JP2020038306A - Focus adjustment assist device and focus adjustment assist method - Google Patents

Abstract

To assist with focus adjustment in a thermography device.SOLUTION: A focus adjustment assist device (10) pertaining to the present application comprises: an image acquisition unit (20) for acquiring a heat image from a thermography device (100) that captures a heat image that indicates the heat distribution of an imaging object; an area search unit (61) for searching the heat image acquired by the image acquisition unit (20) for an area where a temperature change satisfies a prescribed condition; and a determination unit (63) for determining, on the basis of a heat distribution in the area, of a plurality of heat images captured while adjusting the focal distance, that has been searched by the area search unit (61), whether or not the focal distance satisfies a prescribed condition.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a focus adjustment support device and a focus adjustment support method for supporting adjustment of a focal length of a thermal imaging device.

  2. Description of the Related Art Conventionally, there has been known a technique for inspecting various processes and products using a thermographic device that captures a thermal image indicating a thermal distribution of a capturing target. As an example of such a technique, there is known a technique of inspecting an adhesion state by hot melt using a thermography apparatus. For example, it is known to determine the amount, position, splash or elongation of the hot melt based on a thermal image taken using a thermographic device, and to determine the adhesive state of the hot melt based on the determination result. .

JP-A-2005-034778 JP 05-273047 A

  In an inspection using such a thermographic apparatus, focus adjustment of the thermographic apparatus is an important step in order to clearly photograph an inspection target. However, when the operator manually adjusts the focus of the thermographic apparatus, there is a problem in that a region to be focused on when adjusting the focus varies from operator to operator, and as a result, the adjustment results fluctuate, resulting in a variation in inspection.

  On the other hand, there is known a thermographic apparatus including hardware for automatically adjusting a focus. However, if hardware for adjusting the focus is provided, the cost of the thermographic device will increase.

  The present application has been made to solve such a problem, and has as its object to support focus adjustment in a thermographic apparatus.

  The focus adjustment support device according to the present application includes an acquisition unit that acquires a thermal image indicating a heat distribution of an imaging target, and a search unit that searches for an area where a temperature change satisfies a predetermined condition from the thermal image acquired by the acquisition unit. A determination unit that determines whether or not the focal length satisfies a predetermined condition based on a heat distribution in a region searched by the search unit among a plurality of thermal images captured while adjusting the focal length. .

  The focus adjustment support device may further include an output unit that outputs information indicating a determination result by the determination unit.

  In the focus adjustment support device, the search unit may search for a region in the thermal image where the difference between the minimum temperature and the maximum temperature exceeds a predetermined threshold.

  In the focus adjustment support device, the search unit may search for a region in the thermal image in which the variance of the temperature difference exceeds a predetermined threshold.

  In the focus adjustment support device, the determination unit may determine whether the focal length satisfies a predetermined condition based on a temperature difference between adjacent pixels in the area searched by the search unit.

  In the focus adjustment support device, the determination unit may determine that the focal length satisfies a predetermined condition when the sum of the temperature differences exceeds a predetermined threshold.

  In the focus adjustment support device, when the standard deviation of the temperature difference exceeds a predetermined threshold, it may be determined that the focal length satisfies a predetermined condition.

  In the above-described focus adjustment support device, a reception unit that receives, from another focus adjustment support device, region information indicating a region searched for from a thermal image by the focus adjustment support device and in which a temperature change satisfies a predetermined condition. Further, when the determination unit receives the region information from another focus adjustment support device, of the plurality of thermal images taken while changing the focal length, the region information received from the other focus adjustment support device It is determined whether or not the focal length satisfies a predetermined condition based on the heat distribution in the area indicated by.

  In the focus adjustment support device, the receiving unit receives the region information indicating the heat distribution in the region searched by the other focus adjustment support devices, and the determination unit determines a thermal image captured while changing the focal length. A region whose heat distribution is similar to the heat distribution indicated by the region information may be extracted, and whether the focal length satisfies a predetermined condition may be determined based on the heat distribution in the extracted region.

  According to the above-described focus adjustment support device, by searching for a region where the temperature change satisfies a predetermined condition from the thermal image, a region to be focused on at the time of focus adjustment is automatically selected, and the automatically selected region is selected. It is determined whether or not the focal length is appropriate based on the heat distribution in the inside. As a result, the focus adjustment support device can support focus adjustment in the thermography device. In addition, the focus adjustment support device determines whether or not the focal length is appropriate in a state where the regions of interest when adjusting the focus are aligned, so that it is possible to reduce the variation in the inspection standard. Further, since the focus adjustment support device can determine whether or not the focal length is appropriate from the thermal image captured by the thermography device, hardware for focus adjustment can be omitted.

FIG. 1 is a diagram illustrating an example of a thermal image. FIG. 2 is a diagram illustrating an outline of the focus adjustment support device according to the first embodiment. FIG. 3 is a diagram illustrating an example of a functional configuration of the focus adjustment support device according to the first embodiment. FIG. 4 is a diagram illustrating an example of a temperature distribution in a specific region. FIG. 5 is a diagram illustrating an example of thermal images having different focal lengths. FIG. 6 is a diagram for explaining a difference in signal difference between adjacent pixels. FIG. 7 is a flowchart illustrating an example of the focus adjustment support processing according to the first embodiment. FIG. 8 is a diagram illustrating an outline of a focus adjustment support device according to the second embodiment. FIG. 9 is a diagram illustrating an example of a functional configuration of the focus adjustment support device according to the second embodiment. FIG. 10 is a flowchart illustrating an example of the focus adjustment support processing according to the second embodiment.

