Imaging system and imaging method

Abstract

The present invention provides an imaging system and an imaging method. An imaging system according to a first aspect of the present invention includes: an imaging device that images an object and is provided with a polarizing filter; a first mechanism that changes the rotation angle of the polarizing filter; a second mechanism that changes the relative imaging direction of the imaging device with respect to the object; and a processor that controls the first mechanism and the second mechanism. The processor acquires first information pertaining to the setting of two or more different rotation angles in imaging of the object from the same imaging direction, acquires second information pertaining to the setting of two or more different object imaging directions, and determines the control mode for the first mechanism and the second mechanism on the basis of the first information and the second information.

Description

Photography system and photography method

[0001] The present invention relates to a photography system and a photography method.

[0002] US Patent Application Publication No. 2013 / 0129999 discloses a method for generating a 3D view of an object, which includes capturing image data from multiple viewpoints around the object, analyzing the image data for quality, creating an image dataset based on the image data, filtering the image dataset, generating data reference parameters, and uploading the image dataset to a server via a network.

[0003] Special table 2020-527814 publication

[0004] One embodiment of the technique of the present disclosure provides an imaging system and imaging method capable of acquiring images for generating a 3D model.

[0005] A first aspect of the photography system includes a photography device equipped with a polarizing filter for photographing an object, a first mechanism for changing the rotation angle of the polarizing filter, a second mechanism for changing the relative photography direction of the photography device with respect to the object, and a processor for controlling the first and second mechanisms, wherein the processor acquires first information regarding the settings of two or more different rotation angles for photography of the object from the same photography direction, acquires second information regarding the settings of two or more different photography directions for the object, and determines a control method for the first and second mechanisms based on the first and second information.

[0006] In the second aspect of the photography system, in the first aspect, the first information is information relating to the number of times an object is photographed from the same photography direction with different rotation angles of the polarizing filter, or information relating to the rotation angle that is changed for each photograph.

[0007] In the third aspect of the photography system, in the first or second aspect, the second information is information regarding the number of times the object is photographed at the same rotation angle but with different photography directions, or information regarding the angle of the photography direction that is changed for each photograph.

[0008] The fourth aspect of the photography system is any one of the first to third aspects, in which the first information includes a first change time required when changing the rotation angle, and the second information includes a second change time required when changing the photography direction.

[0009] In the imaging system of the fifth aspect, in the fourth aspect, the first change time is variable.

[0010] In the imaging system of the sixth aspect, in the fourth aspect, the second change time is variable.

[0011] The seventh aspect of the photography system is any one of the fourth to sixth aspects, in which at least one of the first change time and the second change time is determined based on at least one of the characteristics of the object and / or the specifications of the second mechanism.

[0012] The eighth aspect of the photography system is any one of the first to seventh aspects, and includes a first and second control methods. The first method is a method in which multiple images are acquired from the same shooting direction but with different polarizing filter rotation angles, and then the shooting direction is changed and multiple images are acquired from the changed shooting direction but with different polarizing filter rotation angles, and this process is repeated. The second method is a method in which multiple images are acquired from different shooting directions but with the same polarizing filter rotation angle, and then the polarizing filter rotation angle is changed and images are acquired from different shooting directions at the changed rotation angle, and this process is repeated.

[0013] A ninth aspect of the photography system is the eighth aspect, in which the processor determines a time Tα as a first method and a time Tβ as a second method, and determines a control method by comparing the time Tα and the time Tβ, where the time Tα is the total time required to change the first information and at least one of the first mechanism or the second mechanism when acquiring each image in each photography when all desired images are photographed, and the time Tβ is the total time required to change the second information and at least one of the first mechanism or the second mechanism when acquiring each image in each photography when all desired images are photographed.

[0014] In a tenth aspect of the imaging system, in the ninth aspect, the processor calculates times Tα and Tβ using the following equations (1) and (2) where X is the angle of change per imaging direction change of the second mechanism, Y is the rotation angle of the first mechanism, Tt is the drive time of the second mechanism, and Tp is the drive time of the first mechanism, and determines either the first method or the second method as the control method. Tα=((360 / X)×Tt)+((360 / X)×(180 / Y)×Tp) (1) Tβ=((360 / X)×(180 / Y)×Tt)+((180 / Y)×Tp) (2)

[0015] In the imaging system of an eleventh aspect, in the tenth aspect, the processor determines the second method when the following formula (3) is satisfied, where Th is a predetermined threshold value: Tβ<Tα+Th (3)

[0016] The imaging system of a twelfth aspect is the eighth aspect, wherein in the second method, the processor corrects positional deviation between a plurality of images captured by the imaging device with the same imaging direction but different rotation angles.

[0017] In the thirteenth aspect of the photography system, in the eighth aspect, in the case of the second method, the processor continuously drives the second mechanism, and when capturing multiple images with the same shooting direction but different rotation angles, the processor uses the first captured image as the reference image and causes the photography device to capture images based on the reference image and the live view image to be captured.

[0018] In the 14th aspect of the photography system, in the 8th aspect, in the case of the second method, the processor places an index on the second mechanism, and when capturing multiple images with the same shooting direction but different rotation angles, causes the photography device to take the images based on the index.

[0019] In the imaging system of the fifteenth aspect, in the eighth aspect, the processor continuously drives the first mechanism in the first method.

[0020] In the imaging system of the sixteenth aspect, in the fifteenth aspect, the processor determines the drive time of the first mechanism based on the imaging conditions of the imaging device in the case of the first method.

[0021] The seventeenth aspect of the photography system is a photography system having a photography device that photographs an object, a polarizing filter that is positioned between the object and the photography device and has a variable rotation angle, a table on which the object is placed and whose photography direction relative to the photography device is variable, and a processor, in which the processor determines a first change condition related to the rotation angle of the polarizing filter and a second change condition related to the photography direction of the table based on the photography time for photographing the object.

[0022] An eighteenth aspect of the imaging system is the seventeenth aspect, wherein the processor determines the first change condition and the second change condition based on the imaging time and the analytical accuracy of the plurality of images to be captured.

[0023] The imaging system of a nineteenth aspect is any one of the first to eighteenth aspects, wherein the processor generates a 3D model based on an image captured by the imaging device.

[0024] The twentieth aspect of the photographing method is a photographing method executed by a photographing system that photographs an object and that includes a photographing device having a polarizing filter and a processor, in which the processor acquires first information regarding the settings of the rotation angles of two or more polarizing filters for photographing the object from the same photographing direction, acquires second information regarding the settings of two or more different photographing directions for the object, and determines a control method for photographing the object based on the first information and the second information.

[0025] FIG. 1 is a diagram illustrating the polarization characteristics of light. FIG. 2 is a diagram illustrating an overview of an imaging system. FIG. 3 is a diagram illustrating an image processing device different from that shown in FIG. 2. FIG. 4 is a block diagram illustrating the schematic configuration of a camera. FIG. 5 is a block diagram illustrating the schematic configuration of a computer. FIG. 6 is a block diagram illustrating processing functions implemented by a processor. FIG. 7 is a diagram illustrating a polarized image of an object captured by a camera. FIG. 8 is a diagram illustrating a polarized image of an object captured by a camera. FIG. 9 is a diagram illustrating a first method. FIG. 10 is a diagram illustrating the first method. FIG. 11 is a diagram illustrating the first method. FIG. 12 is a diagram illustrating the second method. FIG. 13 is a diagram illustrating the second method. FIG. 14 is a diagram illustrating the second method. FIG. 15 is a flowchart illustrating a method of generating a 3D model. FIG. 16 is a flowchart illustrating a method of capturing an image of an object. FIG. 17 is a diagram illustrating the second method after the rotation angle of the polarizing filter has been changed. FIG. 18 is a block diagram illustrating functions related to obtaining an appropriate image. FIG. 19 is a block diagram illustrating functions related to generating a 3D model.

[0026] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

[0027] [Summary] In recent years, the use of 3D content has been expanding in fields such as games, metaverse-type communication spaces, architecture, and video production. Among these, there has been an increase in the use of 3D scanning technology, which uses cameras and specialized equipment to scan real objects in three dimensions and turn them into 3D data. A typical 3D scanning method is photogrammetry, which generates 3D data from data captured from multiple viewpoints using one or more cameras.

[0028] Photogrammetric photography can be automated, for example, by placing the object on a turntable whose rotation can be controlled, rotating and stopping the turntable in increments of a few degrees, and repeatedly taking photos with one or more cameras.

[0029] In photogrammetry, when an object is photographed with a camera, information about specular reflection and / or gloss is acquired and added to the 3D data as material information, thereby generating higher quality 3D data. To acquire the reflection and / or gloss information, for example, a method utilizing the polarization characteristics of light can be applied.

[0030] Ordinary light, such as sunlight or fluorescent light, is composed of light waves that vibrate randomly in all directions and are in an unpolarized state. By using a polarizer such as a polarizing filter, it is possible to extract only the light that vibrates in a certain direction from the unpolarized light.

[0031] As shown in FIG. 1, the light reflected from the object 30 largely includes a regular reflection component L1 (specular reflection) and a diffuse reflection component L2.

[0032] When linearly polarized light L3 is irradiated onto an object 30 from a polarized light source 3 having a light source 3A and a polarizing plate 3B, the specular reflection component L1 remains linearly polarized, and the diffuse reflection component L2 becomes light (unpolarized) that vibrates in various directions.

