Information processing device and monitoring system

Abstract

[Problem] To accurately acquire the state of a water surface by using an SAR image. [Solution] An information processing device comprises at least one memory and at least one processor. The at least one processor acquires an image and estimates a position on a water surface or a position on the ground surface on the basis of reflected light from a reflector in the image.

Description

Information processing apparatus and monitoring system

[0001] The present disclosure is part of the "Research and Development of Elemental Technologies for User-optimal Data Provision of Remote Sensing Technology" project of the Ministry of Internal Affairs and Communications in 2024 (Reiwa 6), and relates to an information processing apparatus and a monitoring system.

[0002] Observing ground conditions using satellite images and the like is widely performed for disaster response and continuous monitoring of ground surfaces, water surfaces, etc. Generally, sensors that receive light in the visible light region are used to monitor the height of water surfaces and the like, but in recent years, there is also a method of acquiring images using satellites equipped with synthetic aperture radar (SAR) sensors.

[0003] In SAR images, bright points are generated by strong scattered light from reflectors or the like pre-installed on the ground or other locations. Some SAR sensors boast a very high horizontal resolution of about 15 cm, but problems remain in terms of resolution and signal-to-noise ratio when, for example, grasping the sediment accumulation status or the flooding status of rivers and lakes.

[0004] Japanese Patent No. 7633747

[0005] One non-limiting problem to be solved by the embodiments of the present disclosure is to accurately acquire the condition of a water surface or the like using an image.

[0006] According to one embodiment, an information processing apparatus comprises at least one memory and at least one processor. The at least one processor acquires an image, and estimates a position of a water surface or a position of a ground surface in the image based on reflected light from a reflector.

[0007] FIG. 1 is a diagram showing an overview of a monitoring system according to one embodiment. FIG. 2 is a flowchart showing a processing flow of an information processing apparatus in a monitoring system according to one embodiment. FIG. 3 is a diagram showing an example of an arrangement of reflectors according to one embodiment. FIG. 4 is a diagram showing an example of an acquired image according to one embodiment. FIG. 5 is a diagram showing an example of an implementation of an information processing apparatus according to one embodiment.

[0008] The problems to be solved by the embodiments of this disclosure are not limited to those described above, but may also include, as examples of several other problems, the problems corresponding to the effects described in the embodiments. In other words, the problems to be solved in this disclosure may include any one of the effects described in the description of the embodiments of this disclosure.

[0009] Embodiments of the present invention will be described below with reference to the drawings. The drawings and descriptions of the embodiments are provided as examples only and do not limit the present invention.

[0010] Figure 1 is a schematic diagram of a monitoring system 1 according to one embodiment. The monitoring system 1 is a system that uses images acquired by an aircraft 2 to acquire the state of at least one of the ground area 3 or the water area 4 using an information processing device 10.

[0011] The flying object 2 is, for example, a satellite equipped with an imaging device. The flying object 2 may be equipped with, for example, a synthetic aperture radar that acquires SAR images as its imaging device. Alternatively, it may be an airplane, an unmanned aerial vehicle (UAV), a drone, etc., instead of a satellite. The flying object 2 acquires an image (SAR image) from above using synthetic aperture radar, for example, an image including at least one of the Earth's surface or the water's surface.

[0012] The information processing device 10 acquires SAR images captured from the aircraft 2. The information processing device 10 may acquire SAR images from the aircraft 2, for example, through direct communication. Alternatively, the information processing device 10 may indirectly acquire SAR images transmitted by the aircraft 2 to another device, for example. Another example, not shown, is that the information processing device 10 is mounted on the aircraft 2.

[0013] The information processing device 10 performs processing to acquire the conditions of the ground surface and / or water surface based on the acquired SAR images. For example, the information processing device 10 acquires the conditions of the ground surface and / or water surface by acquiring SAR images of reflectors that are pre-installed on the ground surface and / or water surface (including underwater).

[0014] Figure 2 is a flowchart illustrating an example of processing by an information processing device 10 according to one embodiment. First, the information processing device 10 acquires an image, for example, a SAR image, from the aircraft 2 (S100). As described above, the information processing device 10 acquires an image directly or indirectly from the aircraft 2. This image is an image of a region that includes a predetermined area. The predetermined area is a region that includes at least one of the ground surface or the water surface as the target of monitoring.

