Method, controller, device, and computer program product for determining a state of a building, and computer readable medium

Abstract

A method for determining a state of a building (40) is described. The method comprises: receiving first image data of a first image from a camera (24, 26), the first image showing at least a first view of the building (40); analysing the first image data with respect to at least one predetermined condition; when the predetermined condition is not fulfilled, determining destination data representing a destination around the building (40) from which a second image of the building (40) can be captured, wherein the second image shows at least a second view of the building (40) and wherein the second image is represented by second image data and wherein the destination data are determined such that the second image data complement the first image data such that overall image data comprising the first image data and the second image data fulfil the predetermined condition; sending the destination data to an output unit (22) of a device (20) comprising the camera (24, 26); receiving the second image data of the second image from the camera (24, 26), the second image showing a second view of the building (40) which is different from the first view of the building (40); and determining the state of the building (40) from the overall image data.

Description

[0001] Method, Controller, Device, and Computer Program Product for determining a State of a Building, and Computer Readable Medium

[0002] The technology described herein generally relates to a method for determining a state of a building, in particular with respect to the thermal insulation of the building and / or a renovation of the building. More particularly, the technology relates to a method, a controller, a device, and a computer program product for determining the state of the building, and to a computer readable medium on which the computer program product is stored.

[0003] EP 4 027 301 Al describes a method in which several images are taken inside a building. The acquisition locations of the images are determined by using data from the multiple devices.

[0004] Before renovating the building, the state of the building has to be determined. For example, when the thermal insulation properties of the building shall be improved by the renovation it is sensible to first determine the present insulation properties of the building which at least in part is representative for the state of the building. However, determining the state of the building may be a cumbersome task and a huge amount of data has to be gathered first before the state of the building can be determined from the gathered data.

[0005] Accordingly, there may be a need for a method, a controller, a device, and a computer program product for determining the state of the building, which enable to determine the state of the building easily, quickly, and / or in a cost-efficient way. Further, there may be a need for a computer readable medium on which the computer program product is stored.

[0006] Such need may be met with the subject-matter of the independent claims. Advantageous embodiments are defined in the dependent claims as well as in the following specification and the associated figures.

[0007] According to a first aspect of the technology described herein, a method for determining a state of a building is described. The method comprises: receiving first image data of a first image from a camera, the first image showing at least a first view of the building; analysing the first image data with respect to at least one predetermined condition; when the predetermined condition is not fulfilled, determining destination data representing a destination around the building from which a second image of the building can be captured, wherein the second image shows at least a second view of the building and wherein the second image is represented by second image data and wherein the destination data are determined such that the second image data complement the first image data such that overall image data comprising the first image data and the second image data fulfil the predetermined condition; sending the destination data to an output unit of a device comprising the camera; receiving the second image data of the second image from the camera, the second image showing a second view of the building which is different from the first view of the building; and determining the state of the building from the overall image data.

[0008] According to a second aspect of the technology described herein, a controller for determining the state of the building is described. The controller comprises: a memory for storing the image data; and a processor communicatively coupled to the memory and being configured for carrying out the method as explained above and in the following based on the image data.

[0009] According to a third aspect of the technology described herein, a device for determining the state of the building is described. The device comprises: the controller as described above and in the following; the camera for capturing the images and for generating the image data being representative of the images, with the camera being communicatively coupled to the controller; and the output unit for outputting information to a person using the device, with the output unit being communicatively coupled to the controller.

[0010] According to a fourth aspect of the technology described herein, a computer program product is described. The computer program product comprises computer readable instructions which, upon being executed by the processor of the controller as described above and in the following, instruct the controller of executing and controlling the method as described above and in the following.

[0011] According to a fifth aspect of the technology described herein, a computer readable medium is described, the computer readable medium comprising stored thereon the computer program product as described above and in the following. The method, the controller, the device, and the computer program enable to gather information of the building from the captured image, in particular the image data, while being guided around the building. This enables to determine the state of the building easily, quickly, and / or in a cost-efficient way. For example, the worker, carrying out any construction tasks at the building may be equipped with the device and may be able to gather the data needed for determining the state of the building during its normal work. In this case, no additional time and no additional person is needed for gathering the data. When the state of the building is determined, tasks which have to be carried out when renovating the building and / or material which is needed to carry out the renovation may be determined very accurately. This may enable to provide the very accurate estimation of working hours and / or costs involved in the renovation. The state of the building, in particular the data representing the state of the building, may be sent from the device to a remote location, for example to a remote server.

