Projection method and projection system

Abstract

To improve the quality of the viewing experience of a user U on the basis of the viewing angle of the user U relative to a projected image PI.SOLUTION: A projection method includes projecting a projection image including a content image onto a projection target PO using a projection device, and adjusting at least one of the size, position, and shape of the content image CI so as to satisfy at least one of a first condition or a second condition on the basis of information indicating the position of a user U relative to the projection target PO, and the first condition is that a first viewing angle of the user to the content image CI in a first direction parallel to a first side of the content image CI is 70 degrees or more and 80 degrees or less, and the second condition is that a second viewing angle of the user U to the content image CI in a second direction parallel to a second side intersecting the first side is 40 degrees or more and 45 degrees or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a projection method and a projection system. [Background technology]

[0002] Conventionally, when a user of a projector views an image projected from the projector, techniques have been used to improve the quality of the viewing experience.

[0003] For example, the display system disclosed in Patent Document 1 includes a display unit that surrounds the front and sides of a user. The display unit includes a hemispherical screen and a projector that projects an image onto the screen. In this display system, the projector is positioned above the field of view of a user seated in a seating area, so that the projector is not within the user's field of view. As a result, the user's level of immersion and concentration in the projected image increases. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-79276 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, although the position of the projector and the shape of the display area are considered in order to improve the quality of the viewing experience, the user's viewing angle with respect to the projected image is not taken into consideration. [Means for solving the problem]

[0006] A projection method according to one embodiment of the present invention includes projecting a projection image including a content image onto a projection target using a projection device, and adjusting at least one of the size, position, and shape of the content image based on information indicating a user's position relative to the projection target so as to satisfy at least one of a first condition or a second condition, wherein the first condition is that a first viewing angle of the user with respect to the content image in a first direction parallel to a first side of the content image is between 70 degrees and 80 degrees, and the second condition is that a second viewing angle of the user with respect to the content image in a second direction parallel to a second side intersecting the first side is between 40 degrees and 45 degrees.

[0007] A projection method according to another aspect of the present invention includes: projecting a projection image including a content image onto a projection target using a projection device; determining, based on information indicating a user's position relative to the projection target, whether the user's position is a position where at least one of a first condition or a second condition is satisfied; if it is determined that the user's position is a position where neither the first condition nor the second condition is satisfied, projecting the projection image in a first aspect; and if it is determined that the user's position is a position where at least one of the first condition or the second condition is satisfied, projecting the projection image in a second aspect different from the first aspect, wherein the first condition is that a first viewing angle in a first direction parallel to a first side of the content image is between 70 degrees and 80 degrees, and the second condition is that a second viewing angle in a second direction parallel to a second side intersecting the first side is between 40 degrees and 45 degrees.

[0008] A projection system according to one aspect of the present invention includes a projector that projects a projection image including a content image onto a projection target using a projection device, and a control device that adjusts at least one of the size, position, and shape of the content image based on information indicating a user's position relative to the projection target so as to satisfy at least one of a first condition or a second condition, wherein the first condition is that a first viewing angle in a first direction parallel to a first side of the content image is between 70 degrees and 80 degrees, and the second condition is that a second viewing angle in a second direction parallel to a second side that intersects with the first side is between 40 degrees and 45 degrees. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a projection system 1A. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a control device 10A. [Figure 3] An explanatory diagram of the triangulation method. [Figure 4] 10A and 10B are diagrams showing examples of aspects of corrected images AI. [Figure 5] 10A and 10B are diagrams showing examples of aspects of corrected images AI. [Figure 6] FIG. 10 is an explanatory diagram of an example of a method for adjusting a content image CI by a projection control unit 126A. [Figure 7] FIG. 10 is an explanatory diagram of an example of a method for adjusting a content image CI by a projection control unit 126A. [Figure 8] FIG. 10 is an explanatory diagram of an example of a method for adjusting a content image CI by a projection control unit 126A. [Figure 9] FIG. 2 is a block diagram showing an example of the configuration of a projector 30. [Figure 10] 4 is a flowchart showing the operation of the control device 10A. [Figure 11] FIG. 2 is a block diagram showing an example of the configuration of a control device 10B. [Figure 12] 10A and 10B are diagrams showing examples of aspects of corrected images AI. [Figure 13] 10 is a flowchart showing the operation of the control device 10B. [Figure 14]10 is a flowchart showing the operation of the control device 10B. [Figure 15] FIG. 2 is a diagram showing a first content image CI1 and a first gaze area WA1 of a subject S. [Figure 16] 10 is a diagram showing a second content image CI2 and a second gaze area WA2 of the subject S. FIG. [Figure 17] FIG. 10 is a diagram showing a third content image CI3 and a third gaze area WA3 of subject S. [Figure 18] FIG. 10 is a diagram showing a fourth content image CI4 and a fourth gaze area WA4 of subject S. [Figure 19] FIG. 10 is an explanatory diagram of how the widths of the first content image CI1 to the fourth content image CI4 are changed. [Figure 20] 10 is an explanatory diagram of the distance between a subject S and a projection surface PF. [Figure 21] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 2 m. [Figure 22] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 2 m. [Figure 23] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 2 m. [Figure 24] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 2 m. [Figure 25] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 3 m. [Figure 26] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 3 m. [Figure 27] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 3 m. [Figure 28] 10 is a graph showing the evaluation results when the distance between the subject S and the projection surface PF is 3 m. [Figure 29] 10 is a table showing the aspect ratio of the test specimen that received the highest evaluation when the first content image CI1 was used. [Figure 30] 10 is a table showing the aspect ratio of the test specimen that received the highest evaluation when the second content image CI2 was used. [Figure 31] 10 is a table showing the aspect ratio of the test specimen that was evaluated most highly when the third content image CI3 was used. [Figure 32] 10 is a table showing the aspect ratio of the test specimen that received the highest evaluation when the fourth content image CI4 was used. [Figure 33] FIG. 10 is a diagram showing a sixth content image CI6. [Figure 34] FIG. 10 is a diagram showing an eighth content image CI8. [Figure 35] FIG. 10 is an explanatory diagram of how the vertical widths of the fifth content image CI5 to the eighth content image CI8 are changed. [Figure 36] FIG. 10 is an explanatory diagram of how to change the vertical width of the fifth content image CI5. [Figure 37] FIG. 10 is an explanatory diagram of how to change the vertical width of the sixth content image CI6. [Figure 38] FIG. 10 is an explanatory diagram of how to change the vertical width of the seventh content image CI7. [Figure 39] FIG. 10 is an explanatory diagram of how to change the vertical width of the eighth content image CI8. [Figure 40] 10 is a graph showing evaluation results when a fifth content image CI5 is used. [Figure 41] 10 is a graph showing evaluation results when a sixth content image CI6 is used. [Figure 42] 10 is a graph showing the evaluation results when a seventh content image CI7 is used. [Figure 43] 10 is a graph showing evaluation results when an eighth content image CI8 is used. [Figure 44] FIG. 10 is a diagram showing a ninth content image CI9. [Figure 45] FIG. 10 is an explanatory diagram of how the seating position of the subject S is changed relative to the ninth content image CI9. [Figure 46] 10 is a graph showing the evaluation results when subject S fixates the first area AR9[1] as the gaze area. [Figure 47] 10 is a graph showing the evaluation results when subject S fixates the second area AR9[2] as the gaze area. [Figure 48]10A and 10B are diagrams showing examples of optimal viewing angles and aspect ratios of content images CI. [Figure 49] 10A and 10B are diagrams showing examples of optimal viewing angles and aspect ratios of content images CI. [Figure 50] FIG. 10 is a diagram showing an example of an optimal seating position for a content image CI. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in each drawing, the dimensions and scale of each part are appropriately different from those of the actual parts. Furthermore, since the embodiments described below are preferred specific examples of the present invention, various technically preferable limitations are applied, but the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited.

[0011] 1: First embodiment A projection method and a projection system 1A according to a first embodiment will be described below with reference to FIGS.

[0012] 1-1: Configuration of the first embodiment 1-1-1: Overall configuration of the projection system 1 is a block diagram showing an example of the configuration of a projection system 1A according to the first embodiment of the present disclosure. As shown in FIG. 1, the projection system 1A includes a control device 10A, an imaging device 20, and a projector 30.

[0013] 1, the imaging device 20 is connected to the control device 10A via a communication line L1 such as a USB (Universal Serial Bus) cable, and the projector 30 is connected to the control device 10A via a communication line L2 such as a USB cable.