  Next, embodiments will be described with reference to the drawings. In the following description, components common to the embodiments will be denoted by the same reference numerals, and repeated description will be omitted.

[Principle 1]
In order to support the focus adjustment of the thermographic apparatus without using additional hardware, it is assumed that the problem is solved by an extended function of software for processing a thermal image obtained by the thermographic apparatus. If the focal length of the thermographic device is appropriate, the infrared image spot emitted from the object to be imaged will form on the infrared detector of the thermographic device without blurring, so the temperature difference between adjacent pixels in the thermal image will be small. Be clear. Therefore, simply, a signal value indicating the amount of infrared rays and the temperature is obtained for each pixel of the thermal image obtained by the thermography device, and the amount of change in the signal value between adjacent pixels (that is, the slope of the difference between the signal values) is calculated. What is necessary is just to adjust the focus so as to maximize it.

  On the other hand, in the entire thermal image obtained by the thermography apparatus, since it is not expected that the variation of the signal value is simultaneously maximized, the variation of the signal value in any region of the thermal image is maximized. Focus adjustment. However, if the region of interest when the focus adjustment is performed by the operator is different, the focal length varies.

  For example, FIG. 1 is a diagram illustrating an example of a thermal image. FIG. 1 shows a thermal image HP1 obtained by the thermography device. Note that the thermal image HP1 is given a color corresponding to the temperature and the signal value for each pixel in order to indicate the heat distribution of a predetermined imaging target, but in the example shown in FIG. An example in which colors are converted to gray scale is shown.

  When comparing the region OA1 and the region OA2, different temperatures are measured in each region. However, in the region OA2, more different temperatures are measured as compared with the region OA1. That is, in the region OA2, since the amount of change in temperature in the entire region is larger than that in the region OA1, the change in the signal value between adjacent pixels appears more clearly. As a result, when the focus adjustment is performed so that the change amount of the signal value in the region OA2 is maximized, it is more appropriate than when the focus adjustment is performed so that the change amount of the signal value in the region OA1 is maximized. It is considered that focus adjustment can be performed on the image.

  Focusing on such a point, for a region to be focused on at the time of focus adjustment, a region where the amount of change in the signal value is large, that is, a region where the temperature change is large is automatically selected, and for that specific region, For example, it has been conceived that the problem can be solved by software if automatic adjustment is performed so that the slope of the signal value change becomes maximum.

[First Embodiment]
Hereinafter, an outline of the first embodiment will be described with reference to FIG. FIG. 2 is a diagram illustrating an outline of the focus adjustment support device according to the first embodiment. In the example shown in FIG. 2, the focus adjustment support device 10 is an information processing device that receives various operations from the operator OP, and is realized by, for example, a PC (Personal Computer). Further, the focus adjustment support device 10 is connected to the thermography device 100, and realizes control of the thermography device 100 according to an operation from the operator OP.

  For example, the thermography apparatus 100 detects infrared rays emitted from the inspection target IT flowing through the inspection line IL1 by using a thermopile array sensor composed of a plurality of thermopiles, and based on the detection result, detects the infrared ray on the surface of the inspection target IT. Measure the temperature distribution. The thermography apparatus 100 may use various thermal infrared sensors such as a microbolometer or a pyroelectric sensor, or may use various quantum infrared sensors. Then, the thermographic device 100 generates a thermal image indicating the measured temperature distribution. For example, the thermography apparatus 100 generates data associating a signal value indicating the amount of infrared rays and the temperature measured for each pixel as a thermal image. Then, the thermographic device 100 provides the generated thermal image to the focus adjustment support device 10 (Step S1).

  On the other hand, when the focus adjustment support device 10 receives the thermal image from the thermographic device 100, the focus adjustment support device 10 searches the received thermal image for a region useful for performing focus adjustment as a specific region (step S2). For example, the focus adjustment support apparatus 10 extracts a region having a predetermined size and shape so as to scan a thermal image. Then, the focus adjustment support device 10 automatically extracts, as a specific region, a region in which the amount of change in temperature in the entire region is large among the extracted regions.

  Subsequently, when the focus adjustment support device 10 receives a focus adjustment operation for adjusting the focal length of the thermography device 100 (step S3), the focus adjustment support device 10 adjusts the focal length of the thermography device 100 according to the focus adjustment operation. The thermal image obtained by the above is acquired at any time (step S4). That is, the focus adjustment support device 10 acquires a plurality of thermal images taken while adjusting the focal length. Then, the focus adjustment support device 10 determines whether or not the focal length satisfies a predetermined condition based on the heat distribution in a specific region of each thermal image (Step S5). For example, the focus adjustment support device 10 calculates a difference in signal value between adjacent pixels in a specific area, and determines that the focal length is appropriate when the calculated difference exceeds a predetermined threshold.

