Projection equipment and projection picture screen entering method

Abstract

The invention provides projection equipment and a projection picture screen entering method, and the method comprises the steps: obtaining a screen key point, and determining a key boundary line in a projection region according to the screen key point; describing the key boundary line based on the pure color line, and searching a target contour shape of the projection medium; when the target contour shape is a non-convex quadrangle, extracting a contour line and smoothing the contour line; performing screening on the smoothed contour lines to retain quasi contour lines; extending the quasi contour line to the boundary of the projection content image, and obtaining a coarse vertex of the projection area according to the extended quasi contour line; determining fine vertexes according to the coarse vertexes and the curtain key points; and calculating a target ray machine image coordinate corresponding to the fine vertex on the light emitting assembly, and controlling the light emitting assembly to project the playing content to the projection medium according to the target ray machine image coordinate. Even if the projection medium is shielded by an obstacle, the target contour shape of the projection medium can be found by the method, and the problem that the projection equipment fails to enter the screen when the projection medium is shielded by the obstacle is solved.

Description

Technical Field

[0001] The present application relates to the technical field of projection equipment, and in particular to a projection equipment and a method for projecting a projection image onto a screen. Background Art

[0002] To enhance user convenience during projection, and considering the cumbersome process of user-adjusting the projection device, the projection device may include an automatic screen-entry function. This automatic screen-entry function allows the projection device to automatically determine the projection area within the projection medium and project the image into that area, eliminating the need for users to manually adjust the angle and position of the projection device, thereby improving the user experience.

[0003] During automatic screen entry, if the screen border is obstructed by an obstacle, the projector may not be able to correctly identify the screen edge. For example, the obstacle may block the light or image emitted by the projector to identify the screen edge, resulting in the projector being unable to correctly identify the screen's position and size. Therefore, when the screen border is obstructed by an obstacle, the projector may be unable to correctly identify the screen's position and size, causing automatic screen entry to fail.

[0004] Therefore, during the process of performing the sensory entry, when the projection medium, such as the border or corner of the screen, is partially blocked, the projection device will fail to automatically enter the screen, affecting the user experience. Summary of the Invention

[0005] Some embodiments of the present application provide a projection device and a method for projecting a projection image onto a screen, so as to solve the problem that the projection device fails to enter the screen when the projection medium is blocked by an obstacle.

[0006] In a first aspect, some embodiments of the present application provide a projection device, including:

[0007] A light emitting component configured to project playback content onto a projection medium;

[0008] an image acquisition device configured to capture an image of the projected content;

[0009] The controller is configured as:

[0010] Acquiring key points of the screen, and when the number of the key points of the screen is greater than a preset number, determining key boundary lines in the projection area according to the key points of the screen;

[0011] Describing the key boundary line based on a solid color line to generate an estimated border line; the estimated border line includes an inner border line, and the area formed by the inner border line is a closed area;

[0012] Searching for a target contour shape of the projection medium in a closed area formed by the inner frame line, and extracting a contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral;

[0013] The smoothed contour lines are screened according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi-contour lines;

[0014] Extending the quasi-contour line to the boundary of the projection content image, and obtaining a coarse vertex of the projection area according to the extended quasi-contour line;

[0015] The fine vertices of the projection area are determined based on the rough vertices and the key points of the screen, and the light-emitting component is controlled to project the playback content onto the projection medium according to the target optical-mechanical image coordinates; the target optical-mechanical image coordinates are calculated based on the homography matrix between the image acquisition device and the light-emitting component and the coordinates of the fine vertices.

[0016] In a second aspect, some embodiments of the present application provide a method for projecting a picture onto a screen, which can be applied to the projection device of the first aspect. The projection device includes a light output component, an image acquisition device, and a controller. The method for projecting a picture onto a screen includes:

[0017] Acquiring key points of the screen, and when the number of the key points of the screen is greater than a preset number, determining key boundary lines in the projection area according to the key points of the screen;

[0018] Describing the key boundary line based on a solid color line to generate an estimated border line; the estimated border line includes an inner border line, and the area formed by the inner border line is a closed area;

[0019] Searching for a target contour shape of the projection medium in a closed area formed by the inner frame line, and extracting a contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral;

[0020] The smoothed contour lines are screened according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi-contour lines;

[0021] Extending the quasi-contour line to the boundary of the projection content image, and obtaining a coarse vertex of the projection area according to the extended quasi-contour line;

[0022] The fine vertices of the projection area are determined based on the rough vertices and the key points of the screen, and the light-emitting component is controlled to project the playback content onto the projection medium according to the target optical-mechanical image coordinates; the target optical-mechanical image coordinates are calculated based on the homography matrix between the image acquisition device and the light-emitting component and the coordinates of the fine vertices.

[0023] As can be seen from the above technical solutions, some embodiments of the present application provide a method for projecting a device and projecting an image onto a screen, the method comprising: obtaining key points of the screen, determining key boundary lines in the projection area based on the key points of the screen; depicting key boundary lines based on solid color lines, and finding the target contour shape of the projection medium; when the target contour shape is a non-convex quadrilateral, extracting the contour lines and performing smoothing on the contour lines; filtering the smoothed contour lines to retain the quasi-contour lines; extending the quasi-contour lines to the boundaries of the projected content image, and obtaining the rough vertices of the projection area based on the extended quasi-contour lines; determining the fine vertices based on the rough vertices and the key points of the screen; calculating the target optical-mechanical image coordinates corresponding to the fine vertices in the light-emitting component, and controlling the light-emitting component to project the playback content onto the projection medium based on the target optical-mechanical image coordinates. Even when there are obstacles blocking the view, the method can find the target contour shape of the projection medium, solving the problem of the failure of the projection device to enter the screen when the projection medium is blocked by obstacles. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate some embodiments of the present application or technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0025] Figure 1 A schematic diagram of the projection placement state of the projection device provided in some embodiments of the present application;

[0026] Figure 2 A schematic diagram of the optical path of a projection device provided in some embodiments of the present application;

[0027] Figure 3 A schematic diagram of the circuit architecture of a projection device provided in some embodiments of the present application;

[0028] Figure 4 A schematic diagram of the structure of a projection device provided in some embodiments of the present application;

[0029] Figure 5 A schematic diagram of the lens structure of a projection device provided in some embodiments of the present application;

[0030] Figure 6 A schematic diagram of the structure of a distance sensor and an image acquisition device for a projection device provided in some embodiments of the present application;

[0031] Figure 7 A schematic diagram of a system framework for implementing display control for a projection device provided in some embodiments of the present application;

[0032] Figure 8A schematic diagram of a flow chart of a projection device performing a method for sensing screen entry according to some embodiments of the present application;

[0033] Figure 9 A schematic diagram of a screen provided in some embodiments of the present application;

[0034] Figure 10 A schematic diagram of the effect of line segment inspection within the projection area provided in some embodiments of the present application;

[0035] Figure 11 A schematic diagram of the boundary line segment effect generated after screening valid line segments provided in some embodiments of the present application;

[0036] Figure 12 A schematic diagram illustrating the effect of forming an intersection after extending boundary segments provided in some embodiments of the present application;

[0037] Figure 13 A schematic diagram illustrating the effect of determining a key boundary line for a projection device provided in some embodiments of the present application;

[0038] Figure 14 A schematic diagram of the effect of estimating border lines provided in some embodiments of the present application;

[0039] Figure 15 Schematic diagram of the effect of the convex quadrilateral in the curtain area provided by some embodiments of the present invention;

[0040] Figure 16 Schematic diagram of the effect of a non-convex quadrilateral in the curtain area provided by some embodiments of the present invention;

[0041] Figure 17 A schematic diagram of a scene for a coarse vertex generation method provided in some embodiments of the present application;

[0042] Figure 18 Schematic diagram of the effect of projection content projected by the projection device according to some embodiments of the present application based on the precise vertex. DETAILED DESCRIPTION

[0043] In order to make the purpose and implementation of this application clearer, the exemplary implementation of this application will be clearly and completely described below in conjunction with the drawings in the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only part of the embodiments of this application, not all of the embodiments.