[0014] The imaging device 20 captures an image of a space SP including a projection target PO and a user U of the projection system 1A. In the present disclosure, the projection target PO is an object having a three-dimensional shape onto which a projection image PI is projected. The projection target PO is, for example, a wall or a screen onto which the projection image PI is projected. The imaging device 20 captures various images under the control of the control device 10A.

[0015] In this embodiment, the imaging device 20 is a stereo camera, for example. As will be described later, when the control device 10A is a PC, a tablet terminal, or a smartphone, the imaging device 20 is an external stereo camera. However, the imaging device 20 may be a stereo camera configured by a camera provided in the PC, tablet terminal, or smartphone and an external camera.

[0016] The control device 10A communicates with the imaging device 20 via the communication line L1, thereby acquiring from the imaging device 20 a captured image GI of the space SP including the projection target PO and the user U. Note that the communication between the control device 10A and the imaging device 20 may be wireless communication.

[0017] The projector 30 projects a projection image PI onto a projection target PO. The projector 30 projects various projection images PI under the control of the control device 10A. The projector 30 is an example of a "projection device."

[0018] The control device 10A communicates with the projector 30 via the communication line L2, causing the projector 30 to project the projection image PI onto the projection target PO. Note that the communication between the control device 10A and the projector 30 may be wireless communication.

[0019] 1, for convenience of explanation, the control device 10A, the image capture device 20, and the projector 30 are depicted as separate entities. However, in the projection system 1A, two or more of these components may be incorporated into a single housing.

[0020] 1-1-2: Configuration of the control device 2 is a block diagram showing an example configuration of the control device 10A. The control device 10A is typically a PC (Personal Computer), but is not limited to this and may be, for example, a tablet terminal or a smartphone. The control device 10A includes a processing device 120A, a storage device 140A, a display device 150, an input device 160, and a communication device 170. The elements of the control device 10A are connected to each other by one or more buses for communicating information.

[0021] The processing device 120A is a processor that controls the entire control device 10A, and is configured, for example, by one or more chips. The processing device 120A is configured, for example, by a central processing unit (CPU) that includes an interface with peripheral devices, an arithmetic unit, and registers. Note that some or all of the functions of the processing device 120A may be realized by hardware such as a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). The processing device 120A executes various processes in parallel or sequentially.

[0022] The storage device 140A is a recording medium readable and writable by the processing device 120A, and stores a plurality of programs including a control program PR1A executed by the processing device 120A. The storage device 140A also stores image information indicating an original image RI of the projection image PI. Furthermore, the storage device 140A stores relationship information indicating the correspondence between a camera coordinate system, which is a coordinate system on the captured image GI captured by the imaging device 20, and a panel coordinate system, which is a coordinate system on the liquid crystal panel provided in the projector 30.

[0023] The storage device 140A may be configured with at least one of, for example, a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), and a random access memory (RAM), etc. The storage device 140A may also be called a register, a cache, a main memory, a primary memory, or the like.

[0024] The display device 150 is a device that displays images and text information. The display device 150 may be a display device separate from the other components of the control device 10A.

[0025] The input device 160 is a device that accepts operations from a user of the projection system 1A. For example, the input device 160 includes a keyboard, a touchpad, a touch panel, or a pointing device such as a mouse. Here, if the input device 160 includes a touch panel, it may also serve as the display device 150.

[0026] The communication device 170 is hardware serving as a transmitting / receiving device for communicating with other devices. The communication device 170 is also called, for example, a network device, a network controller, a network card, or a communication module. The communication device 170 may include a connector for wired connection and an interface circuit corresponding to the connector. The communication device 170 may also include a wireless communication interface. Examples of the connector and interface circuit for wired connection include those compliant with wired LAN (Local Area Network), IEEE 1394, and USB (Universal Serial Bus). Examples of the wireless communication interface include those compliant with wireless LAN, Bluetooth (registered trademark), etc.

[0027] The processing device 120A reads and executes the control program PR1A from the storage device 140A, thereby functioning as a first acquisition unit 121, a second acquisition unit 122, an image adjustment unit 123A, an information calculation unit 124, a determination unit 125, and a projection control unit 126A.

[0028] The first acquisition unit 121 acquires the original image RI of the projection image PI from the storage device 140A. Note that the first acquisition unit 121 may acquire the original image RI from an external device different from the control device 10A, instead of the storage device 140A.

[0029] The second acquisition unit 122 acquires the captured image GI from the imaging device 20.

[0030] The image adjustment unit 123A adjusts the original image RI acquired by the first acquisition unit 121 to generate a projection image PI.

[0031] For example, if the projector 30 is positioned at an angle rather than facing the projection surface PF of the projection target PO, the projector 30 projects the rectangular original image RI as is onto the projection surface PF, and as a result, the content image CI displayed on the projection surface PF becomes a distorted rectangle that is different from a rectangle. Therefore, the image adjustment unit 123A geometrically corrects the original image RI so that the content image CI becomes similar in shape to the original image RI.

[0032] Furthermore, the image adjustment unit 123A adjusts the corrected image AI obtained by geometrically correcting the original image RI, based on information calculated by an information calculation unit 124 (described later) and the determination result by a determination unit 125.

[0033] The information calculation unit 124 calculates information indicating the position of the user U relative to the projection target PO in the space SP captured by the captured image GI, based on the captured image GI acquired by the second acquisition unit 122. As an example, the information calculation unit 124 calculates the information indicating the position of the user U relative to the projection target PO by triangulation using the captured image GI.

[0034] FIG. 3 is an explanatory diagram of a triangulation method. In the space SP shown in FIG. 3, there are a projection target PO, an imaging device 20 which is a stereo camera, and a user U. The imaging device 20 includes a first camera 20[1] and a second camera 20[2]. As a result of projecting a projection image PI onto the projection surface PF, a content image CI included in the projection image PI is displayed on the projection surface PF. The user U views the content image CI displayed on the projection surface PF. Note that in FIG. 3, for ease of explanation, the content image CI is drawn with a thickness.

[0035] Also, in FIG. 3, an xyz space is assumed to have three axes: an x-axis, a y-axis, and a z-axis. The x-axis, the y-axis, and the z-axis are orthogonal to one another. In this xyz space, the z-axis direction is the vertical direction. The z-axis direction is the same direction as the vertical side of the content image CI. The z-axis direction is an example of a "second direction." The vertical side of the content image CI is an example of a "second side." The z-axis direction is a general term for the z1 direction and the z2 direction opposite to the z1 direction. The z1 direction is a direction that extends vertically downward. The z2 direction is a direction that extends vertically upward. The x-axis direction is the same direction as the horizontal side of the content image CI. The x-axis direction is an example of a "first direction." The horizontal side of the content image CI is an example of a "first side." The x-axis direction is a general term for the x1 direction and the x2 direction opposite to the x1 direction. The x1 direction is the right-hand direction of the user U. The x2 direction is the left-hand direction of the user U. The y-axis direction is the normal direction of the projection surface PF on which the content image CI is displayed. The y-axis direction is a general term for the y1 direction and the y2 direction. The y1 direction is the direction from the content image CI to the user U. The y2 direction is the direction from the user U to the content image CI.

[0036] 3, as an example, the user U is located at a distance UD from the projection surface PF. A normal NL of the projection surface PF, which passes through the center point P of the content image CI, passes through the origin O, which is the midpoint between the first camera 20[1] and the second camera 20[2]. The origin O is located at a distance CD from the center point P. Furthermore, the normal NL forms an angle θ with a straight line UL that connects the center point P, which is the intersection of the projection surface PF and the normal NL, with the position of the user U.

[0037] The information calculation unit 124 is capable of calculating information indicating the position of the user U relative to the projection surface PF of the projection target PO, based on a first captured image GI1 in which the projection target PO and the user U are captured by the first camera 20[1] and a second captured image GI2 in which the projection target PO and the user U are captured by the second camera 20[2]. The information indicating the position of the user U includes, for example, the distance UD and angle θ in FIG. 3.

[0038] If there are multiple users U, the information calculation unit 124 first calculates information indicating the position of each of the multiple users U relative to the projection surface PF of the projection target PO. Then, the information calculation unit 124 uses the center of gravity of the multiple positions that correspond one-to-one to these multiple users U as the above-mentioned "position of user U."

[0039] 2, the determination unit 125 determines whether the angle θ is equal to or greater than a first angle and equal to or less than a second angle. This condition is an example of a "third condition."