[0033] Taking advantage of this characteristic, a polarizing filter 50 is also placed between the camera 10 and the object 30, and images are taken while changing the slit direction of the polarizing filter 50. When the slit direction of the polarizing plate on the camera 10 side is aligned with the vibration direction of the specular reflection component L1 (=linearly polarized light), both the specular reflection component L1 and the diffuse reflection component L2 pass through the polarizing filter 50. This allows the camera 10 to capture image A containing both components. On the other hand, when the slit direction of the polarizing filter 50 is aligned perpendicular to the vibration direction of the specular reflection light, the specular reflection component is not transmitted and only the diffuse reflection component is transmitted, resulting in image B containing only the diffuse reflection component. By calculating the difference between image A and image B, an image consisting only of the specular reflection component L1 can be obtained. In photogrammetry, the above-mentioned image is taken from multiple viewpoints, three-dimensional specular reflection information of the object is obtained, and material characteristics can be imparted to the 3D model.

[0034] However, the vibration direction of the specularly reflected light reaching the camera 10 varies depending on the location on the object 30. Therefore, to separate the specular reflection component and the diffuse reflection component of the entire object 30, it is necessary to rotate the polarizing filter 50 on the camera 10 by several degrees and take multiple images while changing the slit direction. Furthermore, to generate a 3D model, it is necessary to change the relative position between the camera 10 and the object 30 and take images of the object 30 from multiple directions. In other words, it takes a certain amount of time to rotate and stop the polarizing filter 50 and to change the camera 10 relative to the object 30. Therefore, the present invention proposes a control method for appropriately capturing images when changing the rotation angle of the polarizing filter and changing the camera's shooting direction relative to the object.

[0035] 2 is a diagram showing an imaging system 1 according to an embodiment. The imaging system 1 includes a plurality of cameras 10, a computer 20, and an imaging stand 42. An object 30 to be imaged is placed on the imaging stand 42.

[0036] The multiple cameras 10 are fixed to a support member 44 and are in a stationary state. The multiple cameras 10 are arranged so that their lenses face the object 30. The support member 44 is composed of an installation base 44A and an arm portion 44B. The arm portion 44B is a curved member attached to the installation base 44A and extends in the vertical direction. The arm portion 44B is arranged so that its recess faces the object 30. The multiple cameras 10 are attached to the arm portion 44B at a predetermined height position. As a result, the multiple cameras 10 are arranged in a line along the arm portion 44B in the so-called vertical direction. However, the arrangement of the multiple cameras 10 is not limited to the case shown in FIG. 1 . Furthermore, only one camera 10 may be used.

[0037] The camera 10 includes a polarizing filter 50. The polarizing filter 50 is configured to be rotatable. The rotation speed and rotation angle of the polarizing filter 50 can be changed as desired. By rotating the polarizing filter 50, the vibration direction of light from the object 30 that reaches the sensor of the camera 10 can be selected. This makes it possible to reduce the influence of reflection from the object 30. The camera 10 is an example of an imaging device of the present invention. The polarizing filter 50 is an example of a polarizing filter of the present invention.

[0038] The type and structure of the lens, sensor, etc. used by the camera 10 are not limited as long as the camera can capture an image of the object 30. The structure and size of the polarizing filter 50 are not limited as long as the polarizing filter can control the polarization of light oscillating in a specific direction and remove light components from a specific direction (e.g., reflected light components).

[0039] The object 30 is placed on an imaging table 42. The imaging table 42 is configured to be able to rotate arbitrarily in the direction indicated by the arrow. The imaging table 42 is equipped with a motor (not shown), which can arbitrarily change the rotation speed, rotation angle, etc. of the imaging table 42. The imaging table 42 is a turntable. Note that the rotation speed and rotation angle can be detected and changed during processing. The imaging table 42 can change the relative imaging direction between the camera 10 and the object 30. The imaging table 42 is an example of a second mechanism of the present invention, and an example of a table.

[0040] A plurality of marks 42B are arranged on the mounting surface 42A of the imaging table 42. The marks 42B serve as indicators for the imaging direction. The marks 42B are arranged at equal intervals (45-degree intervals) on the outer periphery of the mounting surface 42A. The marks 42B may display angles (0 degrees, 45 degrees, 90 degrees, ... 315 degrees) indicating the imaging direction. The mounting surface 42A of the imaging table 42 has a flat, disk-like shape on the top surface. The shape of the imaging table 42 is not limited as long as it can accommodate the object 30. The size, shape, and function of the imaging table 42 are determined taking into consideration the size of the object 30, etc.

[0041] When the entire object 30 is to be photographed, the object 30 is rotated (for example, 360 degrees or more) by the imaging table 42. When a portion of the object 30 is to be photographed, the imaging table 42 rotates the object 30 within a specific range (a range less than 360 degrees).

[0042] The camera 10 can capture images of the object 30 from a plurality of shooting directions while the object 30 is rotated by the shooting stand 42. The camera 10 can capture images of the object 30 by changing the rotation angle of the polarizing filter 50 for each shooting direction. The camera 10 is configured to store images of the object 30 captured through the polarizing filter 50.

[0043] The shooting direction is the relative positional relationship between the camera 10 and the object 30 when the object 30 is photographed by the camera 10. The shooting direction is indicated by an angle from a reference position of the object 30. The rotation angle of the polarizing filter 50 is indicated by an angle from the reference position of the polarizing filter 50. Photographing the object 30, changing the shooting direction of the shooting stand 42, and changing the rotation angle of the polarizing filter 50 can be performed automatically or manually.

[0044] The computer 20 has a display and a keyboard. The display is an example of a display device that displays various information. The keyboard is an example of an input device that allows a user to input instructions. The computer 20 is configured to process various data including images, input and output various data, and store various data. The computer 20 includes a processor, and the processor is configured to execute programs for performing the functions of the computer 20.

[0045] The computer 20 can acquire a plurality of images captured by the camera 10. The images of the object 30 captured by the camera 10 include images in which the rotation angle of the polarizing filter 50 differs for each capturing direction.

[0046] The computer 20 generates or extracts appropriate images suitable for the 3D model for each shooting direction from multiple images (polarized captured images) captured with the polarizing filter 50 at different rotation angles. Basically, a number of appropriate images equal to the number of shooting directions are generated or extracted for each camera 10. Even if the object 30 has a highly reflective surface, the appropriate images are captured through the polarizing filter 50 and are therefore less susceptible to reflections. A three-dimensional (3D) model generated based on the appropriate images can improve image quality.

[0047] Furthermore, specular reflectance and diffuse reflectance at each position on the object 30 may be calculated based on a plurality of polarized images. The specular reflectance and diffuse reflectance can be calculated using a bidirectional reflectance distribution function (BRDF), which is a well-known technique.

[0048] When generating a 3D model, by calculating the specular reflectance and diffuse reflectance, it is possible to express the gloss, diffusion, reflected color, etc. that differ depending on the material of the object 30.

[0049] The object 30 is not particularly limited in shape or size as long as it is an object for which a 3D model is to be generated. The object 30 may be any object having a physical shape.

[0050] FIG. 3 is a diagram showing an overview of an imaging system 2 that generates a 3D model different from that of the imaging system 1. In FIG. 3, parts common to the imaging system 1 described above are assigned the same reference numerals, and their description will be omitted. Like the imaging system 1, the imaging system 2 of FIG. 3 includes multiple cameras 10 fixed to a support member 44, a computer 20, and an imaging stand 46. An object 30 is placed on a mounting surface 46A of the imaging stand 46. Multiple marks 46B are arranged on the mounting surface 46A. The support member 44 is also composed of an installation stand 44A and an arm unit 44B. The cameras 10 and computer 20 of the imaging system 2 are basically the same as the cameras 10 and computer 20 of the imaging system 1.

[0051] Unlike the photography system 1, the photography table 46 of the photography system 2 does not have a motor or the like, and the mounting surface 46A of the photography table 46 does not rotate. While the object 30 is being photographed by the camera 10, the object 30 remains stationary.

[0052] The imaging system 2 also has a transport mechanism 48. The transport mechanism 48 has a guide rail 48A that surrounds the imaging table 46, and a movable stage 48B that can move arbitrarily along the guide rail 48A in the direction indicated by the arrow. A support member 44 is placed on the movable stage 48B. The support member 44 can be moved around the object 30 by the transport mechanism 48.

[0053] As a result, similar to the imaging system 1, the camera 10 can capture images of the object 30 from multiple imaging directions while moving around the object 30. The images of the object 30 captured by the camera 10 include images (polarized captured images) with the polarizing filter 50 rotated at different angles for each imaging direction. The transport mechanism 48 can change the relative imaging direction between the camera 10 and the object 30, and the transport mechanism 48 is an example of the second mechanism of the present invention.

[0054] The computer 20 can generate or extract appropriate images from the multiple polarized images and generate a 3D model.

[0055] [Camera] Fig. 4 is a block diagram showing a schematic configuration of the camera 10. As shown in Fig. 4, the camera 10 includes a lens device 100. The lens device 100 includes an imaging optical system 102 including a lens group 104 and an aperture 106, a lens driver 110, an aperture driver 112, a polarizing filter 50, a filter driver 160, a rotation angle detector 162, and the like.

[0056] The lens device 100 may be detachable from the camera 10 or may be integrated with the camera 10 .

[0057] The lens group 104 includes at least a focus lens that is movable in the optical axis direction. This focus lens is a lens for focus adjustment. The focus of the imaging optical system 102 is adjusted by moving the focus lens back and forth along the optical axis. The focus lens is driven and operated by the lens driver 110. The focus lens can be moved to a focus position where it focuses on the target object 30.

[0058] The diaphragm 106 is configured by, for example, an iris diaphragm. The amount of light passing through the imaging optical system 102 is adjusted by the diaphragm 106. The diaphragm 106 is driven by a diaphragm driver 112 to operate.

