Projection image correction method, projection equipment and storage medium
By capturing a single image for both in-screen and internal distortion correction using stored parameters, the method addresses the inefficiencies of existing two-image calibration methods, improving user experience and efficiency in laser projection systems.
Patent Information
- Application Number
- CN202410050030.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2025-07-15
AI Technical Summary
Existing laser projection equipment requires users to take two photo photos when correcting image distortion, resulting in cumbersome correction process, low efficiency and poor user experience.
By receiving a captured image once, the image acquisition device on the projection host acquires the image of the projection screen and the in-screen correction image card, and combines the pre-stored correction parameters to automatically calculate the in-screen and internal correction parameters to achieve efficient correction of the projection image.
The projected image correction process is simplified, the correction efficiency is improved, the user experience is improved, and the number of user operations is reduced.
Smart Images
Figure CN120321375A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the field of display technology. More specifically, it relates to a method for correcting a projection image, a projection device, and a storage medium. Background Art
[0002] Most laser projections are ultra-short throw projections. The distance between the projection host and the screen is relatively close, and a slight touch will cause the projection image of the projection host to deviate from the screen. Currently, automatic geometric correction can be performed by taking a photo with a terminal device (such as a mobile phone) to align the projection image with the screen. In the screen paired with the projection host, there may be a situation where the screen material in some areas is uneven, resulting in image distortion of the image projected by the projection host on the projection screen. For the distortion phenomenon, internal distortion correction is required to correct the image flat.
[0003] Currently, when correcting the possible distortion phenomenon of laser projection, it is usually achieved through external screen entry correction and internal distortion correction. When performing external screen entry correction, the user needs to take and upload a chart card displayed on the projection screen. The projection host aligns the projection image with the screen edge based on the first chart card photo uploaded by the user to complete image entry into the screen. After completing the image entry into the screen, for internal distortion correction, the user needs to take and upload the chart card displayed on the projection screen again, and the projection host performs distortion image correction based on the second chart card photo uploaded by the user.
[0004] However, the above correction method requires the user to take and upload two chart card photos to complete the distortion image correction. The correction method is relatively cumbersome, the correction efficiency is low, and the user experience is poor. Summary of the Invention
[0005] Exemplary embodiments of the present application provide a method for correcting a projection image, a projection device, and a storage medium, which can improve the correction efficiency of laser projection devices and enhance the efficiency.
[0006] In a first aspect, the present application provides a method for correcting a projection image, including:
[0007] Projecting a projection image where an in-screen correction chart card is located on the projection screen;
[0008] Receiving a captured image obtained by photographing the projection screen, where the captured image includes the projection screen and the in-screen correction chart card;
[0009] Processing the captured image to obtain target in-screen correction parameters;
[0010] Performing in-screen correction on the projection image of the projection screen according to the target in-screen correction parameters;
[0011] According to the target screen entry correction parameters and the pre-stored correction parameters, perform internal correction on the projection image including the internal correction chart card, and the projection image including the internal correction chart card is pre-stored.
[0012] In some embodiments of the present application, the pre-stored correction parameters include the conversion relationship between the screen entry correction parameters and the internal correction parameters, and the conversion relationship is stored when the projection device is first installed;
[0013] The correcting the projection image of the projection screen according to the screen entry correction parameters and the pre-stored correction parameters includes:
[0014] According to the target screen entry parameters and the conversion relationship, determine the target internal correction parameters corresponding to the target screen entry parameters;
[0015] Use the target screen entry parameters and the target internal correction parameters to correct the projection image of the projection screen.
[0016] In some embodiments of the present application, the target screen entry parameters include a first coordinate set of the four vertices of the projection screen in the projection coordinate system; the pre-stored correction parameters further include the positional relationship between the first feature points in the internal correction chart card and the projection screen, and the internal correction chart card is the internal correction chart card used when the projection device is first installed;
[0017] The determining the target internal correction parameters corresponding to the target screen entry parameters according to the target screen entry parameters and the conversion relationship includes:
[0018] According to the first coordinate set of the four vertices of the projection screen in the projection coordinate system and the positional relationship, determine a second coordinate set of the first feature points in the internal correction chart card in the projection coordinate system;
[0019] According to the second coordinate set and the positional deviation parameters included in the conversion relationship, determine the target internal correction parameters.
[0020] In some embodiments of the present application, the processing the captured image to obtain the target screen entry correction parameters includes:
[0021] In the captured image, determine a third coordinate set of the second feature points in the screen entry correction chart card in the photo coordinate system and a fourth coordinate set of the second feature points in the projection coordinate system;
[0022] According to the third coordinate set and the fourth coordinate set, determine the feature matrix;
[0023] Determine a fifth coordinate set of the four vertices of the projection screen in the photo coordinate system;
[0024] Based on the feature matrix and the fifth coordinate set, obtain a first coordinate set of the four vertices of the projection screen in the projection coordinate system to determine the target in-screen calibration parameter.
[0025] In some embodiments of the present application, the method further includes:
[0026] When the projection device is installed for the first time, determine the in-screen calibration parameter according to the received first captured image of the projection screen, where the first captured image includes the projection screen and the in-screen calibration card;
[0027] According to the received second captured image of the projection screen and the in-screen calibration parameter, determine the positional relationship between the first feature point in the internal calibration card and the projection screen, the position deviation parameter, and the internal calibration parameter, where the second captured image includes the projection screen and the internal calibration card;
[0028] Store the positional relationship and the position deviation parameter, and correct the projection image of the projection screen according to the in-screen calibration parameter and the internal calibration parameter.
[0029] In some embodiments of the present application, the determining the positional relationship between the first feature point in the internal calibration card and the projection screen, the position deviation parameter, and the internal calibration parameter according to the received second captured image of the projection screen and the in-screen calibration parameter includes:
[0030] Determine the positional relationship between the first feature point and the projection screen, and the reference coordinate set of the first feature point in the projection coordinate system;
[0031] In the second captured image, determine the sixth coordinate set of the first feature point in the photo coordinate system;
[0032] Transform the sixth coordinate set to the projection coordinate system to obtain the transformed sixth coordinate set;
[0033] Determine the position deviation parameter of the first feature point according to the reference coordinate set and the transformed sixth coordinate set;
[0034] Determine the internal calibration parameter according to the position deviation parameter of the first feature point and the reference coordinate set.
[0035] In some embodiments of the present application, the receiving the captured image of the projection screen includes:
[0036] Receiving a captured image obtained by the image capturing device photographing the projection screen, where the image capturing device is a device installed on the projection host of the projection device.