[0044] It should be noted that the brief descriptions of terms in this application are only for the purpose of facilitating the understanding of the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise specified, these terms should be understood according to their ordinary and usual meanings.

[0045] In the specification and claims of this application and the accompanying drawings, the terms "first," "second," "third," etc. are used to distinguish similar or similar objects or entities, and are not necessarily intended to limit a particular order or sequence, unless otherwise noted. It should be understood that the terms used in this manner are interchangeable under appropriate circumstances.

[0046] The terms "comprise," "comprises," and "having," and any variations thereof, are intended to cover but not exclude inclusion; for example, a product or device comprising a list of components is not necessarily limited to all the components expressly listed but may include other components not expressly listed or inherent to such product or device.

[0047] The term "module" refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or combination of hardware and / or software code that is capable of performing the functionality associated with that element.

[0048] The embodiments of the present application can be applied to various types of projection devices. The following will take a projection device as an example to illustrate the projection device and the automatic focusing method.

[0049] A projector is a display device that projects images or videos onto a screen. It uses optical components to refract laser light of a specific color, creating a specific image. During projection, the projector must maintain a certain distance from the screen so that the image formed on the screen fits within the focal length range of the optical components, ensuring a clear image.

[0050] A projector is a device that projects images or videos onto a screen. It can connect to computers, broadcast networks, the internet, VCDs (Video Compact Discs), DVDs (Digital Versatile Disc Recordables), game consoles, and DVs through various interfaces to play back video signals. Projectors are widely used in homes, offices, schools, and entertainment venues.

[0051] Figure 1 This is a schematic diagram of the projection placement state of the projection device provided in some embodiments of the present application. Figure 2 Schematic diagram of the optical path of a projection device provided in some embodiments of the present application.

[0052] In some embodiments, reference Figure 1-2The present application provides a projection device comprising a projection screen 1 and a projection device 2. The projection screen 1 is fixed in a first position, and the projection device 2 is placed in a second position so that the image it projects matches the projection screen 1. The projection device comprises a light source 100, a light output component 200, a lens 300, and a projection surface 400. The light source 100 provides illumination for the light output component 200, and the light output component 200 modulates the light source beam and outputs it to the lens 300 for imaging, which is then projected onto the projection surface 400 to form a projection image.

[0053] In some embodiments, the light source 100 of the projection device 2 includes a light output component 110 and an optical lens component 120 . The light beam emitted by the light output component 110 can pass through the optical lens component 120 to provide illumination for the light output component 200 .

[0054] It should be noted that in the embodiments of the present application, the light source 100 can be a laser light source, an LED light source, or a liquid crystal display (LCD) light source, and this application does not specifically limit this. For example, taking the light source 100 as a laser light source as an example, when the light source 100 is a laser light source, in some embodiments, the light output component 200 of the projection device 2 can be implemented to include a blue light output component, a green light output component, and a red light output component, and can also include a heat dissipation system, a circuit control system, etc. Figure 3 Schematic diagram of the circuit architecture of a projection device provided in some embodiments of the present application. In some embodiments, the projection device 2 may include a display control circuit 10, a light source 100, at least one light driving component 30, and at least one brightness sensor 40. Still taking the light source 100 as a laser light source as an example, when the light source 100 is a laser light source, the light source 100 may include at least one laser corresponding to the at least one light driving component 30.

[0055] Based on this circuit architecture, the projection device 2 can achieve adaptive adjustment. For example, by arranging a brightness sensor 40 in the light output path of the light source 100 , the brightness sensor 40 can detect a first brightness value of the laser light source and send the first brightness value to the display control circuit 10 .

[0056] The display control circuit 10 can obtain the second brightness value corresponding to the driving current of each laser, and when it is determined that the difference between the second brightness value of the laser and the first brightness value of the laser is greater than the difference threshold, it is determined that a COD fault has occurred in the laser; the display control circuit can then adjust the current control signal of the laser driving component corresponding to the laser until the difference is less than or equal to the difference threshold, thereby eliminating the COD fault of the blue laser; the projection device 2 can eliminate the COD fault of the laser in a timely manner, reduce the damage rate of the laser, and improve the image display effect of the projection device 2.

[0057] Figure 4 A schematic diagram of the projection device structure provided in some embodiments of the present application.

[0058] In some embodiments, still taking the light source 100 as a laser light source as an example, the light source 100 in the projection device 2 can include independently arranged blue laser 101, red laser 102, and green laser 103. When the light source 100 is a laser light source, the projection device 2 can also be called a three-color projection device. The blue laser 101, the red laser 102, and the green laser 103 are all modular lightweight (Mirai Console Loader, MCL) packaged lasers, which are small in size and facilitate compact arrangement of the optical path. It is understandable that the above description is only based on the example of the light source 100 being a laser light source, and the light source 100 is not limited to a laser light source. It can also be an LED light source, an LCD light source, or other forms of light sources.

[0059] In some embodiments, the controller includes at least one of a central processing unit (CPU), a video processor, an audio processor, a graphics processing unit (GPU), RAM Random Access Memory (RAM), ROM (Read-Only Memory, ROM), a first interface to an nth interface for input / output, a communication bus (Bus), etc.

[0060] In some embodiments, after the projection device 2 is started, it can directly enter the display interface of the last selected signal source, or the signal source selection interface, where the signal source can be a preset video on demand program, or at least one of an HDMI interface, a live TV interface, etc. After the user selects a different signal source, the projector can display content obtained from different signal sources.

[0061] In some embodiments, the projection device 2 can be configured with an image acquisition device 700, such as a camera, for operating in conjunction with the projection device 2 to achieve adjustment and control of the projection process. For example, the camera configured with the projection device 2 can be specifically implemented as a 3D camera or a binocular camera. When the camera is implemented as a binocular camera, it specifically includes a left camera and a right camera. The binocular camera can capture the image and playback content presented by the projection medium corresponding to the projection device 2, such as a screen, that is, the projection surface 400. This image or playback content is projected by the light output component 200 built into the projection device 2.