[0040] The image adjustment unit 123A changes the aspect of the corrected image AI obtained by geometrically correcting the original image RI, according to the determination result of the determination unit 125 regarding the "third condition."

[0041] 4 and 5 are diagrams showing examples of the aspect of the corrected image AI. More specifically, FIG. 4 is a diagram showing an example of the aspect of the corrected image AI when the determination result of the "third condition" is negative. In other words, FIG. 4 is a diagram showing an example of the aspect of the corrected image AI when the angle θ is not "greater than the first angle and less than the second angle." On the other hand, FIG. 4 is a diagram showing an example of the aspect of the corrected image AI when the determination result of the "third condition" is positive. In other words, FIG. 5 is a diagram showing an example of the aspect of the corrected image AI when the angle θ is "greater than the first angle and less than the second angle." For convenience of explanation, in FIGS. 4 and 5, the corrected image AI is shown in its shape before geometric correction.

[0042] In the example shown in Fig. 4, a frame line FL is arranged around the periphery of the corrected image AI. The frame line FL is preferably displayed in a predetermined color. On the other hand, in the example shown in Fig. 5, unlike the example shown in Fig. 4, no frame line FL is arranged around the periphery of the corrected image AI.

[0043] The mode of the corrected image AI when the determination result of the determination unit 125 for the "third condition" is negative is an example of the "third mode." Also, the mode of the corrected image AI when the determination result of the determination unit 125 for the "third condition" is positive is an example of the "fourth mode."

[0044] In FIG. 2, the projection control unit 126A causes the projector 30 to project the corrected image AI adjusted by the image adjustment unit 123A as a projection image PI including the content image CI onto the projection surface PF of the projection target PO. In other words, if it is determined that the position of the user U is not a position that satisfies the "third condition," the projection control unit 126A projects the projection image PI in the "third aspect." On the other hand, if it is determined that the position of the user U is a position that satisfies the "third condition," the projection control unit 126A projects the projection image PI in the "fourth aspect." The "third aspect" and the "fourth aspect" are different from each other.

[0045] At this time, the projection control unit 126A adjusts at least one of the size, position, or shape of the content image CI on the projection surface PF so that the viewing angle of the user U to the content image CI in the x-axis direction in the xyz coordinate system of Figure 3 is greater than or equal to the third angle and less than or equal to the fourth angle.

[0046] Alternatively, the projection control unit 126A adjusts at least one of the size, position, or shape of the content image CI on the projection surface PF so that the viewing angle of the user U to the content image CI in the z-axis direction in the xyz coordinate system of Figure 3 is greater than or equal to the fifth angle and less than or equal to the sixth angle.

[0047] Alternatively, the projection control unit 126A adjusts at least one of the size, position, or shape of the content image CI on the projection surface PF so that, in the xyz coordinate system of Figure 3, the viewing angle of the user U to the content image CI in the x-axis direction is greater than or equal to a third angle and less than or equal to a fourth angle, and the viewing angle of the user U to the content image CI in the z-axis direction is greater than or equal to a fifth angle and less than or equal to a sixth angle.

[0048] Here, the "visual angle" refers to the angle between a virtual line connecting the user U's eyes (eyeballs) to one end of the content image CI on the projection surface PF and a virtual line connecting the user U's eyes (eyeballs) to the other end of the content image CI on the projection surface PF. The "visual angle of the user U with respect to the content image CI in the x-axis direction" is an example of a "first visual angle." The "visual angle of the user U with respect to the content image CI in the z-axis direction" is an example of a "second visual angle." The condition that the "visual angle of the user U with respect to the content image CI in the x-axis direction is equal to or greater than a third angle and equal to or less than a fourth angle" is an example of a "first condition." The condition that the visual angle of the user U with respect to the content image CI in the z-axis direction is equal to or greater than a fifth angle and equal to or less than a sixth angle is an example of a "second condition." In this embodiment, the distance between the user U's eyes is sufficiently smaller than the dimensions of the projection image PI and the content image CI in at least one of the x-axis direction and the z-axis direction. Therefore, in this embodiment, the positions of both eyes are not distinguished from each other, and the case where both eyes are considered to be substantially in one position is taken into consideration.

[0049] 6 to 8 are explanatory diagrams of an example of a method for adjusting the content image CI by the projection control unit 126A. For convenience of explanation, it is assumed that the user U is positioned on the normal line NL as shown in Fig. 6, unlike in Fig. 3.

[0050] 7 is a diagram showing a first captured image GI1 captured by the first camera 20[1]. In the first captured image GI1, the projection image PI and the content image CI included in the projection image PI are distorted rectangles that are not rectangular. Furthermore, the content image CI has four vertices, vertices P1 to P4.

[0051] The projection control unit 126A performs projective transformation on the first captured image GI1 acquired by the second acquisition unit 122 to generate a first captured image GI1' after projective transformation shown in Fig. 8. The first captured image GI1' is an image of the space SP when facing directly toward the content image CI displayed on the projection surface PF. The vertices P1 to P4 and the user U on the first captured image GI1 become vertices P1' to P4' and the user U' on the first captured image GI1' after projective transformation.

[0052] Based on the coordinates of vertices P1' to P4' and user U' in the camera coordinate system on the first captured image GI1', the projection control unit 116 calculates the length of side W14 between vertices P1' and P4', the length of side H12 between vertices P1' and P2', the length of side LU1 between user U' and P1', the length of side LU2 between user U' and P2', and the length of side LU4 between user U' and P4'.

[0053] Furthermore, the projection control unit 126A calculates the viewing angle α by applying the law of cosines based on the lengths of sides LU1, LU4, and W14. Similarly, the projection control unit 126A calculates the viewing angle β by applying the law of cosines based on the lengths of sides LU2, LU1, and H12.

[0054] If the viewing angle α is not "greater than the third angle and less than the fourth angle," the projection control unit 126A calculates the length of side W14 so that it satisfies this range. If the viewing angle β is not "greater than the fifth angle and less than the sixth angle," the projection control unit 126A calculates the length of side H12 so that it satisfies this range. Furthermore, the projection control unit 126A newly calculates the coordinates of vertices P1' to P4' so that they satisfy the newly calculated lengths of side W14 and side H12.

[0055] Next, the projection control unit 126A transforms the newly determined coordinates of the vertices P1' to P4' into coordinates in the camera coordinate system on the first captured image GI1 before projective transformation.

[0056] Furthermore, the projection control unit 126A converts the newly determined coordinates of vertices P1' to P4' in the camera coordinate system on the first captured image GI1 before projective transformation into coordinates in the panel coordinate system on the liquid crystal panel provided in the projector 30, using the correspondence between the camera coordinate system and the panel coordinate system stored in the storage device 140A. Finally, the projection control unit 126A causes the projector 30 to project, as a projection image PI, onto the projection surface PF of the projection target PO, using the new coordinates of vertices P1' to P4' converted into coordinates in the panel coordinate system of the projector 30.

[0057] The projection control unit 126A may adjust both the length of side W14 and the length of side H12 so as to satisfy both the "first condition" that the viewing angle α is "not less than the third angle and not more than the fourth angle" and the "second condition" that the viewing angle β is "not less than the fifth angle and not more than the sixth angle." Alternatively, the projection control unit 126A may adjust either the length of side W14 or the length of side H12 so as to satisfy either the "first condition" that the viewing angle α is "not less than the third angle and not more than the fourth angle" or the "second condition" that the viewing angle β is "not less than the fifth angle and not more than the sixth angle."

[0058] In addition, the projection control unit 126A may adjust at least one of the size, position, or shape of the content image CI on the projection surface PF so as to satisfy at least one of the "first condition" or the "second condition" only if the judgment result of the judgment unit 125 of the "third condition" is positive.

[0059] In the above description, it is preferable that the "first angle" is 20 degrees, the "second angle" is 40 degrees, the "third angle" is 70 degrees, the "fourth angle" is 80 degrees, the "fifth angle" is 40 degrees, and the "sixth angle" is 45 degrees. The reasons why these values ​​are preferable will be described later in the explanation of the sensory test.

[0060] 1-1-3: Projector configuration 9 is a block diagram showing an example configuration of projector 30. Projector 30 includes an optical device 310, a processing device 320, a storage device 330, and a communication device 340. The elements of projector 30 are connected to one another by one or more buses for communicating information. Furthermore, each element of projector 30 is composed of one or more devices, and some elements of projector 30 may be omitted.