[0059] The polarizing filter 50 is an optical filter that controls the polarization of light oscillating in a specific direction and removes light components (reflected light components) from a specific direction. The polarizing filter 50 can change its polarization direction by rotating it. The polarizing filter 50 is driven and operated by the filter driver 160. The filter driver 160 is controlled by commands from the system control unit 146. Under the control of the system control unit 146, the filter driver 160 rotates or stops the polarizing filter 50 at a desired rotation speed so that the polarizing filter 50 reaches a desired rotation angle. A user can change the polarization direction by rotating the polarizing filter 50 without using the filter driver 160. The polarizing filter 50 can be detachably attached to the lens device 100. The camera 10 can capture an image of the object 30 without using the polarizing filter 50. The filter driver 160 may include a motor that rotates the polarizing filter 50. The filter driver 160 is an example of a first mechanism of the present invention.

[0060] The rotation angle detection unit 162 detects the rotation angle of the polarizing filter 50 when capturing an image, relative to a reference angle of the polarizing filter 50. The rotation angle detection unit 162 can include, for example, an encoder.

[0061] As shown in FIG. 4, the camera 10 includes an image sensor 130, a shutter 132, a shutter driver 134, a memory 136, a digital signal processor 138, an input / output interface 140, a display 142, an operation unit 144, and a system controller 146.

[0062] The image sensor 130 is, for example, a complementary metal-oxide semiconductor (CMOS) image sensor having a predetermined color filter array (e.g., a Bayer array). In the camera 10 of this embodiment, the image sensor 130 includes a drive unit, an analog-to-digital converter (ADC), a signal processor, and the like. In this case, the image sensor 130 is driven by the built-in drive unit. The signals from each pixel are converted into digital signals by the built-in ADC. Furthermore, the signals from each pixel are subjected to processes such as correlated double sampling, gain processing, and correction processing by the built-in signal processor, as needed. The signal processing can be performed on the analog signals of each pixel, or on the digital signals of each pixel.

[0063] The imaging element 130 may be configured as an organic thin-film imaging element, an XY address type, a CCD (Charged Coupled Device) type, or other image sensor, in addition to a CMOS type image sensor.

[0064] The shutter 132 is disposed between the aperture 106 and the image sensor 130. The shutter 132 is driven to operate by a shutter driver 134. The shutter driver 134 controls the opening and closing of the shutter 132, and controls the exposure time (shutter speed) at the image sensor 130.

[0065] The memory 136 includes a flash memory, a read-only memory (ROM), a random access memory (RAM), an auxiliary storage device, etc. The flash memory and ROM store a camera control program, a focus bracket shooting program for executing shooting in focus bracket shooting mode, an image processing program, various data necessary for camera control, etc. The RAM temporarily stores shooting data and functions as a work area for processing by the system control unit 146. It also temporarily stores the camera control program, image processing program, etc. stored in the flash memory, etc. Note that part of the memory 136 (RAM) may be built into the system control unit 146.

[0066] The digital signal processing unit 138 performs signal processing such as offset processing, gamma correction processing, demosaic processing, and RGB / YCrCb conversion processing on the image obtained by shooting, thereby generating image data.

[0067] The input / output interface 140 includes a connection unit connectable to an external display device, a connection unit connectable to an external recording device, a card connection unit for inserting and removing a memory card, a communication unit connectable to a network, etc. For example, the input / output interface 140 may be a Universal Serial Bus (USB), a High-Definition Multimedia Interface (HDMI) (HDMI is a registered trademark), or the like.

[0068] The display unit 142 is used as a playback monitor when playing back captured images, a live view monitor that displays live view images during capture, and a setting monitor when performing various settings. The display unit 142 is configured with a display such as an LCD (Liquid Crystal Display) or an OLED (Organic Light Emitting Diode), for example.

[0069] The operation unit 144 is configured to include various operation members for operating the camera 10. The operation members include a power button, a shutter button, and various other operation buttons. The various operation buttons include a button for turning the function of the image stabilization mechanism 150 on and off. Furthermore, if the display unit 142 is configured as a display unit with a touch panel, the operation members that make up the operation unit 144 include the touch panel. The operation unit 144 outputs signals corresponding to the operation of each operation member to the system control unit 146. For example, the user can set the conditions for shooting using the polarizing filter 50 (polarized image shooting) from the operation unit 144.

[0070] The system control unit 146 performs overall control of the camera 10. The system control unit 146 also calculates various physical quantities required for control. The system control unit 146 is configured with a microcomputer equipped with a processor, memory, etc. The processor is configured with a CPU (Central Processing Unit), etc. The system control unit 146 can execute a program for capturing polarized images. The system control unit 146 also controls the shake correction mechanism 150.

[0071] The camera 10 may include a shake correction mechanism 150. The shake correction mechanism 150 is a BIS (Body Image Stabilizer) control type shake correction mechanism that corrects shake by shifting (including rotating) the image sensor 130 in a plane perpendicular to the optical axis in the direction opposite to the shake direction. The shake correction mechanism 150 includes a shake control unit 152, an image sensor drive unit 154, a shake detection unit 156, and a position detection unit 158.

[0072] The image sensor driver 154 may include an actuator that moves the image sensor 130. The shake detector 156 may include an acceleration sensor and / or a gyro sensor. The position detector 158 may include a Hall element that generates a voltage signal corresponding to the position of the image sensor 130. The shake controller 152 controls the image sensor driver 154 based on the signals from the shake detector 156 and the position detector 158 to shift the image sensor 130 in a plane perpendicular to the optical axis so as to offset shake of the camera 10. The shake correction mechanism may be provided in the lens apparatus 100.

[0073] [Computer] FIG. 5 is a block diagram showing an example of the hardware configuration of the computer 20. As shown in FIG. 5, the computer 20 includes a processor 200, a RAM 202, a ROM 204, a storage device 206, an input / output interface (IF) 207, an input device 208, and a display device 209. The ROM 204 and / or the storage device 206 store programs executed by the processor 200 and various data. The storage device 206 includes a hard disk drive (HDD), a solid state drive (SSD), or the like. The input device 208 includes a keyboard, a mouse, or the like. The display device 209 includes an LCD, an OLED, or the like. Images captured by the camera 10 are imported into the computer 20 via the input / output interface 207 and stored in the storage device 206, for example. The processor 200 is connected to the camera 10 and the imaging stand 42 via the input / output interface 207, either wired or wirelessly.

[0074] FIG. 6 is a block diagram illustrating the processing functions implemented by processor 200.

[0075] The processor 200 includes an information acquisition unit 210 , a camera control unit 211 , a polarizing filter control unit 212 , an imaging stand control unit 213 , a control method determination unit 214 , an image processing unit 215 , and a three-dimensional model generation unit 216 .

[0076] The information acquisition section 210 acquires rotation angle information relating to the settings of the rotation angles of two or more different polarizing filters 50 when capturing images from the same capturing direction. The rotation angle information is an example of first information of the present invention.

[0077] The rotation angle information is, for example, information regarding the number of times the object 30 is photographed from the same photographing direction with the polarizing filter 50 rotated at different angles, or information regarding the rotation angle that is changed for each photographing. The rotation angle information may also include the angle change time required when the rotation angle is changed. The angle change time is an example of the first change time of the present invention. The angle change time can be changed as desired.

[0078] The information acquisition unit 210 acquires imaging direction information relating to two or more different imaging direction settings for the object 30. The imaging direction information is an example of second information of the present invention.

[0079] The shooting direction information is, for example, information regarding the number of times the object 30 is photographed at the same rotation angle but with different shooting directions, or information regarding the angle of the shooting direction that is changed for each photograph. The shooting direction information may also include the direction change time required when changing the shooting direction. The direction change time is an example of the second change time of the present invention. The direction change time can be changed as desired.

[0080] The rotation angle information and the shooting direction information are stored in, for example, the storage device 206. The user can store the rotation angle information and the shooting direction information in the storage device 206 via the input device 208. The user can input the rotation angle information and the shooting direction information to the information acquisition unit 210 via the input device 208. There are no limitations on the location where the rotation angle information and the shooting direction information are stored.

[0081] In this specification, the term "same" in terms of the rotation angle and the imaging direction includes not only "same" but also "approximately the same."

[0082] The camera control unit 211 causes the camera 10 to capture an image of the object 30 for each shooting direction and each rotation angle of the polarizing filter 50 (each combination of shooting direction and rotation angle). The camera control unit 211 controls the shutter 132 and shutter drive unit 134, the aperture 106 and aperture drive unit 112, and the lens group 104 and lens drive unit 110 via the system control unit 146 of the camera 10, and captures an image of the object 30.

[0083] Based on the rotation angle information, the polarizing filter control unit 212 controls the rotation angle, rotation speed, and rotation stop of the polarizing filter 50. The polarizing filter control unit 212 can drive the polarizing filter 50 via the system control unit 146 and filter drive unit 160 of the camera 10. This allows the rotation angle of the polarizing filter 50 to be changed.

[0084] Based on the imaging direction information, the imaging table control unit 213 controls the rotation angle, rotation speed, and rotation stop of the imaging table 42. This allows the relative imaging direction between the camera 10 and the object 30 to be changed.

[0085] Based on the rotation angle information and the imaging direction information, the control method determination unit 214 determines the control method for the filter driver 160 that drives the polarizing filter 50 and the imaging table 42 that rotates the object 30. The determination of the control method will be described later.

[0086] The image processing unit 215 generates or extracts an appropriate image from a plurality of polarized images captured in the same shooting direction. The processing of the image processing unit 215 will be described later.

[0087] The three-dimensional model generating unit generates a 3D model from a plurality of suitability images generated or extracted by the image processing unit 215. The processing of the three-dimensional model generating unit will be described later.

[0088] <Principle of the Imaging System> Next, the principle of the imaging system will be described. First, a polarized image of the object 30 captured by the camera 10 will be described with reference to Figs.