[0062] The image acquisition device can be used to capture the image displayed on projection surface 400 and can be a camera. The camera can include a lens assembly, which includes a photosensitive element and a lens. The lens refracts light through multiple lens elements, allowing the light of the image of the scene to be illuminated by the photosensitive element.

[0063] Figure 5 Schematic diagram of the lens structure of the projection device provided in some embodiments of the present application. In order to support the automatic focusing process of the projection device 2, such as Figure 5 As shown, the lens 300 of the projection device 2 may further include an optical component 310 and a drive motor 320. The optical component 310 is a lens group composed of one or more lenses, which can refract the light emitted by the light output component 200 so that the light emitted by the light output component 200 can be transmitted to the projection surface 400 to form a transmitted content image.

[0064] The optical assembly 310 may include a lens barrel and a plurality of lenses disposed therein. Depending on whether the lens position is movable, the lenses in the optical assembly 310 may be divided into a movable lens 311 and a fixed lens 312. By changing the position of the movable lens 311 and adjusting the distance between the movable lens 311 and the fixed lens 312, the overall focal length of the optical assembly 310 may be changed. Therefore, the drive motor 320, connected to the movable lens 311 in the optical assembly 310, can drive the movable lens 311 to move its position, thereby achieving an automatic focusing function.

[0065] It should be noted that the focusing process described in some embodiments of the present application refers to changing the position of the movable lens 311 by driving the motor 320, thereby adjusting the distance between the movable lens 311 and the fixed lens 312, that is, adjusting the image plane position. Therefore, the imaging principle of the lens combination in the optical component 310, the adjustment of the focal length is actually adjusting the image distance, but in terms of the overall structure of the optical component 310, adjusting the position of the movable lens 311 is equivalent to adjusting the overall focal length of the optical component 310.

[0066] When the distance between projection device 2 and projection surface 400 varies, the lens of projection device 2 needs to be adjusted to different focal lengths to project a clear image on projection surface 400. During projection, the distance between projection device 2 and projection surface 400 varies depending on the user's placement, requiring different focal lengths. Therefore, to adapt to different usage scenarios, projection device 2 needs to adjust the focal length of optical assembly 310.

[0067] Figure 6 This is a schematic diagram of the distance sensor and image acquisition device structure of the projection device provided in some embodiments of the present application. Figure 6As shown, the projection device 2 may also have a built-in or external image acquisition device 700, which can capture the image projected by the projection device 2 to obtain the projection content image. The distance sensor 600 is configured to detect the distance between the projection surface 400 and the light-emitting component 200. The projection device 2 then determines whether the current lens focal length is appropriate by performing a clarity detection on the projection content image, and adjusts the focal length if it is not appropriate. When automatically focusing based on the projection content image captured by the image acquisition device 700, the projection device 2 can find the focusing position by continuously adjusting the lens position and taking pictures, and by comparing the clarity of the pictures before and after the pictures, thereby adjusting the movable lens 311 in the optical component to the appropriate position.

[0068] Figure 7 Schematic diagram of the system framework for implementing display control of the projection device provided in some embodiments of the present application.

[0069] In some embodiments, the projection device 2 has the characteristics of a telephoto micro-projector, and its controller can control the display of the projected light image through a preset algorithm to achieve functions such as automatic trapezoidal correction of the display screen, automatic screen entry, automatic obstacle avoidance, automatic focusing, and anti-eye-shooting.

[0070] In some embodiments, the projection device 2 is configured with a gyroscope sensor; when the device is moving, the gyroscope sensor can sense the position movement and actively collect movement data; the collected data is then sent to the application service layer through the system framework layer to support the application data required during user interface interaction and application interaction. The collected data can also be used for data calls by the controller in the algorithm service implementation.

[0071] In some embodiments, the projection device 2 is equipped with a time-of-flight sensor. After the time-of-flight sensor collects corresponding data, the data will be sent to the corresponding time-of-flight service of the service layer; after the above-mentioned time-of-flight service obtains the data, it will send the collected data to the application service layer through the process communication framework, and the data will be used for interactive use such as controller data calls, user interfaces, and program applications.

[0072] In some embodiments, the image acquisition device 700 configured for the projection device 2 can be a binocular camera, a depth camera, or a 3D camera, etc.; the image acquisition device 700 collects data and sends it to the camera service, and then the camera service sends the collected image data to the process communication framework and / or the projection device correction service; the projection device correction service can receive the camera acquisition data sent by the camera service, and the controller can call the corresponding control algorithm in the algorithm library according to the different functions to be implemented.

[0073] In some embodiments, data is interacted with the application service through the process communication framework, and then the calculation results are fed back to the correction service through the process communication framework; the correction service sends the obtained calculation results to the operating system of the projection device 2 to generate control signals, and sends the control signals to the light emitting component 200 control drive to control the working condition of the light emitting component 200 and realize automatic correction of the displayed image.

[0074] In some embodiments, when an image correction instruction is detected, projection device 2 can correct the projected image. For projected image correction, a pre-established relationship between distance, horizontal angle, and offset angle can be established. The controller in projection device 2 then obtains the current distance between light emitting assembly 200 and projection surface 400 and, based on the associated relationship, determines the angle between light emitting assembly 200 and projection surface 400 at that moment, thereby achieving projected image correction. Specifically, the angle is the angle between the central axis of light emitting assembly 200 and projection surface 400.

[0075] In some embodiments, the projection device 2 automatically completes the calibration and refocuses, and the controller will detect whether the automatic focus function is turned on; when the automatic focus function is not turned on, the controller will end the automatic focus service; when the automatic focus function is turned on, the projection device 2 will obtain the detection distance of the time of flight sensor through the middleware for calculation.

[0076] Based on the acquired distance, the controller queries a pre-set mapping table to determine the focal length of projector 2. The middleware then sets the acquired focal length to projector 2's light output component 200. The middleware, a suite of applications responsible for focus control, controls the focus adjustment process. After light output component 200 emits laser light at the desired focal length, the camera executes the capture command. The controller then determines whether projector 2's focus adjustment process is complete based on the captured image and the evaluation function.

[0077] If the judgment result meets the preset completion conditions, the control of the automatic focusing process ends; if the judgment result does not meet the preset completion conditions, the middleware will fine-tune the focal length parameters of the light-emitting component 200 of the projection device 2, for example, the focal length can be gradually fine-tuned with a preset step size, and the adjusted focal length parameters can be set to the light-emitting component 200 again; thereby realizing repeated photo taking and clarity evaluation steps, and finally finding the optimal focal length through clarity comparison to complete automatic focusing.

[0078] To enhance user convenience during projection, and considering that it is cumbersome for the user to manually adjust projection device 2, projection device 2 may include an automatic screen entry function. This automatic screen entry function allows projection device 2 to automatically determine the projection area within the projection medium and project the image into that area, eliminating the need for the user to manually adjust the angle and position of projection device 2, thereby improving the user experience.

[0079] In some embodiments, projection device 2 can be configured with an automatic screen entry mode. A user can send an automatic screen entry command to projection device 2, causing it to enter automatic screen entry mode and thereby activate the automatic screen entry function. For example, using a screen as the projection medium, screens can come in a variety of sizes and types. For different screens, projection device 2 requires appropriate adjustments before projection to ensure that the projected content is accurately projected onto the screen. The automatic screen entry function of projection device 2 eliminates the need for users to manually adjust relevant image parameters, thereby enhancing the user experience.