  Then, when determining that the focal length is appropriate, the focus adjustment support apparatus 10 notifies the operator OP that the focal length is appropriate (step S6). For example, the focus adjustment support device 10 may display an indication that the focal length is appropriate on the screen, or may turn on a lamp indicating whether the focal length is appropriate.

[One Example of Functional Configuration in First Embodiment]
Next, an example of a functional configuration of the focus adjustment support device 10 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of a functional configuration of the focus adjustment support device according to the first embodiment. As illustrated in FIG. 3, the focus adjustment support device 10 includes a communication unit 20, a focus control unit 30, a display unit 40, a storage unit 50, and a control unit 60.

  The communication unit 20 controls communication with the thermographic device 100 that obtains a thermal image indicating a heat distribution of the imaging target. For example, the communication unit 20 is realized by a NIC (Network Interface Card), a USB (Universal Serial Bus) port, or the like, and controls communication with the thermographic device 100.

  The focus control unit 30 controls the focal length of the thermography device 100. For example, upon receiving a focus adjustment operation, the focus control unit 30 outputs a signal for changing the focal length to the thermographic device 100, thereby controlling the focal length of the thermographic device 100.

  The display unit 40 is a display device that displays various types of information, and is realized by, for example, various types of liquid crystal displays, LEDs (Light Emitting Diodes), and the like. For example, the display unit 40 may display a thermal image obtained by the thermographic device 100, and may display a determination result as to whether or not the focal length is appropriate.

  The storage unit 50 is a storage device that stores various types of information, and is realized by, for example, a semiconductor memory element such as a random access memory (RAM) or a flash memory, or a storage device such as a hard disk or an optical disk. . For example, the storage unit 50 registers region information 51 indicating a region to be a specific region in the thermal image. In the initial state, information indicating a size and a shape specified in advance as the specific area is registered as the area information 51.

  The control unit 60 executes various programs stored in a storage device inside the focus adjustment support apparatus 10 using a RAM or the like as a work area by a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit). Is realized by: Further, the control unit 60 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

  As illustrated in FIG. 3, the control unit 60 includes an acquisition unit 61, an area search unit 62, a signal value change search unit 63, a determination unit 64, and an output unit 65.

  The acquisition unit 61 acquires a thermal image from the thermography device 100. For example, the acquisition unit 61 acquires thermal images obtained by the thermography device 100 at predetermined time intervals.

  The area search unit 62 searches for a specific area of interest for focus adjustment. For example, the area search unit 62 searches the thermal image acquired as an initial image by the acquisition unit 61 for an area in which the entire temperature change satisfies a predetermined condition as a specific area. As a more specific example, the area search unit 62 scans the entire thermal image in an area having the size and shape indicated by the area information 51, and searches for an area in which the amount of change in temperature as a whole is maximum.

  For example, FIG. 4 is a diagram illustrating an example of a temperature distribution in a specific region. In the example illustrated in FIG. 4, an example of a histogram indicating the number of pixels to which a signal value indicating each temperature is assigned for each of the first area and the second area searched from the thermal image.

  In the example shown in FIG. 4A, the first region includes pixels to which signal values corresponding to the temperatures T1 to T5 are assigned. In the first region, the number of pixels to which a signal value corresponding to the lowest temperature T1 is given is the largest, and the number of pixels to which a signal value corresponding to the highest temperature T5 is given is smaller. Least. In the example shown in FIG. 4B, in the second region, pixels to which signal values corresponding to the temperatures T1 to T9 are added are included. In the second region, the pixels to which the signal value corresponding to the temperature T1 which is the lowest temperature is provided and the pixels to which the signal value corresponding to the temperature T9 which is the highest temperature are provided to the same extent. I have. In the second region, the number of pixels to which signal values corresponding to the temperatures T2 to T8 are assigned is smaller than that of the pixels to which signal values corresponding to the temperature T1 or T9 are assigned. I have.

  When the histograms of the temperatures in the first area and the second area are histograms as shown in FIG. 4, the highest temperature and the lowest temperature appearing in the first area are compared with those in the second area. Is small, and it is estimated that the same temperature is included as a whole. That is, it is estimated that the temperature dispersion is relatively small in the first region. In other words, the difference between the highest temperature and the lowest temperature is larger in the second area than in the first area, and it is estimated that various temperatures are included as a whole. That is, it is estimated that the temperature variance is relatively large in the second region.

  Here, it can be said that the area to be focused on in the focus adjustment is an area in which the inclination of the temperature change between adjacent pixels is likely to be large when performing the focus adjustment. In such a region, the difference between the maximum temperature and the minimum temperature is large, and it is considered that various regions are included. Therefore, the region searching unit 62 searches, as a specific region, a region in the thermal image where the difference between the minimum temperature and the maximum temperature exceeds a predetermined threshold. In addition, for example, the region search unit 62 searches for a region in the thermal image in which the temperature variance exceeds a predetermined threshold as a specific region. For example, the region searching unit 62 sets a region in which the difference between the maximum temperature and the minimum temperature is large and includes more temperatures in the region (that is, a region in which the temperature dispersion is large) as the specific region. Then, the area search unit 62 registers the area information 51 indicating the position of the specific area in the thermal image in the storage unit 50.

