JPH10197348A - Method for processing thermal image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge the existence and the direction of a solar radiation and to estimate the intensity of the solar radiation by processing temperature data on the respective matrix elements of a thermal image measured by a matrix-type infrared sensor. SOLUTION: The existence of a solar radiation to an object to be measured is judged on the basis of the difference between temperature data on the respective matrix elements of a thermal image measured by a matrix-type infrared sensor and a prescribed reference temperature. In addition, the respective matrix elements are discriminated on the basis of the existence of the solar radiation, and the direction of the solar radiation to the object to be measured is estimated on the basis of the arrangement state of a solar-radiation pattern in the thermal image. In addition, the intensity of the solar radiation to the object to be measured is estimated on the basis of the difference between the average of the temperature data on the respective matrix elements in which the existence of the solar radiation of the solar-radiation pattern in the thermal image is judged and the prescribed reference temperature. For example, in the thermal image in which a solar radiation from the left side of a human being exists at an angle of elevation of 45 deg., respective matrix elements are discriminated on the basis of the existence of the solar radiation, and the direction of the solar radiation can be estimated on the basis of their arrangement state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing a thermal image measured by an infrared sensor, and more particularly to a method of processing a thermal image of a human body used for controlling an air conditioner for a vehicle.

[0002]

2. Description of the Related Art Conventionally, the direction of air blown from an air outlet of an air conditioner for a vehicle is adjusted by an occupant by operating a changeover switch provided near a dashboard in a driver's seat, or by adjusting the vehicle. In addition, a solar radiation sensor is provided to control the air blowing direction and the temperature of the conditioned air according to the output of the sensor. However, it is extremely inconvenient for the occupant that comfort cannot be obtained unless the changeover switch is operated to change the air blowing direction in accordance with the situation of solar radiation. Further, even when the direction of air blowing is controlled using the solar radiation sensor, the solar radiation sensor is not installed at the place where the occupant is located. There was a disadvantage that it was not.

Therefore, the inventor of the present invention has disclosed Japanese Patent Application No. 8-10167.
In No. 1, the infrared light emitted from the occupants and seats in the vehicle is detected by an incident light temperature sensor (hereinafter referred to as an infrared sensor), and the temperature distribution of the body surface and the clothing of the occupant is measured. A measuring device is proposed. This is to detect infrared rays emitted by a passenger or the like in a vehicle, calculate temperature data corresponding to an output of an infrared sensor provided in the measuring device, and measure a temperature distribution of an object in a vehicle compartment. . This temperature distribution measuring device is installed near the upper surface of the dashboard or in the room mirror, room lamp, pillar, etc. to detect the required range in the vehicle, and mainly around the thighs of the driver's seat occupant. It is adjusted so that the temperature distribution of the upper body including it can be measured. FIG. 16 shows an example in which the temperature distribution measuring device 1 is arranged substantially in front of an occupant 4 located in a driver's seat 3 in a passenger compartment 2 and near an upper surface of a dash board 5. FIG. 17 shows an example of a thermal image of a vehicle cabin obtained by the temperature distribution measuring device 1. The thermal image is used to determine the temperature of the occupant's face, the seat, and the like, and the presence or absence of a temperature difference between the left and right images. Presence and direction can be estimated.

[0004]

However, in the above conventional example, it is possible to estimate the presence or absence of solar radiation and the direction of solar radiation by causing an image processing device or the like to perform pattern recognition on the created thermal image. No method has been disclosed for directly determining the presence or absence of solar radiation and the direction of solar radiation by directly using the temperature data of the thermal image. Therefore,
It was difficult to utilize the temperature data of the thermal image for controlling the air conditioner for a vehicle. Further, in the above conventional example, there is a disadvantage that the intensity of solar radiation at the time of solar radiation cannot be estimated.

The present invention has been made in view of the conventional problems, and provides a method for processing temperature data of a thermal image by an infrared sensor to determine the presence or absence and direction of solar radiation and to estimate the intensity of solar radiation. The purpose is to do.

