processing of S228 and S229 is performed in S20 of FIG.
6 and S207. Therefore, description will not be repeated.

For example, in the process of S227, FIG.
Images obtained as a result of binarizing the added image shown in FIG. 4 with the first and second threshold values are as shown in FIGS. 19 and 20, respectively. Since the first threshold value is smaller than the second threshold value, the area of the human outline is larger in FIG. On the other hand, the brightness of the portion of the television screen changes greatly, and the density value of the added image shows a large value. Therefore, even when binarization is performed using the second threshold value, the television screen portion is extracted in a complete state. When the difference operation is performed between the image shown in FIG. 19 and the image shown in FIG. 20, an image as shown in FIG. 21 is obtained, and only the human body can be reliably extracted.

As described above, in the air conditioner according to the present embodiment, the difference image between the reference image and the current image is the second image.
By accumulating the value images, even a slight motion of a person can be detected. Therefore, even when a stationary person is present in the room, the position of that person can be accurately detected.

Further, even if the brightness of the room suddenly changes due to turning on / off the lighting, insertion of sunlight, etc., and a difference in brightness occurs between the reference image and the current image, the difference is not changed. The effect is mitigated by accumulating images.
For this reason, erroneous detection can be prevented.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an air conditioner according to a first embodiment.

FIG. 2 is a diagram illustrating a digital image output from an imaging unit 101.

FIG. 3 is a flowchart illustrating an operation of the air conditioner according to the first embodiment.

FIG. 4 is a diagram illustrating an example of a reference image stored in a reference image storage unit 103.

FIG. 5 is a diagram illustrating an example of an image output from an imaging unit.

FIG. 6 is a diagram illustrating an example of a binary image output from a binarizing unit 104.

FIG. 7 is a diagram illustrating an example of a mask image output from a mask image generation unit 107.

FIG. 8 is a diagram showing an example of an image output from a mask calculation unit 108.

FIG. 9 is a block diagram illustrating a configuration of an air conditioner according to a second embodiment.

FIG. 10 is a flowchart illustrating an operation of the air conditioner according to the second embodiment.

11 is a diagram illustrating an example of a reference image stored in a reference image storage unit 103. FIG.

FIG. 12 is a diagram illustrating an example of an image output from the imaging unit 101.

13 is a diagram illustrating an example of a binary image output from a binarizing unit 104. FIG.

FIG. 14 is a diagram illustrating an example of an added image output from an addition operation unit 105.

15 is a diagram illustrating an example of a mask image output from a mask image generation unit 107. FIG.

FIG. 16 is a diagram illustrating an example of an image output from a mask calculation unit 118.

FIG. 17 is a block diagram illustrating a configuration of an air conditioner according to a third embodiment.

FIG. 18 is a flowchart illustrating an operation of the air conditioner according to the third embodiment.

FIG. 19 is a diagram illustrating an example of an image obtained as a result of binarizing an addition image output from the addition operation unit 105 with a first threshold value.

FIG. 20 is a diagram illustrating an example of an image obtained as a result of binarizing an addition image output from the addition operation unit 105 with a second threshold value.

21 is a diagram showing an example of an image obtained as a result of performing a difference operation between the image shown in FIG. 19 and the image shown in FIG. 20;

FIG. 22 is a diagram illustrating an arrangement of an infrared sensor provided in an air conditioner disclosed in Japanese Patent Application Laid-Open No. Hei 5-187682.

[Explanation of symbols]

 Reference Signs List 101 imaging unit 102 difference operation unit 103 reference image storage unit 104 binarization unit 105 addition operation unit 106 addition image storage unit 107 mask image generation unit 108 mask operation unit 109 human body recognition unit 110 control unit

Claims (4)

[Claims] An image pickup unit for picking up an image; a reference image storage unit connected to the image pickup unit for storing an image obtained by the image pickup unit; and a reference image storage unit for storing the image obtained by the image pickup unit. Connected
An image obtained from the imaging unit and a difference calculation unit for creating a difference image by performing a difference between the image held in the reference image storage unit, and a difference calculation unit connected to the difference calculation unit; A binarizing unit for binarizing to generate a binary image; an adding operation unit connected to the binarizing unit for accumulatively adding a predetermined number of binary images to generate an added image; A mask image generation unit connected to the addition operation unit and configured to generate a mask image by binarizing the addition image; connected to the binarization unit and the mask image generation unit; Mask operation means for performing a mask operation with the mask image; connected to the mask operation means, based on the image obtained by the mask operation means, the presence or absence of a human body and the position of the human body And a human recognition means for identification, the human body detecting device. 2. An image pickup unit for picking up an image, a reference image storage unit connected to the image pickup unit, and storing an image obtained by the image pickup unit, and an image pickup unit and the reference image storage unit. Connected
An image obtained from the imaging unit and a difference calculation unit for creating a difference image by performing a difference between the image held in the reference image storage unit, and a difference calculation unit connected to the difference calculation unit; A binarizing unit for binarizing to generate a binary image; an adding operation unit connected to the binarizing unit for accumulatively adding a predetermined number of binary images to generate an added image; A mask image generation unit connected to the addition operation unit and configured to generate a mask image by binarizing the addition image; and a mask image generation unit connected to the addition operation unit and the mask image generation unit. Mask operation means for performing a mask operation between the image and the image; and a presence / absence of a human body and an existing position of the human body based on the image obtained by the mask operation means, connected to the mask operation means. And a human recognition means for recognizing, human body detecting device. 3. An image pickup means for picking up an image, a reference image storage means connected to the image pickup means for storing an image obtained from the image pickup means, and an image pickup means and the reference image storage means. Connected
An image obtained from the imaging unit and a difference calculation unit for creating a difference image by performing a difference between the image held in the reference image storage unit, and a difference calculation unit connected to the difference calculation unit; A binarizing unit for binarizing to generate a binary image; an adding operation unit connected to the binarizing unit for accumulatively adding a predetermined number of binary images to generate an added image; A mask image generating means connected to the addition calculating means for binarizing the added image with first and second threshold values and performing a difference operation between the two images after the binarization; A human body detecting device, which is connected to the mask image generating means and includes a human body recognizing means for recognizing the presence or absence of a human body and the position of the human body based on the image obtained by the mask image generating means. 4. A human body detection device according to claim 1, 2 or 3, and an air conditioner for performing air conditioning in a room; and a presence or absence of a human body connected to the human body recognition unit of the human body detection device. And a control means for controlling the air conditioning means in accordance with the position of the human body.