[0080] Depending on whether a feature card is projected during projection, the screen entry mode can be categorized as either active or passive. In some embodiments, if a feature card is not required during projection, the screen entry mode can be passive. If a feature card is required during projection, the screen entry mode can be active.

[0081] Sensorless projection has the advantage of fast projection speed, but it requires the addition of a distance sensor based on the Time of Flight (TOF) principle, namely a TOF sensor, which requires additional equipment. Moreover, due to the influence of TOF ranging errors, the accuracy of sensorless projection is lower than that of sensor projection. Therefore, to ensure the accuracy of projection, sensor projection can be used.

[0082] In some embodiments, when the projection device 2 performs the sensor-into-screen function, the projection device 2 may capture an image of the projected content based on a solid color chart, such as a white chart. For example, the image capture device 700 may capture the projection image of the projection area to form a projection content image. If a complete effective screen boundary is found within the projection area, the projection area is adjusted to the screen area of ​​the projection medium.

[0083] If the screen border is obstructed by an obstacle, projector 2 may be unable to correctly identify the screen edge. For example, the obstacle may block the light or image emitted by projector 2, which is used to identify the screen edge. This can cause projector 2 to be unable to correctly identify the screen's position and size, unable to locate the complete screen area, and thus fail to automatically enter the screen. Therefore, if the screen border is obstructed by an obstacle, projector 2 may fail to correctly identify the screen's position and size, resulting in a failure to automatically enter the screen.

[0084] Therefore, during the process of performing the conscious entry, when the projection medium, such as the frame or corner of the screen, is partially blocked, the projection device 2 will fail to automatically enter the screen, affecting the user experience.

[0085] In order to solve the problem of the projector 2 failing to automatically enter the screen, some embodiments of the present application provide a projector 2, which may include a light emitting component 200, an image acquisition device 700, and a controller 500. The light emitting component 200 is configured to project playback content onto a projection medium, the image acquisition device 700 is configured to capture an image of the projected content, and the controller 500 is configured to execute a method for entering the screen of the projection image of the projector 2.

[0086] In order to facilitate the understanding of the technical solutions in some embodiments of the present application, each step is described in detail below in conjunction with some specific embodiments and drawings. Figure 8 A flowchart of a projection device performing a method for sensing screen entry is provided in some embodiments of the present application, such as Figure 8 As shown, when the projection device 2 executes the method for projecting a picture onto the screen, the following steps S1-S6 may be included. The specific contents are as follows:

[0087] Step S1: the projection device 2 obtains key points of the screen, and when the number of the key points of the screen is greater than a preset number, determines key boundary lines in the projection area according to the key points of the screen.

[0088] In some embodiments, when the user turns on the projection device 2, the projection device 2 can project the content pre-set by the user onto the projection surface 400. The projection surface 400 can be a wall or other projection media, such as a screen. The projection image can be displayed on the projection surface 400 for the user to watch.

[0089] In some embodiments, taking the projection medium as a screen as an example, the screen can have various specifications and types. For different screens, the projection device 2 needs to be adjusted accordingly before projection to ensure that the content to be projected can be projected onto the screen more accurately.

[0090] Figure 9 A schematic diagram of a curtain provided in some embodiments of the present application, such as Figure 9 As shown, in some embodiments, the screen 21 may include a projection area 211 and an edge line 212. The projection area 211 is used to display the projection content to be projected, such as images, videos, etc. The screen 21 may be provided with different edge lines 212 according to actual needs. Figure 9 In the embodiment, the edges of the curtain 21 are all provided with dark edge lines 212. For example, the four edge lines 212 of the curtain 21 can all be black, and the dark edge lines 212 can have a certain width. Figure 9 The curtain 21 in the figure can be referred to as a four-sided curtain. It is understandable that, in addition to the four-sided curtain, there are other types of curtains 21, which are not specifically limited in this application.

[0091] To perform the sensible on-screen function, projection device 2 needs to determine its projection area. In some embodiments, projection device 2 can determine the projection area as follows. First, a screen entry instruction for projection device 2 to enter the screen is received. In response to the screen entry instruction, a projection content image captured based on a solid color chart is acquired, and a feature image captured by image acquisition device 700 based on a feature chart is acquired. Next, a homography matrix is ​​calculated between image acquisition device 700 and light output assembly 200 based on the feature image. The projection area of ​​projection device 2 is then determined based on the homography matrix and the projection content image.

[0092] For example, a user or control system can send a screen entry command to projection device 2. This command can be triggered manually, such as by a button or interface operation, or automatically, such as by a preset time or condition. The screen entry command instructs projection device 2 to execute the screen entry function. Upon receiving the screen entry command, projection device 2 can first control the optical engine to project a solid-color image card, such as a white image card. The image capture device 700 then captures the projected image of the solid-color image card to generate a projected content image. The solid-color image card provides a uniform background, facilitating the extraction of feature points and edge information of the projection area from the projected content image. Projection device 2 can then control the optical engine to project a feature image card, and then capture a feature image captured by the image capture device 700 based on the feature image card. It will be appreciated that a feature image has specific features, such as corner points, edge lines, or specific patterns or contours. The feature image card can be used to provide a rich set of feature points, facilitating the calculation of the homography matrix between the image capture device 700 and the light output assembly 200 based on these feature points. After the homography matrix is ​​calculated, the pixel coordinates in the projection content image can be mapped to the actual projection area, such as onto a screen, using the homography matrix. Through the mapping process, the projection area that the projection device 2 should project can be determined.

[0093] In order to ensure the docking effect between the projected image and the screen frame, in some embodiments, after obtaining the projection area through the homography matrix of the image acquisition device 700 and the light output component 200, the projection device 2 can perform edge smoothing on the projected content image to generate line segments for representing the frame of the projection medium.

[0094] For example, during the projection process, more attention is paid to the projection area. Therefore, in some embodiments, for the non-projection area, the pixel values ​​of the non-projection area can be set to 0. For example, after the pixel values ​​are set to 0, it is similar to the effect of painting the non-projection area black. In this way, in the final projection effect, the non-projection area will not have corresponding content, which helps to focus the user's attention on the projection area and not be affected by the surrounding irrelevant areas.

[0095] Edge smoothing of the projected content can eliminate the effects of scratches or unevenness on the black border of the screen. Smoothing can be performed using a variety of image processing algorithms, such as Gaussian blur, median filtering, or bilateral filtering, to reduce the visual discontinuity caused by broken screen borders.

[0096] The purpose of performing edge smoothing on the projected content image is to ensure that line segments are aligned as much as possible, reducing the phenomenon of breakage and interlacing. After performing edge smoothing on the projected content image, the line segments contained in the screen border can be generated.

[0097] Because the projected content image itself has a border, which is not the projected content that the user is interested in, in order to ensure that the projected content can be correctly adapted to the screen, in some embodiments, the projection device 2 needs to obtain a retracted feature area of ​​the projection area. The retracted feature area is the projection area formed by retracting the vertex coordinates of the projection area by a preset number of pixels.

