Pattern image detection method, information processing device, detection system, and program

Abstract

To increase the possibility to detect a second pattern image.SOLUTION: A method for detecting a pattern image includes: causing a projector 100 to display a first pattern image PA1; acquiring a first picked-up image PC1 obtained by picking up the first pattern image PA1 by a camera 220; executing processing of detecting a second pattern image PA2 corresponding to the first pattern image PA1 from the first picked-up image PC1; when failing in detecting the second pattern image PA2 from the first picked-up image PC1, executing, on the first picked-up image PC1, first correction processing CP1 of increasing the possibility that detection of the second pattern image PA2 is successful, thereby acquiring a second picked-up image PC2; and executing processing of detecting the second pattern image PA2 from the second picked-up image PC2.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for detecting a pattern image, an information processing apparatus, a detection system, and a program.

Background Art

[0002] Conventionally, various techniques for performing calibration of a projector have been disclosed. For example, Patent Document 1 describes performing the following processing in order to perform calibration of a projector. First, reference points characterizing the four corners of a screen are detected from a captured image captured by a camera. Then, when there is a reference point for which detection has failed among the four corners of the screen, the reference point automatically detected at the time of the previous calibration is used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technique described in Patent Document 1, when a pattern image including a reference point cannot be detected from a captured image, the result of the previous time is used. In this case, when the position of the reference point included in the pattern image in the current captured image is separated from the position of the reference point included in the pattern image in the previous captured image, the detection accuracy of the position of the reference point may decrease. In other words, it is preferable to detect a pattern image from the current captured image.

Means for Solving the Problems

[0005] A method for detecting a pattern image according to one aspect of the present disclosure includes: displaying a first pattern image on a display device; acquiring a first captured image of the first pattern image by a camera; performing a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, performing a first correction process on the first captured image to increase the probability of successful detection of the second pattern image and acquiring a second captured image; and performing a process to detect the second pattern image from the second captured image.

[0006] An information processing device according to another aspect of the present disclosure performs the following actions: displaying a first pattern image on a display device; acquiring a first captured image of the first pattern image captured by a camera; performing a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, performing a first correction process on the first captured image to increase the probability of successful detection of the second pattern image and acquiring a second captured image; and performing a process to detect the second pattern image from the second captured image.

[0007] A detection system according to another aspect of the present disclosure includes a display device, a camera, and an information processing device, wherein the information processing device performs the following: causing the display device to display a first pattern image; acquiring a first captured image of the first pattern image captured by the camera; performing a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, performing a first correction process on the first captured image to increase the probability of successful detection of the second pattern image and acquiring a second captured image; and performing a process to detect the second pattern image from the second captured image.

[0008] A program according to another aspect of the present disclosure causes a computer to perform the following actions: display a first pattern image on a display device; acquire a first captured image of the first pattern image captured by a camera; perform a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, perform a first correction process on the first captured image to increase the probability of successful detection of the second pattern image and acquire a second captured image; and perform a process to detect the second pattern image from the second captured image. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of the configuration of the detection system according to this embodiment. [Figure 2] This figure shows an example of the configuration of a smartphone according to this embodiment. [Figure 3] A diagram showing an example of the first pattern image. [Figure 4] A diagram showing another example of the first pattern image. [Figure 5] A flowchart illustrating an example of smartphone processing. [Figure 6] A flowchart illustrating an example of smartphone processing. [Modes for carrying out the invention]

[0010] The embodiments will be described below with reference to the drawings.

[0011] [1. Detection System Configuration] First, the configuration of the detection system 1 will be described with reference to Figure 1. Figure 1 is a diagram showing an example of the configuration of the detection system 1. As shown in Figure 1, the detection system 1 includes a projector 100 and a smartphone 200. Projector 100 is connected to smartphone 200 in a communication-enabled manner. For example, Projector 100 is connected to smartphone 200 wirelessly in accordance with the Wi-Fi (registered trademark) standard.

[0012] Projector 100 receives, for example, a first pattern image PA1 from a smartphone 200. Then, Projector 100 projects the first pattern image PA1 onto the projection surface SC and displays the projected image PB. The smartphone 200 captures the projected image PB using the camera 220 and generates the first captured image PC1. The smartphone 200 also detects the second pattern image PA2, which corresponds to the first pattern image PA1, from the first captured image PC1. The smartphone 200 then transmits the second pattern image PA2 to the projector 100. Projector 100 compares the first pattern image PA1 and the second pattern image PA2 and performs what is known as "correspondence point detection processing". "Correspondence point detection process" is a process that detects the correspondence between pixels that make up the image projected by the projector 100 and pixels that make up the image captured by the smartphone 200. The first pattern image PA1 will be further explained with reference to Figures 3 and 4. The first captured image PC1 and the second pattern image PA2 will be further explained with reference to Figure 2. Projector 100 corresponds to an example of a "display device". Smartphone 200 corresponds to an example of an "information processing device."

[0013] In this embodiment, a case where the projector 100 is wirelessly communicably connected to the smartphone 200 in accordance with the Wi-Fi (registered trademark) standard will be described, but the present invention is not limited thereto. The projector 100 may be wirelessly communicably connected to the smartphone 200 in accordance with, for example, the Bluetooth (registered trademark) standard. Further, the projector 100 may be wired communicably connected to the smartphone 200 by a cable. The projector 100 may be wired communicably connected to the smartphone 200 by, for example, a USB (Universal Serial Bus) cable.

[0014] [2. Configuration of Projector] Next, the configuration of the projector 100 will be described with reference to FIG. 1. As shown in FIG. 1, the projector 100 includes a projection unit 110 and a drive unit 120 that drives the projection unit 110. The projection unit 110 is an optical device that forms an optical image and projects the image onto the projection surface SC. The projection unit 110 includes a light source unit 111, a light modulation device 112, and a projection optical system 113. The drive unit 120 includes a light source drive unit 121 and a light modulation device drive unit 122.

[0015] The light source unit 111 includes a lamp such as a halogen lamp, a xenon lamp, an ultra-high pressure mercury lamp, or a solid light source such as an LED (Light Emitting Diode) or a laser light source. Further, the light source unit 111 may include a reflector that guides the light emitted from the light source to the light modulation device 112, and an auxiliary reflector. Furthermore, the light source unit 111 may include a lens group, a polarizing plate, or a light control element that reduces the amount of light of the light emitted from the light source on the path to the light modulation device 112 in order to enhance the optical characteristics of the projection light. The light source drive unit 121 is connected to the internal bus 107 and lights and extinguishes the light source of the light source unit 111 in accordance with an instruction from the first control unit 150 that is also connected to the internal bus 107.

[0016] The light modulation device 112 includes, for example, three liquid crystal panels 115 corresponding to the three primary colors of R, G, and B. R indicates red, G indicates green, and B indicates blue. That is, the light modulation device 112 includes a liquid crystal panel 115 corresponding to R-colored light, a liquid crystal panel 115 corresponding to G-colored light, and a liquid crystal panel 115 corresponding to B-colored light. The light emitted by the light source unit 111 is separated into three-color light of RGB and is incident on the corresponding liquid crystal panels 115 respectively. Each of the three liquid crystal panels 115 is a transmissive liquid crystal panel, and modulates the transmitted light to generate image light PL. The image light PL modulated by passing through each liquid crystal panel 115 is synthesized by a synthetic optical system such as a cross dichroic prism and is emitted to the projection optical system 113. Each of the liquid crystal panels 115 may be, for example, a reflective liquid crystal panel or a DMD (Digital Mirror Device), etc.