[0037] In a second aspect, the present application provides a projection device, which includes: a projection host and a projection screen;
[0038] The projection host is configured to:
[0039] Projecting a projection image where the in-screen calibration chart card is located onto the projection screen;
[0040] Receiving a captured image obtained by photographing the projection screen, where the captured image includes the projection screen and the in-screen calibration chart card;
[0041] Processing the captured image to obtain target in-screen calibration parameters;
[0042] Performing in-screen calibration on the projection image of the projection screen according to the target in-screen calibration parameters;
[0043] Performing internal calibration on the projection image including the internal calibration chart card according to the target in-screen calibration parameters and the pre-stored calibration parameters, where the projection image including the internal calibration chart card is pre-stored.
[0044] In a third aspect, the present application provides a computer-readable storage medium, on which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, the method described in the second aspect is implemented.
[0045] The computer-readable storage medium provided in the embodiments of the present application can execute the technical solutions in the above method embodiments, and the beneficial effects are similar, so details will not be described here again.
[0046] In a fourth aspect, the present application provides a computer program product, including a computer program, where when the computer program is executed by a processor, the method described in the second aspect is implemented.
[0047] The computer program product provided in the embodiments of the present application can execute the technical solutions in the above method embodiments, and the beneficial effects are similar, so details will not be described here again. Description of the Drawings
[0048] To more clearly illustrate the embodiments of the present application or the implementation manners in the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.
[0049] Figure 1 The intention of an existing method for correcting a projected image provided by an embodiment of this application;
[0050] Figure 2 Schematic diagrams of two external in-curtain correction feature cards provided by an embodiment of this application;
[0051] Figure 3 Schematic diagram of a user taking an image of a card provided by an embodiment of this application;
[0052] Figure 4 Schematic diagram of an internal correction card provided by an embodiment of this application;
[0053] Figure 5 Schematic flowchart of a method for correcting a projected image provided by an embodiment of this application;
[0054] Figure 6 Schematic flowchart of another method for correcting a projected image provided by an embodiment of this application;
[0055] Figure 7 Schematic flowchart of yet another method for correcting a projected image provided by an embodiment of this application;
[0056] Figure 8 Schematic diagram of a method for correcting a projected image provided by an embodiment of this application;
[0057] Figure 9 Schematic diagram of the architecture of a geometric correction system provided by an embodiment of this application;
[0058] Figure 10 Schematic diagram of a distorted image provided by an embodiment of this application;
[0059] Figure 11 Schematic diagram of the structure of a projection device provided by an embodiment of this application. Detailed implementation manners
[0060] To make the purpose, implementation manners, and advantages of this application clearer, the following will clearly and completely describe the exemplary implementation manners of this application with reference to the accompanying drawings in the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only a part of the embodiments of this application, rather than all the embodiments.
[0061] Based on the exemplary embodiments described in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the claims of this application. In addition, although the disclosure in this application is introduced according to one or several exemplary instances, it should be understood that each aspect of these disclosures can also constitute a complete implementation manner alone.
[0062] It should be noted that the brief description of the terms in this application is only for facilitating the understanding of the following described embodiments, rather than intending to limit the embodiments of this application. Unless otherwise specified, these terms should be understood in their ordinary and common meanings.
[0063] In this application, terms such as "first", "second", "third", etc. in the specification, claims and the above-mentioned drawings are used to distinguish similar or like objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise indicated. It should be understood that such terms can be interchanged under appropriate circumstances, for example, it is possible to implement according to an order other than those given in the illustration or description of the embodiments of this application.
[0064] In addition, the terms "include" and "have" and any variations thereof are intended to cover but not exclusively include. For example, a product or device that includes a series of components does not necessarily have to be limited to those components clearly listed, but may include other components that are not clearly listed or are inherent to these products or devices.
[0065] The term "module" used in this application refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or a combination of hardware or / and software code that can perform functions related to that element.
[0066] Projection devices usually use a projection host and a projection screen in combination. The projection host projects an image on the projection screen through a projection beam. However, there may be a situation where the material of some areas of the projection screen is uneven, resulting in image distortion on the projection screen. Therefore, it is necessary to correct the projection image when it enters the screen and the screen, as well as the distortion of the image projected by the projection host due to the unevenness of the screen material.
[0067] In some implementations, the projection host can achieve the correction of the projection image through in-screen correction and internal correction. Specifically, refer to Figure 1 as shown Figure 1 which is the intention of an existing method for correcting a projection image provided by an embodiment of this application.
[0068] As Figure 1 shown, the method for correcting a projection image in the prior art may include the following steps:
[0069] S101. Start the automatic correction application program.
[0070] S102. The user adjusts the position between the laser TV body and the screen.
[0071] S103. Start the correction, and the projection screen displays an in-screen correction chart card.
[0072] The external in-screen calibration chart card displayed on the projection screen can be referred to Figure 2 as shown in Figure 2 the schematic diagrams of two external in-screen calibration feature chart cards for example.
[0073] S104. The user uses the terminal to take an image of the in-screen calibration chart card and uploads the image.
[0074] Taking the chart card A projected on the projection screen Figure 2 as an example, the scene where the user uses the terminal to take an image of the chart card A can be referred to Figure 3 as shown in Figure 3 which is a schematic diagram of a user taking an image of a chart card provided by an embodiment of the present application.
[0075] As Figure 3 shown, the projection host 101 can project onto the projection screen 102. The outline of the projection image projected by the projection host 101 in the projection screen 102 is different from the outline of the projection screen 102, and the projection image is distorted. In Figure 3 it, the dashed box is the outline of the projection image.
[0076] As Figure 3 shown, when performing in-screen calibration, the projection host 101 can project and display the chart card A on the projection screen 102. The user can use their own terminal to take an image of the chart card A on the projection screen 102 and can send the taken image to the projection host 101, so that the projection host 101 can perform in-screen calibration according to the image sent by the user.
[0077] S105. Whether the user is satisfied with the in-screen calibration effect.
[0078] The projection host performs recognition processing on the captured image through an external in-screen calibration algorithm, aligns the projection image with the edge of the projection screen through the obtained calibration parameters, and completes the in-screen of the projection image. The user can view the effect of the in-screen calibration. If satisfied, a satisfied instruction can be input, and the projection host can execute step S106 according to this instruction; if not satisfied, a dissatisfied instruction can be input, and the projection host can continue to project the in-screen calibration chart card onto the projection screen and can return to step S104.