  Note that the area search unit 62 may employ any condition as long as the area to be focused on in the focus adjustment is the specific area. For example, the region search unit 62 may set the region where the distribution of the temperature spectrum is the maximum as the specific region, and the sum of the score according to the difference between the maximum temperature and the minimum temperature and the score according to the variance of the temperature spectrum is calculated. The largest area may be set as the specific area. The area search unit 62 may set the area where the standard deviation of the temperature is the largest as a whole as the specific area.

  Returning to FIG. 3, the description will be continued. The signal value change search unit 63 searches for a change amount of a signal value in a specific region for a plurality of thermal images taken while adjusting the focal length. For example, the acquisition unit 61 acquires a thermal image as needed along with a focus adjustment operation of the thermography apparatus by the operator OP. Then, the signal value change search unit 63 searches for a slope of a signal value change in a specific region of the plurality of thermal images acquired by the acquisition unit 61. That is, the signal value change search unit 63 extracts a region at the position indicated by the region information 51 from the acquired thermal image as a specific region, and calculates a difference in signal value between adjacent pixels in the extracted specific region.

  The determining unit 64 determines whether or not the focal length satisfies a predetermined condition based on the heat distribution in a specific region of the plurality of thermal images captured while adjusting the focal length. For example, the determination unit 64 determines whether the difference between the signal values calculated by the signal value change search unit 63 satisfies a predetermined condition. Then, when the difference between the signal values satisfies a predetermined condition, the determination unit 64 determines that the focal length adopted when obtaining the acquired thermal image is an appropriate focal length.

  For example, FIG. 5 is a diagram illustrating an example of thermal images having different focal lengths. In the example shown in FIG. 5, an example of the thermal image HP1 and the thermal image HP2 having a more appropriate focal length than the thermal image HP1 are shown. FIG. 5A shows an enlarged image of an area OA2 which is a specific area searched from the thermal image HP1. FIG. 5B shows an enlarged image of a region at the same position as region OA2 in thermal image HP2, that is, region OA3 which is a specific region.

  As shown in FIG. 5, when the enlarged image of the region OA2 is compared with the enlarged image of the region OA3, the temperature change between pixels in the region OA3 is clearer. Therefore, it is considered that the dispersion of the temperature difference (that is, the signal difference) between adjacent pixels is larger in the region OA3 than in the region OA2.

  For example, FIG. 6 is a diagram for explaining a difference in signal difference between adjacent pixels. In FIG. 6, an example of the signal value at each pixel of the thermal image, the amount of change in the signal value between adjacent pixels, and the difference between the signal values when the focal length is appropriate and when the focal length is not appropriate. An example with the histogram is shown. More specifically, in the example illustrated in FIG. 6, the signal values acquired by the thermography apparatus 100 for five pixels in the vertical direction and five pixels in the horizontal direction as a partial area included in the specific area. And a signal value difference between pixels adjacent in the horizontal direction, and a histogram of the signal value difference. In the example illustrated in FIG. 6, the signal value acquired by the thermography device 100 indicates, for example, a temperature of a position corresponding to each pixel in the imaging target in ten levels.

  For example, in a case where the focal length is appropriate, the thermography apparatus 100 outputs signal values such as “10”, “10”, “8”, “3”, and “1” as shown in FIG. It is assumed that it is given to each pixel. In such a case, the difference in signal value between the left and right adjacent pixels is “0”, “2”, “5”, and “2”.

  On the other hand, if the focal length is not appropriate, an infrared image spot emitted from each position of the imaging target forms an image on the infrared detector in a blurred state. For this reason, for example, the thermography apparatus 100 gives to each pixel a signal value whose value is averaged between adjacent pixels. For example, as shown in FIG. 6B, the thermography apparatus 100 assigns signal values such as “10”, “9”, “7”, “4”, and “2” to each pixel. As a result, when the focal length is not appropriate, the difference between the signal values between the adjacent pixels on the left and right is "1", "2", "3", "2", and so on. In comparison, the amount of change is small.

  As a result, as shown in each histogram of FIG. 6, it is estimated that the signal difference between adjacent pixels in the specific region is more scattered when the focal length is appropriate than when the focal length is not appropriate. You. Therefore, the determining unit 64 determines whether the focal length satisfies a predetermined condition based on whether the temperature difference between adjacent pixels satisfies a predetermined condition.

  For example, when the sum of the temperature differences between adjacent pixels exceeds a predetermined threshold, the determination unit 64 determines that the focal length satisfies a predetermined condition. Further, for example, when the standard deviation of the temperature difference exceeds a predetermined threshold, the determination unit 64 determines that the focal length satisfies a predetermined condition. As a result, the determination unit 64 can appropriately determine whether the focal length is appropriate.

  The output unit 65 outputs information indicating the determination result. For example, when the determination unit 64 determines that the focal length satisfies the predetermined condition, the output unit 65 causes the display unit 40 to display that the focal length satisfies the predetermined condition.