[0061] The optical device 310 is a device that projects an image represented by an image signal acquired by an acquisition unit 321 (described later) onto a projection target PO such as a screen or a wall. The optical device 310 projects various images under the control of the processing device 320. The optical device 310 includes, for example, a light source, a liquid crystal panel, and a projection lens, and modulates light from the light source using the liquid crystal panel and projects the modulated light onto a screen, a wall, or the like via the projection lens.

[0062] The processing device 320 is a processor that controls the entire projector 30, and is configured, for example, by one or more chips. The processing device 320 is configured, for example, by a central processing unit (CPU) that includes an interface with peripheral devices, an arithmetic unit, a register, etc. Note that some or all of the functions of the processing device 320 may be realized by hardware such as a DSP, ASIC, PLD, and FPGA. The processing device 320 executes various processes in parallel or sequentially.

[0063] The storage device 330 is a recording medium readable by the processing device 320, and stores a plurality of programs including the control program PR3 executed by the processing device 320. The storage device 330 may be configured with at least one of, for example, a ROM, an EPROM, an EEPROM, and a RAM. The storage device 330 may also be called a register, a cache, a main memory, a primary storage device, or the like.

[0064] The communication device 340 is hardware serving as a transmitting / receiving device for communicating with other devices. The communication device 340 is also called, for example, a network device, a network controller, a network card, or a communication module. The communication device 340 may include a connector for wired connection and an interface circuit corresponding to the connector. The communication device 340 may also include a wireless communication interface. Examples of the connector and interface circuit for wired connection include those compliant with wired LAN, IEEE 1394, and USB. Examples of the wireless communication interface include those compliant with wireless LAN, Bluetooth (registered trademark), etc.

[0065] The processing device 320 reads and executes the control program PR3 from the storage device 330, thereby functioning as an acquisition unit 321 and a projection control unit 322. The control program PR3 may be transmitted from another device, such as a server that manages the projector 30, via a communication network.

[0066] The acquisition unit 321 acquires an image signal corresponding to the projection image PI and a control signal for controlling the projector 30 from the control device 10A.

[0067] The projection control unit 322 causes the optical device 310 to project a projection image PI corresponding to the image signal acquired by the acquisition unit 321 onto the projection target PO based on the control signal acquired by the acquisition unit 321.

[0068] 1-2: Operation of the control device FIG. 10 is a flowchart showing the operation of the control device 10A.

[0069] In step S1, the processing device 120A functions as the first acquisition unit 121. The processing device 120A acquires an original image RI of the projected image PI.

[0070] In step S2, the processing device 120A functions as the second acquisition unit 122. The processing device 120A acquires the captured image GI from the imaging device 20.

[0071] In step S3, the processing device 120A functions as an image adjustment unit 123A. The processing device 120A performs geometric correction on the original image RI.

[0072] In step S4, the processing device 120A functions as the information calculation unit 124. Based on the captured image GI acquired in step S2, the processing device 120A calculates information indicating the position of the user U relative to the projection target PO in the space SP indicated by the captured image GI.

[0073] In step S5, the processing device 120A functions as the determination unit 125. The processing device 120A determines whether the angle θ is equal to or greater than the first angle and equal to or less than the second angle, which satisfies a "third condition." If the determination result is affirmative ("YES" in step S5), the processing device 120A executes the process of step S6. If the determination result is negative ("NO" in step S5), the processing device 120A executes the process of step S7.

[0074] In step S6, the processing device 120A functions as the image adjustment unit 123A. The processing device 120A sets the aspect of the corrected image AI to the fourth aspect.

[0075] In step S7, the processing device 120A functions as the image adjustment unit 123A. The processing device 120A sets the aspect of the corrected image AI to the third aspect.

[0076] In step S8, the processing device 120A functions as the projection control unit 126A. The processing device 120A projects the corrected image AI as a projection image PI.

[0077] In step S9, the processing device 120A functions as the projection control unit 126A. The processing device 120A adjusts the content image CI included in the projection image PI.

[0078] 2: Second embodiment 11 to 14, a projection method and a projection system 1B according to the second embodiment will be described. For the sake of simplicity, the following description will focus on differences between the projection system 1B according to the second embodiment and the projection system 1A according to the first embodiment. Furthermore, among the components of the projection system 1B, the same components as those in the projection system 1A will be designated by the same reference numerals, and a description of their functions may be omitted.

[0079] 2-1: Configuration of the second embodiment 2-1-1: Overall configuration of the projection system Projection system 1B according to the second embodiment of the present disclosure differs from projection system 1A in that it includes control device 10B instead of control device 10A. In other respects, the configuration of projection system 1B is the same as the configuration of projection system 1A shown in FIG. 1, and therefore is not shown in the drawings.

[0080] 2-1-2: Configuration of the control device 11 is a block diagram showing an example of the configuration of the control device 10B. The control device 10B differs from the control device 10A in that it includes a processing device 120B instead of the processing device 120A and a storage device 140B instead of the storage device 140A.

[0081] The storage device 140B stores the control program PR1B instead of the control program PR1A stored in the storage device 140A.

[0082] The processing device 120B functions as a first acquisition unit 121, a second acquisition unit 122, an image adjustment unit 123B, an information calculation unit 124, a projection control unit 126B, a first judgment unit 127, and a second judgment unit 128 by reading and executing the control program PR1B from the storage device 140B.

[0083] The first determination unit 127 determines whether or not the current position of the user U in FIG. 8 is a position where at least one of the above-mentioned "first condition" and "second condition" is satisfied.

[0084] The second determination unit 128 is the same component as the determination unit 125 in the first embodiment. Specifically, the second determination unit 128 determines whether the angle θ is equal to or greater than a first angle and equal to or less than a second angle. This condition is an example of a "third condition."

[0085] The image adjustment unit 123B changes the aspect of the corrected image AI obtained by geometrically correcting the original image RI, according to the determination results of the "first condition" and the "second condition" by the first determination unit 127.

[0086] Fig. 12 is a diagram showing an example of the aspect of the corrected image AI when the current position of the user U does not satisfy both the "first condition" and the "second condition." In other words, Fig. 12 is a diagram showing an example of the aspect of the corrected image AI when the viewing angle α is not "the third angle or more and the fourth angle or less," and the viewing angle β is not "the fifth angle or more and the sixth angle or less." For convenience of explanation, the corrected image AI is shown in FIG. 12 in its shape before geometric correction.

[0087] In the example shown in FIG. 12, a frame line FL is placed around the periphery of the corrected image AI, and a crosshair CR is placed in the center of the corrected image AI so as to cross both the vertical and horizontal directions of the corrected image AI.

[0088] The mode of the corrected image AI when the current position of the user U does not satisfy both the "first condition" and the "second condition" is an example of the "first mode." Furthermore, when the current position of the user U satisfies either the "first condition" or the "second condition," the image adjustment unit 123B changes the mode of the corrected image AI according to the determination result of the "third condition" by the second determination unit 128, as in the first embodiment. When the determination result of the "third condition" by the second determination unit 128 is negative, the image adjustment unit 123B sets the mode of the corrected image AI to the "third mode." Furthermore, when the determination result of the "third condition" by the second determination unit 128 is positive, the image adjustment unit 123B sets the mode of the corrected image AI to the "fourth mode." It should be noted that the "first aspect", "third aspect" and "fourth aspect" are different from each other.

[0089] Similar to the projection control unit 126A according to the first embodiment, the projection control unit 126B causes the projector 30 to project the corrected image AI adjusted by the image adjustment unit 123B as a projection image PI including the content image CI onto the projection surface PF of the projection target PO. However, unlike the projection control unit 126A, the projection control unit 126B does not adjust the size, position, or shape of the content image CI on the projection surface PF.

[0090] In this embodiment, the state of the content image CI displayed on the projection surface PF changes depending on the current position of the user U. When the state of the content image CI is the "first state" or the "third state," the user U is prompted to change his or her position within the space SP.

[0091] 2-2: Operation of the control device 13 and 14 are flowcharts showing the operation of the control device 10B.

[0092] In step S11, the processing device 120B functions as the first acquisition unit 121. The processing device 120B acquires an original image RI of the projected image PI.

[0093] In step S12, the processing device 120B functions as the second acquisition unit 122. The processing device 120B acquires the captured image GI from the imaging device 20.

[0094] In step S13, the processing device 120B functions as an image adjustment unit 123B. The processing device 120B performs geometric correction on the original image RI.