[0015] Next, the information processing device 10 detects the position of the reflector from the acquired image (S102). In the monitoring system 1, for example, one or more reflectors are pre-placed in a predetermined area near the ground surface or near the water surface.

[0016] Figure 3 shows an example of the arrangement of reflectors according to one embodiment. Reflectors R1, R2, R3, R4, R5, and R6 are arranged at different heights near the water surface in the water region 4. The reflectors may be arranged, for example, on the upper surface of a facility having an appropriate length from the bottom of the water, or so that the reflected light from the reflectors reaches the sky. This facility may be an existing facility such as a pier or breakwater, and the reflectors can be installed at an appropriate height on these facilities so that the reflected light reaches the sky.

[0017] The height of each reflector can be expressed using data such as water level, which represents the relative height to the standard plane, or by expressing the reflector's height in terms of elevation.

[0018] Furthermore, although not shown in the diagram, the system can also be installed on the ground surface in a similar manner. When installed on the ground surface, it is possible to position the reflector at an appropriate height, for example, at a predetermined height above the ground surface.

[0019] Each reflector may be positioned at a distance greater than the horizontal resolution of the image-acquiring sensor, such as the sensor that acquires the SAR image. However, each reflector may be positioned so that the positions of the two reflectors are clearly distinguishable in the image, such as the SAR image, at a distance shorter than the resolution.

[0020] It is desirable that the heights of the reflectors be arranged such that the difference between them is greater than the height resolution of the sensor that acquires the image, such as a SAR image. In the figure, the reflectors are at different heights, but this does not rule out the possibility of reflectors being placed at the same height.

[0021] This height can be set, for example, so that it is installed at a height above the water surface and at a height below the water surface relative to a reference water surface. For example, when installing it in the sea, multiple units may be installed so that they are above the water surface and below the water surface at high tide and low tide, respectively, taking into account the ebb and flow of the tide.

[0022] It is desirable that multiple reflectors be arranged such that, for example, one reflector is positioned at a different height than the others. Furthermore, it is even more desirable that reflectors be arranged at multiple heights to obtain the appropriate height for the water surface or other conditions. In other words, it is desirable that reflectors be installed at multiple different heights, some of which may be installed at the same height. The heights of reflectors placed at different heights may be set such that, for example, the difference between them compared to other reflectors is greater than the vertical resolution of the radar.

[0023] The information processing device 10 acquires images of a reflector, such as the one shown in Figure 3, from above via the aircraft 2.

[0024] The information processing device 10 detects information about reflected light from the reflector from the image acquired in S102, and based on this detection result, acquires the state of at least one of the ground surface or the water surface (S104). The information processing device 10 can detect the height of the ground surface or water surface by detecting the position of the reflector in the acquired image.

[0025] Figure 4 shows an example of an image according to one embodiment. In particular, in the case of a SAR image, due to the characteristics of the radar, reflectors above the water surface (e.g., reflectors R0 to R4) appear clearly as bright spots in the image. On the other hand, reflectors below the water surface (e.g., reflectors R5 and R6) do not appear as bright spots in the image due to the characteristics of the radar.

[0026] Based on this characteristic, the information processing device 10 estimates the water surface height from the position of the bright spot. For example, if an image of the state shown in Figure 4 is acquired, the information processing device 10 can acquire the height corresponding to the reflector R4 as the water surface height of the water region 4. In this way, the monitoring system 1 can estimate the water surface height using the information processing device 10.

[0027] The water level can be used to detect the difference between the normal water level and the actual water level in lakes and ponds. Similarly, in the case of the sea, it can detect the difference between the normal water level and the water level considering the tides. For example, if only reflectors at a higher position than normal are detected, it indicates that the water level has risen, suggesting that some kind of anomaly is occurring. Conversely, if reflectors at a lower position than normal are detected in the sea, it can be estimated that there is a possibility of a disaster such as a tsunami occurring.

[0028] If the height of the reflector is expressed in terms of elevation, the information processing device 10 can also calculate the water level, etc., based on the elevation of the reference plane and the elevation of the reflector detected in the image.

[0029] Conversely, if only the reflectors on the shore side are not detected in the image, it can be inferred that there may be an anomaly such as the inflow of sediment from the ground surface.