[0006]

According to a first aspect of the present invention, there is provided a method for processing a thermal image, comprising: calculating a difference between temperature data of each matrix element of a thermal image measured by a matrix type infrared sensor and a predetermined reference temperature; It is characterized in that the presence or absence of solar radiation on the object to be measured is determined based on Here, the thermal image may be a thermal image obtained by temperature data of a plurality of infrared sensors arranged vertically and horizontally and arranged in a matrix, or a plurality of infrared sensors arranged linearly. Using a matrix-type infrared sensor composed of a single array of sensor arrays, a plurality of thermal images (in units of one row) with different directions of incident light are created, and even a matrix-like thermal image obtained by arranging based on the direction of incident light is obtained. Good.

According to a second aspect of the present invention, there is provided a method for processing a thermal image, wherein the direction of the solar radiation to the object to be measured is determined based on the arrangement of the solar radiation pattern of the thermal image in which each matrix element is distinguished by the presence or absence of the solar radiation. It is characterized by estimation. Further, the thermal image processing method according to claim 3 of the present invention measures the thermal image based on the difference between the average of the temperature data of each matrix element determined as having solar radiation of the solar radiation pattern and the predetermined reference temperature. It is characterized by estimating the intensity of solar radiation to the object.

According to the thermal image processing method of the present invention, the difference between the left and right temperature data of the thermal image is expanded or reduced with respect to each temperature data of the thermal image according to the ambient temperature at the time of measurement. It is characterized in that conversion such as reduction is performed, judgment of the presence or absence of solar radiation on the measurement object, and estimation of the intensity of solar radiation are performed. The method of processing a thermal image according to claim 5 of the present invention estimates the ambient temperature from the background temperature data of the thermal image and measures the ambient temperature using the estimated ambient temperature instead of the measured ambient temperature. It is characterized in that it is determined whether or not the object has solar radiation and the intensity of solar radiation is estimated.

In the thermal image processing method according to a sixth aspect of the present invention, a preset reference extraction temperature is subtracted from temperature data of each matrix element of the thermal image, and a matrix element of a human body portion is subtracted from the thermal image. It is characterized by extracting. In the method of processing a thermal image according to a seventh aspect of the present invention, the reference extraction temperature is a temperature that increases or decreases according to the level of the ambient temperature.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a thermal image obtained by the temperature distribution measuring device 1. The temperature distribution measuring device 1 has infrared sensors arranged in a matrix disposed inside a rotating cylinder having a slit, detects infrared rays emitted by occupants and the like in a vehicle, and detects each element of the matrix. The temperature data corresponding to the output of the infrared sensor is obtained to measure the temperature distribution in the vehicle interior. The rotating slit functions as a chopper for passing and blocking incident light. This thermal image is created based on temperature data calculated from the outputs of the infrared sensors arranged in a matrix,
The thermal image consists of 64 matrix elements of 8 rows (1-8) x 8 columns (A-H). In FIG. 1, for simplicity, the matrix elements of the thermal image are displayed in five stages (2.5 ° width) in the display temperature range. First, a method of removing a background screen such as a sheet from the thermal image and extracting a human body region of the occupant will be described. Therefore, a reference extraction temperature is set, and the above-mentioned reference extraction temperature is set as a threshold value, data of each matrix element having a temperature below this threshold value is deleted, and a human body part of the occupant is extracted. Normally, as shown by the solid line in FIG. 2, the distribution of the temperature data of the matrix elements of the thermal image is such that the elements of the background area are distributed at about 20 ° C. to 25 ° C., and the occupant's clothing area (torso) is The occupant's skin area (head) is distributed between about 33 ° C and 37 ° C. In the temperature distribution of the thermal image, the temperature distribution in each region moves to the high temperature side or the low temperature side depending on the temperature Tr (hereinafter, referred to as ambient temperature) in the vehicle cabin. here,
The center temperature of the above-mentioned clothing area is Tb, and the center temperature of the skin area is Th. In this embodiment, since there is solar radiation, FIG.
As shown by the dotted line, the ambient temperature tr, the central temperature tb of the clothing region, and the central temperature th of the skin region move toward the higher temperature side compared to the temperature distribution without solar radiation (solid line in FIG. 2). I have. In order to accurately take in the temperature rise due to the solar radiation, the center temperature tb and the like of the clothing area are actually corrected using the maximum temperature data of the area. The center temperature TB of the clothing region when the ambient temperature is Tr = 25 ° C. and no solar radiation is referred to as the clothing region reference temperature, and the central temperature TH of the skin region is referred to as the skin region reference temperature. FIG.
Is obtained by extracting a human body region from the thermal image shown in FIG. 1 using the reference extraction temperature as the above-mentioned ambient temperature tr. As can be seen from the figure, there is solar radiation, and the direction of the solar radiation is substantially horizontal on the left side of the occupant (right side of the thermal image).

