A projection device and a projection method

Abstract

Some embodiments of the present application provide a projection device and a projection method. The projection device can control the light-emitting assembly to project a first card to a projection surface, and control the camera to capture a first image. The first card does not contain feature points and can be a pure white card. The projection device crops the first card in the first image to obtain a first card image, performs binaryzation processing on the first card image, and obtains a white connected region in the first card image based on the binaryzation result. The projection device locates a to-be-projected region based on the white connected region, and controls the light-emitting assembly to project to-be-projected content to the to-be-projected region. The projection device does not identify the frame of the curtain, but identifies the white connected region in the image, i.e., a continuous closed region. By analyzing the white connected region, the projection region can be determined, i.e., considered as the blank area of the curtain, so as to accurately project the image to the curtain and improve the user experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of projection equipment, and in particular to a projection equipment and a projection method. BACKGROUND

[0002] The projection equipment is a display equipment that can project images or videos onto a screen. During projection, the projection equipment needs to project the projection picture content onto the screen wall through the light-emitting assembly. The screen wall can be a screen matched with the projection equipment, such as a curtain or a Fresnel hard screen. The screen wall can also be a plane, such as a wall or a ceiling, arranged in the projection direction of the light-emitting assembly.

[0003] During the use of the projection equipment, the user can manually adjust the projection angle of the projection equipment, so that the projection equipment projects the content to the area set by the user. If the projection equipment needs to project images and the like to the curtain and the like in a specific area, considering that the manual adjustment operation of the user is relatively cumbersome, the projection equipment can automatically project the images to the curtain. The projection equipment can capture the curtain and identify the rectangular frame of the curtain in the captured image, so as to obtain the blank area in the curtain and use it as the projection area. The projection equipment can project images and the like to the projection area for the user to view.

[0004] However, considering the diversity of the curtain, the frame of the curtain can not be rectangular, or even there can be no frame, so that the projection area of the curtain cannot be obtained. For example, the curtain can be a single-frame, double-frame, triple-frame or even frameless. Even if the projection equipment identifies the frame of the curtain, the blank area of these curtains cannot be obtained, so that the projection area cannot be determined. This causes the projection equipment to fail to accurately project the images to the curtain, affecting the user experience. SUMMARY

[0005] The present application provides a projection equipment and a projection method to solve the problem that the projection equipment cannot accurately project images to the curtain, affecting the user experience.

[0006] In a first aspect, some embodiments of the present application provide a projection equipment, comprising a light-emitting assembly, a camera and a controller. The light-emitting assembly is configured to project projection content to a projection surface. The camera is configured to capture an image in the projection surface. The controller is configured to perform the following steps:

[0007] In response to a projection instruction input by a user, the light-emitting assembly is controlled to project a first image card to the projection surface, and a first image captured by the camera on the first image card on the projection surface is obtained.

[0008] The first image card in the first image is cropped to obtain a first image card image.

[0009] binarize the first card image, and obtain a white connected region in the first card image based on a binarization result;

[0010] locate a to-be-projected region based on the white connected region;

[0011] control the light-emitting component to project to-be-projected content to the to-be-projected region.

[0012] In a second aspect, some embodiments of the present application provide a projection method applied to a projection device, the projection device including a light-emitting component, a camera, and a controller, and the projection method includes:

[0013] in response to a projection instruction input by a user, control the light-emitting component to project a first card to the projection surface, and obtain a first image captured by the camera on the first card on the projection surface;

[0014] crop the first card in the first image to obtain a first card image;

[0015] binarize the first card image, and obtain a white connected region in the first card image based on a binarization result;

[0016] locate a to-be-projected region based on the white connected region;

[0017] control the light-emitting component to project to-be-projected content to the to-be-projected region.