[0098] Exemplarily, the retracted feature area can be a retracted region of interest (ROI) area, and the preset number of pixels can be 3 pixels. The retracted ROI area can be a feature area of ​​interest formed by retracting the coordinates of the four vertices of the projection area by 3 pixels, so as to avoid non-interest areas and facilitate user viewing.

[0099] After determining the line segments and the indented feature area used to represent the frame of the projection medium, the projection device 2 may generate key points of the screen based on the positional relationship between the line segments and the indented feature area.

[0100] To generate screen key points, the projection device 2 can first identify the positional relationship between line segments and the indented feature area, remove line segments outside the indented feature area, and retain line segments within the indented feature area to generate valid line segments. The valid line segments are then screened based on a preset line segment length and the absolute value of a preset horizontal angle of the line segment to retain boundary line segments. The boundary line segments are then extended to the boundary of the projected content image, and the intersection points of the extended boundary line segments are calculated. The intersection points are then screened based on the angle formed between the boundary line segments and the positional relationship between the intersection points and the indented feature area to remove intersection points outside the indented feature area to generate screen key points.

[0101] Exemplarily, by determining whether a line segment is within the shrunk ROI of the projection area, line segments at the edge of the projection area can be removed to retain the line segments within the shrunk feature area, obtaining valid line segments. During the shooting process of the light-emitting component 200, since the placement position of the projection device 2 is not necessarily completely horizontal, the line segments representing the borders of the projection medium may be inclined and have a certain angle. Therefore, further screening can be performed on the valid line segments by presetting the line segment length and the absolute value of the preset line segment horizontal angle to retain the boundary line segments.

[0102] In some embodiments, the preset line segment length Distance and the absolute value of the preset line segment horizontal angle angle can be set according to actual requirements. For example, it can be set in combination with the actual use distance and the side projection angle of the projection device 2. Figure 10 Schematic diagram of the inspection effect of line segments within the projection area provided by some embodiments of the present application, as Figure 10 shown, Figure 10 The ones retained are the valid line segments within the shrunk feature area. Figure 11 Schematic diagram of the effect of the boundary line segments generated after screening the valid line segments provided by some embodiments of the present application, as Figure 11 shown, further screening can be performed on the valid line segments by presetting the line segment length and the absolute value of the preset line segment horizontal angle to generate boundary line segments.

[0103] For example, the valid line segments can be screened according to the following conditions. The preset line segment length needs to satisfy distance > 1 / 6 of the average value of the upper and lower boundary lengths of the projection area, and the absolute value of the preset line segment horizontal angle needs to satisfy 0° < angle < 30° or 150° < angle < 180°. Or, the preset line segment length needs to satisfy distance > 1 / 6 of the average value of the left and right boundary lengths of the projection area, and 60° < angle < 120°. The above are all exemplary descriptions, and in actual use scenarios, it can be set in combination with specific requirements. Combining Figure 10 and Figure 11 it can be found that Figure 10 the two valid line segments on the left are removed due to factors such as length or angle, and finally Figure 11 the boundary line segments shown in

[0104] To obtain the key points of the curtain, after obtaining the boundary line segments, extend the boundary line segments to the boundary of the projection content image and calculate the intersection points of the extended boundary line segments. Figure 12 Schematic diagram of the effect of the intersection points formed after extending the boundary line segments provided by some embodiments of the present application, as Figure 12As shown in the figure, after the boundary line segments are extended to the boundary of the projected content image, multiple intersections will be formed between the multiple boundary line segments. The intersections are then screened based on the angle formed between the boundary line segments and the positional relationship between the intersections and the indented feature area. For example, taking a usage scenario with a distance of 1.5 to 3.0 meters and a maximum side projection angle of 30 degrees as an example, the angle formed between the boundary line segments should be between 60 degrees and 120 degrees. By judging the angle between the two boundary line segments and whether the intersection falls within the indented ROI of the projection area, the intersections can be screened to eliminate the intersections outside the indented feature area, and obtain Figure 12 The soft goods key points shown in .

[0105] To ensure a valid projection area boundary, the number of screen key points should be greater than a preset number. In some embodiments, the preset number can be 3. Thus, the number of screen key points should be greater than 3 so that a convex quadrilateral is formed by the screen key points. After the screen key points are determined, if the number of screen key points exceeds the preset number, projection device 2 can determine a key boundary line in the projection area based on the screen key points.

[0106] To determine the critical boundary lines within the projection area, projection device 2 first records the locations and number of intersection points on the boundary line segment, then calculates the maximum distance between two adjacent intersection points on the boundary line segment and marks the boundary line segment where the two intersection points are located as the maximum distance segment. The absolute horizontal angle of the maximum distance segment is then obtained, and the absolute horizontal angle and maximum distance are used to determine the critical boundary lines within the boundary segment.

[0107] For example, after obtaining the key points of the screen, the projection device 2 can record the location and number of intersections on each boundary line segment, and then find the maximum distance between two adjacent intersections on each boundary line segment. It is understood that there are no other intersections between these two intersections. In some embodiments, the distance between the two intersections can be recorded as maxDistance, and the maximum distance line segment between two adjacent intersections can be recorded as maxDistanceLine. For a boundary line segment with only one intersection, maxDistance = 0.

[0108] In some embodiments, when determining a key boundary line in a boundary segment, the absolute horizontal angle maxDistanceLineAngle of the maximum distance segment maxDistanceLine may be obtained, and maxDistanceLine may be filtered using the absolute horizontal angle maxDistanceLineAngle and maxDistance.

[0109] Figure 13 Schematic diagram of the effect of determining the key boundary line of the projection device provided in some embodiments of the present application, such as Figure 13 As shown, in some embodiments, when determining the critical boundary line, the absolute horizontal angle is required to satisfy 0° < maxDistanceLineAngle < 30° or 150° < maxDistanceLineAngle < 180°, and maxDistance needs to satisfy maxDistance > 1 / 3 of the average value of the upper and lower boundary lengths of the projection area. Or, the absolute horizontal angle is required to satisfy 60° < maxDistanceLineAngle < 120, and maxDistance needs to satisfy maxDistance > 1 / 3 of the average value of the left and right side lengths of the projection area for maxDistanceLine. In this way, the Figure 13 critical boundary line shown can be obtained. After step S1 is completed, the following step S2 can be executed.

[0110] Step S2: Based on the solid color line, depict the critical boundary line to generate a predicted border line.

[0111] Continue to refer to Figure 13 , in some embodiments, the critical boundary line includes an inner border line and an outer border line. In theory, the area formed by the inner border line should be a closed area, and the area formed by the outer border line is a non-closed area. Then, when drawing the critical boundary line based on the solid color line, both the inner border line and the outer border line can be drawn, or only the inner border line can be drawn. This application does not make specific limitations on this.

[0112] In order to enable the projection device 2 to more accurately determine the projection area, in some embodiments, the critical boundary line can be depicted based on the solid color line to generate a predicted border line. Among them, the predicted border line includes an inner border line, and the area formed by the inner border line is a closed area.