[0095] In step S14, the processing device 120B functions as the information calculation unit 124. Based on the captured image GI acquired in step S12, the processing device 120B calculates information indicating the position of the user U relative to the projection target PO in the space SP indicated by the captured image GI.

[0096] In step S15, processing device 120B functions as first determination unit 127. Processing device 120B determines whether or not the viewing angle α is equal to or greater than a third angle and equal to or less than a fourth angle, which satisfies a "first condition." If the determination result is negative ("NO" in step S15), processing device 120B executes the process of step S16. If the determination result is positive ("YES" in step S15), processing device 120B executes the process of step S18.

[0097] In step S16, processing device 120B functions as first determination unit 127. Processing device 120B determines whether or not viewing angle β is equal to or greater than the fifth angle and equal to or less than the sixth angle, which satisfies the "second condition." If the determination result is negative ("NO" in step S16), processing device 120B executes the process of step S17. If the determination result is positive ("YES" in step S16), processing device 120B executes the process of step S18.

[0098] In step S17, the processing device 120B functions as the image adjustment unit 123B. The processing device 120B sets the state of the corrected image AI to the first state. Thereafter, the processing device 120B executes the process of step S21.

[0099] In step S18, the processing device 120B functions as the second determination unit 128. The processing device 120B determines whether the angle θ is equal to or greater than the first angle and equal to or less than the second angle, which satisfies a "third condition." If the determination result is affirmative ("YES" in step S18), the processing device 120B executes the process of step S19. If the determination result is negative ("NO" in step S18), the processing device 120B executes the process of step S20.

[0100] In step S19, the processing device 120B functions as the image adjustment unit 123B. The processing device 120B sets the aspect of the corrected image AI to the fourth aspect.

[0101] In step S20, the processing device 120B functions as the image adjustment unit 123B. The processing device 120B sets the aspect of the corrected image AI to the third aspect.

[0102] In step S21, the processing device 120B functions as the projection control unit 126B. The processing device 120B projects the corrected image AI as a projection image PI.

[0103] 3: Sensory test The contents of the sensory test and the evaluation of the results will be described below with reference to FIGS.

[0104] 3-1: Evaluation of left and right angles To evaluate the optimal left-right angle for each layout of the content image CI displayed on the projection surface PF, eight subjects A to H rated and quantified the visibility of each test specimen of the first content image CI1 to the fourth content image CI4 in four different layouts while changing the width. The eight subjects A to H rated the visibility of the first content image CI1 to the fourth content image CI4 on a four-point scale: "1: Very difficult to view," "2: Somewhat difficult to view," "3: Somewhat easy to view," and "4: Very easy to view." Note that a representative example of the eight subjects A to H will be referred to as "Subject S" hereafter.

[0105] Fig. 15 is a diagram showing a first content image CI1 and a first gaze area WA1 of the subject S. Fig. 16 is a diagram showing a second content image CI2 and a second gaze area WA2 of the subject S. Fig. 17 is a diagram showing a third content image CI3 and a third gaze area WA3 of the subject S. Fig. 18 is a diagram showing a fourth content image CI4 and a fourth gaze area WA4 of the subject S.

[0106] 15, the first content image CI1 is composed of a single first screen MN1. The first gaze area WA1 encompasses the entire first screen MN1. The subject S primarily gazes at the first gaze area WA1 of the first content image CI1 displayed on the projection surface PF. 16, the second content image CI2 is composed of two screens: a first screen MN2[1] and a second screen MN2[2]. The second gaze area WA2 encompasses both the first screen MN2[1] and the second screen MN2[2]. The subject S primarily gazes at the second gaze area WA2 of the second content image CI2 displayed on the projection surface PF. 17, the third content image CI3, like the second content image CI2, is composed of two screens: a first screen MN3[1] and a second screen MN3[2]. The third gaze area WA3 includes only the first screen MN3[1]. The subject S primarily gazes at the third gaze area WA3 of the third content image CI3 displayed on the projection surface PF. As shown in Figure 18, the fourth content image CI4 is composed of three screens: the first screen MN4[1], the second screen MN4[2], and the third screen MN4[3]. The fourth gaze area WA4 includes only the second screen MN4[2]. The subject S primarily gazes at the fourth gaze area WA4 of the fourth content image CI4 displayed on the projection surface PF.

[0107] FIG. 19 is an explanatory diagram of how the widths of the first content image CI1 to the fourth content image CI4 are changed. As shown in FIG. 19, the tester changed the visual angle φ of the first content image CI1 to the fourth content image CI4 while maintaining the first content image CI1 to the fourth content image CI4 in a state where they are symmetrical from the view of the test subject S. The tester also changed the visual angle φ from 60 degrees to 110 degrees in 10-degree increments. Note that, depending on the test environment, the test was conducted at only some of these six angles.

[0108] Fig. 20 is an explanatory diagram of the distance between the subject S and the content image CI displayed on the projection surface PF. As shown in Fig. 20, the test executor conducted the test when the distance between the subject S and the content image CI was 2 m and when it was 3 m.

[0109] 21 to 24 are graphs showing the evaluation results when the distance between the subject S and the content image CI is 2 m.

[0110] Fig. 21 is a graph showing the evaluation results when the first content image CI1 was used. In the graphs of Fig. 21, the graph corresponding to subject A shows the numerical values ​​of the answer results of subject A. The graph corresponding to subject B shows the sum of the numerical values ​​of the answer results of subject A and subject B. Similarly, the graph corresponding to subject H shows the sum of the numerical values ​​of the answer results from subject A to subject H. The same applies to the subsequent graphs.

[0111] As shown in FIG. 21, when the first content image CI1 was used, the test specimens with a visual angle φ of 70 degrees or 80 degrees were evaluated as the highest.

[0112] Fig. 22 is a graph showing the evaluation results when the second content image CI2 was used. As shown in Fig. 22, when the second content image CI2 was used, the evaluation of the test specimen with a viewing angle φ of 70 degrees was the highest.

[0113] Fig. 23 is a graph showing the evaluation results when the third content image CI3 was used. As shown in Fig. 23, when the third content image CI3 was used, the evaluation of the test specimen with a viewing angle φ of 110 degrees was the highest.

[0114] Fig. 24 is a graph showing the evaluation results when the fourth content image CI4 was used. As shown in Fig. 24, when the fourth content image CI4 was used, the evaluation of the test specimen with a viewing angle φ of 90 degrees was the highest.

[0115] 25 to 28 are graphs showing the evaluation results when the distance between the subject S and the content image CI is 3 m.

[0116] Fig. 25 is a graph showing the evaluation results when the first content image CI1 was used. As shown in Fig. 25, when the first content image CI1 was used, the evaluation of the test specimen with a viewing angle φ of 70 degrees was the highest.

[0117] Fig. 26 is a graph showing the evaluation results when the second content image CI2 was used. As shown in Fig. 26, when the second content image CI2 was used, the evaluation of the test specimen with a viewing angle φ of 70 degrees was the highest.

[0118] Fig. 27 is a graph showing the evaluation results when the third content image CI3 was used. As shown in Fig. 27, when the third content image CI3 was used, the evaluation of the test specimen with a viewing angle φ of 100 degrees was the highest.

[0119] Fig. 28 is a graph showing the evaluation results when the fourth content image CI4 was used. As shown in Fig. 28, when the fourth content image CI4 was used, the evaluation of the test specimen with a viewing angle φ of 90 degrees was the highest.

[0120] 29 to 32 are tables showing the aspect ratios of test specimens that were evaluated most highly when each of the first content image CI1 to fourth content image CI4 was used.

[0121] FIG. 29 is a table showing the aspect ratio of the test specimen that was most highly evaluated when the first content image CI1 was used. 29, when the distance between the subject S and the first content image CI1 is 2 m, the optimal viewing angle φ is 70 degrees or 80 degrees. When the viewing angle φ is 70 degrees or 80 degrees, the aspect ratio of the first content image CI1 is 1.83 or 2.19. The same applies to the aspect ratio of the first gaze area WA1. Furthermore, when the distance between the subject S and the first content image CI1 was 3 m, the optimal viewing angle φ was 70 degrees. When the viewing angle φ was 70 degrees, the aspect ratio of the first content image CI1 was 2.1. The same applies to the aspect ratio of the first gaze area WA1.