[0079] S106. The projection screen displays an internal calibration chart card.
[0080] The projection host can project an internal calibration chart card according to the four vertices of the projection image obtained after completing the in-screen calibration, so that the projection screen displays the internal calibration chart card.
[0081] The internal calibration chart card displayed on the projection screen can be referred to Figure 4 as shown in Figure 4A schematic diagram of an internal calibration chart provided by an embodiment of the present application. As Figure 4 shown, the internal calibration chart displayed on the projection screen can be a checkerboard with alternating black and white squares.
[0082] S107. The user uses the terminal to capture an image of the internal calibration chart and upload the image.
[0083] The scenario where the user captures an image of the internal calibration chart is similar to that of capturing an image of the in-screen calibration chart. Refer to the above Figure 2 shown.
[0084] S108. Whether the user is satisfied with the internal calibration effect.
[0085] The projection host performs recognition processing on the captured image to obtain internal calibration parameters, and uses the internal calibration to correct the distorted image, completing the internal calibration. The user can view the effect of the internal calibration. If satisfied, the user can input a satisfied instruction, and the projection host can execute step S109 according to this instruction; if not satisfied, the user can input a dissatisfied instruction, and the projection host can continue to project the internal calibration chart onto the projection screen and return to step S107.
[0086] It should be noted that the internal calibration can be understood as correcting the distortion inside the image projected by the projection host onto the projection screen.
[0087] S109. The projection screen displays a prompt message indicating that the calibration is completed.
[0088] However, in the above implementation, when the projection host performs in-screen calibration, the user needs to capture an image of a chart. When performing internal calibration, the user also needs to capture an image of a chart, making the image calibration process relatively cumbersome, with low calibration efficiency and affecting the user experience.
[0089] Based on this, an embodiment of the present application provides a method for calibrating a projection image. When calibrating the projection image, only the captured image obtained by capturing the projection screen during in-screen calibration needs to be received to obtain the in-screen calibration parameters, and then the projection image on the projection screen can be calibrated according to the in-screen calibration parameters and the pre-stored calibration parameters. In this way, only one captured image needs to be received, and the user does not need to use the terminal to capture images twice, which can simplify the projection image calibration process, improve the projection calibration efficiency, and enhance the user experience.
[0090] It should be noted that the projection image calibration method provided by the embodiment of the present application can be an automatic calibration performed after the projection device is first installed.
[0091] Exemplarily, after the projection device is installed, if during the use of the projection device, the user finds that the projection screen is distorted, the projection device can be operated to start the automatic correction application program installed on the projection device. After the application program is started, the projection image correction method provided by the embodiments of the present application can be used to correct the projection image, so that the corrected projection image fits better with the projection screen and improves the user experience.
[0092] Figure 5 FIG. is a schematic flow chart of a projection image correction method provided by an embodiment of the present application, and the execution subject may be Figure 3 the projection host 101 therein, or a projection image correction device provided in the projection host 101. This device may be a chip, a chip module, or an integrated development environment (IDE), etc. Hereinafter, taking the projection host as the execution subject as an example for description, refer to Figure 5 , including the following steps:
[0093] S501. Project the projection image where the in-screen calibration card is located onto the projection screen.
[0094] When the projection host corrects the projection image on the projection screen, the projection host can project the in-screen calibration card onto the projection screen.
[0095] It can be understood that the projection image on the projection screen may include an in-screen calibration card. And the outline of the projection image is different from the outline of the projection screen, and the projection image is distorted.
[0096] It should be noted that the in-screen calibration card in this step may be projected by the projection host onto the projection screen when the automatic correction application program installed in the projection device is started. The in-screen calibration card may be any one of the cards in Figure 2 or Figure 3 , or other cards. The embodiments of the present application do not make specific limitations on the in-screen calibration card.
[0097] S502. Receive the captured image obtained by photographing the projection screen. The captured image includes the projection screen and the in-screen calibration card.
[0098] Exemplarily, the projection host receiving the captured image obtained by photographing the projection screen may include the following two possible implementations:
[0099] In one possible implementation, an image acquisition device for image acquisition may be installed on the projection host. When the projection host projects the projection image where the in-screen calibration card is located onto the projection screen, the projection host may control the image acquisition device to capture the projection screen and receive the captured image obtained by the image acquisition device.
[0100] Exemplarily, the image acquisition device installed on the projection host for image acquisition may be a device such as a camera, and the embodiments of the present application do not limit this.
[0101] In this way, when the in-screen calibration card is displayed on the projection screen, it is not necessary for the user to use the terminal to capture the image of the projection screen. Instead, the image acquisition device installed on the projection host can be used for capturing, which can improve the efficiency of in-screen calibration and further improve the efficiency of projection image calibration.
[0102] In another possible implementation, when the projection host projects the projection image where the in-screen calibration card is located onto the projection screen, the projection screen displays a capture prompt interface, and the user can capture the projection screen through the terminal device to obtain a captured image, which includes the projection screen and the in-screen calibration card.
[0103] S503. Process the captured image to obtain the target in-screen calibration parameter.
[0104] S504. Perform in-screen calibration on the projection image of the projection screen according to the target in-screen calibration parameter.
[0105] Align the projection image with the contour of the projection screen according to the target in-screen calibration parameter to achieve image in-screen.
[0106] S505. Calibrate the projection image including the internal calibration card according to the target in-screen calibration parameter and the pre-stored calibration parameter.
[0107] In the embodiments of the present application, the projection image including the internal calibration card is pre-stored. This projection image may be the projection image of the internal calibration card projected on the projection screen during the first installation.
[0108] Exemplarily, the pre-stored calibration parameter may be the calibration parameter obtained during the calibration process when the projection device is first installed, or the calibration parameter obtained during the calibration process before the current calibration process. The embodiments of the present application do not limit this.
[0109] Calibrating the projection image including the internal calibration card according to the target in-screen calibration parameter and the pre-stored calibration parameter can achieve internal calibration of the projection image without projecting and displaying the internal calibration card, and of course, it is not necessary for the user to use the terminal to capture images.
[0110] In this way, for the projection image correction method provided in the embodiments of the present application, when correcting the projection image, the projection host only needs to receive the captured image once, and the projection host only needs to project the in-screen calibration card once on the projection screen to complete the correction of the projection image. It is not necessary for the user to use the terminal to take pictures twice, which can improve the efficiency of projection image correction and enhance the user experience.