A method for determining the presence or absence of solar radiation using the temperature data of each matrix element of the thermal image and creating a solar radiation pattern will be described. First, the position of the center line p of the image is calculated from the extracted matrix elements of the human body region, and as shown in FIG. 4, the temperature data of the matrix elements equidistant from this center line, for example, D2 and E
2 and C5 are compared with F5, and the temperature data is compared with a reference temperature. This reference temperature is the central temperature t of the clothing region when the matrix element is the clothing region.
b, in the case of a skin region, the center temperature of the skin region is set to th. The position of the center line p is set on the boundary of the matrix element. The boundary q between the clothing area and the skin area is determined from the number of matrix elements above and below the thermal image (see FIG. 4). However, matrix elements other than the matrix elements that are line-symmetric with respect to the center line are deleted in advance.

FIG. 5 is a flowchart for determining the presence or absence of solar radiation using the temperature data of each matrix element of the thermal image to create a solar radiation pattern. Here, the matrix elements of the clothing area are C elements that are equidistant from the center line.
A case where temperature data of two matrix elements 5 and F5 are compared will be described. In the flowchart, C5 and F5 represent temperature data of matrix elements C5 and F5, respectively. First, the temperature data of the two matrix elements C5 and F5 are compared (step S51). If C5> F5 (C5 = F5 will be described later), C5 is compared with the center temperature tb of the clothing area (step S52). Here, when C5 ≦ tb, since F5 <tb, since both C5 and F5 are equal to or lower than the central temperature tb of the clothing area, it is determined that “no solar radiation”, and the matrix elements of C5 and F5 in the solar radiation pattern Nothing is written (step S53). If C5> tb, F5 is compared with the center temperature tb of the clothing area (step S54). If F5> tb, since both C5 and F5 are higher than the center temperature tb of the clothing area, it is determined that there is "solar radiation" (step S55), and the matrix elements of C5 and F5 of the solar radiation pattern are respectively shown in FIG. As shown in G1, the values of C5-tb and F5-tb are written (step S56). If F5 ≦ tb, C5 is higher than the central temperature tb of the clothing area, but F5 is equal to or lower than the central temperature tb of the clothing area. Therefore, it is determined that there is “insolation” (step S57), and C5 of the insolation pattern is determined. As shown in G2 of FIG. 5, the value of C5-tb is written in the matrix element (step S58). Next, when F5> C5, F5 is compared with the center temperature tb of the clothing area (step S59). Here, when F5 ≦ tb, C5 <tb
Therefore, since both C5 and F5 are equal to or lower than the central temperature tb of the clothing area, it is determined that there is no solar radiation, and the C of the solar radiation pattern is determined.
Nothing is written in the matrix elements 5 and F5 (step S53). If F5> tb, C5 is compared with the center temperature tb of the clothing area (step S60). C5
> Tb, C5 and F5 are both the center temperature tb of the clothing area
Since it is higher, it is determined that there is "solar radiation" (step S6).
1) The matrix elements of C5 and F5 of the solar radiation pattern include C5-tb,
The value of F5-tb is written. (Step S62).
If C5 ≦ tb, F5 is higher than the central temperature tb of the clothing area, but C5 is equal to or lower than the central temperature tb of the clothing area, so that it is determined that there is “insolation” (step S63).
The matrix elements of F5 in the solar radiation pattern include G in FIG.
As shown in FIG. 4, the value of F5-tb is written (step S64). If C5 = F5, C5 is compared with the center temperature tb of the clothing area (step S52).
Here, when C5 ≦ tb, since F5 ≦ tb, C5
Since both F5 and F5 are lower than the central temperature tb of the clothing area,
It is determined that there is no solar radiation, and nothing is written in the matrix elements of C5 and F5 of the solar radiation pattern (step S5).
3). If C5> tb, F5 is compared with the center temperature tb of the clothing area (step S54).
b, it is determined that there is "solar radiation" (step S5).
5) The matrix elements of C5 and F5 of the solar radiation pattern include C5-tb,
The value of F5-tb is written. (Step S56).
By performing the above processing for each matrix element equidistant from all the center lines, a solar radiation pattern of a thermal image as shown in FIG. 6 can be created. In this figure, each of the matrix elements “with solar radiation” is indicated by oblique lines, and it is emphasized that the direction of solar radiation is almost horizontal on the left side of the occupant (right side of the thermal image). The presence or absence of solar radiation is determined to be "with solar radiation" when the number of matrix elements with "solar radiation" among the extracted matrix elements is 20% or more in the extracted human body region. In addition, as shown in FIG. 6, the direction of solar radiation is, for example, the upper right (R
1), lower right (R2), upper left (L1), lower left (L2)
The area is divided into two areas, the ratio of the number of matrix elements with solar radiation in each area to the number of matrix elements of the extracted human body area is calculated, and the ratio is determined by comparing with a preset pattern in the solar radiation direction. In the above description, a thermal image diagram is used for convenience. However, this embodiment does not display and evaluate the thermal image diagram, but compares and calculates the temperature data of each matrix element of the thermal image. Thus, the presence or absence of solar radiation and the direction of solar radiation are determined. For example, the matrix element [C5] of the solar radiation pattern is [C5]
= C5-tb. However, in the following, the present invention will be described with reference to thermal images for convenience.