[0122] FIG. 30 is a table showing the aspect ratio of the test specimen that was evaluated the highest when the second content image CI2 was used. 30, when the distance between the subject S and the second content image CI2 is 2 m, the optimal viewing angle φ is 70 degrees. When the viewing angle φ is 70 degrees, the aspect ratio of the second content image CI2 is 1.83. The same applies to the aspect ratio of the second gaze area WA2. Furthermore, when the distance between the subject S and the second content image CI2 was 3 m, the optimal viewing angle φ was 70 degrees. When the viewing angle φ was 70 degrees, the aspect ratio of the second content image CI2 was 2.1. The same applies to the aspect ratio of the second gaze area WA2.

[0123] FIG. 31 is a table showing the aspect ratio of the test specimen that was evaluated the highest when the third content image CI3 was used. 31, when the distance between the subject S and the third content image CI3 is 2 m, the optimal viewing angle φ is 110 degrees. When the viewing angle φ is 110 degrees, the aspect ratio of the third content image CI3 is 3.73. The aspect ratio of the third gaze area WA3 is 1.87. Furthermore, when the distance between the subject S and the third content image CI3 was 3 m, the optimal viewing angle φ was 100 degrees. When the viewing angle φ was 100 degrees, the aspect ratio of the third content image CI3 was 3.58. The aspect ratio of the third gaze area WA3 was 1.79.

[0124] FIG. 32 is a table showing the aspect ratio of the test specimen that was evaluated the highest when the fourth content image CI4 was used. 32, when the distance between the subject S and the fourth content image CI4 is 2 m, the optimal viewing angle φ is 90 degrees. When the viewing angle φ is 90 degrees, the aspect ratio of the fourth content image CI4 is 2.61. The aspect ratio of the fourth gaze area WA4 is 1.57. Furthermore, when the distance between the subject S and the fourth content image CI4 was 3 m, the optimal viewing angle φ was 90 degrees. When the viewing angle φ was 90 degrees, the aspect ratio of the fourth content image CI4 was 3. The aspect ratio of the fourth gaze area WA4 was 1.98.

[0125] 3-2: Evaluation of vertical angle In order to evaluate the optimal vertical angle for each layout of the content image CI displayed on the projection surface PF, eight subjects A to H rated and quantified the visibility of each test specimen of the fifth content image CI5 to the eighth content image CI8 in four different layouts while changing the vertical width. Specifically, subjects A to H rated the visibility of the fifth content image CI5 to the eighth content image CI8 on a four-point scale: "1: Very difficult to view," "2: Somewhat difficult to view," "3: Somewhat easy to view," and "4: Very easy to view."

[0126] The fifth content image CI5 and the seventh content image CI7 are basically the same image as the first content image CI1. As described below, the tester conducted the test while expanding the fifth content image CI5 upward. Also, as described below, the tester conducted the test while expanding the seventh content image CI7 downward.

[0127] Fig. 33 is a diagram showing a sixth content image CI6, and Fig. 34 is a diagram showing an eighth content image CI8.

[0128] The sixth content image CI6 has a main screen MN6[1] and a sub-screen MN6[2]. In the sixth content image CI6, the sub-screen MN6[2] is adjacent to the upper side of the main screen MN6[1]. As described below, the tester conducted the test while expanding the sub-screen MN6[2] upward. The eighth content image CI8 has a main screen MN8[1] and a sub-screen MN8[2]. In the eighth content image CI8, the sub-screen MN8[2] is adjacent to the bottom of the main screen MN8[1]. As described below, the tester conducted the test while expanding the sub-screen MN8[2] downward.

[0129] 35 to 39 are explanatory diagrams of how to change the vertical widths of the fifth content image CI5 to the eighth content image CI8.

[0130] As shown in Figure 35, the tester changed the visual angle ξ so that the fifth content image CI5 to the eighth content image CI8 were extended upward or downward from a reference line SL, which is at the same height as the line of sight of the test subject S when the line of sight is horizontal. More specifically, the tester changed the visual angle ξ from 15 degrees to 35 degrees upward from the reference line SL. The tester also changed the visual angle ξ from 15 degrees to 30 degrees downward from the reference line SL.

[0131] Fig. 36 is an explanatory diagram of how to change the vertical width of the fifth content image CI5. As shown in Fig. 36, the tester expanded the shape of the area AR5[2] above the reference line SL in the fifth content image CI5 upward while keeping the shape of the area AR5[1] below the reference line SL fixed.

[0132] 37 is an explanatory diagram of how to change the vertical width of the sixth content image CI6. As shown in FIG. 37, the test executor expanded the area of ​​the sub-screen MN6[2] upward in the sixth content image CI6 while keeping the main screen MN6[1] fixed. More specifically, the test executor expanded the area of ​​the sub-screen MN6[2] upward by increasing the number of rows of elements included in the sub-screen MN6[2].

[0133] Fig. 38 is an explanatory diagram of how to change the vertical width of the seventh content image CI7. As shown in Fig. 38, the tester expanded the shape of the area AR7[2] below the reference line SL in the seventh content image CI7 downward, while keeping the shape of the area AR7[1] above the reference line SL fixed.

[0134] 39 is an explanatory diagram of how to change the vertical width of the eighth content image CI8. As shown in FIG. 39, the test executor expanded the area of ​​the sub-screen MN8[2] downward, while keeping the main screen MN8[1] fixed, of the eighth content image CI8. More specifically, the test executor expanded the area of ​​the sub-screen MN8[2] downward by increasing the number of rows of elements included in the sub-screen MN8[2].

[0135] Fig. 40 is a graph showing the evaluation results when the fifth content image CI5 was used. As shown in Fig. 40, when the fifth content image CI5 was used, the evaluation of the test specimen with a visual angle ξ above the reference line SL of 20 degrees was the highest.

[0136] Fig. 41 is a graph showing the evaluation results when the sixth content image CI6 was used. As shown in Fig. 41, when the sixth content image CI6 was used, the evaluation of the test specimen with a visual angle ξ above the reference line SL of 20 degrees was the highest.

[0137] Fig. 42 is a graph showing the evaluation results when the seventh content image CI7 was used. As shown in Fig. 42, when the seventh content image CI7 was used, the evaluation of the test specimens with a visual angle ξ below the reference line SL of 20 degrees or 25 degrees was the highest.

[0138] Fig. 43 is a graph showing the evaluation results when the eighth content image CI8 was used. As shown in Fig. 43, when the eighth content image CI8 was used, the evaluation of the test specimen with a visual angle ξ below the reference line SL of 25 degrees was the highest.

[0139] 3-3: Viewing angle evaluation In order to evaluate the optimal viewing angle for the content image CI displayed on the projection surface PF, the ninth content image CI9 was used as a test object, and eight subjects A to H rated and quantified the visibility of each image while changing their seating position relative to the ninth content image CI9. Specifically, subjects A to H rated the visibility of the ninth content image CI9 on a four-point scale: "1: Very difficult to view," "2: Somewhat difficult to view," "3: Somewhat easy to view," and "4: Very easy to view" while changing their seating position relative to the ninth content image CI9.

[0140] FIG. 44 is a diagram showing a ninth content image CI9. The ninth content image CI9 has a first area AR9[1] and a second area AR9[2]. The first area AR9[1] is, for example, an area where conference materials are displayed. The second area AR9[2] is, for example, an area where images of multiple people are displayed. As shown in FIG. 44, the first area AR9[1] is adjacent to and above the second area AR9[2].

[0141] FIG. 45 is an explanatory diagram of how the seating position of subject S was changed relative to the ninth content image CI9. As shown in FIG. 45, the tester changed the angle ω between the normal NL of the projection surface PF, which passes through the center point P of the ninth content image CI9, and the line SL connecting the center point P and the position of subject S. The tester also changed the angle ω from 0 degrees to 80 degrees in 20-degree increments. The tester also changed the angle ω from 0 degrees to 80 degrees in both the left and right directions as viewed from subject S. The angle ω corresponds to the viewing angle in this embodiment.

[0142] The test executor also conducted the test in two cases: one in which the subject S fixed his / her gaze on the first area AR9[1], and the other in which the subject S fixed his / her gaze on the second area AR9[2].

[0143] Fig. 46 is a graph showing the evaluation results when the subject S fixates the first area AR9[1]. As shown in Fig. 46, when the subject S fixates the first area AR9[1], the seating position where the angle ω is from 40 degrees left to 40 degrees right was evaluated as good.

[0144] Fig. 47 is a graph showing the evaluation results when subject S fixates the second area AR9[2] as the fixation area. As shown in Fig. 47, even when the second area AR9[2] is the fixation area, the seating position where the angle ω is from 40 degrees left to 40 degrees right was evaluated as good.