[0017] The light modulation device 112 is driven by a light modulation device driving unit 122. The light modulation device driving unit 122 is connected to the image processing unit 145. Image data corresponding to each primary color of R, G, and B is input from the image processing unit 145 to the light modulation device driving unit 122. The light modulation device driving unit 122 converts the input image data into a data signal suitable for the operation of the liquid crystal panel 115. Based on the converted data signal, the light modulation device driving unit 122 applies a voltage to each pixel of each liquid crystal panel 115 and draws an image corresponding to the projected image PB on each liquid crystal panel 115. In the present embodiment, the light modulation device driving unit 122 draws a first pattern image PA1 on each liquid crystal panel 115.

[0018] The projection optical system 113 includes lenses, mirrors, etc. that form an image of the incident image light PL on the projection surface SC. Further, the projection optical system 113 may include a zoom mechanism that enlarges or reduces the image projected on the projection surface SC, a focus adjustment mechanism that adjusts the focus, etc.

[0019] The projector 100 further comprises an operation unit 131, a remote control receiver 133, an input interface 135, a storage unit 137, a first communication interface 141, a frame memory 143, an image processing unit 145, and a first control unit 150. The input interface 135, storage unit 137, first communication interface 141, image processing unit 145, and first control unit 150 are connected to each other via an internal bus 107 so as to be able to communicate data.

[0020] The control unit 131 is equipped with various buttons and switches on the surface of the projector 100's housing, and generates operation signals corresponding to the operation of these buttons and switches, and outputs them to the input interface 135. The input interface 135 outputs the operation signals received from the control unit 131 to the first control unit 150.

[0021] The remote control receiver 133 receives infrared signals transmitted from the remote control 5, decodes the received infrared signals, and generates operation signals. The remote control receiver 133 includes, for example, a light-receiving element that receives infrared signals. The remote control receiver 133 outputs the generated operation signals to the input interface 135. The input interface 135 outputs the operation signals input from the remote control receiver 133 to the first control unit 150.

[0022] The storage unit 137 is a non-volatile storage device such as an HDD (Hard Disk Drive) or SSD (Solid State Drive). The storage unit 137 stores programs executed by the first control unit 150, data processed by the first control unit 150, image data, and the like.

[0023] The first communication interface 141 includes a connector and an interface circuit and is connected to the smartphone 200 for communication. In this embodiment, the first communication interface 141 is an interface for communicating with the smartphone 200, for example, in accordance with the Wi-Fi® standard. The first communication interface 141 receives the second pattern image PA2 from the smartphone 200.

[0024] The first control unit 150 includes a first processor 150A and a first memory 150B. The first memory 150B is a storage device that non-volatilely stores programs and data executed by the first processor 150A. The first memory 150B is composed of a magnetic storage device, a semiconductor storage element such as flash ROM (Read Only Memory), or other types of non-volatile storage devices. The first memory 150B may also include RAM (Random Access Memory) which constitutes the work area of ​​the first processor 150A. The first memory 150B may also include a non-volatile storage device such as an HDD or SSD. The first memory 150B stores data processed by the first control unit 150 and the first control program PG1 executed by the first processor 150A.

[0025] The first processor 150A may consist of a single processor, or multiple processors may function as the first processor 150A. The first processor 150A executes the first control program PG1 to control various parts of the projector 100. For example, the first processor 150A outputs to the image processing unit 145 an execution instruction for image processing corresponding to an operation received by the operation unit 131 or the remote control 5, and parameters used for this image processing. The parameters include, for example, geometric correction parameters for correcting the geometric distortion of the projected image PB projected onto the projection surface SC. The first processor 150A also controls the light source drive unit 121 to control the turning on and off of the light source unit 111.

[0026] Each of the drive unit 120, image processing unit 145, and first control unit 150 can be configured, for example, by an integrated circuit. Integrated circuits include LSIs, ASICs (Application Specific Integrated Circuits), and PLDs (Programmable Logic Devices). PLDs include, for example, FPGAs (Field-Programmable Gate Arrays). Furthermore, analog circuits may be included as part of the configuration of the integrated circuit, or it may be a combination of a processor and an integrated circuit. A combination of a processor and an integrated circuit is called a microcontroller (MCU), SoC (System-on-a-chip), system LSI, chipset, etc.

[0027] The image processing unit 145 expands the image data stored in the first memory 150B or the storage unit 137 into the frame memory 143. The frame memory 143 comprises multiple banks. Each bank has a storage capacity capable of writing image data for one frame. The frame memory 143 is configured, for example, as SDRAM (Synchronous Dynamic Random Access Memory).

[0028] The image processing unit 145 performs image processing on the image data expanded in the frame memory 143 according to instructions from the first control unit 150, such as resolution conversion or resizing, distortion correction, shape correction, digital zoom, and adjustment of image color and brightness.

[0029] The first processor 150A of the first control unit 150 executes the following processes, for example, by executing the first control program PG1. The first processor 150A causes the first communication interface 141 to receive the first pattern image PA1 from the smartphone 200. The first processor 150A then displays the first pattern image PA1 on the liquid crystal panel 115 via the optical modulation device drive unit 122. Furthermore, the first processor 150A causes the projection unit 110 to project image light PL representing the first pattern image PA1 onto the projection surface SC via the drive unit 120. In this way, the projector 100 displays the projected image PB corresponding to the first pattern image PA1 on the projection surface SC.

[0030] Furthermore, the first processor 150A causes the first communication interface 141 to receive the second pattern image PA2 from the smartphone 200. The first processor 150A then compares the first pattern image PA1 and the second pattern image PA2 and performs what is known as "correspondence point detection processing".

[0031] [3. Smartphone Configuration] Next, the configuration of the smartphone 200 will be described with reference to Figure 2. Figure 2 is a diagram showing an example of the configuration of the smartphone 200 according to this embodiment. As shown in Figure 2, the smartphone 200 includes a second control unit 210, a camera 220, a display 230, a touch panel 240, and a second communication interface 250.

[0032] The second control unit 210 includes a second processor 210A and a second memory 210B. The second memory 210B is a storage device that non-volatilely stores programs and data executed by the second processor 210A. The second memory 210B is composed of a magnetic storage device, a semiconductor storage element such as flash ROM, or other types of non-volatile storage devices. The second memory 210B may also include RAM which constitutes the work area of ​​the second processor 210A. The second memory 210B may also include a non-volatile storage device such as an SSD. The second memory 210B stores data processed by the second control unit 210 and the second control program PG2 executed by the second processor 210A.

[0033] The second processor 210A may consist of a single processor, or multiple processors may function as the second processor 210A. The second processor 210A executes the second control program PG2 to control the various parts of the smartphone 200.