[0089] As shown in 7-1 of FIG. 7, the relative position between the camera 10 and the object 30 is determined so as to obtain a predetermined shooting direction. The shooting direction is expressed as an angle between the camera 10 and the object 30. The reference position from which shooting begins is defined as a shooting direction θ=0 degrees. As the shooting direction θ, for example, 15 degrees, 30 degrees, 45 degrees, ... 330 degrees, and 345 degrees are defined at 15-degree intervals from the reference position. The shooting direction θ (15 degrees) is the angle difference with respect to the shooting direction θ (0 degrees). The same applies to the shooting direction θ (30 degrees) ... shooting direction θ (345 degrees).

[0090] The rotation angle φ of the polarizing filter 50 when photographing the object 30 in the photographing direction θ (0 degrees) is predetermined. In 7-2 of FIG. 7, for example, 0 degrees, 30 degrees, 90 degrees, 135 degrees, and 175 degrees are defined as the rotation angle φ. The rotation angle φ = 0 degrees is the rotation angle when photographing begins and serves as the reference position. The rotation angle φ (30 degrees) is the angle difference with respect to the rotation angle φ (0 degrees). The same applies to the rotation angle φ (90 degrees)...the rotation angle φ (175 degrees).

[0091] 7, the camera 10 captures an image of the object 30 at each rotation angle φ. Each polarization-captured image is associated with the capture direction θ and the rotation angle φ, and is stored in the memory 136, for example, as Img(0,0), Img(0,30), Img(0,90), ..., Img(0,175).

[0092] Next, as shown in 8-1 of FIG. 8, the relative position between the camera 10 and the object 30 is changed, and the photographing direction is changed to θ (15 degrees).

[0093] 8, the camera 10 captures an image of the object 30 at each rotation angle φ. Each polarization-captured image is associated with the capture direction θ and the rotation angle φ, and is stored in the memory 136, for example, as Img(15,0), Img(15,30), Img(15,90), ..., Img(15,175).

[0094] As shown in Figures 7 and 8, each polarization-captured image can be represented by Img(θm, φn). As mentioned above, θ is the capture direction, and φ is the rotation angle. m is a parameter for identifying the capture direction, and n is a parameter for identifying the rotation angle. In the above example, the capture direction θ1 is 0 degrees, and the capture direction θ2 is 15 degrees. The rotation angle φ1 is 0 degrees, the rotation angle φ2 is 30 degrees, and the rotation angle φ5 is 175 degrees. The camera 10 captures images of the object 30 for each capture direction θ and rotation angle φ until the capture direction θ24 = 345 degrees is reached.

[0095] In this example, the camera 10 captures images of the object 30 at Img(0,0) . . . Img(345,175) as polarization captured images.

[0096] In order for the camera 10 to capture images Img(0,0)...Img(345,175), it is necessary to control the change in the shooting direction of the shooting stand 42 and the change in the rotation angle of the polarizing filter 50. Two control methods are possible.

[0097] First, the first control method will be described with reference to Figures 9 to 11. First, as shown in Figure 9, the relative positions of the object 30 and the imaging stand 42 are determined so that the imaging direction θ between the camera 10 and the object 30 is 0 degrees. The rotation angle φ of the polarizing filter 50 of the camera 10 is changed to 0 degrees. The imaging direction θ is maintained at 0 degrees, and the position of the object 30 is fixed. The filter driver 160 changes the rotation angle φ of the polarizing filter 50 from 0 degrees to 175 degrees, and the camera 10 images the object 30 at each rotation angle φ with the imaging direction θ at 0 degrees, thereby obtaining multiple polarized images.

[0098] Next, as shown in Figure 10, the relative positions of the camera 10 and the object 30 are changed so that the imaging direction θ is 5 degrees. Specifically, the imaging table 42 is controlled to rotate the object 30 by 5 degrees. The imaging direction θ is maintained at 5 degrees, and the position of the object 30 is fixed. The filter driving unit 160 changes the rotation angle φ of the polarizing filter 50 from 0 degrees to 175 degrees, and the camera 10 captures images of the object 30 at each rotation angle φ with the imaging direction θ being 5 degrees, thereby obtaining multiple polarized images.

[0099] Furthermore, the imaging platform 42 is controlled to rotate the object 30 by 5 degrees at a time. The imaging direction θ is maintained, and the position of the object 30 is fixed. The rotation angle φ of the polarizing filter 50 is changed from 0 to 175 degrees, and the object 30 is imaged by the camera 10 for each rotation angle φ, thereby obtaining multiple polarized images. The changes in the imaging direction θ and the rotation angle φ are repeated.

[0100] 11 , the imaging table 42 is controlled to maintain the imaging direction θ at 355 degrees, fixing the position of the object 30. The filter driver 160 changes the rotation angle φ of the polarizing filter 50 from 0 degrees to 175 degrees, and the camera 10 images the object 30 at each rotation angle φ with the imaging direction θ at 355 degrees, obtaining multiple polarized images, and then imaging of the object 30 is completed.

[0101] As already mentioned, the first method is a method in which multiple images are acquired from the same shooting direction θ with different rotation angles φ of the polarizing filter 50, and then the shooting direction θ is changed and multiple images are acquired from the changed shooting direction θ with different rotation angles φ of the polarizing filter 50.

[0102] First, the second control method will be described with reference to Figures 12 to 14. First, as shown in Figure 12, the relative positions of the camera 10 and the object 30 are determined so that the shooting direction θ between the camera 10 and the object 30 is 0 degrees. The filter driver 160 changes the rotation angle φ of the polarizing filter 50 of the camera 10 to 0 degrees. The rotation angle φ is maintained at 0 degrees, and the polarizing filter 50 is fixed. The shooting direction θ of the object 30 is changed from 0 degrees to 355 degrees by the shooting stand 42, and the camera 10 captures images of the object 30 for each shooting direction θ at a rotation angle φ of 0 degrees, thereby obtaining multiple polarized images.

[0103] 13 , the filter driver 160 changes the rotation angle φ of the polarizing filter 50 of the camera 10 to 30 degrees. The rotation angle φ is maintained at 30 degrees, and the polarizing filter 50 is fixed. The imaging direction θ of the object 30 is changed from 0 degrees to 355 degrees by the imaging stand 42, and the camera 10 images the object 30 for each imaging direction θ at a rotation angle φ of 30 degrees, thereby obtaining multiple polarized images. The changes in the rotation angle φ and the imaging direction θ are repeated.

[0104] 14 , the filter driver 160 is controlled to maintain the rotation angle φ at 175 degrees and fix the polarizing filter 50. The imaging direction θ of the object 30 is changed from 0 degrees to 355 degrees using the imaging table 42, and the camera 10 images the object 30 for each imaging direction θ at a rotation angle φ of 30 degrees, obtaining multiple polarized images, and then imaging of the object 30 is completed.

[0105] As already mentioned, the second method involves repeatedly acquiring images with different shooting directions θ at the same rotation angle φ of the polarizing filter 50, then changing the rotation angle φ of the polarizing filter 50 and acquiring images with different shooting directions θ at the changed rotation angle φ.

[0106] In both the first and second methods, the number of polarization images captured by the camera 10 is the same. However, there is a possibility that the total imaging time will differ between the first and second methods.

[0107] The total imaging time for the first and second methods can be calculated, for example, as follows.

[0108] The total shooting time can be calculated by adding together the shooting time of the camera 10, the driving time of the shooting stand 42, and the driving time of the polarizing filter 50. Here, the total shooting time in the first method is T1 (sec), and the total shooting time in the second method is T2 (sec). The shooting time per shot by the camera 10 is Tc (sec), the time required to rotate and stop the shooting stand 42 is Tt (sec), and the time required to rotate and stop the polarizing filter 50 is Tp (sec). Furthermore, if the angle of the shooting direction θ that is changed for each shot is X (degrees), and the angle of the rotation angle φ that is changed for each shot is Y (degrees), the total shooting time can be calculated using the following formula. T1 = camera shooting time + shooting stand driving time + polarizing filter rotation time = ((360 / X) x 180 / Y) x Tc) ​​+ ((360 / X) x Tt)) + ((360 / X) x (180 / Y) x Tp) T2 = camera shooting time + shooting stand driving time + polarizing filter rotation time = ((360 / X) x 180 / Y) x Tc) ​​+ ((360 / X) x (180 / Y) x Tt) + ((180 / Y) x Tp)

[0109] The calculation results of T1 and T2 differ depending on the conditions of X, Y, Tt, and Tp. For example, in Example 1, when X = 5 degrees, Y = 22.5 degrees, Tc = 0.1 sec, Tt = 1 sec, and Tp = 1 sec, T1 and T2 are as follows: T1 = 706 sec, T2 = 642 sec. Since T1 > T2, the total imaging time is shorter with the second method than with the first method. On the other hand, in Example 2, when X = 5 degrees, Y = 22.5 degrees, Tc = 0.1 sec, Tt = 2 sec, and Tp = 1 sec, T1 and T2 are as follows: T1 = 778 sec, T2 = 1218 sec. Since T1 < T2, the total imaging time is shorter with the first method than with the second method.

[0110] Based on these considerations, the control method determination unit 214 according to the present disclosure determines a control method based on conditions related to the driving of the polarizing filter 50 and conditions related to the imaging stand 42. The conditions related to the driving of the polarizing filter 50 include the angle Y (degrees) of the rotation angle φ of the polarizing filter 50, which is changed for each image capture, and the time Tp (sec) required for rotating and stopping the polarizing filter 50. The conditions related to the driving of the imaging stand 42 include the time Tt (sec) required for rotating and stopping the imaging stand 42, and the angle X (degrees) of the imaging direction θ, which is changed for each image capture. The conditions related to the driving of the polarizing filter 50 are an example of the first condition of the present invention. The conditions related to the driving of the imaging stand 42 are an example of the second condition of the present invention. The angle Y (degrees) of the rotation angle φ of the polarizing filter 50, which is changed for each image capture, may be the number of times that image capture is performed with the rotation angle φ of the polarizing filter 50 changed. Furthermore, the angle X (degrees) of the imaging direction θ, which is changed for each image capture, may be the number of times that image capture is performed with the imaging direction θ changed.