[0111] Figure 6 FIG. is a schematic flowchart of another projection image correction method provided in the embodiments of the present application. The execution subject may be Figure 3 the projection host 101 therein, or a projection image correction device provided in the projection host 101. This device may be a chip, a chip module, or an IDE, etc. Hereinafter, the projection host is taken as an example of the execution subject for description. Refer to Figure 6 , and the method includes the following steps:
[0112] S601. Process the captured image to obtain target in-screen calibration parameters.
[0113] In the embodiments of the present application, the projection host obtaining the target in-screen calibration parameters may include: in the captured image, determining a third coordinate set of the second feature points in the in-screen calibration card in the photo coordinate system and a fourth coordinate set of the second feature points in the projection coordinate system; determining a feature matrix according to the third coordinate set and the fourth coordinate set; determining a fifth coordinate set of the four vertices of the projection screen in the photo coordinate system. According to the feature matrix and the fifth coordinate set, obtain a first coordinate set of the four vertices of the projection screen in the projection coordinate system to determine the target in-screen calibration parameters.
[0114] Taking any one of the in-screen calibration cards as Figure 2 an example, the projection host may perform feature point detection on the captured image in the captured image to detect the second feature points in the captured image, and determine a third coordinate set of the second feature points in the photo coordinate system and a fourth coordinate set of the second feature points in the projection coordinate system. At the same time, the projection host may determine the target contour of the projection screen and determine a fifth coordinate set of the four vertices of the target contour in the photo coordinate system.
[0115] Exemplarily, the projection host can perform polygon fitting on the target contour to determine four vertices, and the coordinates of the four vertices can be stored in a set to form a fifth coordinate set. Since the fifth coordinate set of the four vertices obtained is sorted in the clockwise order of the contour, the projection host can compare the abscissas and ordinates of the four coordinates and determine the upper left vertex as the vertex with the smallest sum of the ordinate and abscissa. For example, the coordinates of the four vertices can be screen_point[0], screen_point[1], screen_point[2], and screen_point[3] respectively.
[0116] S602. Determine the target internal correction parameter corresponding to the target entry screen parameter according to the target entry screen parameter and the conversion relationship.
[0117] In the embodiment of the present application, the pre-stored correction parameters include the conversion relationship between the entry screen correction parameter and the internal correction parameter, and the conversion relationship can be stored when the projection device is first installed. Since the correction performed when the projection device is first installed requires projecting an entry screen correction chart first to obtain the entry screen correction parameter for entry screen correction, and then projecting an internal correction chart to obtain the internal correction parameter for internal correction. Therefore, during the correction process when the projection device is first installed, the conversion relationship between the entry screen correction parameter and the internal correction parameter can be determined.
[0118] Exemplarily, the target entry screen parameter can include the first coordinate set of the four vertices of the projection screen in the projection coordinate system; the pre-stored correction parameters further include the positional relationship between the first feature points in the internal correction chart and the projection screen, and the internal correction chart is the internal correction chart used when the projection device is first installed.
[0119] When the projection host determines the target internal correction parameter corresponding to the target entry screen parameter according to the target entry screen parameter and the conversion relationship, the projection host can determine the second coordinate set of the first feature points in the internal correction chart in the projection coordinate system according to the first coordinate set and the positional relationship of the four vertices of the projection screen in the projection coordinate system; and determine the target internal correction parameter according to the second coordinate set and the positional deviation parameter included in the conversion relationship.
[0120] In this way, by using the four vertices of the projection screen in the coordinates and the positional deviation parameter to determine the target internal correction parameter, it is not necessary to capture an image of the internal correction chart, which can reduce the number of times the user captures an image while realizing internal correction and improve the efficiency of projection image correction.
[0121] S603. Use the target entry screen parameter and the target internal correction parameter to perform internal correction on the projection image including the internal correction chart.
[0122] Using the target screen entry parameters and the target internal calibration parameters to perform internal calibration on the projection image including the internal calibration chart card can correct the distortion in the projection image.
[0123] In this way, according to the pre-stored conversion relationship, the target internal calibration can be obtained based on the target screen entry calibration parameters, so that the projection host can use the target screen entry parameters and the target internal calibration parameters to correct the projection image of the projection screen. There is no need for the projection host to project the internal calibration chart card on the projection screen, and there is no need for the user to photograph the internal chart card, reducing the number of times the user photographs the image during the projection image calibration process, effectively improving the efficiency of the projection image calibration and enhancing the user experience.
[0124] Since the parameters pre-stored in the embodiments of the present application can be obtained and stored when the projection device is first installed, the method for calibrating the projection image when the projection device is first installed will be described below.
[0125] The projection image calibration performed when the projection device is first installed includes two parts: screen entry calibration and internal calibration, and may include the following steps:
[0126] Step 1: When the projection device is first installed, determine the screen entry calibration parameters according to the first captured image obtained by capturing the projection screen. The first captured image includes the projection screen and the screen entry calibration chart card.
[0127] In the embodiments of the present application, the projection image calibration methods for different projection hosts on the projection screen may be different.
[0128] In a possible implementation, when the projection screen is a normal screen, the projection calibration here may include screen entry calibration of the projection image. That is, for a normal screen, the projection host may not perform internal calibration and can complete the screen entry calibration.
[0129] In another possible implementation, when the projection screen is a distorted screen, the projection calibration here may include screen entry calibration and internal calibration of the projection image, and the projection host needs to perform screen entry calibration and internal calibration of the projection image.
[0130] When the projection host is first installed, the projection host may display a parameter selection interface. If the projection screen paired with the projection host is a normal screen, the installer can select the parameters corresponding to the normal screen in the parameter selection interface, so that the projection host does not perform internal calibration when calibrating the projection image.
[0131] If the projection screen paired with the projection host is a distorted screen, the installer can select the parameters corresponding to the distorted screen in the parameter selection interface, so that the projection host performs screen entry calibration and internal calibration of the projection image when calibrating the projection image.
[0132] In a possible implementation, before the projection host corrects the image projected onto the projection screen, the projection host may display an indication interface. For example, the indication interface may be displayed on the projection screen by projection. The indication interface is used to indicate the user to place the projection host so that a preset box in the indication interface is within the projection screen. For example Figure 3 the rectangular box within the projection screen is the preset box, and the position of the preset box may correspond to the position where the in-screen calibration card is located. Then the projection host may obtain an indication corresponding to the confirmation operation input by the user.