[0034] Camera 220 is equipped with an image sensor such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) and captures a projected image PB, generating a first captured image PC1. Camera 220 also has an autofocus function. The user positions the smartphone 200 so that the entire projected image PB is included within the imaging area of ​​the camera 220, causing the camera 220 to generate the first captured image PC1.

[0035] The display 230 is equipped with an LCD (Liquid Crystal Display) and displays various images on the LCD according to instructions from the second control unit 210. The touch panel 240 is equipped with a touch sensor and accepts user input. The touch panel 240 also generates an operation signal corresponding to the input and outputs the generated operation signal to the second control unit 210. The touch panel 240 is integrally formed with the LCD display surface of the display 230.

[0036] The second communication interface 250 includes a connector and an interface circuit and is connected to the projector 100 in a communicative manner. In this embodiment, the second communication interface 250 is an interface for communicating with the projector 100, for example, in accordance with the Wi-Fi® standard. The second communication interface 250 transmits the first pattern image PA1 and the second pattern image PA2 to the projector 100 according to instructions from the second control unit 210.

[0037] As shown in Figure 2, the second control unit 210 includes a display instruction unit 211, an acquisition unit 212, a detection unit 213, a correction unit 214, a notification unit 215, a second communication control unit 216, and an image storage unit 217. Specifically, the second processor 210A of the second control unit 210 executes the second control program PG2 stored in the second memory 210B, thereby functioning as the display instruction unit 211, the acquisition unit 212, the detection unit 213, the correction unit 214, the notification unit 215, and the second communication control unit 216. Furthermore, the second processor 210A of the second control unit 210 executes the second control program PG2 stored in the second memory 210B, causing the second memory 210B to function as the image storage unit 217. The second processor, 210A, corresponds to an example of a "computer". The second control program PG2 corresponds to an example of a "program".

[0038] The image storage unit 217 pre-stores the first pattern image PA1. The first pattern image PA1 is read from the image storage unit 217 by the display instruction unit 211.

[0039] The display instruction unit 211 causes the projector 100 to display the first pattern image PA1. The display instruction unit 211 performs the following processes, for example: First, the display instruction unit 211 reads the first pattern image PA1 from the image storage unit 217. Then, the display instruction unit 211 transmits the first pattern image PA1 to the projector 100. The display instruction unit 211 also causes the projector 100 to display the first pattern image PA1 as a projected image PB on the projection surface SC.

[0040] The acquisition unit 212 acquires the first captured image PC1, which is the first pattern image PA1, i.e., the projected image PB, displayed on the projection surface SC, captured by the camera 220. The acquisition unit 212 performs the following processing, for example. First, the acquisition unit 212 instructs the user to position the smartphone 200 so that the entire projected image PB is included in the imaging area of ​​the camera 220. The acquisition unit 212 displays an instruction image on the display 230, for example, indicating that the smartphone 200 should be positioned so that the entire projected image PB is included in the imaging area of ​​the camera 220. Then, when the smartphone 200 is positioned so that the entire projected image PB is included in the imaging area of ​​the camera 220, the acquisition unit 212 instructs the camera 220 to focus on the projected image PB and capture the projected image PB. The camera 220 also captures the projected image PB and generates the first captured image PC1. The acquisition unit 212 acquires the generated first captured image PC1.

[0041] The detection unit 213 executes a process to detect the second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1. The first captured image PC1 includes the first pattern image PA1 displayed on the projection surface SC. The detection unit 213 executes a process to detect the second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1, which includes the first pattern image PA1 displayed on the projection surface SC. Furthermore, the detection unit 213 determines whether the process of detecting the second pattern image PA2 was successful. If the detection unit 213 was able to detect the second pattern image PA2, it determines that the process of detecting the second pattern image PA2 was successful. If the detection unit 213 was unable to detect the second pattern image PA2, it determines that the process of detecting the second pattern image PA2 was unsuccessful.

[0042] In this embodiment, the first pattern image PA1 is, for example, a dot pattern image PD. Alternatively, the first pattern image PA1 may be, for example, a checkerboard pattern image PF. The dot pattern image PD will be explained further with reference to Figure 3. The checkerboard pattern image PF will be explained further with reference to Figure 4.

[0043] If the first pattern image PA1 is a dot pattern image PD, the detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if the following conditions are met. That is, the detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if 90% or more of the dot images PP included in the dot pattern image PD have been detected. In this embodiment, the number of dot images PP is, for example, 1089. Point image PP will be explained further with reference to Figure 3.

[0044] If the first pattern image PA1 is a checkerboard pattern image PF, the detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if the following conditions are met. That is, the detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if all of the first rectangular images PF1 and the second rectangular images PF2 included in the checkerboard pattern image PF of the second pattern image PA2 have been detected. In this embodiment, the number of first rectangular images PF1 and second rectangular images PF2 is 144. The first rectangular image PF1 and the second rectangular image PF2 will be further explained with reference to Figure 4.

[0045] If the detection of the second pattern image PA2 from the first captured image PC1 fails, the correction unit 214 applies a first correction process CP1 to the first captured image PC1 to increase the probability of successful detection of the second pattern image PA2, and acquires the second captured image PC2. The detection unit 213 also executes a process to detect the second pattern image PA2 corresponding to the first pattern image PA1 from the second captured image PC2.

[0046] If the first pattern image PA1 is a dot pattern image PD, the correction unit 214 performs a process to reduce noise contained in the first captured image PC1 as the first correction process CP1. The correction unit 214 performs an averaging process using an averaging filter, for example, as the first correction process CP1. In this embodiment, the case in which the first pattern image PA1 is a dot pattern image PD and the first correction process CP1 is an averaging process using an averaging filter is described, but the embodiment is not limited to this. The first correction process CP1 may be, for example, a high-frequency reduction process using an LPF (Low Pass Filter).

[0047] If the first pattern image PA1 is a checkerboard pattern image PF, the correction unit 214 performs a contrast adjustment process as the first correction process CP1. As the first correction process CP1, the correction unit 214 applies a process to increase the contrast of the first captured image PC1, for example. The following describes the case where the first pattern image PA1 is a checkerboard pattern image PF, and the first correction process CP1 is a contrast adjustment process, but is not limited to this. The correction unit 214 may, for example, apply edge enhancement processing as the first correction process CP1 to the first captured image PC1.

[0048] If the detection of the second pattern image PA2 from the second captured image PC2 fails, the correction unit 214 applies a second correction process CP2 with a stronger correction intensity than the first correction process CP1 to the first captured image PC1 to acquire the third captured image PC3. The detection unit 213 also executes a process to detect the second pattern image PA2 corresponding to the first pattern image PA1 from the third captured image PC3.

[0049] In this embodiment, the case in which the correction unit 214 applies a second correction process CP2, which has a greater correction intensity than the first correction process CP1, to the first captured image PC1 to obtain the third captured image PC3 is described, but the embodiment is not limited to this. The correction unit 214 may also apply the first correction process CP1 to the second captured image PC2 to obtain the third captured image PC3. In this case, the processing of the correction unit 214 can be simplified because the first correction process CP1 is applied repeatedly.