Here, the above-mentioned pattern in the solar radiation direction will be described. FIGS. 7A, 7B, and 7C show a range W in which the temperature rises depending on the direction of the solar radiation when the human body has horizontal solar radiation, and FIG. 7A shows the left side of the human body. (B) is solar radiation from a 45-degree forward direction,
(C) is a top view when solar radiation is received from the front.
The hatched portions S written in the front views of the human body shown in FIGS. 7D, 7E, and 7F indicate portions where the temperature has increased due to the solar radiation at that time. FIGS. 7 (g), (h) and (f)
7 (a), 7 (b) and 7 (c) are thermal images after extracting a human body region corresponding to the direction of insolation. FIG.
Shows a thermal image after the extraction of the human body region when the elevation angle is 45 degrees and there is solar radiation from the left side of the human body. 9 (a) to 9 (f)
Shows the pattern of the solar radiation of the thermal image from these typical thermal images, where (a) is the solar radiation from 0 ° elevation angle and 0 ° horizontal angle (left side of the human body), and (b) is the 0 ° elevation angle (C) is solar radiation from a 0 ° elevation angle and 90 ° horizontal angle (in front of the human body), (d) is solar radiation from a 45 ° elevation angle and 0 ° horizontal angle (upper left side of the human body), ( e) 45 ° elevation angle, 45 ° horizontal angle
(F) is an example in the case of solar radiation from an elevation angle of 45 degrees and a horizontal angle of 90 degrees (obliquely above the front of the human body). In the experiment to create the pattern of the solar radiation direction, wear typical clothes for summer and winter on the thermal mannequin in a constant temperature room,
The solar radiation was performed by irradiating a light of a predetermined wattage from one direction. In the above experiment, the wattage of irradiation and the temperature in the thermostatic chamber (corresponding to the ambient temperature) were arbitrarily changed, and the effects of the intensity of solar radiation and the ambient temperature on the temperature distribution of the thermal image were examined. The pattern (a) in the solar radiation direction is digitized as follows, for example. Region R1
Is 7 and the number of matrices with solar radiation is 3, the element ratio r1 = 0.43. Since the number of human body extraction matrices in the region R2 is 12, and the number of matrices with solar radiation is 4, the element ratio r1 = 0.33. In the regions L1 and L2, the number of matrices with solar radiation is 0,
Element ratio r1 = 0. That is, the pattern of the solar radiation direction (a)
Is set to [0.43, 0.33, 0, 0]. In the case of FIG. 9B, similarly, [1,1,0,0]
Is set. Similarly, the other patterns in FIG. 9 can be set numerically.