[0030] If reflectors are placed on the ground surface, as described above, if reflectors that can normally be detected in an image cannot be detected as bright spots, it is possible to infer some kind of anomaly, such as the reflector being buried in the ground due to a landslide, or the reflector's position changing due to a disaster such as an earthquake.

[0031] Thus, monitoring system 1 makes it possible to determine the water level and sediment accumulation in reservoirs, rivers, and the sea. In particular, when using SAR images, the water area appears dark due to the characteristics of the radar. Therefore, it is possible to determine whether an area is below the water surface or on land. By placing reflectors at appropriate positions on the ground surface or close to the water surface, clear bright spots will appear in the SAR image unless they are obstructed by trees, etc., making it possible to detect the possibility of some kind of anomaly occurring due to a disaster or other event.

[0032] Furthermore, using SAR images makes it possible to perform accurate estimations even at night. Since the information processing device 10 only performs image analysis, estimation can be performed with almost no power consumption. In addition, since it can be implemented simply by installing a reflector, equipment costs can be kept low, while accurate judgments can be made based on the characteristics of the SAR image.

[0033] The contents of this disclosure can also be summarized as follows:

[0034] (1) An information processing device comprising at least one memory and at least one processor, wherein the at least one processor acquires an image and estimates the position of the water surface or the ground surface based on the reflected light from a reflector in the image.

[0035] (2) The information processing device described in (1), wherein the image is a SAR image acquired by a synthetic aperture radar sensor.

[0036] (3) The information processing apparatus according to (1), wherein the at least one processor detects a water surface height based on reflected light from the reflector.

[0037] (4) The information processing apparatus according to (1), wherein the at least one processor detects whether sediment is inflowing based on reflected light from the reflector.

[0038] (5) The information processing apparatus according to any one of (1) to (4), wherein the reflector is disposed to have a predetermined height.

[0039] (6) The information processing apparatus according to any one of (1) to (5), wherein a plurality of the reflectors are disposed.

[0040] (7) The information processing apparatus according to any one of (1) to (6), wherein at least one of the reflectors is disposed at a height different from that of other reflectors.

[0041] (8) A monitoring system comprising: a reflector; and an information processing apparatus that acquires an image; wherein the information processing apparatus detects the reflector in the acquired image, and grasps topography based on a detection result.

[0042] (9) The monitoring system according to (8), wherein a plurality of the reflectors are disposed, and at least one of the plurality of reflectors is disposed at a height different from that of other reflectors.

[0043] (10) The monitoring system according to (8) or (9), wherein the image is a SAR image acquired by a synthetic aperture radar sensor.

[0044] (11) The monitoring system according to any one of (8) to (10), wherein the information processing apparatus detects a water level based on detection results of the plurality of reflectors in the image.

[0045] (12) The monitoring system according to any one of (8) to (10), wherein the information processing device detects whether or not soil is flowing in based on the detection results of the plurality of reflectors in the image.

[0046] In the embodiments described above, some or all of the devices (information processing devices) may be composed of hardware, or they may be composed of information processing by software (programs) executed by a CPU (Central Processing Unit) or GPU (Graphics Processing Unit), etc. If the information processing is composed of software, the software that realizes at least some of the functions of each device in the embodiments described above may be stored on a non-temporary storage medium (non-temporary computer-readable medium) such as a CD-ROM (Compact Disc-Read Only Memory) or USB (Universal Serial Bus) memory, and the software information processing may be executed by loading it into a computer. Alternatively, the software may be downloaded via a communication network. Furthermore, all or part of the software processing may be implemented in a circuit such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), so that the information processing by the software is executed by hardware.

[0047] The storage medium for the software may be a removable medium such as an optical disc, or a fixed storage medium such as a hard disk or memory. Furthermore, the storage medium may be located inside the computer (main memory or auxiliary storage, etc.) or outside the computer.

[0048] FIG. 5 is a block diagram showing an example of the hardware configuration of each device (information processing device) in the foregoing embodiment. As an example, each device may be implemented as a computer 7 comprising a processor 71, a main storage device 72 (memory), an auxiliary storage device 73 (memory), a network interface 74, and a device interface 75, which are connected via a bus 76.