[0111] The time Tp (sec) required for the polarizing filter 50 to rotate and stop can be changed by adjusting the rotation speed and angle Y. In other words, the time Tp is variable. The time Tt (sec) required for the imaging table 42 to rotate and stop can be changed by adjusting the rotation speed and angle X. In other words, the time Tt is variable. The time Tp is an example of a first change time according to the present invention. The time Tt is an example of a second change time according to the present invention.

[0112] The control method determination unit 214 of the present disclosure can determine the first method or the second method based on the total imaging time. For example, in Example 1, the control method determination unit 214 determines the second method as the control method. In Example 2, the control method determination unit 214 determines the first method as the control method. Since the control method determination unit 214 can select the optimal control method based on the relationship between the rotation conditions of the imaging table 42 and the polarizing filter 50 and the time required for driving and stopping, the total imaging time can be minimized.

[0113] In the above explanation, the total shooting time T1 of the first method was compared with the total shooting time T2 of the second method. The formula for calculating the camera shooting time included in the total shooting times T1 and T2 is the same. Therefore, the length of the total shooting time of the first and second methods can be determined using the following formulas (1) and (2), excluding the common camera shooting time. Here, time Tα is the calculation formula for determining the total shooting time of the first method, and time Tβ is the calculation formula for determining the total shooting time of the second method. Tα = ((360 / X) x Tt) + ((360 / X) x (180 / Y) x Tp) (1) Tβ = ((360 / X) x (180 / Y) x Tt) + ((180 / Y) x Tp) (2)

[0114] [Generation of 3D Model] Next, a method for generating a 3D model from a polarized image of the object 30 using the camera 10, the polarizing filter 50, the computer 20, and the imaging stand 42 will be described. Fig. 15 is a flowchart showing the method for generating a 3D model.

[0115] As shown in FIG. 15, a plurality of polarized images of the object 30 are taken using the camera 10, the polarizing filter 50, and the photographing stand 42 (step S1).

[0116] 16 is a flowchart showing a method for photographing an object 30. First, at least one camera 10 and an imaging stand 42 on which the object 30 can be placed and whose rotation can be controlled are prepared. A polarizing filter 50 is placed between the camera 10 and the object 30. The polarizing filter 50 is configured so that it can be rotated around the optical axis of the camera.

[0117] First, the user determines the drive conditions for the polarizing filter 50 of the imaging stand 42 (step S11). Specifically, the user sets the angle X (degrees) of the imaging stand 42 and the angle Y (degrees) of the polarizing filter 50, which will be different for each imaging session. The user also determines the reference positions of the polarizing filter 50 and the imaging stand 42. The first and second information are acquired by the information acquisition unit 210. The entire circumference of the object 30 can be captured by capturing images of the imaging stand 42 from directions (360 (degrees) / X (degrees)) in increments of angle X (degrees) based on the initial position. For example, if angle X = 5 (degrees), there are 72 directions. Conversely, if the number of directions in which the object 30 is captured based on the initial position is P directions, the entire circumference of the object 30 can be captured by capturing images in increments of angle (360 (degrees) / P (directions)).

[0118] By photographing the polarizing filter 50 from the direction of (1800 (degrees) / Y (degrees)) in increments of angle Y (degrees) with respect to the initial position, the polarizing filter 50 can be rotated halfway to photograph the object 30. For example, if angle X = 22.5 (degrees), there are eight directions. If the number of times the polarizing filter 50 is rotated is Q, the polarizing filter 50 can be rotated halfway to photograph the object 30 in increments of angle (180 (degrees) / Q (times)).

[0119] In the above example, each camera 10 captures 72 (capturing directions) x 8 (rotation directions) = 576 polarization images (Img(θ1, φ1) ... Img(θ72, φ8)). Here, if a polarization image is Img(θm, φn), m and n can take values ​​of 1≦m≦72 and 1≦n≦8, respectively (m and n are integers).

[0120] If the number of cameras 10 is N, the cameras 10 capture N x 72 x 8 polarization images of the object 30. The N cameras 10 capture images of the object 30 substantially simultaneously.

[0121] Furthermore, the information acquisition unit 210 acquires information on the time Tp (sec) required for rotational driving and stopping of the polarizing filter 50, and the conditions related to the driving of the imaging table 42, such as the time Tt (sec) required for rotational driving and stopping of the imaging table 42. As described above, the time Tp (sec) and the time Tt (sec) can be changed within the range of the characteristics of the motor, etc.

[0122] Next, the positions of the imaging stand 42 and the polarizing filter 50 are initialized (step S12). Specifically, the imaging stand control unit 213 drives and rotates the imaging stand 42, thereby positioning the object 30 so that the imaging direction θ1 = 0 degrees. Furthermore, the polarizing filter control unit 212 drives the filter drive unit 160 to rotate the polarizing filter 50, thereby positioning the polarizing filter 50 so that the rotation angle φ1 = 0 degrees.

[0123] Next, a control method for photographing the object 30 with the camera 10 is determined (step S13). Specifically, the control method determination unit 214 acquires first information related to the driving of the polarizing filter 50 and second information related to the photographing stand 42, and determines the control method (first method or second method) based on the first information and the second information. When the total photographing time is used as a reference, the control method determination unit 214 calculates time Tα (sec) from equation (1) and calculates time Tβ (sec) from equation (2). Next, the time Tα and the time Tβ are compared, and the control method with the smaller numerical value is selected.

[0124] Next, a case where the first method is selected as the control method will be described. Once the first method is selected, the process proceeds to photographing the object 30 by the camera 10 (step S14). Specifically, the camera control unit 211 controls the camera 10 via the system control unit 146 to photograph a polarized image (Img(θ1, φ1)) of the object 30 at the reference position (photographing direction θ1, rotation angle φ1). The polarized image (Img(θ1, φ1)) is stored in, for example, the storage device 206.

[0125] Next, it is determined whether or not imaging has been completed for all rotation angles φ of the polarizing filter 50 (step S15). Specifically, the polarizing filter control unit 212 determines whether the parameter n of the rotation angle φn of the polarizing filter 50 exceeds 8 (rotation direction). In this case, the rotation angle φ1 = 0 degrees, and the parameter n = 1, which is less than 8. Therefore, the polarizing filter control unit 212 determines that imaging has not been completed for all rotation angles φ, i.e., determines "No."

[0126] If the answer is "No" in step S15, the polarizing filter 50 is rotated to change the rotation angle φ (step S17). Specifically, the polarizing filter control unit 212 rotates the polarizing filter 50 by an angle Y (degrees). The parameter n is incremented by 1.

[0127] The process proceeds to photographing the object 30 using the camera 10 (step S14). Here, the camera 10 photographs and stores a polarization image (Img(θ1, φ2)) of the object 30. The process proceeds to step S15, where steps S14, S15, and S17 are repeated until the parameter n becomes 8 or greater.

[0128] If the answer is "Yes" in step S15 (if imaging has been completed for all rotation angles φ), the process proceeds to step S16.

[0129] Next, it is determined whether imaging has been completed in all imaging directions θ for the imaging table 42 (step S16). Specifically, the imaging table control unit 213 determines whether the parameter m of the imaging direction θm of the imaging table 42 exceeds 72 (imaging direction). In this case, the imaging direction θ1 = 0 degrees, and the parameter m = 1, which is smaller than 72. Therefore, the imaging table control unit 213 determines that imaging has not been completed in all imaging directions θ, i.e., determines "No."

[0130] If the answer is "No" in step S16, the imaging table 42 is rotated to change the imaging direction θ (step S18). Specifically, the imaging table control unit 213 rotates the imaging table 42 by an angle X (degrees). The parameter m is incremented by 1, and the parameter n is reset to 1. In addition, the polarizing filter 50 is positioned at its initial position (rotation angle φ1 = 0 degrees).

[0131] The process proceeds to photographing the object 30 using the camera 10 (step S14). Here, the camera 10 photographs and stores a polarized image (Img(θ2, φ1)) of the object 30. The process proceeds to step S15, where steps S14, S15, and S17 are repeated until the parameter n becomes 8 or greater.

[0132] Finally, steps S14, S15, S16, S17 and S18 are repeated until the parameter m becomes 72 or greater.

[0133] If the answer to step S16 is "Yes" (if imaging has been completed in all imaging directions θ), the polarization image capturing is terminated.

[0134] Next, a case where the second method is selected as the control method will be described. Once the second method is selected, the process proceeds to photographing the object 30 by the camera 10 (step S19). Specifically, the camera control unit 211 causes the camera 10 to capture a polarized image (Img(θ1, φ1)) of the object 30 at the reference position (photographing direction θ1, rotation angle φ1) via the system control unit 146. The polarized image (Img(θ1, φ1)) is stored in, for example, the storage device 206.

[0135] Next, it is determined whether imaging has been completed in all imaging directions θ for the imaging table 42 (step S20). Specifically, the imaging table control unit 213 determines whether the parameter m of the imaging direction θm of the imaging table 42 exceeds 72 (imaging direction). In this case, the imaging direction θ1 = 0 degrees, and the parameter m = 1, which is smaller than 72. Therefore, the imaging table control unit 213 determines that imaging has not been completed in all imaging directions θ, i.e., determines "No."

[0136] If the answer is "No" in step S20, the imaging table 42 is rotated to change the imaging direction θ (step S22). Specifically, the imaging table control unit 213 rotates the imaging table 42 by an angle X (degrees). The parameter m is incremented by 1.