[0012] The device may be carried by a person determining the state of the building. The device may be carried by the person from one position to another position around the building. The device may be a smartphone, a tablet-computer, a notebook, or a piece of clothing comprising the camera, e.g. a vest, a jacket, or a helmet. The output unit may be a display or a speaker. The output unit may be configured for outputting the destination based on the destination data.

[0013] That an image shows “at least” a view of the building may mean in this description that the image shows the corresponding view of the building and eventually the whole building seen from a current position of the device.

[0014] Any position data mentioned in this description, including the destination data, may be representative of the position of the device which may be given in real-world coordinates, for example, and optionally an orientation of the device, in particular of the camera, at the corresponding position. So, the position data may comprise orientation data. In this way, the view or current field of view of the camera at the corresponding position may be unambiguously determined from the corresponding position data. The orientation data may be determined by an Inertial Measurement Unit (IMU) of the device. The IMU may be configured for determining the orientation of the device, in particular of the camera. When the predetermined condition is fulfilled, the state of the building may be determined from the first image data.

[0015] According to an embodiment, the method comprises before receiving the first image data: determining first current position data representing a first current position of the device; determining starting position data representing a starting position from which the first image shall be captured; comparing the first current position and the starting position by comparing the first current position data with the starting position data; when the first current position corresponds to the starting position, sending a first approval signal to the output unit, and / or sending a first capturing signal to the camera, wherein the capturing signal and the camera are configured such that the camera captures the first image upon receiving the capturing signal.

[0016] Vividly spoken, the device may be configured for checking the current position of the device and for detecting when the device arrives at the starting position from which the first image shall be captured. Then, the device may be configured for sending the first approval signal to the output unit such that the person carrying the device recognizes that he / she arrived at the starting position and can trigger capturing the first image. Alternatively or additionally to sending the first approval signal, the device may be configured for capturing the first image automatically when the device arrives at the starting position. Alternatively, the camera may capture images of the building permanently, e.g. by capturing a video of the building, while the device is carried from the current position to the starting position, and the device recognizes when it arrives at the starting position and is able to determine that image of the video as the first image which is captured at the starting position.

[0017] When the first current position does not correspond to the starting position, further current position data may be determined representing further current positions of the device, the further current positions may be compared with the starting position by comparing the further current position data with the starting position data, and the first capturing signal may be sent to the camera upon the further current position corresponding to the starting position. So, the current position of the device may be compared to the starting position again and again until the device arrives at the starting position.

[0018] Any current position mentioned in this description may refer to a current position at which the device is positioned in the moment the corresponding current position is determined. So, when the first current position data are determined the device is at the first current position in that moment and when second current position data are determined the device is at a second current position in that moment, which is different from the first current position. Any current position may be determined by a positioning unit of the device. The positioning unit may comprise a GPS-receiver.

[0019] According to an embodiment, the method comprises, when the first current position does not correspond to the starting position: sending a first routing signal to the output unit, wherein the first routing signal is configured such that a person carrying the device is guided to the starting position by the output unit. The first routing signal may be representative of first routing information which is needed to arrive at the starting position starting from the first current position. The first routing information may be outputted by the output unit one after the other.

[0020] According to an embodiment, the method comprises, after sending the destination data and before receiving the second image data: determining second current position data representing a second current position of the device; and comparing the second current position with the destination by comparing the second current position data with the destination data; and when the second current position corresponds to the destination, sending a second approval signal to the output unit, and / or sending a second capturing signal to the camera, wherein the second capturing signal and the camera are configured such that the camera captures the second image upon receiving the second capturing signal.