[Example of Operation in First Embodiment]
Next, an example of the operation timing of the focus adjustment support device 10 according to the first embodiment will be described with reference to FIG. FIG. 7 is a flowchart illustrating an example of the focus adjustment support processing according to the first embodiment.

  For example, the acquisition unit 61 acquires a thermal image from the thermography device 100 as an initial distribution image (Step S101). In such a case, the region search unit 62 scans a region of a predetermined size in the thermal image, and searches for a region where the temperature change in the entire region satisfies the condition (step S102). Then, the area search unit 62 stores the area information 51 indicating the position of the searched area (Step S103).

  Subsequently, the focus control unit 30 determines whether or not a focus adjustment operation has been received (step S104), and if it has been received (step S104: Yes), adjusts the focal length of the thermographic apparatus 100 according to the focus adjustment operation. (Step S105). In such a case, the communication unit 20 acquires a new thermal image (step S106). Then, the signal value change search unit 63 searches for a difference between signal values in the area indicated by the area information 51 in the newly acquired thermal image (step S107). That is, the signal value change search unit 63 calculates a difference in signal value between adjacent pixels.

  Then, the determination unit 64 determines whether the difference between the signal values satisfies a predetermined condition (Step S108). For example, the determination unit 64 determines whether or not the variance of the difference between signal values between adjacent pixels exceeds a predetermined threshold. When it is determined that the difference between the signal values satisfies the predetermined condition (Step S108: Yes), the output unit 65 notifies the operator that the focal length is appropriate (Step S109).

  After the process of step S109, the focus adjustment support device 10 determines whether the focus adjustment is completed (step S110), and when it is determined that the focus adjustment is completed (step S110: Yes), the focal length is fixed. Inspection is started in this state (step S111), and the process ends. On the other hand, when the focus control unit 30 has not received the focus adjustment operation (step S104: No), the difference between the signal values does not satisfy the predetermined condition (step S108: No), or the focus adjustment has been completed. If not (step S110: No), it is determined again whether a focus adjustment operation has been accepted (step S104).

[Effects in First Embodiment]
As described above, the focus adjustment support apparatus 10 searches for a region where the temperature change satisfies the predetermined condition from the thermal image indicating the heat distribution of the imaging target. Then, the focus adjustment support device 10 determines whether or not the focal length satisfies a predetermined condition based on the heat distribution in the searched area of the plurality of thermal images captured while adjusting the focal length. . As a result of such processing, the focus adjustment support device 10 automatically searches for a specific area to be noted when adjusting the focus, and determines whether the focal length is appropriate based on the heat distribution in the searched specific area. Since the determination is made, the focus adjustment operation can be supported regardless of the skill level of the operator.

[Principle 2]
In the first embodiment described above, the single focus adjustment support apparatus 10 searches for a specific area and determines whether or not the focal length is appropriate based on the temperature distribution in the specific area. Here, when a plurality of operators OP individually use a plurality of thermography apparatuses 100, it has been conceived to suppress variation in inspection by sharing a specific region of interest.

[Second embodiment]
Hereinafter, an outline of the second embodiment will be described with reference to FIG. FIG. 8 is a diagram illustrating an outline of a focus adjustment support device according to the second embodiment. In the example illustrated in FIG. 8, the focus adjustment support devices 10a and 10b are information processing devices that receive various operations from the operator OP, like the focus adjustment support device 10 illustrated in FIG. Is done.

  Here, the focus adjustment support device 10a is connected to a thermography device 100a that obtains a thermal image from infrared rays emitted from an inspection target flowing through the inspection line IL1. Further, the focus adjustment support device 10b is connected to a thermography device 100b that obtains a thermal image from infrared rays emitted from an inspection object flowing on the inspection line IL2. The thermographic devices 100a and 100b have the same functions as the thermographic device 100 according to the first embodiment, and a description thereof will be omitted.

  For example, when receiving a thermal image from the thermography device 100a, the focus adjustment support device 10a searches for a region useful for performing focus adjustment from the received thermal image as a specific region, as in the first embodiment (Step S10). S11). Then, the focus adjustment support device 10a determines whether or not the focal length is appropriate based on the heat distribution in the specified specific region, and transmits region information indicating the position and the like of the specified specific region to the thermography device 100b. Is transmitted (step S12).

  On the other hand, the focus adjustment support apparatus 10b does not search for a specific area in the apparatus itself, and obtains the area indicated by the area information received from the focus adjustment support apparatus 10a as a specific area while adjusting the focal length of the thermography apparatus 100b. With respect to the plurality of thermal images, it is determined whether or not the focal length of the thermographic device 100b is appropriate based on the thermal distribution in the specific area (Step S13).

  That is, the focus adjustment support device 10a transmits, as a master, region information of a specific region specified from the thermal image acquired from the thermography device 100a to the focus adjustment support device 10b, which is a slave. Then, the focus adjustment assisting device 10b, which is a slave, uses the region indicated by the region information received from the focus adjustment assisting device 10a as the specific region in the thermal image obtained by the thermography device 100b, and determines the region based on the heat distribution in the specific region. Then, it is determined whether or not the focal length of the thermography device 100b is appropriate.