[0050] If detection of the second pattern image PA2 from the second captured image PC2 fails, the correction unit 214 performs the following process. That is, the correction unit 214 performs the correction process CP until the number of executions NP of the correction process CP, including the first correction process CP1, reaches the threshold number NPA, or until the time TP required for the correction process CP reaches the threshold time TPA, thereby acquiring the fourth captured image PC4. The threshold number NPA is, for example, 3 times. The threshold time TPA is, for example, 0.3 seconds.

[0051] In the following explanation, we will describe the case in which the correction unit 214 applies correction processing CP to the first captured image PC1 until the number of executions NP of the correction processing CP, including the first correction processing CP1, reaches the threshold number NPA, thereby acquiring the fourth captured image PC4. Note that the larger the number of executions NP of the correction processing CP, the greater the intensity of the correction processing CP. In other words, the correction processing CP applied this time, i.e., when the number of executions is (NP) times, is stronger than the correction processing CP applied the previous time, i.e., when the number of executions was (NP-1), as the correction processing CP applied this time, i.e., when the number of executions is (NP). Furthermore, each time the correction unit 214 performs the correction process CP, the detection unit 213 performs the process of detecting the second pattern image PA2 on the captured image PC after the correction process CP has been applied. If the detection of the second pattern image PA2 is successful, the correction process CP by the correction unit 214 is terminated. If the detection of the second pattern image PA2 fails, the correction process CP is repeatedly executed. For example, if the detection of the second pattern image PA2 from the third captured image PC3 fails, the detection unit 213 executes a process to detect the second pattern image PA2 from the fourth captured image PC4.

[0052] The notification unit 215 notifies that the detection of the second pattern image PA2 from the fourth captured image PC4 has failed. If the detection of the second pattern image PA2 from the fourth captured image PC4 fails, the notification unit 215 displays, for example, a notification image on the display 230 indicating that the detection of the second pattern image PA2 has failed.

[0053] If the second communication control unit 216 successfully detects the second pattern image PA2, it transmits the second pattern image PA2 to the projector 100. If the detection of the second pattern image PA2 fails, it transmits notification information indicating that the detection of the second pattern image PA2 failed to the projector 100.

[0054] In this embodiment, we will describe a case where the second control unit 210 of the smartphone 200 includes a display instruction unit 211, an acquisition unit 212, a detection unit 213, a correction unit 214, a notification unit 215, a second communication control unit 216, and an image storage unit 217, but we are not limited to this. For example, the first control unit 150 of the projector 100 may include a display instruction unit 211, an acquisition unit 212, a detection unit 213, a correction unit 214, a notification unit 215, a second communication control unit 216, and an image storage unit 217. In this case, the smartphone 200 only needs to include a camera 220. In this case, the detection system 1 includes the projector 100 and the camera 220. In this case, the first processor 150A corresponds to an example of a "processor".

[0055] [4. Specific examples of the first pattern image] Next, an example of the first pattern image PA1 will be described with reference to Figure 3. Figure 3 is a diagram showing an example of the first pattern image PA1. As shown in Figure 3, the first pattern image PA1 is a dot pattern image PD. The lower part of Figure 3 shows the entire dot pattern image PD, and the upper part of Figure 3 shows a magnified view PDP of the first region AR1 of the dot pattern image PD. In the first region AR1, nine point images PP are arranged in a grid. Each point image PP is circular in shape. The point images PP are formed, for example, in black. The point images PP are arranged at equal intervals in the left-right direction. Also, the point images PP are arranged at equal intervals in the up-down direction. In this embodiment, the case in which the point image PP is formed in black is described, but it is not limited to this. The point image PP may be formed in a chromatic color. The point image PP may be formed in red, for example. The point image PP may also be formed in green, for example. The point image PP may also be formed in blue, for example.

[0056] In a dot pattern image PD, the number of dots arranged in the left-right direction, NDH, is, for example, 33. In a dot pattern image PD, the number of dots arranged in the up-down direction, NDV, is, for example, 33. In this case, the number of dot images PP included in the dot pattern image PD is 1089 (=33 × 33). The detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if it can detect 90% or more of the 1089 dot images PP included in the dot pattern image PD from the captured image PC. That is, for example, the detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if it can detect 981 or more dot images PP from the captured image PC. The captured image PC includes the first captured image PC1, the second captured image PC2, the third captured image PC3, and the fourth captured image PC4.

[0057] Next, with reference to Figure 4, another example of the first pattern image PA1 will be described. Figure 4 shows another example of the first pattern image PA1. As shown in Figure 4, the first pattern image PA1 is the checkerboard pattern image PF. The lower part of Figure 4 shows the entire checkerboard pattern image PF, and the upper part of Figure 4 shows a magnified view PFP of the second region AR2 of the checkerboard pattern image PF. In the second region AR2, nine small images PQ are arranged in a grid. The nine small images PQ consist of a first rectangular image PF1 and a second rectangular image PF2. The first rectangular image PF1 and the second rectangular image PF2 are arranged to form a so-called "checkerboard pattern". The first rectangular image PF1 is a rectangular image of the first color C1, and the second rectangular image PF2 is a rectangular image of the second color C2, which is different from the first color C1. The first color C1 is, for example, black, and the second color C2 is, for example, white. In this embodiment, the case where the first color C1 is black and the second color C2 is white is described, but the embodiment is not limited to this. At least one of the first color C1 and the second color C2 may be a chromatic color. For example, the first color C1 may be red, green, or blue, and the second color C2 may be white.

[0058] In the checkerboard pattern image PF, the number of small images PQ arranged in the left-right direction, i.e., the first rectangular image PF1 and the second rectangular image PF2, NFH, is, for example, 16. In the checkerboard pattern image PF, the number of small images PQ arranged in the up-down direction, i.e., the first rectangular image PF1 and the second rectangular image PF2, NFV, is, for example, 9. In this case, the number of small images PQ included in the checker pattern image PF, i.e., the first rectangular image PF1 and the second rectangular image PF2, is 144 (= 16 × 9). The detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if it has detected all of the small images PQ included in the checker pattern image PF, i.e., the first rectangular image PF1 and the second rectangular image PF2, from the captured image PC. In other words, the detection unit 213 determines that the process of detecting the second pattern image PA2 has been successful if, for example, all of the small images PQ, i.e., the first rectangular image PF1 and the second rectangular image PF2, have been detected from the captured image PC. The captured image PC includes the first captured image PC1, the second captured image PC2, the third captured image PC3, and the fourth captured image PC4.

[0059] [5. Smartphone Processing] Next, an example of the processing of the second control unit 210 of the smartphone 200 will be described with reference to Figures 5 and 6. Figures 5 and 6 are flowcharts showing an example of the processing of the second control unit 210 of the smartphone 200. Figures 5 and 6 illustrate the case in which the correction unit 214 applies the correction process CP to the first captured image PC1 until the number of executions NP of the correction process CP, including the first correction process CP1, reaches the threshold number NPA. Figures 5 and 6 also illustrate the case where the threshold number NPA is 3. Furthermore, Figures 5 and 6 illustrate the case in which the projector 100 displays the first pattern image PA1 as a projected image PB on the projection surface SC.