[0145] 48 and 49 are diagrams showing examples of optimal viewing angles and aspect ratios for the content image CI based on the evaluation results of the sensory test described above.

[0146] 48, when viewing the first content image CI1 composed of a single first screen MN1, the optimal viewing angle is 70 degrees and the optimal aspect ratio is 15.2:9. As an example, it is preferable that the first content image CI1 has a width of 2,800 mm, a height of 1,660 mm, and a height of the base from the floor of 267 mm.

[0147] As shown in Figure 49, when viewing the fourth content image CI4, which is composed of three screens, the first screen MN4[1], the second screen MN4[2], and the third screen MN4[3], the optimal viewing angle is 90 degrees and the optimal aspect ratio is 21.7:9. As an example, it is preferable that the width of the fourth content image CI4 is 4,000 mm, the height is 1,660 mm, and the height of the base from the floor is 267 mm.

[0148] FIG. 50 is a diagram showing an example of an optimum seating position for a content image CI based on the evaluation results of the sensory test.

[0149] As shown in Figure 50, it is preferable that the angle ω formed by the normal NL of the projection surface PF, which passes through the center point P of the content image CI, and the straight line UL connecting the center point P and the position of the user U, be within 40 degrees to the left and right toward the projection surface PF.

[0150] 4: Variation The above embodiments can be modified in various ways. Specific modified embodiments are exemplified below. The embodiments exemplified below and the embodiments described above can be combined as appropriate within the scope of not mutually contradicting each other. Note that for elements in the modified embodiments exemplified below that have the same actions and functions as the embodiments, the reference numerals referenced in the above explanation will be used and detailed explanations of each element will be omitted as appropriate.

[0151] 4-1: Variation 1 The projection system 1A according to the first embodiment includes an imaging device 20 serving as a stereo camera. However, the projection system 1A may include a single imaging device 20 and a ToF (Time of Flight) sensor instead of the imaging device 20 serving as a stereo camera. In this case, the single imaging device 20 captures a captured image GI, and the ToF sensor generates a depth map of the space SP. The information calculation unit 124 calculates information indicating the position of the user U relative to the projection target PO based on the captured image GI and the depth map generated by the ToF sensor. The same applies to the projection system 1B according to the second embodiment.

[0152] 4-2: Variation 2 In the projection system 1A according to the first embodiment, the processing device 120A of the control device 10A may be incorporated into the projector 30, so that the projector 30 operates in the same manner as the control device 10A according to the first embodiment. The same applies to the projection system 1B according to the second embodiment.

[0153] 4-3: Variation 3 In the projection system 1A according to the first embodiment, the control device 10A does not need to include the image adjustment unit 123A and the determination unit 125. In this case, the control device 10A does not change the mode of the corrected image AI to the third mode, but causes the projector 30 to project the corrected image AI as the projection image PI onto the projection surface PF.

[0154] 4-4: Variation 4 In the projection system 1B according to the second embodiment, the control device 10B may not include the second determination unit 128. In this case, the image adjustment unit 123B determines the mode of the corrected image AI based only on the determination results of the "first condition" and the "second condition" by the first determination unit 127. As an example, if the determination results of both the "first condition" and the "second condition" are "negative," the image adjustment unit 123B sets the corrected image AI to the first mode illustrated in FIG. 12. On the other hand, if the determination result of either the "first condition" or the "second condition" is "positive," the image adjustment unit 123B sets the corrected image AI to the mode illustrated in FIG. 5. In this fourth modification, the mode of the corrected image AI when the determination result of either the "first condition" or the "second condition" is "positive" is an example of the "second mode."

[0155] 4-5: Variation 5 In the projection system 1A according to the first embodiment, the projection control unit 126A included in the control device 10A adjusts at least one of the size, position, and shape of the content image CI on the projection surface PF. However, the image adjustment unit 123A, rather than the projection control unit 126A, may adjust the corrected image AI to adjust at least one of the size, position, and shape of the content image CI on the projection surface PF. The same applies to the projection system 1B according to the second embodiment.

[0156] 4-6: Variation 6 In the projection system 1A according to the first embodiment and the projection system 1B according to the second embodiment, the projector 30 projects a projection image PI including a content image CI onto a projection surface PF of a projection target PO. The projection system 1A and the projection system 1B can be used, for example, in a conference system.

[0157] However, the projection system 1A and the projection system 1B may include a liquid crystal display used for signage, etc., instead of the projector 30. In this case, the projection system 1A and the projection system 1B can be used as an advertising system, for example.

[0158] 5: Summary of this disclosure A summary of this disclosure is provided below.

[0159] (Supplementary Note 1) A projection method comprising: projecting a projection image including a content image onto a projection target using a projection device; and adjusting at least one of the size, position, and shape of the content image so as to satisfy at least one of a first condition or a second condition based on information indicating a user's position relative to the projection target, wherein the first condition is that a first viewing angle of the user with respect to the content image in a first direction parallel to a first side of the content image is between 70 degrees and 80 degrees, and the second condition is that a second viewing angle of the user with respect to the content image in a second direction parallel to a second side intersecting the first side is between 40 degrees and 45 degrees.

[0160] This makes it possible to improve the quality of the viewing experience of the user U based on the viewing angle of the user U relative to the projected image PI. Furthermore, the above-mentioned first visual angle range and second visual angle range indicate the range of visual angles within which the user U can comfortably accept information. According to the above configuration, it is possible to adjust at least one of the size, position, and shape of the content image CI so as to satisfy the first condition and the second condition. As a result, a system that makes it easy for the user U to communicate can be provided.

[0161] (Supplementary Note 2) A projection method including: projecting a projection image including a content image onto a projection target using a projection device; determining whether the user's position is a position where at least one of a first condition or a second condition is satisfied based on information indicating the user's position with respect to the projection target; projecting the projection image in a first manner if it is determined that the user's position is a position where neither the first condition nor the second condition is satisfied; and projecting the projection image in a second manner different from the first manner if it is determined that the user's position is a position where at least one of the first condition or the second condition is satisfied, wherein the first condition is that a first viewing angle in a first direction parallel to a first side of the content image is between 70 degrees and 80 degrees, and the second condition is that a second viewing angle in a second direction parallel to a second side intersecting the first side is between 40 degrees and 45 degrees.

[0162] This makes it possible to improve the quality of the viewing experience of the user U based on the viewing angle of the user U relative to the projected image PI. Furthermore, the above-mentioned first viewing angle range and second viewing angle range indicate viewing angle ranges within which the user U can comfortably perceive information. According to the above configuration, the user U can easily determine whether he or she is in an optimal position by checking whether the projection image PI is projected in the first aspect or the second aspect.

[0163] (Supplementary Note 3) The projection method of Supplementary Note 1 includes: determining, based on the information, whether the user's position is a position where a third condition is satisfied; and if it is determined that the user's position is not a position where the third condition is satisfied, projecting the projection image in a third manner; and if it is determined that the user's position is a position where the third condition is satisfied, projecting the projection image in a fourth manner different from the third manner, wherein the third condition is that, in a first direction parallel to a first side of the content image, an angle formed between a normal to a projection surface of the projection target that passes through a center point of the content image and a straight line connecting the intersection of the projection surface and the normal and the user's position is between 20 degrees and 40 degrees.

[0164] This allows the user U to easily determine whether the projection image PI is projected in the third aspect or the fourth aspect, thereby making it possible for the user U to easily determine whether he or she is in an optimal position.

[0165] (Supplementary Note 4) The projection method of Supplementary Note 1, comprising: determining, based on the information, whether the user's position is a position where a third condition is satisfied; adjusting at least one of the size, position, and shape of the content image so as to satisfy at least one of the first condition or the second condition, if it is determined that the user's position is a position where the third condition is satisfied; and projecting, as the projection image, an image indicating that the user's position is inappropriate, if it is determined that the user's position is not a position where the third condition is satisfied, wherein the third condition is that, in a first direction parallel to a first side of the content image, an angle formed between a normal to a projection surface of the projection target and a line connecting the intersection of the projection surface and the normal and the user's position is between 20 degrees and 40 degrees.

[0166] This makes it possible to improve the quality of the viewing experience of the user U based on the seating position of the user U relative to the projection image PI. Furthermore, if it is determined that the position does not satisfy the third condition, an image indicating that the position of the user U is not appropriate is projected as the projection image PI, so that the user U can easily determine whether or not they are in an optimal position.