[One Example of Functional Configuration in Second Embodiment]
Next, an example of a functional configuration of the focus adjustment support devices 10a and 10b will be described with reference to FIG. FIG. 9 is a diagram illustrating an example of a functional configuration of the focus adjustment support device according to the second embodiment.

  As shown in FIG. 9, the focus adjustment support device 10a includes a communication unit 20a, a focus control unit 30a, a display unit 40a, a storage unit 50a, a control unit 60a, and a transmission unit 70. The communication unit 20a, the focus control unit 30a, the display unit 40a, and the storage unit 50a exhibit the same functions as those of the communication unit 20, the focus control unit 30, the display unit 40, and the storage unit 50 illustrated in FIG. The description is omitted.

  The control unit 60a exhibits the same function as the control unit 60 shown in FIG. For example, the control unit 60a includes an acquisition unit 61a, an area search unit 62a, a signal value change search unit 63a, a determination unit 64a, and an output unit 65a. The acquisition unit 61a, the area search unit 62a, the signal value change search unit 63a, the determination unit 64a, and the output unit 65a are the acquisition unit 61, the area search unit 62, the signal value change search unit 63, and the determination unit shown in FIG. 64 and the same functions as the output unit 65.

  The transmitting unit 70 transmits the region information 51a indicating the specific region searched by the region searching unit 62a to the focus adjustment support device 10b, which is a slave. For example, when the area search unit 62a stores the area information 51a in the storage unit 50a, the transmission unit 70 transmits the area information 51a to the focus adjustment support device 10b.

  On the other hand, the focus adjustment support device 10b includes a communication unit 20b, a focus control unit 30b, a display unit 40b, a storage unit 50b, a control unit 60b, and a reception unit 80. The communication unit 20b, the focus control unit 30b, the display unit 40b, and the storage unit 50b exhibit the same functions as those of the communication unit 20, the focus control unit 30, the display unit 40, and the storage unit 50 illustrated in FIG. The description is omitted.

  The receiving unit 80 receives, from another focus adjustment support apparatus 10a, area information indicating an area that is searched from the thermal image by the focus adjustment support apparatus 10a and that has a temperature change that satisfies a predetermined condition. For example, when the receiving unit 80 receives the region information 51a from the focus adjustment support device 10a, the receiving unit 80 stores the received region information 51a as the region information 51b in the storage unit 50b.

  The control unit 60b exhibits the same function as the control unit 60 shown in FIG. For example, the control unit 60b includes an acquisition unit 61b, a signal value change search unit 63b, a determination unit 64b, and an output unit 65b. Note that the acquisition unit 61b, the signal value change search unit 63b, the determination unit 64b, and the output unit 65b exhibit the same functions as the signal value change search unit 63, the determination unit 64, and the output unit 65 illustrated in FIG. Shall be.

  For example, similarly to the signal value change search unit 63, the signal value change search unit 63b may determine the signal value between adjacent pixels in the region indicated by the region information 51b for a plurality of thermal images obtained while adjusting the focal length. Search for the difference between That is, the signal value change search unit 63b is not the focus adjustment support device 10b but the specific region searched from the thermal image obtained by the focus adjustment support device 10a from the thermography device 100a, in the thermal image obtained from the thermography device 100b. A similar region is extracted, and a difference in signal value between adjacent pixels is searched for in the extracted region.

  Then, the determining unit 64b determines whether the focal length of the thermographic device 100b is appropriate based on the search result by the signal value change searching unit 63b. Thereafter, the output unit 65b outputs the result of the determination by the determination unit 64b.

[Example of Operation in Second Embodiment]
Next, an example of operation timings of the focus adjustment support devices 10a and 10b according to the second embodiment will be described with reference to FIG. FIG. 10 is a flowchart illustrating an example of the focus adjustment support processing according to the second embodiment. In the following description, the focus adjustment support devices 10a and 10b are collectively referred to as the focus adjustment support device 10.

  For example, the focus adjustment support device 10 determines whether or not the device itself is a master (Step S201). If the device itself is the master (Step S201: Yes), the focus adjustment assisting device 10 notifies the other focus adjustment assisting devices 10 of the region searched from the thermal image, that is, the specific region, as a slave. (Step S202). Then, the focus adjustment support device 10 supports the adjustment of the focal length based on the difference between the signal values in the searched area (step S203), and ends the processing.

  On the other hand, when the focus adjustment support device 10 determines that the device itself is a slave (step S201: No), it receives a notification of the area searched by the master (step S204). Then, the focus adjustment support device 10 supports the adjustment of the focal length based on the signal value difference in the notified area (step S205), and ends the processing.

[Effect in Second Embodiment]
As described above, the focus adjustment support device 10a serving as the master searches for a region where the temperature change satisfies the predetermined condition from the thermal image indicating the heat distribution of the imaging target. Then, the focus adjustment support device 10a transmits region information indicating the specific region to the focus adjustment support device 10b serving as a slave. On the other hand, the focus adjustment support device 10b determines whether the focal length satisfies a predetermined condition based on the heat distribution in the specific region indicated by the region information notified from the focus adjustment support device 10a. As a result of such processing, the focus adjustment support devices 10a and 10b can share a specific area to be focused on in focus adjustment, and thus can suppress a variation in inspection.