[0137] The process proceeds to photographing the object 30 using the camera 10 (step S19). Here, the camera 10 photographs and stores a polarization image (Img(θ2, φ1)) of the object 30. The process proceeds to step S20, where steps S19, S20, and S22 are repeated until the parameter m becomes 72 or greater.

[0138] If the answer is "Yes" in step S20 (if imaging has been completed in all imaging directions θ), the process proceeds to step S21.

[0139] Next, it is determined whether or not imaging has been completed for all rotation angles φ of the polarizing filter 50 (step S21). Specifically, the polarizing filter control unit 212 determines whether the parameter n of the rotation angle φn of the polarizing filter 50 exceeds 8 (rotation direction). In this case, the rotation angle φ1 = 0 degrees, and the parameter n = 1, which is less than 8. Therefore, the polarizing filter control unit 212 determines that imaging has not been completed for all rotation angles φ, i.e., determines "No."

[0140] If step S21 is "No," the polarizing filter 50 is rotated to change the rotation angle φ (step S23). Specifically, the polarizing filter control unit 212 rotates the polarizing filter 50 by an angle Y (degrees). The parameter m is reset to 1, and the parameter n is incremented by 1. In addition, the imaging platform 42 is positioned at the initial position (imaging direction θ1 = 0 degrees).

[0141] The process proceeds to photographing the object 30 using the camera 10 (step S19). Here, the camera 10 photographs and stores a polarization image (Img(θ1, φ2)) of the object 30. The process proceeds to step S20, where steps S19, S20, and S22 are repeated until the parameter m becomes 72 or greater.

[0142] Finally, steps S19, S20, S21, S22 and S23 are repeated until the parameter n becomes 8 or more.

[0143] If the answer to step S21 is "Yes" (if image capture has been completed for all rotation angles φ), the polarized light image capture is terminated.

[0144] In the present disclosure, by determining the control method, it is possible to shorten the total imaging time when capturing a large number of polarization-imaged images.

[0145] Note that the first and second methods may be used to capture not only still images but also video images of successive images in time. In the case of video capture, frame images extracted at a desired time in the desired shooting direction θ and rotation angle φ may be used as the captured polarized image.

[0146] All polarization-captured images are stored in the storage device 206 of the computer 20, with the imaging direction θm and rotation angle φn associated with each other, as shown in Table 1 below. Table 1 includes polarization images captured at imaging directions θ1 to θm and rotation angles φ1 to φn. The conditions (number of images, polarization direction, etc.) of the included polarization-captured images do not all need to be consistent for imaging directions θ1 to θm. Furthermore, when recording polarization-captured images, positional information of the camera 10, for example (X, Y, Z, Pitch, Yaw, Roll) = (1, 1, 1.2, 3, 3, 5), may be stored as additional information associated with the polarization images. Furthermore, the output value of the shake detection unit 156 may also be stored in association with the polarization images.

[0147]

[0148] [Other Preferred Modes] Preferred modes for determining conditions, the first method, and the second method will be described below.

[0149] <Condition Determination> In determining the conditions in step S11, the information acquisition unit 210 has been described as setting the angle X (degrees) of the imaging stand 42, which is changed for each imaging session, to 5 degrees (imaging direction θ=(0 degrees, 5 degrees, 10 degrees, ... 355 degrees)). Also, the information acquisition unit 210 has been described as setting the angle Y (degrees) of the polarizing filter 50 to 22.5 degrees (rotation angle φ=(0 degrees, 22.5 degrees, 45 degrees, ... 157.5 degrees)).

[0150] However, the present invention is not limited to this. For example, the imaging direction θ may be set at intervals of varying imaging angles, such as 0 degrees, 1 degree, 5 degrees, 13 degrees, 14 degrees, 15 degrees, 16 degrees, 17 degrees, 18 degrees, 19 degrees, 20 degrees, 25 degrees, 35 degrees, 45 degrees, etc. The object 30 may have a surface portion with fine irregularities and a surface portion with little change, and the imaging direction θ may be determined according to the surface properties of the object 30. For example, when imaging a surface portion with fine irregularities, the intervals of the imaging direction θ are made small. For surface portions with little change, the intervals of the imaging direction θ are made large.

[0151] Furthermore, the rotation angle φ of the polarizing filter 50 may be different for each shooting direction θ. For example, when the shooting direction θ is 0 degrees, the rotation angle φ of the polarizing filter 50 is set to four rotation directions: 0 degrees, 45 degrees, 90 degrees, and 135 degrees. When the shooting direction θ is 1 degree, the rotation angle φ of the polarizing filter 50 is set to six rotation directions: 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, and 150 degrees. Furthermore, when the shooting direction θ is 13 degrees, the rotation angle φ of the polarizing filter 50 may be set to two rotation directions: 0 degrees and 90 degrees.

[0152] That is, the user can arbitrarily set the shooting direction θ for obtaining a desired polarized photographed image and the rotation angle φ (2 or more) of the polarizing filter 50 for each shooting direction θ.

[0153] The shooting direction θ and rotation angle φ may be set manually by the user or automatically based on the results of analyzing a pre-3D model generated by pre-shooting. The pre-shooting is images of the object 30 captured by the camera 10 from multiple shooting directions before acquiring the polarized light-captured image. The pre-3D model is a 3D model generated from multiple images. Information useful for the final 3D model may be obtained from this pre-3D model.

[0154] The first information about the polarizing filter 50 and the second information about the imaging stand 42 may be conditions that are fixed due to mechanical constraints. Mechanical constraints refer to cases where the polarizing filter 50 can only be rotated in increments of α degrees, or where the imaging stand 42 can only be rotated in increments of β degrees. Even in cases where there are mechanical constraints, the information acquisition unit 210 may acquire this information when determining the conditions in step S11.

[0155] The polarizing filter 50 has been described as being attached to the tip of the lens device 100, as shown in FIG. 4 . The polarizing filter 50 may also be a separate polarizing plate that is slightly separated from the lens device 100. The polarizing plate is attached to, for example, a rotation mechanism, and is rotated and stopped by the polarizing filter control unit 212. This rotation mechanism is an example of the first mechanism of the present invention. The polarizing plate only needs to be able to select the vibration direction of light from the object 30 that reaches the sensor of the camera 10, thereby suppressing the effects of reflection from the object 30.

[0156] Furthermore, the angle change time, which is an example of the first change time, and the direction change time, which is an example of the second change time, are determined based on the characteristics of the object 30 or the specifications of the imaging stand 42 .

[0157] Here, the characteristics of the object 30 are determined based on its weight, size, and shape (balance). It is particularly important that the object 30 does not move or tip over during imaging. The likelihood of the object 30 tipping over is related to, for example, the height of the center of gravity of the object 30, the installation area relative to the imaging stand 42, and the acceleration applied to the object 30. The height of the center of gravity of the object 30 and the installation area relative to the imaging stand 42 remain constant during imaging. Therefore, it is preferable to determine the time for changing the direction of the imaging stand 42, which is related to acceleration, within a range in which the object 30 does not tip over.

[0158] It is also preferable to determine the angle change time and the direction change time based on the specifications of the filter drive unit 160 and the imaging table 42, such as the friction coefficient or output torque of these mechanisms, because the angle change time and the direction change time depend on the characteristics of the filter drive unit 160 and the imaging table 42.

[0159] A first change condition related to the rotation angle of the polarizing filter 50 and a second change condition related to the shooting direction of the shooting stand 42 may be determined based on the shooting time for shooting the object 30. As described above, the shooting time can be calculated from the first information related to the rotation angle of the polarizing filter 50 and the second information related to the shooting direction of the shooting stand 42. Alternatively, an initial target shooting time may be set, and a condition related to the rotation angle of the polarizing filter 50 (time Tp or angle Y) that is optimal for that shooting time may be determined, or a condition related to the rotation angle of the shooting stand 42 (time Tt or angle X) may be determined. However, when determining the conditions, the specifications of the filter driver 160 and the shooting stand 42, or the analytical accuracy of the polarized image to be captured may be taken into consideration.

[0160] <First Method> In the first method, the object 30 may be photographed by the camera 10 while continuously rotating the polarizing filter 50. This makes it possible to shorten the time Tp (sec) required for the polarizing filter 50 to rotate and stop.

[0161] It is preferable that the speed at which the polarizing filter 50 is rotated is determined in accordance with the exposure time (shutter speed, time until photographing is completed) of the camera 10 .

[0162] For example, when the rotation speed of the polarizing filter 50 is increased, it is preferable to shorten the exposure time of the camera 10 .

[0163] In the first method, whether to take pictures by rotating the polarizing filter 50 intermittently or continuously is determined based on the shooting time, the exposure time of the camera 10, the quality of the polarized image, etc.

[0164] <Second Method> A preferred embodiment of the second method will be described. First, the characteristics of the second method will be described. FIG. 17 is a diagram showing the second method after changing the rotation angle φ of the polarizing filter 50. As shown in FIG. 17, when the rotation angle φ of the polarizing filter 50 is set to 0 degrees, polarized images of the object 30 are captured in 5-degree increments from the shooting direction θ (0 degrees) to the shooting direction θ (355 degrees). After all shooting directions θ are completed, the rotation angle of the polarizing filter 50 is changed to φ (30 degrees), and the shooting direction θ (355 degrees) is changed back to the initial position of the shooting direction θ (0 degrees). However, as shown in FIG. 17, due to the rotation accuracy of the shooting stand 42 and the influence of any play or rattle of the shooting stand 42, there is a concern that the shooting direction θ may be 0.1 degrees instead of 0 degrees at the rotation angle φ (30 degrees). In other words, each time the rotation angle φ is changed, a slight deviation may occur in the same shooting direction θ. This slight deviation results in a deviation in the angle of view (a positional deviation between images), which affects the generation or extraction of an appropriate image from multiple polarized images captured at different rotation angles φ. In particular, multiple polarized images captured at different rotation angles φ are analyzed to measure the specular reflection component for each location on the object 30, so if there is a deviation in the angle of view between these images, the correspondence between pixels will be disrupted, reducing the accuracy of the analysis.