[0021] Vividly spoken, the device may be configured for checking the current position of the device and for detecting when the device arrives at the destination from which the second image shall be captured. Then, the device may be configured for sending the second approval signal to the output unit such that the person recognizes that he / she arrived at the destination and can trigger capturing the second image. Alternatively or additionally to sending the second approval signal, the device may be configured for capturing the second image automatically when the device arrives at the destination. Alternatively, the camera may capture images of the building permanently, e.g. by capturing a video of the building, while the device is carried from the current position to the destination and the device recognizes when it arrives at the destination and is able to determine that image of the video as the second image which is captured at the destination.

[0022] When the second current position does not correspond to the destination, further current position data may be determined representing further current positions of the device, the further current positions may be compared with the destination by comparing the further current position data with the destination data, and the second capturing signal may be sent to the camera when the first one of the further current positions corresponds to the destination. So, the second current position of the device may be compared to the destination again and again until the device arrives at the destination.

[0023] According to an embodiment, the method comprises, when the second current position does not correspond to the destination: sending a second routing signal to the output unit, wherein the second routing signal is configured such that the person carrying the device is guided to the destination by the output unit. The second routing signal may be representative of second routing information which is needed to arrive at the destination starting from the second current position. The second routing information may be outputted by the output unit one after the other.

[0024] According to an embodiment, the predetermined condition is at least one condition out of a group of conditions, the group comprising: the first image data contain sufficient information for determining the state of the building; and a digital model of the building contains sufficient information to reconstruct the state of the building from the digital model. When the predetermined condition is that the digital model of the building contains sufficient information to reconstruct the state of the building from the digital model, the analysing of the first image data may comprise determining whether the digital model needs to be complemented in order to be able to derive the state of the building from the digital model and to check whether information retrievable from the first image data is sufficient in order to complement the digital model such that the state of the building is retrievable from the digital model. In this case, the determining of the destination data may comprise determining which view of the building, e.g. the second view, is needed to complement the digital model such that the state of the building may be retrieved form the digital model.

[0025] According to an embodiment, the predetermined condition is that the digital model of the building contains sufficient information to reconstruct the state of the building from the digital model, and the determining of the state of the building from the overall image data comprises complementing the digital model of the building from the first and / or second image data and determining the state of the building from the complemented digital model.

[0026] According to an embodiment, the state of the building refers to thermal insulation properties of the building, the camera is or comprises a thermal camera, and the image data comprise thermal insulation information of the building. When the camera is the thermal camera, the device may comprise another camera for capturing “normal” images within the visible spectrum in parallel to the thermal images. When the camera comprises the thermal camera, the camera may comprise the other camera for capturing the “normal” images within the visible spectrum in parallel to the thermal images. So, in any case, the device may be able to capture images in the visible spectrum and images in the thermal spectrum.

[0027] When the predetermined condition is that the first image data contain sufficient information for determining the state of the building and when the state of the building refers to thermal insulation properties, analysing the first image data may comprise analysing whether the first image data contain sufficient information for determining the insulation properties of the building, in particular from the thermal information retrieved from the first image data. In this case, the determining of the destination data may comprise determining from which view the building must be seen in order to retrieve further information for determining the insulation properties of the building. For example, in case of the first image showing a thermal leakage at an opening of the building, e.g. a door or a window of the building, at least another view of the same opening, e.g. the second view, may be necessary, in order to be able to determine the insulation property at this opening accurately. Such a variation of the views may be determined in advance, e.g. empirically or by simulation, and may be stored in a memory of the device. Alternatively, the destination data may be determined from a current position of the device in a fixed way. For example, when the first image is taken from a starting position at a first angle, the destination may be determined such that the second image is taken at a second angle having a fixed relation to the first angle. For example, when both angles lie completely in a horizontal plane, the first angle may defer from the second angle by a fixed angle. The fixed angle may range from 1 to 90 degree, e.g. from 10 to 50 degree, e.g. from 20 to 30 degree.

[0028] According to an embodiment, the camera is or comprises a thermal camera.

[0029] Embodiments of the method described herein may be implemented in hardware, software or a combination thereof. The computer program may be provided in any computer readable language. The computer readable medium may be for example a volatile or nonvolatile data memory. For example, the computer readable medium may be a flash memory, a DVD, a CD, a ROM, a RAM, an EPROM or similar devices. Alternatively, the computer readable medium may be part of another computer or server or of a data cloud from which the computer program product may be downloaded for example via a network such as the Internet.