[0060] As shown in Figure 5, in step S101, the acquisition unit 212 acquires the first pattern image PA1, i.e., the projection image PB, which is the first captured image PC1 captured by the camera 220. Next, in step S103, the detection unit 213 executes the process of detecting a second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1. Next, in step S105, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the first captured image PC1 has failed. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the first captured image PC1 has not failed (step S105; NO), the process proceeds to step S107. Then, in step S107, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the first captured image PC1 was successful in order to check for the presence or absence of errors. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the first captured image PC1 has not been successful (step S107; NO), the process returns to step S103. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the first captured image PC1 has been successful (step S107; YES), the process proceeds to step S135 in Figure 6. If there is no need to check for errors, step S107 may be omitted. In this case, if the detection unit 213 determines that the detection process of the second pattern image PA2 from the first captured image PC1 has not failed (step S105; NO), the process may proceed to step S135 in Figure 6.

[0061] If the detection unit 213 determines that the detection process of the second pattern image PA2 from the first captured image PC1 has failed (step S105; YES), the process proceeds to step S109. Then, in step S109, the correction unit 214 performs a first correction process CP1 on the first captured image PC1 to acquire the second captured image PC2. Next, in step S111, the detection unit 213 performs the process of detecting the second pattern image PA2 from the second captured image PC2. Next, in step S113, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the second captured image PC2 has failed. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the second captured image PC2 has not failed (step S113; NO), the process proceeds to step S115. Then, in step S115, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the second captured image PC2 was successful in order to check for the presence or absence of errors. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the second captured image PC2 has not been successful (step S115; NO), the process returns to step S111. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the second captured image PC2 has been successful (step S115; YES), the process proceeds to step S135 in Figure 6. If there is no need to check for errors, step S115 may be omitted. In this case, if the detection unit 213 determines that the detection process of the second pattern image PA2 from the second captured image PC2 has not failed (step S113; NO), the process may proceed to step S135 in Figure 6.

[0062] If the detection unit 213 determines that the detection process of the second pattern image PA2 from the second captured image PC2 has failed (step S113; YES), the process proceeds to step S117. Then, in step S117, the correction unit 214 applies a second correction process CP2 to the first captured image PC1 to acquire a third captured image PC3. The second correction process CP2 is a process that applies a stronger correction than the first correction process CP1. Next, in step S119, the detection unit 213 performs the process of detecting the second pattern image PA2 from the third captured image PC3. Next, in step S121, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the third captured image PC3 has failed. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the third captured image PC3 has not failed (step S121; NO), the process proceeds to step S123. Then, in step S123, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the third captured image PC3 was successful in order to check for the presence or absence of errors. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the third captured image PC3 has not been successful (step S123; NO), the process returns to step S119. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the third captured image PC3 has been successful (step S123; YES), the process proceeds to step S135 in Figure 6. If there is no need to check for errors, step S123 may be omitted. In this case, if the detection unit 213 determines that the detection process of the second pattern image PA2 from the third captured image PC3 has not failed (step S121; NO), the process may proceed to step S135 in Figure 6.

[0063] If the detection unit 213 determines that the detection process of the second pattern image PA2 from the third captured image PC3 has failed (step S121; YES), the process proceeds to step S125 in Figure 6. Then, as shown in Figure 6, in step S125, the correction unit 214 applies a third correction process CP3 to the first captured image PC1 to acquire a fourth captured image PC4. The third correction process CP3 is a process that applies a stronger correction than the second correction process CP2. Next, in step S127, the detection unit 213 performs the process of detecting the second pattern image PA2 from the fourth captured image PC4. Next, in step S129, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the fourth captured image PC4 has failed. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the fourth captured image PC4 has failed (step S129; YES), the process proceeds to step S133. Then, in step S133, the notification unit 215 notifies that the detection of the second pattern image PA2 has failed. After that, the process ends.

[0064] If the detection unit 213 determines that the detection process of the second pattern image PA2 from the fourth captured image PC4 has not failed (step S129; NO), the process proceeds to step S131. Then, in step S131, the detection unit 213 determines whether the detection process of the second pattern image PA2 from the fourth captured image PC4 was successful in order to check for the presence or absence of errors. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the fourth captured image PC4 has not been successful (step S131; NO), the process returns to step S127. If the detection unit 213 determines that the detection process of the second pattern image PA2 from the fourth captured image PC4 has been successful (step S131; YES), the process proceeds to step S135. Then, in step S135, the second communication control unit 216 transmits the second pattern image PA2 to the projector 100. After that, the process ends. If there is no need to check for errors, step S131 may be omitted. In this case, if the detection unit 213 determines that the detection process of the second pattern image PA2 from the fourth captured image PC4 has not failed (step S129; NO), the process may proceed to step S135 in Figure 6.

[0065] In this way, the correction unit 214 repeatedly performs correction processing on the first captured image PC1. Furthermore, each time the correction unit 214 performs correction processing, the detection unit 213 performs detection processing for the second pattern image PA2 on each of the second captured image PC2, third captured image PC3, and fourth captured image PC4 that have been corrected by the correction unit 214. Therefore, the probability of successful detection of the second pattern image PA2 can be increased.

[0066] [6. This Embodiment and its Effects] As described above with reference to Figures 1 to 6, the method for detecting the second pattern image PA2 according to this embodiment includes: displaying the first pattern image PA1 on the projector 100; acquiring a first captured image PC1 of the first pattern image PA1 captured by the camera 220; executing a process to detect the second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1; if the detection of the second pattern image PA2 from the first captured image PC1 fails, applying a first correction process CP1 to the first captured image PC1 to increase the probability of successful detection of the second pattern image PA2 and acquiring a second captured image PC2; and executing a process to detect the second pattern image PA2 from the second captured image PC2. In this configuration, if the detection of the second pattern image PA2 from the first captured image PC1 acquired by the camera 220 fails, the following process is executed. Specifically, a first correction process CP1 is applied to the first captured image PC1 to increase the probability of successfully detecting the second pattern image PA2, and the second captured image PC2 is acquired. Then, the process of detecting the second pattern image PA2 from the second captured image PC2 is executed. Therefore, a first correction process CP1 is applied to the first captured image PC1 to increase the probability of successfully detecting the second pattern image PA2, and the second captured image PC2 is obtained. As a result, the probability of detecting the second pattern image PA2 from the second captured image PC2 is higher than the probability of detecting the second pattern image PA2 from the first captured image PC1. Thus, the probability of detecting the second pattern image PA2 can be increased.

[0067] Furthermore, in the detection method for the second pattern image PA2 according to this embodiment, the first pattern image PA1 is a dot pattern image PD that includes a plurality of dot images PP. In this configuration, the first pattern image PA1 is a dot pattern image PD that includes multiple dot images PP. Therefore, a suitable image can be displayed on the projector 100 as the first pattern image PA1.

[0068] Furthermore, in the detection method for the second pattern image PA2 according to this embodiment, the first correction process CP1 includes a process to reduce noise contained in the first captured image PC1. In this configuration, the first correction process CP1 includes a process to reduce noise contained in the first captured image PC1. Therefore, by applying the first correction process CP1 to the first captured image PC1, a second captured image PC2 can be obtained with reduced noise contained in the first captured image PC1. Thus, the probability of detecting the second pattern image PA2 from the second captured image PC2 can be increased compared to the probability of detecting the second pattern image PA2 from the first captured image PC1. Consequently, the probability of detecting the second pattern image PA2 can be increased.