[0049] Although the computer 7 in FIG. 5 includes one of each component, it may include a plurality of the same components. Further, although one computer 7 is shown in FIG. 5, software may be installed on a plurality of computers, and each of the plurality of computers may execute the same or different partial processing of the software. In this case, the configuration may be in the form of distributed computing in which each computer communicates via the network interface 74 or the like to execute processing. In other words, each device (information processing device) in the foregoing embodiment may be configured as a system that implements functions by one or more computers executing instructions stored in one or more storage devices. Further, the configuration may be such that information transmitted from a terminal is processed by one or more computers provided on a cloud, and the processing result is transmitted back to the terminal.

[0050] Various calculations of each device (information processing device) in the foregoing embodiment may be executed in parallel processing using one or more processors, or using a plurality of computers via a network. Further, various calculations may be distributed to a plurality of calculation cores in a processor and executed in parallel processing. Also, part or all of the processing, means, etc. of the present disclosure may be implemented by at least one of a processor and a storage device provided on a cloud that can communicate with the computer 7 via a network. As described above, each device in the foregoing embodiment may be in the form of parallel computing implemented by one or more computers.

[0051] The processor 71 may be an electronic circuit (processing circuit, processing circuitry, CPU, GPU, FPGA, ASIC, etc.) that performs at least one of the following: control of a computer or calculations. The processor 71 may also be a general-purpose processor, a dedicated processing circuit designed to perform specific calculations, or a semiconductor device including both a general-purpose processor and a dedicated processing circuit. Furthermore, the processor 71 may include optical circuits or quantum computing-based calculation functions.

[0052] The processor 71 may perform calculations based on data and software input from various devices within the computer 7, and may output calculation results and control signals to these devices. The processor 71 may also control the various components of the computer 7 by executing the computer 7's OS (Operating System) or applications.

[0053] Each of the devices (information processing devices) in the embodiments described above may be implemented by one or more processors 71. Here, processor 71 may refer to one or more electronic circuits arranged on one chip, or one or more electronic circuits arranged on two or more chips or two or more devices. When multiple electronic circuits are used, each electronic circuit may communicate by wire or wireless.

[0054] The main memory 72 may store instructions executed by the processor 71 and various data, and the information stored in the main memory 72 may be read by the processor 71. The auxiliary storage device 73 is a storage device other than the main memory 72. These storage devices refer to any electronic component capable of storing electronic information, and may be semiconductor memory. The semiconductor memory may be either volatile memory or non-volatile memory. In each of the devices (information processing devices) in the embodiments described above, the storage device for storing various data may be implemented by the main memory 72 or the auxiliary storage device 73, or by the built-in memory of the processor 71. For example, the storage unit in the embodiments described above may be implemented by the main memory 72 or the auxiliary storage device 73.

[0055] In the embodiments described above, if each device (information processing device) consists of at least one storage device (memory) and at least one processor connected to (coupled with) this at least one storage device, then at least one processor may be connected to one storage device. Also, at least one storage device may be connected to one processor. Furthermore, the configuration may include at least one processor among a plurality of processors being connected to at least one storage device among a plurality of storage devices. This configuration may also be realized by storage devices and processors included in a plurality of computers. Moreover, the configuration may include a storage device integrated with a processor (for example, a cache memory including an L1 cache and an L2 cache).

[0056] The network interface 74 is an interface for connecting to the communication network 8 wirelessly or via a wired connection. The network interface 74 can be any appropriate interface, such as one conforming to existing communication standards. Information may be exchanged between the computer 7 and an external device 9A connected via the communication network 8 through the network interface 74. The communication network 8 may be a WAN (Wide Area Network), LAN (Local Area Network), PAN (Personal Area Network), or a combination thereof, as long as information is exchanged between the computer 7 and the external device 9A. An example of a WAN is the Internet; an example of a LAN is IEEE 802.11 or Ethernet (registered trademark); and an example of a PAN is Bluetooth (registered trademark) or NFC (Near Field Communication).

[0057] Device interface 75 is an interface such as USB that connects directly to the external device 9B.

[0058] External device 9A is a device connected to computer 7 via a network. External device 9B is a device directly connected to computer 7.

[0059] External device 9A or external device 9B may, for example, be an input device. The input device may be, for example, a camera, microphone, motion capture device, various sensors, keyboard, mouse, or touch panel, and will provide the acquired information to computer 7. Alternatively, it may be a device equipped with an input unit, memory, and processor, such as a personal computer, tablet terminal, or smartphone.