[0113] In order to generate a predicted border line, in some embodiments, the projection device 2 can first obtain the position where the critical boundary line is located, then set the line color, line style, and stroke mode for depicting the critical boundary line, and then draw the critical boundary line at the position based on the line color, line style, and stroke mode to generate a predicted border line.

[0114] Figure 14 is a schematic diagram of the effect of the predicted border line provided by some embodiments of this application. As Figure 14 shown, in some embodiments, the solid color line can be a pure black line. Since the borders of the effective area of the curtain are mostly black, when depicting the critical boundary line, a black line can be used for depiction, which is closer to the actual border color and improves the accuracy of projection onto the curtain. In theory, the inner border line of the critical boundary line should be closed, but in some cases, when the border is damaged or wrinkled, it is also possible for the inner border line to be unclosed, which is not conducive to the projection device entering the curtain.

[0115] Therefore, the process of delineating the critical boundary lines with black lines is actually equivalent to the process of completing the critical boundary lines that may be broken. For example, the broken inner and outer border lines are completed by drawing. It can be understood that after the critical boundary lines are completed by drawing, the area formed by the inner border lines is a closed area, and the outer border remains an open area, only the broken parts are connected.

[0116] Exemplarily, the process of generating an estimated border line may be to first identify the location where the key border line needs to be drawn. For example, the pixel changes of the image can be analyzed by an edge detection algorithm to find the possible boundary location. After determining the location of the key boundary line, the line properties that depict these boundary lines need to be set, which may include but are not limited to the color of the line, the line style and the stroke mode. The choice of line color can be combined with the actual curtain border color, and the line style can be a solid line, a dotted line, a dashed line, etc. The stroke mode can define how the line is drawn on the key boundary line, which can be a fill mode or an edge-only mode, etc. After setting the line properties, the key boundary line can be drawn. According to the previously located position and the set line properties, the boundary line can be drawn using the corresponding drawing tool or algorithm, and the final drawing is the estimated border line. After step S2 is completed, the following step S3 can be executed.

[0117] Step S3: searching for the target contour shape of the projection medium in the closed area formed by the inner frame line, and extracting the contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral.

[0118] After generating the estimated frame line, the projection device 2 can search for the target contour shape of the projection medium in the closed area formed by the inner frame line. In other words, the contour shape of the projection medium is extracted in the closed area formed by the inner frame line, and the closed area is the effective area of ​​the projection.

[0119] For example, after the inner border is completed, the target outline of the projection medium can be found. It is understood that the outline of the projection medium is related to obstacles. If the target outline is a convex quadrilateral, the rough vertices of the projection area can be determined based on the convex quadrilateral. Then, the fine vertices of the projection area can be determined based on the rough vertices and the key points of the screen, and subsequent steps can be performed.

[0120] In some embodiments, when the overall color of the obstacle is lighter, the projection device 2 can identify a convex quadrilateral outline. Figure 15 This is a schematic diagram of the effect of the convex quadrilateral of the curtain area provided in some embodiments of the present application, such as Figure 15As shown, when the projection device 2 finds a convex quadrilateral outline, the four rough vertex coordinates of the screen area can be directly obtained, so that the subsequent steps can be continued.

[0121] In some embodiments, when the overall color of the obstacle is very close to the actual color of the screen border, the outline shape found by the projecting device 2 may be a non-quadrilateral convex polygon, that is, a non-convex quadrilateral. Figure 16 There are some embodiments of the present invention that provide schematic diagrams of the effect of a non-convex quadrilateral in the curtain area, such as Figure 16 As shown, when there is a dark obstacle, the projection device 2 finds a non-convex quadrilateral, such as a convex pentagon, a convex hexagon, etc., and the four coarse vertices of the screen area cannot be obtained at this time.

[0122] In order to search for the target contour shape of the projection medium in the closed area formed by the inner frame line, the projection device 2 can first obtain multiple contour shapes of the projection medium to be searched in the closed area, then set a preset area ratio and a preset shape, and then filter the contour shapes according to the preset area ratio and the preset shape to retain the target contour shape.

[0123] For example, there may be multiple contour shapes in a closed area, and the projection device 2 can set a screening condition to filter out a target contour shape from the multiple contour shapes. For example, the screening condition can be to set a preset area ratio and a preset shape. In some embodiments, the preset area ratio can be used to compare the actual area of ​​the contour and the area of ​​the entire closed area. The specific ratio value can be set according to actual needs. The preset shape may include the geometric characteristics of the contour, such as whether it is a convex polygon. If it is a concave polygon, it is directly eliminated. In actual use scenarios, it is not limited to these two screening conditions and can be set according to actual needs.

[0124] That is, in this application, the target outline shape is not affected by obstacles, and the target outline shape can be found regardless of whether there are obstacles at the corners or the frame. Therefore, the projection device 2 in this application is compatible with screen entry even when the frame is blocked or the corners are blocked, solving the problem of being unable to enter the screen when the screen is partially blocked, and improving the screen entry robustness of the projection device.

[0125] After the target contour shape is found, the projection device 2 can extract the contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral, and perform smoothing on the contour line. In other words, after extracting the contour line of the non-convex quadrilateral, the present application can further perform smoothing on the contour line to reduce the edge breakage of the contour line and make it smoother.

[0126] Exemplarily, when extracting the contour line, the edge point coordinates of the non-convex quadrilateral can be extracted first to form a sequence of points, and these points together constitute the contour line of the non-convex quadrilateral. Since noise may be introduced or other factors may affect the contour extraction process, the obtained contour line may not be smooth enough. Therefore, the contour line can be smoothed. The smoothing process can be performed by various algorithms. For example, moving average filtering, Gaussian filtering, median filtering, or using Bezier curve fitting can be used. By smoothing the contour line, the sense of break of the contour line can be reduced, and at the same time, the influence of irregular shapes on the projection effect can be reduced. After step S3 is completed, the following step S4 can be performed.

[0127] Step S4: Screen the smoothed contour line according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi contour line.

[0128] After the contour line smoothing process is completed, the projection device 2 can also screen the smoothed contour line according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi contour line. In some embodiments, the preset line segment length can satisfy distance > 1 / 6 of the average value of the upper and lower boundary lengths of the projection area, and the absolute value of the preset line segment horizontal angle can satisfy 0° < angle < 30° or 150° < angle < 180°. Or, the preset line segment length needs to satisfy distance > 1 / 6 of the average value of the left and right boundary lengths of the projection area, 60° < angle < 120°, and finally the qualified quasi contour line is retained. The method of screening and retaining the boundary line segment for the effective line segment can be referred to, and this application will not repeat the description here.

[0129] That is to say, in the embodiments of this application, there are two times of performing smoothing processing and screening of line segments. One is to screen the effective line segments according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the boundary line segments, and the other is to screen the smoothed contour line to retain the quasi contour line. Through the two screenings, the final quasi contour line can better meet the actual requirements of the projection area, which helps to reduce misidentification and projection errors, and further improve the projection accuracy of the projection device. After step S4 is completed, the following step S5 can be performed.