As shown in FIGS. 6 and 9, each matrix element of the solar radiation pattern includes, as described above, the difference (Tm-t) between the temperature data Tm of each part of the human body and the area center temperature.
b or Tm-th), this data is converted to the absolute temperature difference (Tm-Tb or Tm-T) using the clothing area reference temperature TB or the skin area reference temperature TH.
h), and the intensity of solar radiation can be estimated from the average value of the absolute temperature differences of the converted matrices. That is, since the intensity of solar radiation and the average value of the absolute temperature difference of each matrix are in a proportional relationship as shown in FIG. 10, it is possible to estimate the intensity of solar radiation from the average value of the absolute temperature difference of each matrix. it can. At this time, as the intensity of the solar radiation, a value based on the wattage of the lamp used in the experiment for creating the above-described pattern of the solar radiation direction is used.

By the way, even if the solar radiation condition is the same, the temperature difference of the human body region caused by the solar radiation is affected by the ambient temperature. For example, in the case of solar radiation from an elevation angle of 0 degrees and a horizontal angle of 45 degrees, as shown in FIG. The difference tends to be smaller. Therefore, when the ambient temperature is 25 ° C. or more, if the left and right temperature difference is set to 0.3 ° or less as a criterion, it is determined that there is no left and right temperature difference. Therefore, in order to reduce the influence of measurement accuracy and data variation, when the left and right temperature difference is equal to or less than t ° C., the left and right temperatures may be treated as the same. Unless t is corrected, the ratio when the left and right temperatures are treated as the same condition in the solar radiation determination flow changes. For example, when t is fixed at 0.3 ° C., if the ambient temperature is 25 ° C. or more, it is determined that there is a left-right temperature difference due to the insolation, and the data to be treated in the insolation determination flow is treated as having the same left and right temperatures. Therefore, after creating a solar radiation pattern, the regions R1, R2, L
1 and L2, a temperature correction based on the number of matrix elements having solar radiation, for example, in the case of FIG. 9B, the measured temperature + 0.2 ° C. in the regions R1 and R2, and the regions L1 and L2
Then, after performing temperature correction such as setting the measurement temperature to −0.2 ° C., the accuracy can be improved by creating a solar radiation pattern. However, it goes without saying that the temperature data is restored to the original value after the solar radiation pattern is created. Also,
As shown in FIG. 12, the temperature difference in the human body region caused by the solar radiation changes depending on the intensity of the solar radiation. Therefore, the pattern of the solar radiation can be corrected based on this data.

FIG. 12 shows the average of the difference between the ambient temperature and the thermal image data when solar radiation of a constant intensity is given.
From the experimental data of the above, it is possible to roughly estimate the presence or absence of solar radiation and the solar radiation intensity. That is, the average value of the left-right difference of the measured temperature data of the thermal image, and three values obtained by substituting the ambient temperature into the three linear formulas of solar radiation intensity, solar radiation, and solar radiation weakness set in advance by the above experiment. Than comparing
The presence or absence of solar radiation and the intensity of solar radiation can be obtained. For example, when the ambient temperature is 25 ° C., if the average value of the left and right difference of the measured thermal image temperature data is 0.1, the solar radiation is weak, and 0.3
If so, it can be determined that the solar radiation is in progress, and if it is 0.5, it can be determined that the solar radiation is strong.

Further, in the experiment for creating a pattern in the solar radiation direction described above, when the temperature (corresponding to the ambient temperature Ti) in the constant temperature room is changed, the background average temperature F of the thermal image is changed.
Between T and the ambient temperature, as shown in FIG.
= 1.14 × FT−8.57. Therefore, from this relational expression, the ambient temperature Ti can be estimated from the background average temperature FT of the thermal image,
The processing of the temperature data of the thermal image can be performed without actually measuring the ambient temperature. Since the FT naturally changes due to the difference in the emissivity of the object constituting the background, the two constants in the above equation are unique to the measurement range.