[0060] Furthermore, external device 9A or external device 9B may, for example, be an output device. The output device may be a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) panel, or a speaker that outputs sound, etc. It may also be a device equipped with an output unit, memory, and a processor, such as a personal computer, tablet terminal, or smartphone.

[0061] Furthermore, external device 9A or external device 9B may be a storage device (memory). For example, external device 9A may be network storage, and external device 9B may be storage such as an HDD.

[0062] Furthermore, the external device 9A or external device 9B may be a device having some of the functions of the components of each device (information processing device) in the embodiments described above. In other words, the computer 7 may transmit some or all of the processing results to the external device 9A or external device 9B, or may receive some or all of the processing results from the external device 9A or external device 9B.

[0063] Where the expression "at least one of a, b, and c" or "at least one of a, b, or c" (including similar expressions) is used herein (including the claims), it includes any of a, b, c, a-b, a-c, b-c, or a-b-c. It also includes multiple instances of any element, such as a-a, a-b-b, a-a-b-b-c-c, etc. Furthermore, it includes adding other elements other than the enumerated elements (a, b, and c), such as a-b-c-d which has d.

[0064] In this specification (including the claims), when expressions such as "using data as input / based on data / according to / in accordance with data" (including similar expressions) are used, unless otherwise specified, this includes using the data itself or using data that has been processed in some way (e.g., data with added noise, normalized data, features extracted from the data, an intermediate representation of the data, etc.). Furthermore, when it is stated that some result is obtained "using data as input / based on data / according to / in accordance with data" (including similar expressions), unless otherwise specified, this includes cases where the result is obtained based solely on the data in question or where the result is influenced by other data, factors, conditions, and / or states other than the data in question. Furthermore, when it is stated that "data is output" (including similar expressions), unless otherwise specified, this includes cases where the data itself is used as output or where data that has been processed in some way (e.g., data with added noise, normalized data, features extracted from the data, an intermediate representation of the data, etc.) is used as output.

[0065] Where the terms “connected” and “coupled” are used herein (including in the claims), they are intended to be non-restrictive terms that include any direct connection / coupling, indirect connection / coupling, electrical connection / coupling, communicative connection / coupling, operational connection / coupling, or physical connection / coupling. The terms should be interpreted as appropriate in the context in which they are used, but any form of connection / coupling that is not intentionally or naturally excluded should be interpreted non-restrictively as being included in the terms.

[0066] In this specification (including the claims), when the expression "A configured to B" is used, it may include that the physical structure of element A has a configuration capable of performing operation B, and that the permanent or temporary setting / configuration of element A is configured to actually perform operation B. For example, if element A is a general-purpose processor, it is sufficient that the processor has a hardware configuration capable of performing operation B, and that it is configured to actually perform operation B by the setting of a permanent or temporary program (instruction). Furthermore, if element A is a dedicated processor or dedicated arithmetic circuit, it is sufficient that the circuit structure of the processor is implemented to actually perform operation B, regardless of whether control instructions and data are actually attached.

[0067] Wherever terms meaning "comprising" or "having" are used in this specification (including the claims), they are intended to be open-ended terms, including cases where the subject matter of such terms is not the object of the term. Where the object of such terms meaning "comprising" or "having" is an expression that does not specify a quantity or suggests a singular number (an expression with the article a or an), such expression should be interpreted as not being limited to a specific number.

[0068] In this specification (including the claims), even if expressions such as "one or more" or "at least one" are used in one place, and expressions that do not specify a quantity or suggest singularity (expressions using the articles a or an) are used in another place, the latter expressions are not intended to mean "one." In general, expressions that do not specify a quantity or suggest singularity (expressions using the articles a or an) should be interpreted as not necessarily limited to a specific number.

[0069] In this specification, if a particular configuration of an embodiment is described as yielding a specific advantage or result, it should be understood, unless otherwise stated, that the same advantage or result can also be obtained from one or more other embodiments having that configuration. However, it should be understood that the presence or absence of such advantage or result generally depends on various factors, conditions, and / or states, and that the configuration does not necessarily guarantee that the advantage or result can be obtained. The advantage or result can only be obtained from the configuration described in the embodiment when various factors, conditions, and / or states are met, and the advantage or result cannot necessarily be obtained in the invention claimed to define that configuration or a similar configuration.