[0030] It shall be noted that features, and / or advantages of the technology described may be described herein with respect to one of the above aspects only. However, a person skilled in the art will recognize that these features and / or advantages may be suitably transferred from one aspect to another aspect and / or may be modified, adapted, combined and / or replaced, etc. in order to come to further embodiments of the technology described herein.

[0031] In the following, advantageous embodiments of the technology described herein will be described with reference to the enclosed drawing. However, neither the drawing nor the description shall be interpreted as limiting the technology described herein.

[0032] Fig. 1 shows a front view of a device for determining a state of the building, according to an embodiment of the technology described herein. Fig. 2 shows a view of the building and a person carrying the device according to figure 1.

[0033] Fig. 3 shows a flow chart of a method for determining the state of a building, according to an embodiment of the technology described herein.

[0034] The figure is only schematic and not to scale. Same reference signs refer to same or similar features.

[0035] Fig. 1 shows a front view of a device 20 for determining a state of a building 40 (see figure 2), according to an embodiment of the technology described herein. The device 20 comprises: a controller 30, at least one camera, e.g. a first camera 24 and a second camera 26, for capturing images and for generating corresponding image data being representative of the captured images, and an output unit 22 for outputting information to a person 50 (see figure 2) using the device 20. The device 20 may be a smartphone, a tablet-computer, a notebook, or a piece of clothing comprising the camera 24, 26, e.g. a vest, a jacket, or a helmet. The output unit 22 may be or may comprise a display and / or a speaker.

[0036] The controller 30 is configured for determining the state of the building 40. The controller 30 comprises a memory 32 for storing the image data, and a processor 34 communicatively coupled to the memory 32. The processor 34 may be configured for carrying out the method explained with respect to figure 3, based on the image data. The camera 24, 26 is or comprises a thermal camera. For example, the first camera 24 is a thermal camera capturing pictures in a region of thermal radiation and the second camera 26 is a “normal” camera capturing images in the visible light spectrum. When the device 20 is a piece of clothing, the camera 24, 26 may be referred to as “body-cam”.

[0037] Fig. 2 shows a view of the building 40 and a person 50 carrying the device 20 according to figure 1. The building 40 may comprise a door 44 and / or one or more windows 42. However, the building 40 may comprise more or less windows 42 and / or doors 44.

[0038] The device 20 may be carried by the person 50 when determining the state of the building 40. The device 20 may be carried by the person 50 from one position around the building to another position around the building 40, as explained with respect to figure 3. In figure 2, the person 50 is shown at two exemplary positions, wherein the person 50 depicted by solid lines may be at a first position around the building 40 and the person 50 depicted in dashed lines may be at a second position around the building 40.

[0039] The camera 24, 26 of the device 20 may have a fixed field of view. When the device 20 is carried around by the person 50, a size of the field of view and an orientation of the field of view with respect to the rest of the device 20 stays the same. However, the field of view with respect to the real world changes, when the position and / or an orientation of the device 20 are changed by carrying the device 20 around the building 40. To take this under consideration, a first field of view 52 and a second field of view 56 are shown in figure 2, wherein the first field of view 52 corresponds to the field of view of the camera 24, 26 at the first position and the second field of view 56 corresponds to the field of view of the camera 24, 26 at the second position. As explained in the foregoing, the sizes and the orientations of the first and second field of views 52, 56 with respect to the device 20 are the same. However, in the real world, the first field of view 52 has another orientation than the second field of view 56 and a centre of the first field of view 52 is different from a centre of the second field of view 56.

[0040] A first orientation of the first field of view 52 may be defined by a first bisectrix 54 of the first field of view 52. A second orientation of the second field of view 56 may be defined by a second bisectrix 58 of the second field of view 52. A difference between the first and second orientations may be defined by an angle 60 between the first and second bisectrices 54, 58.