[0130] Step S5: Extend the quasi contour line to the boundary of the projection content image, and obtain the rough vertices of the projection area according to the extended quasi contour line.

[0131] Figure 17 For the scenario schematic diagram of the rough vertex generation method provided by some embodiments of this application, as Figure 17As shown, in some embodiments, after determining the quasi-contour, projection device 2 can extend the quasi-contour to the boundary of the projected content image and obtain coarse vertices of the projection area based on the extended quasi-contour. By extending the quasi-contour to the boundary of the projected content image, it is possible to ensure that the projection area completely covers the target contour shape, and the obtained coarse vertices provide a basis for precise positioning of the projection area.

[0132] For example, first, the projection device 2 needs to extend the contour line to ensure that it completely covers the boundary of the projected content image. During the extension process, the endpoints of the contour line can be interpolated or curve fitting technology can be used to ensure the continuity and smoothness of the extended part with the original contour line. Figure 17 In the example, the lower right corner is the rough vertex formed by the intersection of the extended quasi-contour lines, and the vertices of the other corner points can also be obtained by the same method. After step S5 is completed, the following step S6 can be executed.

[0133] Step S6: Determine the fine vertex of the projection area based on the rough vertex and the key point of the screen, and control the light-emitting component to project the playback content to the projection medium according to the target optical-mechanical image coordinates; the target optical-mechanical image coordinates are calculated based on the homography matrix between the image acquisition device and the light-emitting component and the coordinates of the fine vertex.

[0134] Since the coarse vertex may not fit the screen border line perfectly, in some embodiments, in order to obtain more precise vertices, the projection device 2 may determine the fine vertex of the projection area based on the coarse vertex and the key points of the screen to improve the accuracy of the projection onto the screen.

[0135] In some embodiments, when determining the precise vertices of the projection area based on the coarse vertices and screen key points, the projection device 2 may first obtain the coarse vertex, then obtain screen key points that are less than a preset distance from the coarse vertex, and then mark the screen key point with the minimum distance from the coarse vertex as the precise vertex of the projection area. In other words, using a minimum distance matching method, the coordinates of the four coarse vertices in the projection area are used to match the screen key points. This method can find the four screen key points that are closest to the coarse vertex, resulting in four more precise vertices, namely, the precise vertices.

[0136] For example, first, projection device 2 acquires the coarse vertices of the projection area. While these coarse vertices can roughly determine the projection area, their accuracy is insufficient. Therefore, to improve projection accuracy, the following processing can also be performed. Projection device 2 can use a minimum distance matching method to obtain the fine vertices corresponding to the coarse vertices. For each coarse vertex, four screen key points are distributed around it. The screen key point with the closest distance is selected, and this closest point is considered the fine vertex corresponding to the coarse vertex. Through the minimum distance matching method, projection device 2 can find a corresponding screen key point for each coarse vertex. These screen key points actually constitute a more accurate projection area boundary, representing the exact location where the projected content should be aligned. This not only improves the accuracy of the projected content and ensures that the image is fully presented on the screen, but also prevents the projected content from exceeding the screen range, causing image distortion or waste. At the same time, the acquisition of fine vertices also provides a more reliable basis for subsequent projection adjustment and optimization, allowing projection device 2 to flexibly adjust according to actual conditions to achieve better projection effects.

[0137] After the precise vertex is determined, the projection device 2 can calculate the corresponding target optical-mechanical image coordinates in the light-emitting component 200 based on the homography matrix between the image acquisition device 700 and the light-emitting component 200 and the coordinates of the precise vertex, and control the light-emitting component 200 to project the playback content to the projection medium according to the target optical-mechanical image coordinates.

[0138] When calculating the target optomechanical image coordinates, that is, when the projection device 2 homographs the four precise vertices of the projection medium to the optomechanical image coordinates, if the calculated homography matrix is ​​H and the four precise vertex coordinates are represented as C, then the target optomechanical image coordinates P = H*C.

[0139] When projecting content, projector 2 first obtains the target optical-mechanical image coordinates. It then determines the target projection position based on the target optical-mechanical image coordinates. The area encompassing the target projection positions is then defined as the target entry area for the projection medium. Projector 2 then enters the screen based on the target entry area. In other words, the area encompassed by the target optical-mechanical image coordinates represents the area of ​​screen 21.

[0140] Figure 18 This is a schematic diagram of the effect of the projection device according to some embodiments of the present application projecting the projection content according to the fine vertex, such as Figure 18 As shown, when projecting content, the projection device 2 converts the coordinates of the four screen vertices on the projected content image into the optical coordinate system and performs screen entry in the optical coordinate system. It is understood that before performing screen entry, functions such as calibration can be triggered to ensure the accuracy of screen entry.

[0141] It should be noted that in the embodiment of the present application, since an estimated border line is generated based on the key boundary line drawn with a solid color line, and the target contour shape of the projection medium is searched within the inner border line of the estimated border line, the target contour shape can be found even when there is an obstacle blocking the view, and the coarse and fine vertices of the projection area are determined in sequence based on the target contour shape. Therefore, even in the presence of an obstacle blocking the view, the projection device 2 can still achieve screen entry, thereby improving the robustness of automatic screen entry and resolving the problem of the projection device failing to enter the screen when the projection medium is blocked by an obstacle.

[0142] As can be seen from the above technical solution, the above embodiment provides a projection device, which obtains the key points of the screen, determines the key boundary lines in the projection area based on the key points of the screen; depicts the key boundary lines based on pure color lines, and searches for the target contour shape of the projection medium in the closed area formed by the inner frame line; when the target contour shape is a non-convex quadrilateral, extracts the contour line of the non-convex quadrilateral, and performs smoothing on the contour line; performs screening on the smoothed contour line to retain the quasi-contour line; extends the quasi-contour line to the boundary of the projected content image, and obtains the coarse vertex of the projection area based on the extended quasi-contour line; determines the fine vertex of the projection area based on the coarse vertex and the key points of the screen; calculates the target optical image coordinates corresponding to the fine vertex in the light-emitting component, and controls the light-emitting component to project the playback content to the projection medium according to the target optical image coordinates. The projection device can find the target contour shape of the projection medium even when there is an obstacle blocking it, solving the problem of the projection device failing to enter the screen when the projection medium is blocked by an obstacle.

[0143] Based on the projection device 2 in the above embodiment, some embodiments of the present application further provide a method for projecting a picture onto a screen, which can be applied to the projection device 2 in the above embodiment. In some embodiments, the method may include the following contents:

[0144] Acquiring key points of the screen, and when the number of the key points of the screen is greater than a preset number, determining key boundary lines in the projection area according to the key points of the screen;

[0145] Describing the key boundary line based on a solid color line to generate an estimated border line; the estimated border line includes an inner border line, and the area formed by the inner border line is a closed area;

[0146] Searching for a target contour shape of the projection medium in a closed area formed by the inner frame line, and extracting a contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral;

[0147] The smoothed contour lines are screened according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi-contour lines;

[0148] Extending the quasi-contour line to the boundary of the projection content image, and obtaining a coarse vertex of the projection area according to the extended quasi-contour line;

[0149] The fine vertices of the projection area are determined based on the rough vertices and the key points of the screen, and the light-emitting component is controlled to project the playback content onto the projection medium according to the target optical-mechanical image coordinates; the target optical-mechanical image coordinates are calculated based on the homography matrix between the image acquisition device and the light-emitting component and the coordinates of the fine vertices.