[0069] Furthermore, in the detection method for the second pattern image PA2 according to this embodiment, the first pattern image PA1 is a checker pattern image PF that includes a first rectangular image PF1 of a first color C1 and a second rectangular image PF2 of a second color C2 different from the first color C1. According to this configuration, the first pattern image PA1 is a checker pattern image PF that includes a first rectangular image PF1 of the first color C1 and a second rectangular image PF2 of the second color C2, which is different from the first color C1. Therefore, a suitable image can be displayed on the projector 100 as the first pattern image PA1.

[0070] Furthermore, in the detection method for the second pattern image PA2 according to this embodiment, the first correction process CP1 includes a contrast adjustment process for the first captured image PC1. In this configuration, the first correction process CP1 includes contrast adjustment processing for the first captured image PC1. Therefore, by applying the first correction process CP1 to the first captured image PC1, a second captured image PC2 can be obtained with enhanced contrast from the first captured image PC1. Thus, the probability of detecting the second pattern image PA2 from the second captured image PC2 can be increased compared to the probability of detecting the second pattern image PA2 from the first captured image PC1. Consequently, the probability of detecting the second pattern image PA2 can be increased.

[0071] Furthermore, in the method for detecting the second pattern image PA2 according to this embodiment, if the detection of the second pattern image PA2 from the second captured image PC2 fails, the method includes applying a second correction process CP2, which has a greater correction intensity than the first correction process CP1, to the first captured image PC1 to obtain a third captured image PC3, and executing a process to detect the second pattern image PA2 from the third captured image PC3. In this configuration, if detection of the second pattern image PA2 from the second captured image PC2 fails, a second correction process CP2 with a stronger correction intensity than the first correction process CP1 is applied to the first captured image PC1 to obtain the third captured image PC3. Then, the process of detecting the second pattern image PA2 from the third captured image PC3 is executed. Therefore, a second correction process CP2, which has a stronger correction intensity than the first correction process CP1, is applied to the first captured image PC1 to obtain the third captured image PC3. This increases the probability of detecting the second pattern image PA2 from the third captured image PC3 compared to detecting the second pattern image PA2 from the second captured image PC2. Thus, the probability of detecting the second pattern image PA2 can be increased.

[0072] Furthermore, in the method for detecting the second pattern image PA2 according to this embodiment, if the detection of the second pattern image PA2 from the second captured image PC2 fails, the method includes applying a first correction process CP1 to the second captured image PC2 to obtain a third captured image PC3, and executing a process to detect the second pattern image PA2 from the third captured image PC3. In this configuration, if the detection of the second pattern image PA2 from the second captured image PC2 fails, the first correction process CP1 is applied to the second captured image PC2 to acquire the third captured image PC3. Then, the process of detecting the second pattern image PA2 from the third captured image PC3 is executed. Therefore, the first correction process CP1 is applied to the second captured image PC2 to acquire the third captured image PC3. This increases the probability of detecting the second pattern image PA2 from the third captured image PC3 compared to detecting the second pattern image PA2 from the second captured image PC2. Thus, the probability of detecting the second pattern image PA2 can be increased.

[0073] Furthermore, in the method for detecting the second pattern image PA2 according to this embodiment, if the detection of the second pattern image PA2 from the second captured image PC2 fails, the correction process CP is performed until the number of executions NP of the correction process CP including the first correction process CP1 reaches a threshold number NPA, or until the time TP required for the correction process CP reaches a threshold time TPA, and the fourth captured image PC4 is acquired; and if the detection of the second pattern image PA2 from the fourth captured image PC4 fails, the failure to detect the second pattern image PA2 is reported. In this configuration, if the detection of the second pattern image PA2 from the second captured image PC2 fails, the following process is executed. Specifically, the correction process CP is performed until the number of executions NP of the correction process CP, including the first correction process CP1, reaches the threshold number NPA, or until the time TP required for the correction process CP reaches the threshold time TPA, and the fourth captured image PC4 is acquired. Then, the process of detecting the second pattern image PA2 from the fourth captured image PC4 is executed. Furthermore, if the detection of the second pattern image PA2 from the fourth captured image PC4 fails, a notification is given that the detection of the second pattern image PA2 has failed. Therefore, the correction process CP is performed until the number of executions NP of the correction process CP reaches the threshold number NPA, or until the time TP required for the correction process CP reaches the threshold time TPA, and the fourth captured image PC4 is acquired. This increases the probability of detecting the second pattern image PA2 from the fourth captured image PC4 compared to detecting the second pattern image PA2 from the second captured image PC2. Thus, the probability of detecting the second pattern image PA2 can be increased. Furthermore, if the detection of the second pattern image PA2 from the fourth captured image PC4 fails, the system notifies the user that the detection of the second pattern image PA2 has failed, allowing the user to confirm that the detection of the second pattern image PA2 has failed.

[0074] Furthermore, the smartphone 200 according to this embodiment performs the following: displaying a first pattern image PA1 on the projector 100; acquiring a first captured image PC1 of the first pattern image PA1 captured by the camera 220; executing a process to detect a second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1; if the detection of the second pattern image PA2 from the first captured image PC1 fails, applying a first correction process CP1 to the first captured image PC1 to increase the probability of successful detection of the second pattern image PA2 and acquiring a second captured image PC2; and executing a process to detect the second pattern image PA2 from the second captured image PC2. With this configuration, the smartphone 200 according to this embodiment achieves the same effect as the detection method for the second pattern image PA2 according to this embodiment.

[0075] The detection system 1 according to this embodiment includes a projector 100, a camera, and a smartphone 200. The smartphone 200 performs the following actions: causes the projector 100 to display a first pattern image PA1; acquires a first captured image PC1 of the first pattern image PA1 captured by the camera; performs a process to detect a second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1; if the detection of the second pattern image PA2 from the first captured image PC1 fails, performs a first correction process CP1 on the first captured image PC1 to increase the probability of successful detection of the second pattern image PA2, acquires a second captured image PC2, and performs a process to detect the second pattern image PA2 from the second captured image PC2. With this configuration, the detection system 1 according to this embodiment achieves the same effect as the detection method for the second pattern image PA2 according to this embodiment.

[0076] The second control program PG2 according to this embodiment causes the second processor 210A to perform the following actions: display a first pattern image PA1 on the projector 100; acquire a first captured image PC1 of the first pattern image PA1 captured by the camera 220; perform a process to detect a second pattern image PA2 corresponding to the first pattern image PA1 from the first captured image PC1; and, if the detection of the second pattern image PA2 from the first captured image PC1 fails, perform a first correction process CP1 on the first captured image PC1 to increase the probability of successful detection of the second pattern image PA2, acquire a second captured image PC2, and perform a process to detect the second pattern image PA2 from the second captured image PC2. With this configuration, the second control program PG2 according to this embodiment has the same effect as the detection method for the second pattern image PA2 according to this embodiment.