[0041] Fig. 3 shows a flow chart of a method for determining the state of a building, e.g. the building 40, according to an embodiment of the technology described herein. In order to determine the state of the building 40 the person 50 carrying the device 20 may be guided to several positions around the building 40 and to capture images of different views of the building 40. In this way, data referring to the state of the building 40 may be gathered by carrying the device 20 around the building 40. Then, the state of the building 40 may be determined, when sufficient data for determining the state of the building 40 are present. The method, in particular the steps of the method described in the following, may be carried out by the controller 30. When the person 50 is guided to several positions around the building 40, known methods for determining the best route may be used, e.g. as described in “Classical and Heuristic Approaches for Mobile Robot Path Planning: A Survey”, by Jaafar Ahmed Abdulsaheb and Dheyaa Jasim Kadhim, Department of Electrical Engineering, College of Engineering, University of Baghdad, Robotics 2023, 12(4), 93; “Autonomous Service Robots for Urban Waste Management - Multiagent Route Planning and Cooperative Operation”, by Abhishek Gupta et al., IEEE Robotics and Automation Letters ( Volume: 7, Issue: 4, October 2022), pages: 8972 - 8979; or “The Right Direction to Smell: Efficient Sensor Planning Strategies for Robot Assisted Gas Tomography”, by Muhammad Asif Arain, presented at IEEE International Conference on Robotics and Automation (ICRA), Stockholm, Sweden, May 16-21, 2016.

[0042] In an optional step S2, first current position data representing a first current position of the device 20 may be determined. The first current position data and all other current position data may be determined by a positioning unit (not shown) of the device 20, with the positioning unit being communicatively coupled to the controller 30. The positioning unit may be configured to determine the current position of the device 20, e.g. the first current position, to generate corresponding current position data and to provide the current position data to the controller 30. The positioning unit may be or may comprise a GPS-receiver. The first current position may correspond to the first position at which the person 50 is positioned in figure 2, for example.

[0043] Any position data mentioned in this description, for example the first current position data or any position data mentioned in the following, may be representative of the position of the device 20 which may be given in real-world coordinates, for example in longitude and latitude, and optionally an orientation of the device 20, in particular of the camera 24, 26, at the corresponding position. The orientation of the device 20 may correspond to the first bisectrix 54 at the first position and to the second bisectrix 58 at the second position. So, the position data may comprise orientation data. In this way, the view or current field of view 52, 56 of the camera 24, 26 at the corresponding position may be unambiguously determined from the corresponding position data. The orientation data may be determined by an Inertial Measurement Unit (IMU) of the device 20 (not shown). The IMU may be configured for determining the orientation of the device 20, in particular of the camera 24, 26.

[0044] In an optional step S4, starting position data representing a starting position from which a first image shall be captured by the camera 24, 26 may be determined. The starting position may be any position around the building 40 or a specific position around the building 40. For example, when any critical areas of the building 40 are known in advance, the starting position may be chosen such that the critical areas are within the field of view 52, 56 of the camera 24, 26. Such a critical area may refer to the real building 40. For example, when analysing the insulation properties of the building 40, it is already known that the windows 42 and / or the door 44 may be within such a critical area. Then, the starting position may be chosen such that the corresponding window 42 or, respectively, door 44 is within the first field of view 52. Alternatively, such a critical area may refer to a digital model of the building 40. For example, it may be known in advance that some parts of the digital model are not accurate enough to be able to determine the state of the building 40 from the digital model. In this case, the starting position may be chosen such that those parts of the building 40 are within the first field of view 52 from which it is known that the corresponding digital parts of the digital model of the building 40 are not accurate enough.

[0045] In an optional step S6, the first current position and the starting position may be determined by comparing the first current position data with the starting position data. When the first current position corresponds to the starting position, an optional step S8 may be carried out. When the first current position does not correspond to the starting position, an optional step S10 may be carried out.

[0046] In optional step S8, a first approval signal may be sent to the output unit 22. Alternatively or additionally, a first capturing signal may be sent to the camera 24, 26, wherein the capturing signal and the camera 24, 26 are configured such that the camera 24, 26 captures the first image upon receiving the capturing signal.

[0047] So, the device 20 may be configured for checking the current position of the device 20 and for detecting when the device 20 arrives at the starting position from which the first image shall be captured. Then, the device 20 may be configured for sending the first approval signal to the output unit 22 such that the person 50 carrying the device 20 recognizes that he / she arrived at the starting position and can trigger capturing the first image. Alternatively or additionally to sending the first approval signal, the device 20 may be configured for capturing the first image automatically when the device 20 arrives at the starting position. Alternatively, the camera 24, 26 may capture images of the building 40 permanently, e.g. by capturing a video of the building 40, while the device 20 is carried from the current position to the starting position, and the device 20 may recognize when it arrives at the starting position and is able to determine that image of the video as the first image which is captured at the starting position.