[0165] As mentioned above, the second method involves fixing the rotation angle φ of the polarizing filter 50 and rotating the imaging table 42, and is therefore susceptible to the influence of the rotational drive and stopping accuracy of the imaging table 42. Therefore, the first method is superior in terms of analytical accuracy.

[0166] Therefore, as a first preferred embodiment, the control method determination unit 214 predetermines a threshold value Th, even when the calculation result is time Tα > time Tβ, and determines the second method as the control method when time Tβ < Tα + Th is satisfied. By determining either the first method or the second method while also taking into consideration the accuracy of rotational driving and stopping of the imaging table 42, a balance between accuracy and time can be maintained. The second method is selected when the time-saving effect is significant, and the first method is selected otherwise, prioritizing accuracy. The threshold value Th can be determined, for example, by experiment or empirical rule.

[0167] As a second preferred embodiment, a method for correcting angle of view deviation will be described. To minimize the effect of angle of view deviation at the same shooting direction θ, feature points are extracted from multiple polarization images captured at different rotation angles φ from the same shooting direction θ. Corresponding feature points in the different polarization images are set as corresponding points, and corresponding point detection is performed. By performing corresponding point detection, angle of view deviation between the different polarization images can be detected, and the polarization images can be corrected using a geometric transformation method such as projective transformation to correct the angle of view deviation. Even if the rotation accuracy of the shooting table 42 is low, angle of view deviation can be minimized by adjusting the angle of view using image processing. A control method can be determined solely from the perspective of the length of the shooting time. Correction of angle of view deviation can be performed by the image processing unit 215.

[0168] A third preferred embodiment will now be described. In this third preferred embodiment, when the same shooting direction θ is used, the camera 10 automatically captures an image of the object 30. Specifically, the rotation angle of the polarizing filter 50 is set to φ1, and the shooting stand 42 is continuously rotated to continuously rotate the object 30. That is, the shooting stand 42 is rotated once (first revolution) at the rotation angle φ1. While the object 30 is rotating once, the camera 10 captures an image of the object 30 for each shooting direction θ, and stores the captured polarized images as reference images.

[0169] Next, the polarizing filter 50 is rotated at a rotation angle of φ2, and the object 30 is rotated continuously (second rotation). The live view image of the camera 10 is compared with the reference image, i.e., a correspondence check is performed. When the positions of the object 30 and the imaging stand 42 are the same as those of the object 30 and the imaging stand 42 in the first rotation, the camera 10 automatically captures the object 30.

[0170] From the second revolution onwards, the camera 10 automatically photographs the object 30 in the same manner until photographs are taken at all rotation angles φ.

[0171] Even if the rotation accuracy of the imaging table 42 is low, imaging can be performed without deviation in the angle of view, and the control method can be determined solely from the perspective of the length of the total imaging time. Note that the comparison of the live view image with the reference image can be performed by the image processing unit 215.

[0172] A fourth preferred embodiment will now be described. In the fourth preferred embodiment, a mark 42B placed on the mounting surface 42A of the imaging table 42 is used. The mark 42B is provided with a numerical value representing the angle for each imaging direction θ. By imaging based on the angle, the rotational accuracy of the imaging table 42 can be substantially improved, so that the second method can be applied without being affected by the rotational accuracy of the imaging table 42. The mark 42B is an example of an index of the present invention.

[0173] 15, once the capture of multiple polarization images (step S1) is complete, the process proceeds to generation or extraction of an appropriate image (step S3). The generation or extraction of an appropriate image is performed by the image processing unit 215. Specifically, an appropriate image is generated or extracted from two or more polarization images captured with the same capture direction θ and different rotation angles φ, with the specular reflection component removed or reduced. The image processing unit 215 obtains the appropriate image by performing comparative dark compositing of the two or more polarization images. Note that the technique of comparative dark compositing itself is well known. The process is outlined below.

[0174] Fig. 18 shows functional blocks related to generation of an appropriate image by the image processing unit 215. As shown in Fig. 8, the image acquisition unit 215A acquires all polarization captured images for the capturing directions from the storage device 206 (1: Img(θ1, φ1), Img(θ1, φ2) ... Img(θ1, φn), 2: Img(θ2, φ1), Img(θ2, φ2) ... Img(θ2, φn), ..., m: Img(θm, φ1), Img(θm, φ2) ... Img(θm, φn)).

[0175] The alignment unit 215B aligns the two or more polarization images used to acquire an appropriate image. For example, if image misalignment occurs, the multiple polarization images may be aligned to the same coordinate system using a geometric transformation such as an affine transformation. Alignment to the same coordinate system may involve using one of the two or more polarization images as a reference polarization image and aligning the other polarization images with the reference polarization image, or the two or more polarization images may be aligned to a different coordinate system. Known techniques can be applied to determine whether or not image misalignment occurs. By accurately aligning the positions of the multiple polarization images in this way, unnatural edges and blurring can be prevented when combining the images.

[0176] The image analysis unit 215C of the image processing unit 215 selects the pixel value with the lowest brightness for pixels at the same coordinates in the polarization-captured images captured in the shooting direction θ1 (for example, Img(θ1, φ1), Img(θ1, φ2), ... Img(θ1, φn)) as the pixel value for that coordinate position. In other words, the image analysis unit 215C performs image analysis on pixels (pixel-by-pixel) at the same coordinates in each polarization-captured image captured in the same shooting direction θ but with different rotation angles φ.

[0177] Next, the synthesis unit 215D of the image processing unit 215 replaces the pixel value at the same pixel position in two or more polarization-captured images with the smaller pixel value selected for each pixel, and obtains a new appropriate image.

[0178] This is because the more appropriate the polarization direction is for removing specular reflection components, the weaker the intensity of light reaching each pixel, resulting in a smaller pixel value.

[0179] Even if the object 30 has a surface texture with high reflectivity, the computer 20 can acquire an appropriate image in which the effects of reflection are suppressed, and generate a high-quality three-dimensional (3D) model.

[0180] Alternatively, the specular reflectance and diffuse reflectance at each position (in this case, each coordinate in the polarized image) of the object 30 may be calculated from a plurality of polarized images and the rotation angle. The specular reflectance and diffuse reflectance can be calculated using the well-known technique of BRDF (Bidirectional Reflectance Distribution Function).

[0181] By calculating the specular reflectance and diffuse reflectance, it is possible to express the gloss, diffusion, and reflected color, which differ depending on the material of the object 30, when a 3D model is generated.

[0182] The composition unit 215D obtains an appropriate image (Img_syn(θ1), Img_syn(θ2) ... Img_syn(θm)) from the polarization captured images (1: Img(θ1, φ1), Img(θ1, φ2) ... Img(θ1, φn), 2: Img(θ2, φ1), Img(θ2, φ2) ... Img(θ2, φn), ..., m: Img(θm, φ1), Img(θm, φ2) ... Img(θm, φn)). The image analysis and composition methods used in comparative dark composition are not particularly limited, and known techniques can be applied.

[0183] When an appropriate image is acquired for the shooting direction, the image processing unit 215 stores the appropriate image (Img_syn(θ1), Img_syn(θ2), ... Img_syn(θm)) in the storage device 206. Furthermore, the appropriate image may be stored in association with additional information of the polarized image, such as specular reflectance or diffuse reflectance.

[0184] In the above description, an example has been described in which an appropriate image is acquired from two or more polarization images in the imaging directions θ1 to θm. However, this is not limiting, and for example, the rotation angle φ may be determined for a certain imaging direction θ. In other words, this is a case in which multiple polarization images are not acquired in a certain imaging direction θ. Therefore, in the imaging direction θi, one polarization image is acquired, and that polarization image is selected as the appropriate image.

[0185] Next, returning to FIG. 15, once the generation or extraction of the appropriate image (step S3) is completed, the process proceeds to the creation of a 3D model (step S5).

[0186] Next, the computer 20 generates a 3D model from the plurality of first images (step S9). Note that the technology for generating a 3D model using photogrammetry is a well-known technology. The outline of this process is as follows.

[0187] Fig. 19 shows functional blocks related to 3D model generation by the three-dimensional model generation unit 216. As shown in Fig. 9, the image acquisition unit 216A acquires first images (Img_syn(θ1), Img_syn(θ2), ... Img_syn(θm)) in the shooting direction from the storage device 206, thereby acquiring a plurality of first images.

[0188] The point cloud data generation unit 216B analyzes multiple first images and generates three-dimensional point cloud data of feature points. The point cloud data generation unit 216B extracts feature points from each first image. Next, the point cloud data generation unit 216B matches corresponding feature points between different first images. The point cloud data generation unit 216B estimates camera parameters (e.g., fundamental matrix, fundamental matrix, internal parameters, etc.) of the camera and estimates the shooting position and orientation based on the estimated camera parameters. Then, the three-dimensional positions of the feature points of the object 30 are determined. Bundle adjustment is performed as necessary. The three-dimensional coordinates of the estimated feature points are combined to generate point cloud data.

[0189] The 3D patch model generation unit 216C performs processing to generate a 3D patch model of the subject based on the three-dimensional point cloud data of the object 30 generated by the point cloud data generation unit 216B. Specifically, patches (meshes) are generated from the generated three-dimensional point cloud to generate a 3D patch model. This makes it possible to represent the surface undulations with a small number of points.