[0150] As can be seen from the above technical solution, the above embodiment provides a method for projecting an image onto the screen. The method preliminarily generates an estimated border line based on a solid color line depicting a key boundary line, and searches for the target contour shape of the projection medium within the inner border line of the estimated border line. Even in the presence of obstructions, the target contour shape can be found, and the coarse and fine vertices of the projection area are sequentially determined based on the target contour shape. Therefore, even in the presence of obstructions, the projection device 2 can achieve screen entry, thereby improving the robustness of automatic screen entry and resolving the problem of the projection device failing to enter the screen when the projection medium is obstructed by an obstacle.

[0151] The same and similar parts between the various embodiments in this specification can be referenced to each other and will not be repeated here.

[0152] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software plus a necessary general-purpose hardware platform. Based on this understanding, the technical solutions in the embodiments of the present invention, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of various embodiments of the present invention or certain portions of the embodiments.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0154] For ease of explanation, the above description has been made with reference to specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Based on the above teachings, various modifications and variations are possible. The above embodiments are selected and described to better explain the principles and practical applications, so that those skilled in the art can better utilize the embodiments and various different variations of the embodiments suitable for specific use considerations.

Claims

1. A projection device, characterized in that: include: A light emitting component configured to project playback content onto a projection medium; an image acquisition device configured to capture an image of the projected content; The controller is configured as: Acquiring key points of the screen, and when the number of the key points of the screen is greater than a preset number, determining key boundary lines in the projection area according to the key points of the screen; Describing the key boundary line based on a solid color line to generate an estimated border line; the estimated border line includes an inner border line, and the area formed by the inner border line is a closed area; Searching for a target contour shape of the projection medium in a closed area formed by the inner frame line, and extracting a contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral; The smoothed contour lines are screened according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi-contour lines; Extending the quasi-contour line to the boundary of the projection content image, and obtaining a coarse vertex of the projection area according to the extended quasi-contour line; Determine the fine vertex of the projection area according to the rough vertex and the key point of the screen, and control the light output component to project the playback content onto the projection medium according to the target optical machine image coordinates; The target optical-mechanical image coordinates are calculated based on the homography matrix between the image acquisition device and the light output component and the coordinates of the precise vertex.

2. The projection device according to claim 1, wherein: The controller is further configured to: receiving a screen entry instruction for a projection device to enter the screen; In response to the screen entry instruction, acquiring a projection content image captured based on a pure color chart, and acquiring a feature image captured by an image acquisition device based on a feature chart; Calculating a homography matrix between the image acquisition device and the light output component according to the characteristic image; A projection area of ​​the projection device is determined according to the homography matrix and the projection content image.

3. The projection device according to claim 1, wherein: The controller is further configured to: Get the projection area of ​​the projection device; performing edge smoothing processing on the projection content image to generate line segments for representing a frame of the projection medium; Acquire a retracted feature area of ​​the projection area, where the retracted feature area is a projection area formed by retracting the vertex coordinates of the projection area by a preset number of pixels; The curtain key point is generated according to the positional relationship between the line segment and the indented feature area.

4. The projection device according to claim 3, characterized in that The controller generates curtain key points according to the positional relationship between the line segment and the indented feature area, and is further configured to: Identifying a positional relationship between the line segment and the indented feature area; Eliminating the line segments outside the indented feature area and retaining the line segments within the indented feature area to generate valid line segments; Screening the valid line segments according to a preset line segment length and an absolute value of a preset line segment horizontal angle to retain boundary line segments; Extending the boundary line segment to the boundary of the projection content image; Calculate the intersection points of the extended boundary segments; The intersection points are screened according to the angle formed between the boundary line segments and the positional relationship between the intersection points and the indented feature area, so as to eliminate the intersection points outside the indented feature area and generate curtain key points.

5. The projection device according to claim 4, characterized in that: The controller is further configured to: Recording the positions and number of intersections on the boundary line segments; Calculating the maximum distance between two adjacent intersection points on the boundary line segment, and marking the boundary line segment where the two intersection points are located as the maximum distance line segment; Obtaining the absolute horizontal angle of the maximum distance line segment; A key boundary line in the boundary line segment is determined by the absolute horizontal angle and the maximum distance value.

6. The projection device according to claim 1, wherein: The controller executes drawing the key boundary line based on a solid color line to generate an estimated border line, and is further configured to: Obtaining the position of the key boundary line; Setting the line color, line style, and stroke mode for depicting the key boundary line; The key boundary line is drawn at the position based on the line color, the line style, and the stroke mode to generate an estimated border line.

7. The projection device according to claim 1, characterized in that The controller searches for a target contour shape of the projection medium in a closed area formed by the inner frame line, and is further configured to: Acquire a plurality of contour shapes of the projection medium found in the closed area; Set preset area ratio and preset shape; The contour shape is screened according to the preset area ratio and the preset shape to retain a target contour shape.

8. The projection device according to claim 7, characterized in that The controller is further configured to: When the target contour is a convex quadrilateral, determining the rough vertices of the projection area according to the convex quadrilateral; The step of determining the fine vertices of the projection area according to the rough vertices and the curtain key points is performed.

9. The projection device according to claim 1, wherein: The controller is further configured to determine the fine vertex of the projection area according to the rough vertex and the curtain key point: Obtaining the rough vertex; Obtaining a curtain key point that is less than a preset distance from the rough vertex; The key point of the curtain with the minimum distance from the rough vertex is marked as the fine vertex of the projection area.

10. A method for projecting a picture onto a screen, applied to the projection device according to any one of claims 1 to 9, wherein the projection device comprises a light output component, an image acquisition device, and a controller, and is characterized in that: The method for projecting the image onto the screen includes: Acquiring key points of the screen, and when the number of the key points of the screen is greater than a preset number, determining key boundary lines in the projection area according to the key points of the screen; Describing the key boundary line based on a solid color line to generate an estimated border line; the estimated border line includes an inner border line, and the area formed by the inner border line is a closed area; Searching for a target contour shape of the projection medium in a closed area formed by the inner frame line, and extracting a contour line of the non-convex quadrilateral when the target contour shape is a non-convex quadrilateral; The smoothed contour lines are screened according to the preset line segment length and the absolute value of the preset line segment horizontal angle to retain the quasi-contour lines; Extending the quasi-contour line to the boundary of the projection content image, and obtaining a coarse vertex of the projection area according to the extended quasi-contour line; The fine vertices of the projection area are determined based on the rough vertices and the key points of the screen, and the light-emitting component is controlled to project the playback content onto the projection medium according to the target optical-mechanical image coordinates; the target optical-mechanical image coordinates are calculated based on the homography matrix between the image acquisition device and the light-emitting component and the coordinates of the fine vertices.

Images