[0048] In optional step S10, a first routing signal may be sent to the output unit 22. The first routing signal may be configured such that the person 50 carrying the device 20 is guided to the starting position by the output unit 22. The first routing signal may be representative of first routing information which is needed to arrive at the starting position starting from the first current position. The first routing information may be outputted by the output unit one after the other. Alternatively or additionally, further current position data may be determined representing further current positions of the device 20, the further current positions may be compared with the starting position by comparing the further current position data with the starting position data, and the first capturing signal may be sent to the camera 24, 26 when the first one of the further current positions corresponds to the starting position. So, the current position of the device 20 may be compared to the starting position again and again until the device 20 arrives at the starting position. This may be done by carrying out steps S2 to S6 as until the current position corresponds to the starting position.

[0049] In a step S12, first image data of a first image from may be received, e.g. by the controller, from the camera 24, 26. The first image shows at least a first view of the building 40. The first image may be captured when the person 50 is at the first position in figure 2. The first view may correspond to the first field of view 52.

[0050] In a step S 14, the first image data may be analysed with respect to at least one predetermined condition. The predetermined condition may be at least one condition out of a group of conditions. For example, the group of conditions may comprise two conditions. According to a first condition of the two conditions, the first image data contain sufficient information for determining the state of the building 40. According to a second condition of the two conditions, the digital model of the building 40 contains sufficient information to reconstruct the state of the building 40 from the digital model.

[0051] Whether the digital model of the building 40 contains sufficient information may be determined as described in “ActiveNeRF : Learning where to See with Uncertainty Estimation”, by Xuran Pan et al., Tsinghua University, Beijing 100084, China, arXiv:2209.08546vl [cs.CV] 18. Sep. 2022.

[0052] In a step SI 6, when the predetermined condition is fulfilled, the state of the building may be determined from the first image data. In this case, the method may be terminated.

[0053] In a step SI 8, when the predetermined condition is not fulfilled, destination data representing a destination around the building 40 from which a second image of the building can be captured may be determined. The second image shows at least a second view of the building 40. The second image is represented by second image data generated by the corresponding camera 24, 26. The destination data are determined such that the second image data complement the first image data such that overall image data comprising the first image data and the second image data fulfil the predetermined condition. The destination may for example correspond to the second position of the person 50 in figure 2.

[0054] When the predetermined condition is that the digital model of the building 40 contains sufficient information to reconstruct the state of the building 40 from the digital model, the analysing of the first image data may comprise determining whether the digital model needs to be complemented in order to be able to derive the state of the building 40 from the digital model and to check whether information retrievable from the first image data is sufficient in order to complement the digital model such that the state of the building 40 is retrievable from the digital model. In this case, the determining of the destination data may comprise determining which view of the building 40, e.g. a second view, is needed to complement the digital model such that the state of the building 40 may be retrieved form the digital model. When the predetermined condition is that the first image data contain sufficient information for determining the state of the building 40 and when the state of the building 40 refers to thermal insulation properties, analysing the first image data may comprise analysing whether the first image data contain sufficient information for determining the insulation properties of the building 40, in particular from the thermal information retrieved from the first image data. In this case, the determining of the destination data in step S 18 may comprise determining from which view the building 40 must be seen in order to retrieve further information for determining the insulation properties of the building 40. For example, in case of the first image showing a thermal leakage at an opening of the building, e.g. the door 44 or one of the windows 42 of the building 40, at least another view of the same opening, e.g. the second view, may be necessary, in order to be able to determine the insulation property at this opening accurately. Such a variation of the views may be determined in advance, e.g. empirically or by simulation, and may be stored in the memory 32 of the device 20. Alternatively, the destination data may be determined from a current position of the device 20 in a fixed way. For example, when the first image is taken from the starting position at a first angle, e.g. represented by the first bisectrix 54, the destination may be determined such that the second image is taken at a second angle, e.g. represented by the second bisectrix 58, having a fixed relation to the first angle. For example, when both angles lie completely in a horizontal plane, the first angle may defer from the second angle by a fixed angle which may be represented by the above-mentioned angle 60. The angle 60 may range from 1 to 90 degree, e.g. from 10 to 50 degree, e.g. from 20 to 30 degree.