[0133] The projection host may, in response to the confirmation operation, display a shooting prompt interface. For example, the shooting prompt interface may be displayed on the projection screen by projection. The shooting prompt interface may include an in-screen calibration card, and the in-screen calibration card includes feature points for performing in-screen calibration on the projection image. The shooting prompt interface is used to prompt the user to shoot the correctly placed projection screen 102. The projection host 101 may receive a captured image sent by the terminal device 103, and the captured image is obtained by the user shooting the projection screen 102 with the terminal device 103. The projection host 101 may determine in-screen calibration parameters according to the captured image, and use the in-screen calibration parameters to correct the projection image of the projection screen 102.
[0134] Exemplarily, the method by which the projection host 101 determines and uses in-screen calibration parameters to correct the projection image of the projection screen 102 may refer to the method by which the projection host 101 determines and uses target in-screen calibration parameters to correct the projection image of the projection screen 102 described in the foregoing embodiments, and will not be elaborated herein.
[0135] Step 2: According to the second captured image obtained by shooting the projection screen and the in-screen calibration parameters, determine the positional relationship, positional deviation parameters, and internal calibration parameters between the first feature points in the internal calibration card and the projection screen. The second captured image includes the projection screen and the internal calibration card.
[0136] Exemplarily, the projection host may determine the positional relationship between the first feature points and the projection screen, and the set of reference coordinates of the first feature points in the projection coordinate system; in the second captured image, determine the set of sixth coordinates of the first feature points in the photo coordinate system; transform the set of sixth coordinates into the projection coordinate system to obtain the transformed set of sixth coordinates; determine the positional deviation parameters of the first feature points according to the set of reference coordinates and the transformed set of sixth coordinates; and determine the internal calibration parameters according to the positional deviation parameters of the first feature points and the set of reference coordinates.
[0137] Taking the internal calibration card as Figure 4Taking the checkerboard pattern card shown as an example, the projection host can obtain the length and width of the checkerboard. The length and width can be represented by the number of pixels. That is, the projection host can obtain the number of pixels occupied by the length of the checkerboard and the number of pixels occupied by the width of the checkerboard. Then, taking the projection coordinate system corresponding to the screen entry correction parameters as a reference, the projection host can transform the sixth coordinate set of multiple checkerboards to the projection coordinate system corresponding to the screen entry correction parameters according to the length and width of each checkerboard, and obtain the transformed sixth coordinate set.
[0138] Then, according to the reference coordinates of multiple checkerboards and the transformed sixth coordinate set, the position deviation of multiple checkerboards is determined. That is to say, the projection host can determine the position difference according to the ideal positions of multiple checkerboards and the positions of multiple checkerboards projected onto the projection screen, and determine the internal correction parameters according to the position deviation and the reference coordinates of multiple checkerboards.
[0139] In a possible implementation, the projection host can determine the above position deviation according to the checkerboard ratio of multiple checkerboards projected onto the projection screen (that is, for the checkerboards in each row, the ratio of each checkerboard to the checkerboards in that row). Specifically, the checkerboard ratio can be determined according to the transformed sixth coordinate set, and then according to the reference coordinate set. For example, if there are m×n checkerboards, the length occupied by each checkerboard is determined, and then the above position deviation is determined according to this length and the checkerboard ratio.
[0140] Exemplarily, in the embodiments of the present application, the coordinates in the sixth coordinate set or the reference coordinate set can be the coordinates of the upper left corner of the checkerboard, or the coordinates of the upper right corner, or the coordinates of any corner of the checkerboard. The present application does not limit this.
[0141] Exemplarily, for any checkerboard, the projection host can determine the new coordinates of the checkerboard in the projection coordinate system according to the sum of the position deviation corresponding to the checkerboard and the reference coordinates, and determine the new coordinates as the internal correction parameters of the checkerboard.
[0142] In another possible implementation, the projection host can determine the internal correction parameters according to the following method:
[0143] Perform checkerboard corner detection in the color image (obtained after color processing of the captured image) to obtain the sixth coordinate set of the first feature points in the photo coordinate system, and determine the reference coordinate set of the first feature points according to the screen entry correction parameters. Transform the sixth coordinate set of multiple checkerboards to the projection coordinate system corresponding to the screen entry correction parameters to obtain the transformed sixth coordinates. Determine the position deviation of the first feature points according to the reference coordinates of the first feature points and the transformed sixth coordinate set, and then determine the internal correction parameters according to the position deviation of the first feature points and the reference coordinate set.
[0144] For the specific implementation in this implementation manner, reference can be made to the implementation manner of determining the internal calibration parameters corresponding to the above first feature point outside multiple checkerboards, which will not be elaborated here.
[0145] Step 3: Store the position relationship and position deviation parameters, and correct the projected image of the projection screen according to the screen entry calibration parameters and internal calibration parameters.
[0146] Exemplarily, the projection host can store the position relationship and position deviation parameters so that the position relationship and position deviation parameters can be used for subsequent calibration. The method of using the position relationship and position deviation parameters for subsequent calibration can be referred to the above embodiments and will not be elaborated here.
[0147] Based on the above embodiments, when the projection host performs calibration after the first calibration, reference can be made to Figure 7 as shown in Figure 7 which is a schematic flowchart of another method for calibrating a projected image provided by an embodiment of the present application. The execution subject can be Figure 3 the projection host 101 therein, or a projection image calibration device provided in the projection host 101. This device can be a chip, a chip module, or an integrated development environment (IDE), etc. Hereinafter, an example will be given with the projection host as the execution subject. Referring to Figure 7 , the following steps are included:
[0148] S701: Start the automatic calibration application program.
[0149] S702: The user adjusts the position between the laser TV body and the screen.
[0150] S703: Start calibration, and the projection screen displays the screen entry calibration chart.
[0151] For the external screen entry calibration chart displayed on the projection screen, reference can be made to Figure 2 as shown in Figure 2 which is a schematic diagram of two external screen entry calibration feature charts for example.
[0152] S704: The user uses the terminal to capture an image of the screen entry calibration chart and uploads the image.
[0153] Taking the chart A shown in Figure 2 displayed on the projection screen as an example, the scenario where the user uses the terminal to capture an image of chart A can be referred to Figure 3 as shown in Figure 3 which is a schematic diagram of a user capturing an image of the chart provided by an embodiment of the present application.
[0154] As shown in Figure 3As shown, the projection host 101 can project onto the projection screen 102. The outline of the projected image projected by the projection host 101 on the projection screen 102 is different from the outline of the projection screen 102, and the projected image is distorted. In Figure 3 The dashed box is the outline of the projected image.