[0070] In this specification (including the claims), when terms such as "maximize" are used, they include finding the global maximum value, finding an approximation of the global maximum value, finding the local maximum value, and finding an approximation of the local maximum value, and should be interpreted appropriately depending on the context in which the terms are used. They also include finding approximations of these maximum values ​​probabilistically or heuristically. Similarly, when terms such as "minimize" are used, they include finding the global minimum value, finding an approximation of the global minimum value, finding the local minimum value, and finding an approximation of the local minimum value, and should be interpreted appropriately depending on the context in which the terms are used. They also include finding approximations of these minimum values ​​probabilistically or heuristically. Similarly, when terms such as "optimize" are used, they include finding the global optimal value, finding an approximation of the global optimal value, finding the local optimal value, and finding an approximation of the local optimal value, and should be interpreted appropriately depending on the context in which the terms are used. This also includes finding approximate values ​​of these optimal values ​​probabilistically or heuristically.

[0071] In this specification (including the claims), when multiple hardware components perform a predetermined process, each component may cooperate to perform the predetermined process, or some components may perform all of the predetermined process. Alternatively, some components may perform part of the predetermined process, while other components perform the remainder. In this specification (including the claims), when expressions such as "one or more hardware components perform a first process, and the one or more hardware components perform a second process" (including similar expressions) are used, the hardware component performing the first process and the hardware component performing the second process may be the same or different. In other words, it is sufficient that the hardware component performing the first process and the hardware component performing the second process are included in the one or more hardware components. Hardware may include electronic circuits or devices containing electronic circuits.

[0072] In this specification (including the claims), when multiple storage devices (memories) store data, each of the multiple storage devices may store only a portion of the data or the entire data. Furthermore, a configuration in which some of the multiple storage devices store data is also included.

[0073] While embodiments of this disclosure have been described in detail above, this disclosure is not limited to the individual embodiments described above. Various additions, modifications, substitutions, and partial deletions are possible, provided that they do not deviate from the conceptual idea and spirit of this disclosure derived from the claims and their equivalents. For example, where numerical values ​​or mathematical formulas are used in the description of the embodiments described above, these are provided for illustrative purposes only and do not limit the scope of this disclosure. Similarly, the sequence of operations shown in the embodiments is also illustrative and does not limit the scope of this disclosure.

[0074] 1: Surveillance system, 10: Information processing device, R1, R2, R3, R4, R5, R6: Reflector, 2: Aircraft, 3: Ground area, 4: Water area

Claims

1. An information processing device comprising at least one memory and at least one processor, wherein the at least one processor acquires an image and estimates the position of the water surface or the ground surface based on the reflected light from a reflector in the image.

2. The information processing apparatus according to claim 1, wherein the image is a SAR image acquired by a synthetic aperture radar sensor.

3. The information processing apparatus according to claim 1, wherein the at least one processor detects the height of the water surface based on the reflected light from the reflector.

4. The information processing apparatus according to claim 1, wherein the at least one processor detects whether or not soil is flowing in based on the reflected light from the reflector.

5. The information processing apparatus according to any one of claims 1 to 4, wherein the reflector is arranged to have a predetermined height.

6. The information processing apparatus according to any one of claims 1 to 5, wherein a plurality of reflectors are arranged.

7. The information processing apparatus according to any one of claims 1 to 6, wherein at least one of the reflectors is arranged to be at a different height from the other reflectors.

8. A monitoring system comprising a reflector and an information processing device for acquiring images, wherein the information processing device detects the reflector in the acquired image and grasps the terrain based on the detection result.

9. The monitoring system according to claim 8, wherein a plurality of reflectors are arranged, and at least one of the plurality of reflectors is arranged at a different height from the other reflectors.

10. The monitoring system according to claim 8 or 9, wherein the image is a SAR image acquired by a synthetic aperture radar sensor.

11. The monitoring system according to any one of claims 8 to 10, wherein the information processing device detects the water level based on the detection results of the plurality of reflectors in the image.

12. The monitoring system according to any one of claims 8 to 10, wherein the information processing device detects whether or not soil is flowing in based on the detection results of the plurality of reflectors in the image.

Images