[0077] [7. Other Embodiments] The embodiment described above is a preferred embodiment. However, it is not limited to the embodiment described above, and various modifications can be made without departing from the spirit of the invention.

[0078] In this embodiment, the case where the "display device" is a projector 100 is described, but it is not limited to this. The "display device" may be, for example, an LCD, or for example, an organic EL (Electro-Luminescence) display.

[0079] In this embodiment, the case where the "information processing device" is a smartphone 200 is described, but it is not limited to this. The "information processing device" may also be a PDA (Personal Digital Assistant), a tablet device, a personal computer, etc.

[0080] In this embodiment, the case in which the "information processing device" includes a camera 220 is described, but it is not limited to this. The camera may be configured separately from the "information processing device". In this case, the detection system 1 includes a "display device" such as a projector 100, an "information processing device" such as a smartphone 200, and a camera.

[0081] In this embodiment, the case in which the projector 100 performs the so-called "correspondence point detection process" is described, but the embodiment is not limited to this. For example, the smartphone 200 may perform the so-called "correspondence point detection process".

[0082] Furthermore, the functional components shown in Figure 2 represent functional configurations, and their specific implementation forms are not particularly limited. In other words, it is not necessarily required that hardware corresponding to each functional component be implemented individually; it is certainly possible to have a configuration in which a single processor executes a program to realize the functions of multiple functional components. Also, in the above embodiment, some of the functions realized by software may be realized by hardware, or vice versa. In addition, the specific detailed configurations of other parts of the smartphone 200 can be arbitrarily changed without departing from the main purpose.

[0083] Furthermore, the processing units in the flowcharts shown in Figures 5 and 6 are divided according to their main processing content in order to facilitate understanding of the processing of the second control unit 210. The way in which the processing units are divided and the names of the processing units shown in the flowcharts in Figures 5 and 6 do not limit the process; it is possible to further divide the processing into more processing units depending on the processing content, or to divide it so that one processing unit contains even more processing. Also, the processing order in the flowcharts described above is not limited to the examples shown.

[0084] Furthermore, the detection method for the second pattern image PA2 can be implemented by having the second processor 210A of the smartphone 200 execute a second control program PG2 that corresponds to the detection method for the second pattern image PA2. This second control program PG2 can also be recorded on a recording medium that is readable by a computer. Magnetic, optical, or semiconductor memory devices can be used as the recording medium. Specifically, examples include portable or fixed recording media such as flexible disks, HDDs, CD-ROMs (Compact Disk Read Only Memory), DVDs, Blu-ray® Discs, magneto-optical disks, flash memory, and card-type recording media. Alternatively, the recording media may be non-volatile storage devices such as RAM, ROM, and HDDs, which are internal storage devices of image processing equipment. Furthermore, the detection method for the second pattern image PA2 can also be implemented by storing a second control program PG2, which corresponds to the detection method for the second pattern image PA2, in a server device, and then downloading the second control program PG2 from the server device to the smartphone 200.

[0085] In this embodiment, we will describe a case where the second control unit 210 of the smartphone 200 includes a display instruction unit 211, an acquisition unit 212, a detection unit 213, a correction unit 214, a notification unit 215, a second communication control unit 216, and an image storage unit 217, but we are not limited to this. For example, the first control unit 150 of the projector 100 may include a display instruction unit 211, an acquisition unit 212, a detection unit 213, a correction unit 214, a notification unit 215, a second communication control unit 216, and an image storage unit 217. In this case, the smartphone 200 only needs to include a camera 220. In this case, the detection system 1 includes the projector 100 and the camera 220. In this case, the first processor 150A corresponds to an example of a "computer." Also, the first control program PG1 corresponds to an example of a "program."

[0086] In this case, the method for detecting the second pattern image PA2 can be realized by having the first processor 150A of the projector 100 execute a first control program PG1 corresponding to the method for detecting the second pattern image PA2. Furthermore, this first control program PG1 can also be recorded on a recording medium that is readable by a computer. A magnetic, optical, or semiconductor memory device can be used as the recording medium. Specifically, examples include portable or fixed recording media such as flexible disks, HDDs, CD-ROMs, DVDs, Blu-ray® Discs, magneto-optical disks, flash memory, and card-type recording media. Alternatively, the recording media may be non-volatile storage devices such as RAM, ROM, and HDDs, which are internal storage devices of image processing equipment. Furthermore, the detection method for the second pattern image PA2 can also be implemented by storing the first control program PG1, which corresponds to the detection method for the second pattern image PA2, in a server device or the like, and then downloading the first control program PG1 from the server device to the projector 100.

[0087] [8. Summary of this disclosure] A summary of this disclosure is provided below. (Note 1) A method for detecting a pattern image, comprising: displaying a first pattern image on a display device; acquiring a first captured image of the first pattern image by a camera; performing a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, performing a first correction process on the first captured image to increase the probability of successful detection of the second pattern image and acquiring a second captured image; and performing a process to detect the second pattern image from the second captured image.

[0088] This process applies a first correction process to the first captured image to increase the probability of successfully detecting the second pattern image, and then acquires the second captured image. Therefore, the probability of detecting the second pattern image from the second captured image is higher than the probability of detecting it from the first captured image. Thus, the probability of detecting the second pattern image can be increased.

[0089] (Note 2) The method for detecting a pattern image according to Appendix 1, wherein the first pattern image is a dot pattern image containing multiple point images. This allows the display device to show a suitable image as the first pattern image.

[0090] (Note 3) The first correction process includes a process for reducing noise contained in the first captured image, as described in Appendix 2, for the pattern image detection method. This allows for the acquisition of a second image with reduced noise by applying a first correction process to the first image. Therefore, the probability of detecting a second pattern image from the second image is higher than the probability of detecting a second pattern image from the first image. Consequently, the probability of detecting a second pattern image can be increased.

[0091] (Note 4) The method for detecting a pattern image according to Appendix 1, wherein the first pattern image is a checkerboard pattern image including a rectangular image of a first color and a rectangular image of a second color different from the first color. This allows the display device to show a suitable image as the first pattern image.

[0092] (Note 5) The first correction process includes a contrast adjustment process for the first captured image, as described in Appendix 4, for the pattern image detection method. This allows for the acquisition of a second image with enhanced contrast by applying a first correction process to the first image. Therefore, the probability of detecting a second pattern image from the second image is higher than the probability of detecting a second pattern image from the first image. Consequently, the probability of detecting a second pattern image can be increased.

[0093] (Note 6) A method for detecting a pattern image according to any one of Appendix 1 to Appendix 5, comprising: if the detection of the second pattern image from the second captured image fails, applying a second correction process with a greater correction intensity than the first correction process to the first captured image to obtain a third captured image; and executing a process to detect the second pattern image from the third captured image. This allows a second correction process, with a stronger correction intensity than the first correction process, to be applied to the first captured image, thereby acquiring a third captured image. Consequently, the probability of detecting the second pattern image from the third captured image is increased compared to the probability of detecting the second pattern image from the second captured image. Therefore, the probability of detecting the second pattern image can be increased.