[0155] As Figure 3 shown, when performing screen entry correction, the projection host 101 can project and display Chart A on the projection screen 102. The user can use their terminal to take an image of Chart A on the projection screen 102 and send the captured image to the projection host 101, enabling the projection host 101 to perform screen entry correction based on the image sent by the user.
[0156] Of course, in this step, it can also be that the projection host uses the image acquisition device installed on the projection host to acquire the image. Refer to the above embodiments for details and will not be elaborated here.
[0157] S705. Whether the user is satisfied with the screen entry correction effect.
[0158] The projection host performs recognition processing on the captured image through an external screen entry correction algorithm, aligns the projected image with the edge of the projection screen through the obtained correction parameters, and completes the entry of the projected image into the screen. The user can view the effect of the screen entry correction. If satisfied, the user can input a satisfied instruction, and the projection host can execute step S706 according to this instruction; if not satisfied, the user can input a dissatisfied instruction, and the projection host can continue to project the screen entry correction chart onto the projection screen and return to step S704.
[0159] S706. The projection host performs internal correction based on the pre-stored correction parameters and the parameters obtained during screen entry correction.
[0160] S707. The projection screen displays a prompt message indicating that the correction is completed.
[0161] To facilitate understanding of the projection image correction method provided by the embodiments of the present application, the entire process of the projection host performing projection image correction will be described below. As Figure 8 shown, Figure 8 is a schematic diagram of a projection image correction method provided by an embodiment of the present application.
[0162] As Figure 8 shown, when the projection host is first installed, initial correction is required. The initial correction can include screen entry correction and internal correction. When the projection host is first installed, first, image screen entry correction is performed. The host obtains a projection feature image 1 containing the screen and the screen entry chart through a sensor device. The correction algorithm integrated in the projection host performs recognition and detection on the projection feature image 1 to obtain screen entry correction parameters, and uses the screen entry correction parameters to correct the image to enter the screen.
[0163] Subsequently, the projection host can perform image distortion correction. The projection host can obtain a projection feature image 2 including the screen and the internal calibration card through the sensor device. The calibration algorithm integrated in the projection host identifies and detects the projection feature image 2 to obtain internal calibration parameters, and uses the internal calibration parameters to correct the image distortion. At this time, the projection host analyzes and saves the internal calibration parameters obtained by the second internal distortion correction, which are the distortion parameters of this screen. Further, the conversion relationship between the screen entry calibration parameters and the internal calibration parameters can be determined.
[0164] When performing automatic calibration using the calibration application program subsequently, the projection host only needs to repeat the process of screen entry calibration to obtain new screen entry calibration parameters, and use the new screen entry calibration parameters and the conversion relationship between the two calibration parameters to obtain new internal calibration parameters, that is, new distortion parameters. The projection host can use the new distortion parameters to correct the image distortion, thereby completing the automatic calibration.
[0165] Combined with the above actual examples, below, the calibration method of the projection image provided by the embodiments of the present application will be described in the form of functional modules. The overall system architecture of the geometric calibration system corresponding to the calibration method of the projection image described in the embodiments of the present application can be seen Figure 9 as shown Figure 9 which is a schematic diagram of the architecture of a geometric calibration system provided by the embodiments of the present application.
[0166] As Figure 9 shown, the geometric calibration system can include an image acquisition module, an image recognition and detection module, a data storage module, a geometric calibration module, and an optical display module. Among them, the image acquisition module can be jointly implemented by the projection host and the image acquisition sensor.
[0167] When the automatic calibration function of the projection host is turned on, the projection host can project and display a calibration feature card on the projection screen. The image acquisition sensor acquires the images of the feature card and the projection screen, and transmits the acquired images to the image recognition and detection module. The image recognition and detection algorithm is integrated in the image recognition and detection module, which can be used to perform screen vertex detection and related feature point detection on the acquired images to obtain the coordinates of the feature points. The data storage module can store the coordinates of the detected feature points, mainly used to store the screen distortion parameters detected for the first time, and used to obtain the internal distortion correction deformation amount during each subsequent calibration.
[0168] The geometric correction module can be used to perform internal correction processing on the projected image according to the parameters detected by image recognition and the stored parameters. The optical display module consists of a light source, a light modulation device, and a projection lens. The light source emits a light signal, which is modulated by the light modulation device and then projected onto the screen by the lens. The image signals before and after internal correction are both projected by the optical display module.
[0169] Combined with the above embodiments, the specific methods for determining the screen entry correction parameters, internal correction parameters, and the parameter correspondence relationship during the first correction will be described below.
[0170] Exemplarily, the method for determining the screen entry correction parameters, internal correction parameters, and the parameter correspondence relationship during the first correction can be implemented through the following steps:
[0171] Exemplarily, when the projection device is first installed, if there is a screen distortion situation, the first correction is performed.
[0172] Step 1: Perform image entry into the screen through the projection host. The projection host can project a screen entry correction feature card, and the user can use the terminal to capture an image of the screen entry correction feature card and upload the image to the projection host. The projection host can calculate the coordinates of the 4 vertices of the projection screen in the projection coordinate system through the screen entry correction algorithm. For example, the coordinate values of the determined 4 vertices in the projection coordinate system can be screen_point[0], screen_point[1], screen_point[2], and screen_point[3].
[0173] It should be noted that the projection host can perform screen entry correction on the projected image according to the coordinates of the 4 vertices of the projection screen in the projection coordinate system.
[0174] Step 2: Perform internal correction through the projection host. For the internal distortion correction function, a photo correction process needs to be performed when the function is enabled for the first time to determine and store the distortion information of the projection screen.
[0175] The projection host can project an internal correction feature card onto the projection screen, and the image acquisition sensor on the projection host can acquire an image of the internal correction feature card and transmit the image to the projection host.
[0176] Exemplarily, the internal correction feature card can be as Figure 4As shown, it is composed of checkerboards, and the number of checkerboards can be m×n. The projection host can correct the distortion by identifying and detecting the distance of each corner point of the checkerboard from the original straight line. The number of checkerboards is determined according to the calibration accuracy. The more checkerboards within a certain pixel value range, the smaller the distance between each corner point, and the higher the calibration accuracy. Specifically, the following steps can be referred to:
[0177] Step 21: In the projection coordinate system, taking the 4 vertices of the projection screen as the reference four vertices, divide it into m×n checkerboards, and the reference coordinates of each checkerboard corner point can be obtained, so as to obtain the reference coordinate set composed of the reference coordinates of all checkerboards.