When the ambient temperature increases, the average background temperature, average clothing temperature, average skin temperature, and average human body temperature of the thermal image also increase. However, as shown in FIG. 14, the rise rates of the ambient temperature, the clothing average temperature, the skin average temperature, and the human body average temperature with respect to the increase of the background average temperature (FIG.
Are not parallel to each other, and there is a tendency that the values of the average temperatures approach each other as the background average temperature increases. Therefore, a clear thermal image can be obtained regardless of the ambient temperature by setting the setting of the human body extraction temperature to a temperature that increases or decreases according to the level of the ambient temperature. FIG. 15 is experimental data showing the relationship between the average skin temperature, the minimum skin temperature, the average human body temperature, and the minimum human body temperature with respect to the average background temperature. In this case, too, the average skin temperature increases with the increase in the average background temperature. It can be seen that the difference between the skin temperature and the skin minimum temperature and the difference between the average human body temperature and the minimum human body temperature are small. Therefore, in consideration of the change in the average human body temperature in FIG. 14 and the change in the minimum human body temperature in FIG. 15, the human body extraction temperature Ty is set by Ty = 0.93 × FT + 2.97, and the skin extraction temperature Tz is By setting the temperature set by Tz = 0.5 × FT + 17 as the extraction temperature, the direction of solar radiation and the intensity of solar radiation can be accurately obtained even if the ambient temperature changes. Since the FT naturally changes due to the difference in emissivity of the object constituting the background, the two constants in the above equations of Ty and Tz are unique to the measurement range. Further, the clothing region can be extracted by removing the skin region from the human body region.

In the above embodiment, for simplicity,
Although the number of matrix elements of the thermal image was set to 8 × 8 = 16,
It is not limited to this. That is, if the number N of matrix elements of the thermal image is increased, the ratio n / N of the number n of matrix elements representing the temperature of the target increases, and the average temperature of a plurality of targets at the boundary of the target is obtained. Since the ratio m / N of the number m of the matrix elements is reduced, it is apparent that a detailed solar radiation pattern can be obtained and the accuracy of the solar radiation intensity is improved. Also, if the number of matrix elements in the thermal image is increased, the number of area divisions performed when determining the pattern of the solar radiation direction can be increased, so that it is needless to say that the determination of the solar radiation direction becomes accurate.

[0020]

As described above, according to the thermal image processing method of the present invention, the difference between the temperature data of each matrix element of the thermal image measured by the matrix type infrared sensor and the predetermined reference temperature. The presence or absence of solar radiation on the object to be measured is determined based on the above, so it is possible to directly determine the presence or absence of solar radiation from the temperature data of each matrix element of the thermal image without creating a thermal image and pattern recognition. it can. According to the thermal image processing method of the present invention, the direction of the solar radiation to the measurement object is estimated from the arrangement state of the solar radiation pattern of the thermal image in which each matrix element is distinguished by the presence or absence of the solar radiation. Therefore, the direction of solar radiation can be directly specified from the temperature data of each matrix element of the thermal image. Furthermore, according to the thermal image processing method of the third aspect, the measurement target is based on the difference between the average of the temperature data of each matrix element determined as having solar radiation of the solar radiation pattern of the thermal image and the predetermined reference temperature. Since the intensity of the solar radiation to the object is estimated, it is possible to obtain a precise intensity of the solar radiation that cannot be obtained from the pattern of the thermal image.

According to the thermal image processing method of the present invention, the difference between the left and right temperature data of the thermal image is enlarged or reduced with respect to each temperature data of the thermal image in accordance with the ambient temperature at the time of measurement. Such a conversion is performed to determine the presence or absence of solar radiation on the object to be measured and to estimate the intensity of solar radiation, so that the direction of solar radiation and the intensity of solar radiation can be accurately obtained. According to the thermal image processing method of the fifth aspect, the ambient temperature is estimated from the background temperature data of the thermal image, and the measurement target is used by using the estimated ambient temperature instead of the measured ambient temperature. Since the determination of the presence or absence of solar radiation on the object and the estimation of the intensity of the solar radiation are performed, the direction and intensity of the solar radiation can be obtained only from the temperature data of the thermal image without measuring the ambient temperature.