[0094] (Note 7) A method for detecting a pattern image according to any one of Appendix 1 to Appendix 5, comprising: if the detection of the second pattern image from the second captured image fails, applying the first correction process to the second captured image to obtain a third captured image; and executing a process to detect the second pattern image from the third captured image. This allows the second captured image to undergo a first correction process, thereby acquiring a third captured image. Consequently, the probability of detecting the second pattern image from the third captured image is increased compared to the probability of detecting the second pattern image from the second captured image. Therefore, the probability of detecting the second pattern image can be increased.

[0095] (Note 8) A method for detecting a pattern image according to any one of Appendix 1 to Appendix 7, comprising: if detection of the second pattern image from the second captured image fails, performing the correction process until the number of executions of the correction process including the first correction process reaches a threshold number of executions, or until the time required for the correction process reaches a threshold time, thereby acquiring a fourth captured image; executing a process to detect the second pattern image from the fourth captured image; and if detection of the second pattern image from the fourth captured image fails, notifying that detection of the second pattern image has failed. This allows the system to perform correction processing until the number of correction processing attempts reaches a threshold number, or until the time required for correction processing reaches a threshold time, thereby acquiring the fourth image. This increases the probability of detecting the second pattern image from the fourth image compared to detecting it from the second image. Therefore, the probability of detecting the second pattern image is increased. Furthermore, if detection of the second pattern image from the fourth image fails, the system notifies the user of this failure, allowing them to confirm that the detection of the second pattern image has failed.

[0096] (Note 9) An information processing device that performs the following actions: displaying a first pattern image on a display device; acquiring a first captured image of the first pattern image using a camera; performing a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, performing a first correction process on the first captured image to increase the probability of successful detection of the second pattern image, and acquiring a second captured image; and performing a process to detect the second pattern image from the second captured image. As a result, the information processing device described in Appendix 9 has the same effect as the pattern image detection method described in Appendix 1.

[0097] (Note 10) A detection system comprising a display device, a camera, and an information processing device, wherein the information processing device performs the following: causing the display device to display a first pattern image; acquiring a first captured image of the first pattern image captured by the camera; performing a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, performing a first correction process on the first captured image to increase the probability of successful detection of the second pattern image and acquiring a second captured image; and performing a process to detect the second pattern image from the second captured image. As a result, the detection system described in Appendix 10 has the same effect as the pattern image detection method described in Appendix 1.

[0098] (Note 11) A program that causes a computer to perform the following actions: display a first pattern image on a display device; acquire a first captured image of the first pattern image using a camera; perform a process to detect a second pattern image corresponding to the first pattern image from the first captured image; if the detection of the second pattern image from the first captured image fails, perform a first correction process on the first captured image to increase the probability of successful detection of the second pattern image, acquire a second captured image, and perform a process to detect the second pattern image from the second captured image. As a result, the program described in Appendix 11 has the same effect as the pattern image detection method described in Appendix 1. [Explanation of symbols]

[0099] 1...Display system, 100...Projector (display device), 110...Projection unit, 112...Optical modulation device, 115...Liquid crystal panel, 150...First control unit, 150A...First processor (computer), 150B...First memory, 200...Smartphone (information processing device), 210A...Second processor (computer), 210B...Second memory, 211...Display instruction unit, 212...Acquisition unit, 213...Detection unit, 214...Correction unit, 215...Notification unit, 216...Second communication control unit, 217...Image storage unit, 220...Camera, 230...D Display, 240...Touch panel, Second communication interface, CP...Correction processing, CP1...First correction processing, CP2...Second correction processing, CP3...Third correction processing, PA1...First pattern image, PA2...Second pattern image, PC...Captured image, PC1...First captured image, PC2...Second captured image, PC3...Third captured image, PC4...Fourth captured image, PD...Dot pattern image, PF...Checker pattern image, PF1...First rectangular image, PF2...Second rectangular image, PG1...First control program, PG2...Second control program (program).

Claims

1. To display the first pattern image on the display device, The first pattern image is captured by a camera to obtain a first captured image, The process of detecting a second pattern image corresponding to the first pattern image from the first captured image is performed, If the detection of the second pattern image from the first captured image fails, A first correction process is applied to the first captured image to increase the probability of successful detection of the second pattern image, thereby acquiring a second captured image. The process of detecting the second pattern image from the second captured image is performed, A method for detecting pattern images, including [specific details omitted].

2. The method for detecting a pattern image according to claim 1, wherein the first pattern image is a dot pattern image containing a plurality of point images.

3. The method for detecting a pattern image according to claim 2, wherein the first correction process includes a process for reducing noise contained in the first captured image.

4. The method for detecting a pattern image according to claim 1, wherein the first pattern image is a checkerboard pattern image including a rectangular image of a first color and a rectangular image of a second color different from the first color.

5. The method for detecting a pattern image according to claim 4, wherein the first correction process includes a contrast adjustment process for the first captured image.

6. If detection of the second pattern image from the second captured image fails, A third image is obtained by applying a second correction process, which has a greater correction intensity than the first correction process, to the first image. The process of detecting the second pattern image from the third captured image is performed, A method for detecting a pattern image according to any one of claims 1 to 5, including the method described in any one of claims 1 to 5.

7. If detection of the second pattern image from the second captured image fails, The second captured image is subjected to the first correction process to obtain a third captured image, The process of detecting the second pattern image from the third captured image is performed, A method for detecting a pattern image according to any one of claims 1 to 5, including the method described in any one of claims 1 to 5.

8. If detection of the second pattern image from the second captured image fails, The correction process is performed until the number of times the correction process, including the first correction process, is executed reaches a threshold number of times, or until the time required for the correction process reaches a threshold time, thereby acquiring a fourth image. The process of detecting the second pattern image from the fourth ROM image is performed, If the detection of the second pattern image from the fourth captured image fails, the system will notify that the detection of the second pattern image has failed. A method for detecting a pattern image according to any one of claims 1 to 5, including the method described in any one of claims 1 to 5.

9. To display the first pattern image on the display device, The first pattern image is captured by a camera to obtain a first captured image, The process of detecting a second pattern image corresponding to the first pattern image from the first captured image is performed, If the detection of the second pattern image from the first captured image fails, A first correction process is applied to the first captured image to increase the probability of successful detection of the second pattern image, thereby acquiring a second captured image. The process of detecting the second pattern image from the second captured image is performed, An information processing device that performs this task.

10. Includes a display device, a camera, and an information processing device. The aforementioned information processing device The display device is to display the first pattern image, The first pattern image is obtained by acquiring a first image captured by the camera, The process of detecting a second pattern image corresponding to the first pattern image from the first captured image is performed, If the detection of the second pattern image from the first captured image fails, A first correction process is applied to the first captured image to increase the probability of successful detection of the second pattern image, thereby acquiring a second captured image. The process of detecting the second pattern image from the second captured image is performed, A detection system that performs this task.

11. To display the first pattern image on the display device, The first pattern image is captured by a camera to obtain a first captured image, The process of detecting a second pattern image corresponding to the first pattern image from the first captured image is performed, If the detection of the second pattern image from the first captured image fails, A first correction process is applied to the first captured image to increase the probability of successful detection of the second pattern image, thereby acquiring a second captured image. The process of detecting the second pattern image from the second captured image is performed, A program that causes a computer to execute something.

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