[0055] In a step S20, the destination data may be sent to the output unit 22 of the device 20 comprising the camera 24, 26. The output unit 22 may be configured for outputting the destination based on the destination data.

[0056] In an optional step S22, second current position data representing a second current position of the device 20 may be determined. The second current position is different from the first current position. The second current position data may be determined corresponding to the first current position data.

[0057] In an optional step S24, the second current position may be compared with the destination by comparing the second current position data with the destination data. When the second current position corresponds to the destination, the method proceeds in optional step S26. When the second current position does not correspond to the destination, the method proceeds in optional step S28.

[0058] In optional step S26, a second approval signal may be sent to the output unit 22. Alternatively or additionally a second capturing signal may be sent to the camera 24, 26, wherein the second capturing signal and the camera 24, 26 are configured such that the camera 24, 26 captures the second image upon receiving the second capturing signal. So, the device 20 may be configured for checking the current position of the device 20 and for detecting when the device 20 arrives at the destination from which the second image shall be captured. The device 20 may be configured for sending the second approval signal to the output unit 22 such that the person 50 recognizes that he / she arrived at the destination and can trigger capturing the second image. Alternatively or additionally to sending the second approval signal, the device 20 may be configured for capturing the second image automatically when the device 20 arrives at the destination. Alternatively, the camera 24, 26 may capture images of the building 40 permanently, e.g. by capturing a video of the building 40, while the device 20 is carried from the current position to the destination. Then the device 20 may be configured for recognizing when it arrives at the destination and is able to determine that image of the video as the second image which is captured at the destination.

[0059] In optional step S28, a second routing signal may be sent to the output unit 22. The second routing signal may be configured such that the person 50 carrying the device 20 may be guided to the destination by the output unit 22. The second routing signal may be representative of second routing information which is needed to arrive at the destination starting from the second current position. The second routing information may be outputted by the output unit 22 one after the other. Alternatively or additionally, further current position data may be determined representing further current positions of the device 20, the further current positions may be compared with the destination by comparing the further current position data with the destination data, and the second capturing signal may be sent to the camera 24, when the first one of the further current positions corresponds to the destination, e.g. by carrying out the steps S22 and S24 until the second current position corresponds to the destination. So, the second current position of the device 20 may be compared to the destination again and again until the device 20 arrives at the destination.

[0060] In a step S30, the second image data of the second image may be received from the camera 24, 26. The second image shows the second view of the building 40 which is different from the first view of the building 40. The first and second image data may be used to overall image data. In case of the digital model, the first and / or second image data may be used to complement, to correct, and / or improve the digital model.

[0061] In a step S32, the state of the building 40 may be determined from the overall image data. In addition, the state of the building 40, in particular the data representing the state of the building, may be sent from the device 20 to a remote location, for example to a remote server, for further processing and / or further analyses. When the predetermined condition is that the digital model of the building 40 contains sufficient information to reconstruct the state of the building 40 from the digital model, and the determining of the state of the building 40 from the overall image data comprises complementing the digital model of the building 40 from the first and / or second image data and determining the state of the building 40 from the complemented digital model.

[0062] The method is explained with respect to two positions, e.g. the first and second position, or the start position and the destination, and correspondingly two images, i.e. the first image and the second image only. However, three or more images may be taken from correspondingly three or more positions in order to have sufficient information to determine the state of the building 40. In this case, the second position may be the starting position to determine the third position, which is the destination in this context, the third position may be starting position for the fourth position, which is the destination in this context, and so on. For example, the first and / or second position and in case further positions and the corresponding angles 60 may be determined such that images of all sides or all facades of the building 40 are captured.

[0063] The method may be embodied as a computer program product. The computer program product comprises computer readable instructions which, upon being executed by the processor 54 of the controller 30, instruct the controller 30 of executing and controlling the method, e.g. with the help of the camera 24, 26 and the output unit 22. The computer program product may be stored on a computer readable medium.