[Expansion of Embodiment]
In the above, an example of the focus adjustment support processing executed by the focus adjustment support device 10 has been described. However, embodiments are not limited to this. Hereinafter, variations of the process performed by the focus adjustment support device 10 will be described.

(1: About conditions of temperature change in specific area)
In the above-described embodiment, the focus adjustment support device 10 searches for a region where the variance of the temperature (signal value) of each pixel in the region is the largest or a region where the difference between the maximum temperature and the minimum temperature is the largest as the specific region. . However, embodiments are not limited to this. For example, the focus adjustment support device 10 may search for a region where the standard deviation of the temperature of each pixel in the region is the largest as the specific region.

  Further, the focus adjustment support device 10 may count the number of temperatures of each pixel included in the region, and set the region having the largest number as the specific region. In addition, the focus adjustment support device 10 calculates a score based on factors such as the difference between the highest temperature and the lowest temperature, the variance of the temperature, the standard deviation, the number of temperatures, and the like. Good. At this time, the focus adjustment support device 10 may apply a predetermined weight to each element.

  That is, the focus adjustment support device 10 can automatically search for an area estimated to be useful in focus adjustment (that is, an area including various temperatures) as a specific area based on an arbitrary condition. Alternatively, a search for a specific area may be performed.

(2: Conditions for determining whether the focal length is appropriate)
In the above-described embodiment, the focus adjustment support device 10 outputs a signal between adjacent pixels in a specific region for a plurality of thermal images (that is, a plurality of thermal images having different focal lengths) obtained while adjusting the focal length. It was determined whether or not the focal length was appropriate based on whether or not the value difference satisfied a predetermined condition. Here, the focus adjustment support device 10 may determine whether the focal length is appropriate based on an arbitrary condition. For example, when the sum, variance, or standard deviation of the signal value difference exceeds a predetermined threshold, the focus adjustment support device 10 may output to the user that the focal length is appropriate. Good.

  Further, for example, the focus adjustment support apparatus 10 calculates a difference between adjacent signal values in a specific region for each of the plurality of thermal images obtained while adjusting the focal length, and calculates the sum of the differences between the signal values and the variance. Alternatively, the thermal image having the maximum standard deviation is specified. Then, the focus adjustment support device 10 may output information indicating the focal length when the specified thermal image is obtained. That is, the focus adjustment support apparatus 10 may acquire all of a plurality of thermal images having different focal lengths in advance, and specify a thermal image having the most appropriate focal length among the acquired thermal images.

  Further, for example, each time the thermal image is acquired, the focus adjustment support apparatus 10 determines whether the focal length is more appropriate than the previously acquired thermal image, and determines whether the focal length is longer than the previously acquired thermal image. If it is no longer appropriate, the fact that the focus has been optimized in the acquired thermal image may be output to the user. To give a more specific example, the focus adjustment support apparatus 10 calculates a difference between adjacent signal values in a specific region every time a thermal image is obtained. Subsequently, the focus adjustment support device 10 compares the sum, variance, or standard deviation of the calculated signal value difference with the sum, variance, or standard deviation of the signal value difference calculated from the previously obtained thermal image. I do.

  Then, the focus adjustment assisting apparatus 10 notifies the user when the sum of the differences between the signal values, the variance, or the standard deviation is larger in the newly obtained thermal image than in the previously obtained thermal image. And a new thermal image is acquired. In addition, the focus adjustment support apparatus 10 acquires the sum, variance, or standard deviation of the difference between the signal values when the newly obtained thermal image is smaller than the previously obtained thermal image. The fact that the focus has been optimized in the thermal image may be output to the user.

  In addition, the focus adjustment support apparatus 10 may use any method as long as it determines whether or not the focal length is appropriate based on the heat distribution in the specific area in addition to the difference between the signal values of adjacent pixels. May be employed. For example, the focus adjustment support device 10 determines whether or not a color boundary line is clear in a specific region using an image analysis technique or the like. It may be determined that it is appropriate. Even when such a process is performed, the focus adjustment support apparatus 10 can determine whether or not the focal length is appropriate from the thermal image using only software.

(3: About output)
In the example described above, the focus adjustment support device 10 has provided a notification to the user that the focal length is appropriate. However, embodiments are not limited to this. For example, when it is determined that the focal length is not appropriate, the focus adjustment support device 10 may provide a notification to the user that the focal length is not appropriate. When it is determined that the focal length is appropriate, the focus adjustment support device 10 may fix the focal length. For example, when the focus adjustment support device 10 determines that the focal length of the previously acquired thermal image is appropriate, the focus adjustment support device 10 changes the focal length of the thermography device 100 to the focal length determined to be appropriate. The distance may be fixed.

  Further, the focus adjustment support device 10 may automatically adjust the focal length of the thermographic device 100 based on the determination result. For example, the focus adjustment support device 10 automatically changes the focal length of the thermographic device 100 until it is determined that the focal length is appropriate, and changes the focal length when it is determined that the focal length is appropriate. It may be fixed.

(4: About area information)
Further, in the above-described second embodiment, the focus adjustment support device 10a serving as the master has transmitted the region information 51a indicating the position, size, and shape of the region serving as the specific region in the thermal image. However, embodiments are not limited to this.