[0178] Step 22: In the photo coordinate system, according to the color range, the photo checkerboard has two colors, color1 and color2 respectively; change the image value of color1 in the checkerboard to 0, and the image value of the other color color2 to 255 to obtain image1. Change the image value of color1 in the checkerboard to 255, and the image value of the other color color2 to 0 to obtain image2. Then perform an addition operation on images image1 and image2 to obtain image picture. Then obtain the outer contour of the checkerboard through contour search, so that the coordinates of the four vertices of the contour in the photo coordinate system, border_point[0], border_point[1], border_point[2], and border_point[3], can be obtained.
[0179] Step 23: The perspective transformation matrix can be calculated from the coordinates of the four vertices of the contour in the photo coordinate system and the coordinates of the 4 vertices of the projection screen, and the checkerboard part in the photo is perspective-transformed into the projection coordinate system to obtain image image3.
[0180] Step 24: Use the algorithm to identify and detect the checkerboard corner points in image image3 to obtain m×n corner point coordinates arranged in order from left to right, that is, the corners set; compare and subtract the corner point coordinates in the reference coordinate set with the corner point coordinates in the corners set, which is the distortion parameter of the screen.
[0181] Exemplarily, for the distorted image for internal calibration, refer to Figure 10 as shown Figure 10 which is a schematic diagram of a distorted image provided by an embodiment of the present application.
[0182] Step 3: After obtaining the distortion parameters of the screen, store them on the projection host. When using the geometric correction function for the next time (not the first time), after the projection host calls the in-curtain correction algorithm, obtain the coordinates of m×n points in the projection coordinate system according to the four in-curtain point coordinates, and superimpose the obtained coordinates with the stored screen distortion parameters, that is, the internal correction can be completed without taking pictures for the second time.
[0183] It should be noted that the distortion parameters can be the pre-stored correction parameters described in the above embodiments, which will not be elaborated here.
[0184] Figure 11 This is a schematic structural diagram of a projection device provided by an embodiment of the present application. The projection device 200 includes at least one of a projection host 210, a communicator 220, a tuner demodulator 230, an external device interface 240, an audio output interface 250, a memory 260, a power supply 270, and a user interface 280.
[0185] In a possible implementation manner, the projection host 210 includes a controller including at least one of a Central Processing Unit (CPU), a video processor, an audio processor, a Graphics Processing Unit (GPU), a Random Access Memory (RAM), a Read-Only Memory (ROM), a first interface to an nth interface for input / output, and a communication bus (Bus).
[0186] In a possible implementation manner, the communicator 220 is a component for communicating with external devices or servers according to various communication protocol types. For example: the communicator 220 may include at least one of a Wireless Fidelity (WIFI) module, a Bluetooth module, a wired Ethernet module, other network communication protocol chips or near-field communication protocol chips, and an infrared receiver. The projection device 200 can establish the sending and receiving of control signals and data signals with an external control device or server through the communicator 220.
[0187] In a possible implementation manner, the tuner demodulator 230 receives radio and television signals through wired or wireless reception, and demodulates audio and video signals, such as electronic program guide (EPG) data signals, from multiple radio or wired radio and television signals.
[0188] In a possible implementation, the external device interface 240 may include, but is not limited to, the following: High Definition Multimedia Interface (HDMI), analog or digital high-definition component input interface (component), composite video input interface (Composite Video Broadcast Signal, CVBS), Universal Serial Bus (USB), red green blue (RGB) color mode port, or any one or more of such interfaces. It may also be a composite input / output interface formed by the above multiple interfaces.
[0189] In a possible implementation, the audio output interface 250 is an interface for outputting audio information. The audio output interface may include, but is not limited to, the following: microphone interface, headphone interface, etc.
[0190] In a possible implementation, the projection host 210 controls the operation of the display device and responds to user operations through various software control programs stored in the memory 260. The projection host 210 controls the overall operation of the display device 200.
[0191] In a possible implementation, the projection host 210 includes a Television System on Chip (TV SOC) and an Application Specific Integrated Circuit (ASIC). The CPU, video processor, audio processor, graphics processor, etc. can be integrated in the TV SOC.
[0192] Specifically, the projection host 210 is configured to:
[0193] Project the projection image where the screen correction chart card is located onto the projection screen.
[0194] Receive the captured image obtained by photographing the projection screen, where the captured image includes the projection screen and the screen correction chart card.
[0195] Process the captured image to obtain the target screen correction parameter.
[0196] Perform screen correction on the projection image of the projection screen according to the target screen correction parameter;
[0197] Perform internal correction on the projection image including the internal correction chart card according to the target screen correction parameter and the pre-stored correction parameter, where the projection image including the internal correction chart card is pre-stored.
[0198] In a possible implementation, the TV SOC is configured such that: the pre-stored calibration parameters include the conversion relationship between the on-screen calibration parameters and the internal calibration parameters, and the conversion relationship is stored when the projection device is first installed; according to the target on-screen parameters and the conversion relationship, determine the target internal calibration parameters corresponding to the target on-screen parameters; use the target on-screen parameters and the target internal calibration parameters to calibrate the projection image of the projection screen.
[0199] In a possible implementation, the TV SOC is configured such that: the target on-screen parameters include the first coordinate set of the four vertices of the projection screen in the projection coordinate system; the pre-stored calibration parameters further include the positional relationship between the first feature points in the internal calibration card and the projection screen, and the internal calibration card is the internal calibration card used when the projection device is first installed; according to the first coordinate set of the four vertices of the projection screen in the projection coordinate system and the positional relationship, determine the second coordinate set of the first feature points in the internal calibration card in the projection coordinate system; according to the second coordinate set and the positional deviation parameters included in the conversion relationship, determine the target internal calibration parameters.
[0200] In a possible implementation, the TV SOC is configured such that: in the captured image, determine the third coordinate set of the second feature points in the on-screen calibration card in the photo coordinate system and the fourth coordinate set of the second feature points in the projection coordinate system; according to the third coordinate set and the fourth coordinate set, determine the feature matrix; determine the fifth coordinate set of the four vertices of the projection screen in the photo coordinate system; according to the feature matrix and the fifth coordinate set, obtain the first coordinate set of the four vertices of the projection screen in the projection coordinate system to determine the target on-screen calibration parameters.
[0201] In a possible implementation, the TV SOC is configured such that: when the projection device is first installed, according to the first captured image received by photographing the projection screen, determine the on-screen calibration parameters, and the first captured image includes the projection screen and the on-screen calibration card; according to the second captured image received by photographing the projection screen and the on-screen calibration parameters, determine the positional relationship between the first feature points in the internal calibration card and the projection screen, the positional deviation parameters, and the internal calibration parameters, and the second captured image includes the projection screen and the internal calibration card; store the positional relationship and the positional deviation parameters, and calibrate the projection image of the projection screen according to the on-screen calibration parameters and the internal calibration parameters.