[0064] Finally, it should be noted that the term “comprising” does not exclude other elements or steps and the “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims

Claims:

1. Method for determining a state of a building (40), the method comprising: receiving first image data of a first image from a camera (24, 26), the first image showing at least a first view of the building (40); analysing the first image data with respect to at least one predetermined condition; when the predetermined condition is not fulfilled, determining destination data representing a destination around the building (40) from which a second image of the building (40) can be captured, wherein the second image shows at least a second view of the building (40) and wherein the second image is represented by second image data and wherein the destination data are determined such that the second image data complement the first image data such that overall image data comprising the first image data and the second image data fulfil the predetermined condition; sending the destination data to an output unit (22) of a device (20) comprising the camera (24, 26); receiving the second image data of the second image from the camera (24, 26), the second image showing a second view of the building (40) which is different from the first view of the building (40); and determining the state of the building (40) from the overall image data.

2. Method of claim 1, before receiving the first image data comprising: determining first current position data representing a first current position of the device (20); determining starting position data representing a starting position from which the first image shall be captured; comparing the first current position and the starting position by comparing the first current position data with the starting position data; when the first current position corresponds to the starting position, sending a first approval signal to the output unit (22), and / or sending a first capturing signal to the camera (24, 26), wherein the capturing signal and the camera (24, 26) are configured such that the camera (24, 26) captures the first image upon receiving the capturing signal.

3. Method of claim 2, when the first current position does not correspond to the starting position comprising: sending a first routing signal to the output unit (22), wherein the first routing signal is configured such that a person (50) carrying the device (20) is guided to the starting position by the output unit (22).

4. Method of one of the preceding claims, after sending the destination data and before receiving the second image data comprising: determining second current position data representing a second current position of the device (20); and comparing the second current position with the destination by comparing the second current position data with the destination data; and when the second current position corresponds to the destination, sending a second approval signal to the output unit (22), and / or sending a second capturing signal to the camera (24, 26), wherein the second capturing signal and the camera (24, 26) are configured such that the camera (24, 26) captures the second image upon receiving the second capturing signal.

5. Method of claim 4, when the second current position does not correspond to the destination comprising: sending a second routing signal to the output unit (22), wherein the second routing signal is configured such that the person (50) carrying the device (20) is guided to the destination by the output unit (22).

6. Method of one of the preceding claims, wherein the predetermined condition is at least one condition out of a group of conditions, the group comprising: the first image data contain sufficient information for determining the state of the building (40); a digital model of the building (40) contains sufficient information to reconstruct the state of the building (40) from the digital model.

7. Method of claim 6. wherein the predetermined condition is that the digital model of the building (40) contains sufficient information to reconstruct the state of the building (40) from the digital model, and the determining of the state of the building (40) from the overall image data comprises complementing the digital model of the building (40) from the first and / or second image data and determining the state of the building (40) from the complemented digital model.

8. Method of one of the preceding claims, wherein the state of the building (40) refers to thermal insulation properties of the building (40), the camera (24, 26) is or comprises a thermal camera (24, 26), and the image data comprise thermal insulation information of the building (40).

9. Controller for determining a state of a building (40), the controller (30) comprising: a memory (32) for storing image data; and a processor (34) communicatively coupled to the memory (32) and being configured for carrying out the method in accordance with one of the preceding claims based on the image data.

10. Device for determining a state of a building (40), the device (20) comprising: a controller (30) in accordance with claim 9; a camera (24, 26) for capturing images and for generating image data being representative of the images, with the camera (24, 26) being communicatively coupled to the controller (30); and an output unit (22) for outputting information to a person (50) using the device (20), with the output unit (22) being communicatively coupled to the controller (30).

11. Device according to claim 10, wherein the camera (24, 26) is or comprises a thermal camera (24, 26).

12. Computer program product comprising computer readable instructions which, upon being executed by a processor (34) of a controller (30) according to claim 9, instruct the controller (30) of executing and controlling a method according to one of claims 1 to 8.

13. Computer readable medium comprising stored thereon a computer program product according to claim 12.

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