According to the thermal image processing method of the present invention, a preset reference extraction temperature is subtracted from the temperature data of each matrix element of the thermal image, and a matrix element of a human body portion is extracted from the thermal image. As a result, the number of temperature data of the thermal image is reduced, and the complexity of data processing can be eliminated. In the thermal image processing method according to claim 7 of the present invention, the reference extraction temperature is set to a temperature that increases or decreases in accordance with the level of the ambient temperature. The intensity of solar radiation can be determined accurately.

[Brief description of the drawings]

FIG. 1 is an example of a thermal image according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a temperature distribution of a thermal image according to the embodiment of the present invention.

FIG. 3 is a thermal image after extracting a human body region according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining a method of selecting a matrix element when obtaining a solar radiation pattern according to the embodiment of the present invention.

FIG. 5 is a flowchart for obtaining a solar radiation pattern according to the embodiment of the present invention.

FIG. 6 is a diagram showing an example of a solar radiation pattern according to the embodiment of the present invention.

FIG. 7 is a thermal image after human body extraction when the solar radiation direction is the horizontal direction according to the embodiment of the present invention.

FIG. 8 is an elevation angle of 45 according to the embodiment of the present invention.
It is a thermal image after human body extraction in the case of a degree direction.

FIG. 9 is a view showing a solar radiation pattern according to the solar radiation direction according to the embodiment of the present invention.

FIG. 10 is a diagram showing the relationship between the intensity of solar radiation and the absolute temperature difference according to the embodiment of the present invention.

FIG. 11 is a diagram illustrating a relationship between an ambient temperature and an average of left and right temperature differences of thermal image data according to the embodiment of the present invention.

FIG. 12 is a diagram showing the relationship between the ambient temperature and the average of the left and right temperature differences of thermal image data when the solar radiation conditions are changed according to the embodiment of the present invention.

FIG. 13 is a diagram illustrating a relationship between an average background temperature and an ambient temperature according to the embodiment of the present invention.

FIG. 14 is a diagram illustrating a relationship between an average background temperature and an average temperature of each region according to the embodiment of the present invention.

FIG. 15 is a diagram illustrating a relationship between a background average temperature and a minimum temperature of each region according to the embodiment of the present invention.

FIG. 16 is a diagram for explaining an arrangement of a temperature distribution measuring device used in a conventional vehicle air conditioner.

FIG. 17 is an example of a thermal image obtained by a conventional temperature distribution measuring device.

[Explanation of symbols]

 Reference Signs List 1 Temperature distribution measuring device 2 Vehicle 3 Driver's seat (seat) 4 Crew 5 Dash board

Claims (7)

[Claims] 1. A method for determining the presence or absence of solar radiation on an object to be measured based on a difference between temperature data of each matrix element of a thermal image measured by a matrix type infrared sensor and a predetermined reference temperature. Image processing method. 2. The thermal image processing according to claim 1, wherein the direction of the solar radiation toward the object to be measured is estimated from the arrangement state of the solar radiation pattern of the thermal image in which each matrix element is distinguished by the presence or absence of the solar radiation. Method. 3. A method for estimating the intensity of insolation on an object to be measured based on a difference between an average of temperature data of each matrix element determined as having solar radiation in a solar radiation pattern of a thermal image and a predetermined reference temperature. The thermal image processing method according to claim 2, wherein 4. A conversion is performed on each temperature data of the thermal image to enlarge or reduce a difference between right and left temperature data of the thermal image according to an ambient temperature at the time of measurement, and whether or not there is insolation on the object to be measured The thermal image processing method according to claim 1 or 2, wherein the determination of the intensity of the solar radiation is performed. 5. An ambient temperature is estimated from background temperature data of a thermal image, and the presence or absence of solar radiation to the object to be measured and the intensity of solar radiation are determined using the estimated ambient temperature instead of the measured ambient temperature. 2. The method of claim 1, further comprising:
Or the thermal image processing method according to claim 2. 6. The matrix element of a human body portion is extracted from the thermal image by subtracting a preset reference extraction temperature from temperature data of each matrix element of the thermal image. Thermal image processing method. 7. The thermal image processing method according to claim 6, wherein the reference extraction temperature is increased or decreased according to the level of the ambient temperature.