[0167] (Supplementary Note 5) The projection method according to Supplementary Note 2, comprising: determining, based on the information, whether the user's position is a position where a third condition is satisfied; and if it is determined that the user's position is not a position where the third condition is satisfied, projecting the projection image in a third mode different from the first mode and the second mode; and if it is determined that the user's position is a position where the third condition is satisfied, projecting the projection image in a fourth mode different from the third mode, wherein the third condition is that, in a first direction parallel to a first side of the content image, an angle formed between a normal to a projection surface of the projection target and a line connecting the intersection of the projection surface and the normal and the user's position is between 20 degrees and 40 degrees.

[0168] This makes it possible to improve the quality of the viewing experience of the user U based on the seating position of the user U relative to the projection image PI. Furthermore, if it is determined that the position does not satisfy the third condition, an image indicating that the position of the user U is not appropriate is projected as the projection image PI, so that the user U can easily determine whether or not they are in an optimal position.

[0169] (Supplementary Note 6) The projection method according to Supplementary Note 1 or Supplementary Note 2, wherein information indicating positions of centers of gravity of a plurality of users with respect to the projection target is used as the information indicating the positions of the users with respect to the projection target.

[0170] This makes it possible to execute each control by using the positions of the centers of gravity of the multiple users U as representative positions of the multiple users U.

[0171] (Supplementary Note 7) A projection system including: a projector that projects a projection image including a content image onto a projection target using a projection device; and a control device that adjusts at least one of the size, position, and shape of the content image based on information indicating a user's position relative to the projection target so as to satisfy at least one of a first condition or a second condition, wherein the first condition is that a first viewing angle in a first direction parallel to a first side of the content image is between 70 degrees and 80 degrees, and the second condition is that a second viewing angle in a second direction parallel to a second side that intersects with the first side is between 40 degrees and 45 degrees.

[0172] This makes it possible to improve the quality of the viewing experience of the user U based on the viewing angle of the user U relative to the projected image PI. Furthermore, the above-mentioned first visual angle range and second visual angle range indicate the range of visual angles within which the user U can comfortably accept information. According to the above configuration, it is possible to adjust at least one of the size, position, and shape of the content image CI so as to satisfy the first condition and the second condition. As a result, a system that makes it easy for the user U to communicate can be provided. [Explanation of symbols]

[0173] 1A: Projection system, 1B: Projection system, 10A: Control device, 10B: Control device, 20[1]: First camera, 20[2]: Second camera, 20: Imaging device, 30: Projector, 116: Projection control unit, 120A: Processing device, 120B: Processing device, 121: First acquisition unit, 122: Second acquisition unit, 123A: Image adjustment unit, 123B: Image adjustment unit, 124: Information calculation unit, 125: Determination unit, 126A: Projection control unit, 126B: Projection control unit, 127: First determination unit, 128: Second determination unit, 140A: Storage device, 140B: Storage device, 150: Display device, 160: Input device, 170: communication device, 310: optical device, 320: processing device, 321: acquisition unit, 322: projection control unit, 330: storage device, 340: communication device, A: subject, AI: corrected image, AR5: area, AR7: area, AR9[1]: first area, AR9[2]: second area, B: subject, CD: distance, CI: content image, CI1: first content image, CI2: second content image, CI3: third content image, CI4: fourth content image, CI5: fifth content image, CI6: sixth content image, CI7: seventh content image, CI8: eighth content image Content image, CI9: 9th content image, CR: crosshair, FL: frame line, GI: captured image, GI1: 1st captured image, GI1': 1st captured image, GI2: 2nd captured image, H: subject, H12: edge, L1: communication line, L2: communication line, LU1: edge, LU2: edge, LU4: edge, MN1: 1st screen, MN2[1]: 1st screen, MN2[2]: 2nd screen, MN3[1]: 1st screen, MN3[2]: 2nd screen, MN4[1]: 1st screen, MN4[2]: 2nd screen, MN4[3]: 3rd screen, MN6[1]: main screen, MN6[2]: sub-screen, MN8[1]: main screen ,MN8[2]: Sub-screen, NL: Normal, O: Origin, P: Center point, P1: Vertex, P1': Vertex, P2': Vertex, P4: Vertex, P4': Vertex, PF: Projection surface, PI: Projected image, PO: Projection target, PR1A: Control program, PR1B: Control program, PR3: Control program, RI: Original image, S: Subject, SL: Reference line, SP: Space, U: User, U': User, UD: Distance, W14: Side, WA1: First gaze area, WA2: Second gaze area, WA3: Third gaze area, WA4: Fourth gaze area, α: Visual angle, β: Visual angle, θ: Angle, ξ: Visual angle, φ: Visual angle, ω: Angle

Claims

1. projecting a projection image including a content image onto a projection target by a projection device; adjusting at least one of a size, a position, and a shape of the content image based on information indicating a position of a user relative to the projection target so as to satisfy at least one of a first condition and a second condition; Including, the first condition is that a first viewing angle of the user with respect to the content image in a first direction parallel to a first side of the content image is equal to or greater than 70 degrees and equal to or less than 80 degrees; A projection method, wherein the second condition is that a second viewing angle of the user with respect to the content image in a second direction parallel to a second side intersecting the first side is greater than or equal to 40 degrees and less than or equal to 45 degrees.

2. projecting a projection image including a content image onto a projection target by a projection device; determining whether or not the user's position satisfies at least one of a first condition and a second condition based on information indicating the user's position relative to the projection target; If it is determined that the user's position is a position that does not satisfy either the first condition or the second condition, the projection image is projected in a first manner; When it is determined that the user's position is a position where at least one of the first condition or the second condition is satisfied, projecting the projection image in a second aspect different from the first aspect; Including, the first condition is that a first viewing angle in a first direction parallel to a first side of the content image is equal to or greater than 70 degrees and equal to or less than 80 degrees; The projection method, wherein the second condition is that a second viewing angle in a second direction parallel to a second side intersecting the first side is equal to or greater than 40 degrees and equal to or less than 45 degrees.

3. determining whether the user's location is a location where a third condition is satisfied based on the information; If it is determined that the user's position is not a position where the third condition is satisfied, the projection image is projected in a third manner; When it is determined that the user's position is a position where the third condition is satisfied, projecting the projection image in a fourth aspect different from the third aspect; Including, The third condition is that, in a first direction parallel to a first side of the content image, an angle formed between a normal to a projection surface of the projection target, which passes through a center point of the content image, and a straight line connecting an intersection of the projection surface and the normal to the position of the user is between 20 degrees and 40 degrees. The projection method according to claim 1 .

4. determining whether the user's location satisfies a third condition based on the information; When it is determined that the user's position is a position where the third condition is satisfied, adjusting at least one of a size, a position, and a shape of the content image so as to satisfy at least one of the first condition and the second condition; when it is determined that the user's position is not a position that satisfies the third condition, projecting, as the projection image, an image indicating that the user's position is not appropriate; Including, the third condition is that, in a first direction parallel to a first side of the content image, an angle formed between a normal to a projection surface of the projection target and a line connecting an intersection of the projection surface and the normal to the user's position is greater than or equal to 20 degrees and less than or equal to 40 degrees; The projection method according to claim 1 .

5. determining whether the user's location is a location where a third condition is satisfied based on the information; If it is determined that the user's position is not a position where the third condition is satisfied, the projection image is projected in a third aspect different from the first aspect and the second aspect; When it is determined that the user's position is a position where the third condition is satisfied, projecting the projection image in a fourth aspect different from the third aspect; Including, the third condition is that, in a first direction parallel to a first side of the content image, an angle formed between a normal to a projection surface of the projection target and a line connecting an intersection of the projection surface and the normal to the user's position is greater than or equal to 20 degrees and less than or equal to 40 degrees; The projection method according to claim 2 .

6. information indicating positions of centers of gravity of a plurality of users with respect to the projection target is used as the information indicating the positions of the users with respect to the projection target; The projection method according to claim 1 or 2.

7. a projector that projects a projection image including a content image onto a projection target using a projection device; a control device that adjusts at least one of a size, a position, and a shape of the content image based on information indicating a position of a user relative to the projection target so as to satisfy at least one of a first condition and a second condition; Including, the first condition is that a first viewing angle in a first direction parallel to a first side of the content image is equal to or greater than 70 degrees and equal to or less than 80 degrees; The second condition is that a second viewing angle in a second direction parallel to a second side intersecting the first side is equal to or greater than 40 degrees and equal to or less than 45 degrees.

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