[0202] In a possible implementation, the TV SOC is configured to: determine the positional relationship between the first feature point and the projection screen, and the set of reference coordinates of the first feature point in the projection coordinate system; in the second captured image, determine the set of sixth coordinates of the first feature point in the photo coordinate system; transform the set of sixth coordinates to the projection coordinate system to obtain the transformed set of sixth coordinates; determine the position deviation parameter of the first feature point according to the set of reference coordinates and the transformed set of sixth coordinates; and determine the internal calibration parameter according to the position deviation parameter of the first feature point and the set of reference coordinates.
[0203] In a possible implementation, the TV SOC is configured to: receive a captured image obtained by an image capturing device capturing the projection screen, where the image capturing device is a device installed on the projection host of the projection device.
[0204] The present application also provides a computer-readable storage medium, which may include: various media capable of storing program codes such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disc. Specifically, program instructions are stored in the computer-readable storage medium, and the program instructions are used for the method in the foregoing embodiments.
[0205] The present application also provides a program product, which includes execution instructions stored in a readable storage medium. At least one control module of the display device can read the execution instructions from the readable storage medium, and at least one control module executes the execution instructions to enable the display device to implement the projection image correction method provided by the above various implementation manners.
[0206] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present application.
[0207] For the sake of convenience in explanation, the above description has been made in connection with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be derived according to the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, so that those skilled in the art can better use the embodiments and various different modified embodiments suitable for specific usage considerations.
Claims
1. A method for correcting a projected image, characterized in that, Including: Projecting an image of the in-screen calibration card onto the projection screen; Receiving a captured image obtained by photographing the projection screen, where the captured image includes the projection screen and the in-screen calibration card; Processing the captured image to obtain target in-screen calibration parameters; Performing in-screen calibration on the projected image of the projection screen according to the target in-screen calibration parameters; Performing internal calibration on a projected image including an internal calibration card according to the target in-screen calibration parameters and pre-stored calibration parameters, where the projected image including the internal calibration card is pre-stored; 2. The method according to claim 1, wherein The pre-stored calibration parameters include the conversion relationship between the in-screen calibration parameters and the internal calibration parameters, and the conversion relationship is stored when the projection device is first installed; The performing internal calibration on a projected image including an internal calibration card according to the in-screen calibration parameters and the pre-stored calibration parameters includes: Determining target internal calibration parameters corresponding to the target in-screen parameters according to the target in-screen parameters and the conversion relationship; Using the target in-screen parameters and the target internal calibration parameters to perform internal calibration on a projected image including an internal calibration card.
3. The method according to claim 2, characterized in that The target in-screen parameters include a first coordinate set of the four vertices of the projection screen in the projection coordinate system; the pre-stored calibration parameters further include the positional relationship between the first feature points within the internal calibration card and the projection screen, and the internal calibration card is the internal calibration card used when the projection device is first installed; The determining target internal calibration parameters corresponding to the target in-screen parameters according to the target in-screen parameters and the conversion relationship includes: Determining a second coordinate set of the first feature points within the internal calibration card in the projection coordinate system according to the first coordinate set of the four vertices of the projection screen in the projection coordinate system and the positional relationship; Determining target internal calibration parameters according to the second coordinate set and the positional deviation parameters included in the conversion relationship.
4. The method according to any one of claims 1 to 3, characterized in that The processing the captured image to obtain target in-screen calibration parameters includes: In the captured image, determining a third coordinate set of the second feature points in the in-screen calibration card in the photo coordinate system and a fourth coordinate set of the second feature points in the projection coordinate system; Determining a feature matrix according to the third coordinate set and the fourth coordinate set; Determining a fifth coordinate set of the four vertices of the projection screen in the photo coordinate system; Obtaining a first coordinate set of the four vertices of the projection screen in the projection coordinate system according to the feature matrix and the fifth coordinate set to determine the target in-screen calibration parameters.
5. The method according to any one of claims 1 to 3, characterized in that The method further includes: When the projection device is first installed, determining in-screen calibration parameters according to a first captured image obtained by photographing the projection screen, where the first captured image includes the projection screen and the in-screen calibration card; Determine the positional relationship between the first feature points in the internal calibration card and the projection screen, the position deviation parameters, and the internal calibration parameters according to the received second captured image of the projection screen and the screen entry calibration parameters. The second captured image includes the projection screen and the internal calibration card. Store the positional relationship and the position deviation parameters, and correct the projection image of the projection screen according to the screen entry calibration parameters and the internal calibration parameters.
6. The method according to claim 5, characterized in that, The determining the positional relationship between the first feature points in the internal calibration card and the projection screen, the position deviation parameters, and the internal calibration parameters according to the received second captured image of the projection screen and the screen entry calibration parameters includes: Determine the positional relationship between the first feature points and the projection screen, and the set of reference coordinates of the first feature points in the projection coordinate system. In the second captured image, determine the set of sixth coordinates of the first feature points in the photo coordinate system. Transform the set of sixth coordinates to the projection coordinate system to obtain the transformed set of sixth coordinates. Determine the position deviation parameters of the first feature points according to the set of reference coordinates and the transformed set of sixth coordinates. Determine the internal calibration parameters according to the position deviation parameters of the first feature points and the set of reference coordinates.
7. The method according to any one of claims 1 to 3, characterized in that, The receiving the captured image obtained by capturing the projection screen includes: Receive the captured image obtained by the image capturing device capturing the projection screen. The image capturing device is a device installed on the projection host of the projection device.
8. A projection device, characterized in that, Includes: A projection host and a projection screen; The projection host is configured to: Project the projection image where the screen entry calibration card is located on the projection screen; Receive the captured image obtained by capturing the projection screen. The captured image includes the projection screen and the screen entry calibration card; Process the captured image to obtain the target screen entry calibration parameters; Perform screen entry calibration on the projection image of the projection screen according to the target screen entry calibration parameters; Perform internal calibration on the projection image including the internal calibration card according to the target screen entry calibration parameters and the pre-stored calibration parameters. The projection image including the internal calibration card is pre-stored.
9. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored on the computer-readable storage medium. When the computer-executable instructions are executed by a processor, the method according to any one of claims 1-7 is implemented.
10. A computer program product, characterized in that, Includes a computer program which, when executed by a processor, implements the method according to any one of claims 1-7.