[0190] The 3D model generation unit 216D generates a textured 3D model (three-dimensional model) by performing texture mapping on the 3D patch model generated by the 3D patch model generation unit 216C. The 3D model generation unit 216D maps the texture onto the mesh to give the 3D patch model a realistic appearance of the object 30. By adding specular reflectance and diffuse reflectance, the material, etc. of the object 30 can be expressed when the 3D model is generated.

[0191] The data of the generated 3D model is stored in the storage device 206, etc. Furthermore, the data of the 3D model is displayed on the display device 209 as necessary.

[0192] In the embodiment, the case of the photography system 1 has been described in which the object 30 is placed on the photography stand 42 and the camera 10 moves around the object 30. However, the present invention is not limited to this, and a 3D model can also be generated in the photography system 2.

[0193] In the embodiment, a 3D model is generated by photogrammetry from a plurality of first images of the object 30 in which reflections are suppressed, so that a highly accurate 3D model can be generated.

[0194] When creating a 3D model, the size of the 3D model can be determined by providing information about the distance between the two marks 42A on the imaging stand 40. The positional relationship between the camera 10 and the object 30 can be determined based on the multiple marks 42B on the imaging stand 42, and a 3D model can be generated.

[0195] The processor 200 may be configured with one or more pieces of hardware, and the type of hardware is not limited. For example, the processor 200 may be configured with hardware such as a programmable logic device such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or an FPGA (Field Programmable Gate Array), a dedicated circuit for executing specific processes such as an ASIC (Application Specific Integrated Circuit), a GPU (Graphic Processing Unit), or an NPU (Neural Processing Unit). The processor 200 also includes various units or means for executing various processes in this embodiment. The hardware may also be a combination of different types of hardware. When multiple pieces of hardware are configured to execute one or more processes of a certain processor, the multiple pieces of hardware may exist in physically separate devices or in the same device. In any of the embodiments, the order of each process performed by the processor is not particularly limited and may be changed as appropriate. The hardware may be configured with an electrical circuit or the like that combines circuit elements such as semiconductor devices.

[0196] Furthermore, in this embodiment, the processor 200 may be implemented by hardware, software, firmware, microcode, or a combination thereof. Software, firmware, and microcode are configured by a program. A program may also be, for example, a group of program modules, each function of which may be implemented by a processor configured to execute the respective function. The program may be program code or multiple code segments stored in one or more non-transitory, tangible computer-readable media (e.g., storage media or other storage, such as the ROM 204 or the storage device 206 (hereinafter the same)). The program may be stored in multiple non-transitory, tangible computer-readable media that are physically separate from each other. The program code or code segment may represent a procedure, a function, a subprogram, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. The program code or code segment may be connected to another code segment or a hardware circuit by transmitting or receiving information, data, arguments, parameters, or memory contents.

[0197] In this embodiment, the term "non-transitory tangible computer-readable medium" does not include non-tangible recording media such as carrier signals or propagated signals. The processor 200 can use the RAM 202 as a temporary storage area or a working area when processing using a program.

[0198] The functions of the processor 200 described above may be realized by various types of AI (Artificial Intelligence). Such AI may be, for example, an AI that performs image recognition, segmentation, feature extraction, or the like, or an AI that generates an image from given information. These AIs may also be realized by hardware, software, firmware, microcode, or a combination thereof, as described above.

[0199] Although the present invention has been described above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the spirit of the present invention.

[0200] DESCRIPTION OF SYMBOLS 1...Photographing system 2...Photographing system 3...Polarized illumination 3A...Illumination 3B...Polarizing plate 10...Camera 20...Computer 30...Object 40...Photographing stand 42...Photographing stand 42A...Placement surface 42B...Mark 44...Support member 44A...Installation stand 44B...Arm section 46...Photographing stand 46A...Placement surface 46B...Mark 48...Transport mechanism 48A...Guide rail 48B...Moving stage 50...Polarizing filter 100...Lens device 102...Photographing optical system 104...Lens group 110...Lens driving section 112...Driver 130...Image sensor 132...Shutter 134...Shutter driving section 136...Memory 138...Digital signal processing section 140...Input / output interface 142...Display section 144...Operation section 146...System control section 150...Correction mechanism 152...Control unit 154...Image sensor driving unit 156...Detection unit 158...Position detection unit 160...Filter driving unit 162...Rotation angle detection unit 200...Processor 202...RAM 204...ROA 206...Storage device 207...Input / output interface 208...Input device 209...Display device 210...Information acquisition unit 211...Camera control unit 212...Polarization filter control unit 213...Photography table control unit 214...Control method determination unit 215...Image processing unit 215A...Image acquisition unit 215B...Positioning unit 215C...Image analysis unit 215D...Synthesis unit 216...3D model generation unit 216A...Image acquisition unit 216B...Point cloud data generation unit 216C...3D patch model generation unit 216D...3D model generation unit L1...Specular reflection component L2...Diffuse reflection component L3...Linearly polarized light

Claims

1. An imaging system comprising: an imaging device equipped with a polarizing filter for photographing an object; a first mechanism for changing the rotation angle of the polarizing filter; a second mechanism for changing the relative imaging direction of the imaging device with respect to the object; and a processor for controlling the first and second mechanisms, wherein the processor obtains first information regarding the settings of two or more different rotation angles for imaging the object from the same imaging direction; obtains second information regarding the settings of two or more different imaging directions for the object; and determines a control method for the first and second mechanisms based on the first and second information.

2. The photographing system of claim 1, wherein the first information is information regarding the number of times the object is photographed from the same photographing direction with the rotation angle of the polarizing filter changed, or information regarding the rotation angle that is changed for each photographing.

3. The photographing system according to claim 1 or 2, wherein the second information is information relating to the number of times the object is photographed at the same rotation angle but with different photographing directions, or information relating to the angle of the photographing direction which is changed for each photograph.

4. The photography system according to claim 1, wherein the first information includes a first change time required to change the rotation angle, and the second information includes a second change time required to change the photography direction.

5. The imaging system according to claim 4, wherein the first change time is variable.

6. The imaging system according to claim 4, wherein the second change time is variable.

7. An imaging system described in any one of claims 4 to 6, wherein at least one of the first change time or the second change time is determined based on at least one of the characteristics of the object and / or the specifications of the second mechanism.

8. The photographing system of claim 1, wherein the control method comprises a first method and a second method, wherein the first method is a method of repeatedly acquiring multiple images with different rotation angles of the polarizing filter from the same photographing direction, then changing the photographing direction, and acquiring multiple images with different rotation angles of the polarizing filter from the changed photographing direction, and the second method is a method of repeatedly acquiring images with different photographing directions with the same rotation angle of the polarizing filter, then changing the rotation angle of the polarizing filter, and acquiring images with different photographing directions with the changed rotation angle.

9. The photographing system of claim 8, wherein the processor determines the control method by calculating a time Tα for the first method and a time Tβ for the second method, and comparing the time Tα with the time Tβ, wherein the time Tα is the total time required to change the first information and at least one of the first mechanism or the second mechanism when acquiring each image in each photograph when photographing all of the desired images, and the time Tβ is the total time required to change the second information and at least one of the first mechanism or the second mechanism when acquiring each image in each photograph when photographing all of the desired images.

10. The imaging system according to claim 9, wherein the processor calculates the times Tα and Tβ using the following formulas (1) and (2) where X is the angle of change per imaging direction change of the second mechanism, Y is the rotation angle of the first mechanism, Tt is the drive time of the second mechanism, and Tp is the drive time of the first mechanism, and determines either the first method or the second method as the control method. Tα=((360 / X)×Tt)+((360 / X)×(180 / Y)×Tp) (1) Tβ=((360 / X)×(180 / Y)×Tt)+((180 / Y)×Tp) (2) 11. The imaging system according to claim 10, wherein the processor determines the second method when the following formula (3) is satisfied, where Th is a predetermined threshold: Tβ<Tα+Th (3) 12. The photographing system according to claim 8, wherein, in the second method, the processor corrects positional deviation between multiple images photographed by the photographing device in the same photographing direction but with different rotation angles.

13. The photographing system described in claim 8, wherein, in the case of the second method, the processor continuously drives the second mechanism to photograph a plurality of images in the same photographing direction but with different rotation angles, the processor uses the first photographed image as a reference image and causes the photographing device to photograph based on the reference image and the live view image to be photographed.

14. The photographing system of claim 8, wherein, in the case of the second method, an index is placed on the second mechanism, and when photographing multiple images with the same photographing direction but different rotation angles, the processor causes the photographing device to photograph based on the index.

15. The imaging system according to claim 8, wherein the processor continuously drives the first mechanism in the first mode.

16. The imaging system according to claim 15, wherein the processor, in the case of the first method, determines the drive time of the first mechanism based on the imaging conditions of the imaging device.

17. A photography system comprising: a photography device for photographing an object; a polarizing filter arranged between the object and the photography device and having a variable rotation angle; a table on which the object is placed and whose photography direction relative to the photography device is variable; and a processor, wherein the processor determines a first change condition related to the rotation angle of the polarizing filter and a second change condition related to the photography direction of the table based on the photography time for photographing the object.

18. The imaging system according to claim 17, wherein the processor determines the first change condition and the second change condition based on the imaging time and the analytical accuracy of the plurality of images to be captured.

19. The imaging system of claim 1 or 17, wherein the processor generates a 3D model based on images captured by the imaging device.

20. A photographing method carried out by a photographing system for photographing an object, comprising a photographing device having a polarizing filter and a processor, wherein the processor: acquires first information regarding the settings of two or more rotation angles of the polarizing filter when photographing the object from the same photographing direction; acquires second information regarding the settings of two or more different photographing directions for the object; and determines a control method for photographing the object based on the first information and the second information.

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