  For example, even if the plurality of thermography apparatuses 100a and 100b are capturing the same type of target, the position where the target is captured in the thermal image slightly changes. In order to absorb such a change, for example, a method of setting the size of the specific region to some extent is conceivable, but in order to more appropriately share the specific region, information on the heat distribution in the specific region specified by the master is used. The slave may be notified.

  For example, the focus adjustment support device 10a transmits information on heat distribution in a specific region as the region information 51a. In such a case, the focus adjustment support device 10b may search, as a specific region, a region similar to the heat distribution indicated by the region information 51a in the thermal image acquired from the thermography device 100b. Further, the focus adjustment support device 10a may transmit region information 51a indicating the position of the specific region and the heat distribution. In such a case, the focus adjustment support device 10b may search for an area whose heat distribution is similar to the heat distribution indicated by the area information 51a from near the position indicated by the area information 51a.

(5: Other)
Note that the focus adjustment support device 10 serving as a master may transmit the area information to an arbitrary number of focus adjustment support devices 10 serving as slaves. That is, the focus adjustment support device 10 may share a specific area among an arbitrary number of devices.

  Further, the focus adjustment support device 10 may be the same device as the thermography device 100. In addition, the various processes described above may be automatically executed by the focus adjustment support device 10, and any one of the processes may be manually performed.

  The example of the embodiment has been described above, but these are merely examples, and the present embodiment is not limited to the above description. The configurations and details of the embodiments, including the aspects described in the section of disclosure of the invention, can be implemented in other forms with various modifications and improvements based on the knowledge of those skilled in the art. In addition, the respective embodiments can be arbitrarily combined and implemented without contradicting each other.

10, 10a, 10b Focus adjustment support device 20, 20a, 20b Communication unit 30, 30a, 30b Focus control unit 40, 40a, 40b Display unit 50, 50a, 50b Storage unit 51, 51a, 51b Area information 60, 60a, 60b Control unit 61, 61a, 61b Acquisition unit 62, 62a Area search unit 63, 63a, 63b Signal value change search unit 64, 64a, 64b Judgment unit 65, 65a, 65b Output unit 70 Transmission unit 80 Reception unit 100, 100a, 100b Thermography equipment

Claims (10)

An acquisition unit that acquires a thermal image indicating a heat distribution of an imaging target,
From the thermal image acquired by the acquiring unit, a search unit that searches for an area where a temperature change satisfies a predetermined condition,
A determination unit that determines whether or not the focal length satisfies a predetermined condition based on a heat distribution in a region searched by the search unit among a plurality of thermal images captured while adjusting the focal length. Focus adjustment support device. The focus adjustment support device according to claim 1,
A focus adjustment support device, further comprising: an output unit that outputs information indicating a result of the determination by the determination unit. The focus adjustment support device according to claim 1 or 2,
The focus adjustment support device, wherein the search unit searches for an area in the thermal image where a difference between a minimum temperature and a maximum temperature exceeds a predetermined threshold. The focus adjustment support device according to any one of claims 1 to 3,
The focus adjustment support device, wherein the search unit searches for a region in the thermal image in which the variance of the temperature exceeds a predetermined threshold. The focus adjustment support device according to any one of claims 1 to 4,
The focus adjustment support device, wherein the determination unit determines whether a focal length satisfies a predetermined condition based on a temperature difference between adjacent pixels in an area searched by the search unit. The focus adjustment support device according to claim 5,
The focus adjustment support device, wherein the determination unit determines that the focal length satisfies a predetermined condition when the sum of the temperature differences exceeds a predetermined threshold. The focus adjustment support device according to claim 5 or 6,
The focus adjustment support device, wherein the determination unit determines that the focal length satisfies a predetermined condition when a standard deviation of the temperature difference exceeds a predetermined threshold. The focus adjustment support device according to any one of claims 1 to 7,
A receiving unit that receives, from another focus adjustment support apparatus, area information indicating an area searched for from the thermal image by the other focus adjustment support apparatus, the area indicating a temperature change that satisfies a predetermined condition;
When the determination unit receives the region information from another focus adjustment support device, the region information received from the other focus adjustment support device among a plurality of thermal images captured while changing the focal length is A focus adjustment support device, which determines whether or not a focal length satisfies a predetermined condition based on a heat distribution in the indicated area. The focus adjustment support device according to claim 8,
The receiving unit receives area information indicating a heat distribution in an area searched by the other focus adjustment support device,
The determination unit extracts an area in which the heat distribution is similar to the heat distribution indicated by the area information from the thermal image captured while changing the focal length, and based on the heat distribution in the extracted area, the focal length is A focus adjustment support device that determines whether a predetermined condition is satisfied. A first step in which the information processing apparatus acquires a thermal image indicating a heat distribution of the imaging target;
A second step in which the information processing apparatus searches for a region where a temperature change satisfies a predetermined condition from the thermal image acquired in the first step;
The information processing apparatus determines whether the focal length satisfies a predetermined condition based on the heat distribution in the area searched for in the second step, of the plurality of thermal images captured while adjusting the focal length. And a third step of determining.