[0018] According to the above technical solutions, the projection device and the projection method provided in some embodiments of the present application can, in response to a projection instruction input by a user, control the light-emitting component to project a first card to the projection surface, and control the camera to capture the first card on the projection surface to obtain a first image. The first card does not include a feature point and can be a pure white card. The projection device crops the first card in the first image to obtain a first card image, binarizes the first card image, and obtains a white connected region in the first card image based on a binarization result. The projection device locates a to-be-projected region based on the white connected region, and controls the light-emitting component to project to-be-projected content to the to-be-projected region. Instead of recognizing the frame of the curtain, the projection device recognizes the white connected region in the image, i.e., a continuous closed region. By analyzing the white connected region, the projection region, i.e., the blank region of the curtain, can be determined, so that the image can be accurately projected to the curtain, and the user experience is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0020] Figure 1 The swing diagram of the projection device of some embodiments of the present application is shown;

[0021] Figure 2 The light path diagram of the projection device of some embodiments of the present application is shown;

[0022] Figure 3 The circuit architecture diagram of the projection device of some embodiments of the present application is shown;

[0023] Figure 4 The structure diagram of the projection device of some embodiments of the present application is shown;

[0024] Figure 5 The system framework diagram of the projection device of some embodiments of the present application is shown;

[0025] Figure 6 The diagram of the projection screen in some embodiments is shown;

[0026] Figure 7 The component diagram of the projection device in some embodiments is shown;

[0027] Figure 8 The interaction flowchart of the components of the projection device in some embodiments is shown;

[0028] Figure 9 The diagram of the connected region of the first card image in some embodiments is shown;

[0029] Figure 10 The diagram of the connected region of the first card image in some embodiments is shown;

[0030] Figure 11 The diagram of the connected region of the first card image in some embodiments is shown;

[0031] Figure 12 The diagram of the connected region of the first card image in some embodiments is shown;

[0032] Figure 13 The diagram of the maximum rectangle in some embodiments is shown;

[0033] Figure 14 The diagram of the second card in some embodiments is shown;

[0034] Figure 15A schematic diagram of a second card in some embodiments is shown. DETAILED DESCRIPTION

[0035] For the purpose of clarity and enabling embodiments of the present application, the following will describe exemplary embodiments of the present application with reference to the accompanying drawings. It is apparent that the exemplary embodiments described are only a part of the embodiments of the present application, and are not all the embodiments of the present application.

[0036] It should be noted that the brief description of the terms in the present application is only for the convenience of understanding the following described embodiments, and is not intended to limit the embodiments of the present application. Unless otherwise specified, these terms should be understood according to their ordinary and general meanings.

[0037] The terms "first", "second", "third", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar or similar objects or entities, and do not necessarily mean a specific order or sequence, unless otherwise noted. It should be understood that the terms used in this way can be interchanged under appropriate circumstances.

[0038] The terms "include" and "have" and any variations thereof are intended to cover but not exclusive inclusion, for example, a product or device including a series of components does not necessarily limit to all components clearly listed, but can include other components not clearly listed or inherent to these products or devices.

[0039] The term "module" refers to any known or later developed hardware, software, firmware, artificial intelligence, fuzzy logic, or a combination of hardware or / and software code capable of performing functions associated with the element.

[0040] The embodiments of the present application can be applied to various types of projection devices. In the following, a projector will be taken as an example to describe the projection device and the automatic focusing method.

[0041] A projector is a device that can project an image or video onto a screen. The projector can be connected to a computer, a broadcast network, the Internet, a VCD (Video Compact Disc), a DVD (Digital Versatile Disc Recordable), a game console, a DV, etc. through different interfaces to play corresponding video signals. The projector is widely used in homes, offices, schools, and entertainment venues, etc.

[0042] Figure 1 A schematic diagram of the projection device of some embodiments of the present application is shown, Figure 2 A light path schematic diagram of the projection device of some embodiments of the present application is shown.

[0043] In some embodiments, with reference to Figures 1-2 The projection device provided in the present application comprises a projection screen 1 and a projection device 2. The projection screen 1 is fixed at a first position, and the projection device 2 is placed at a second position so that the projection picture projected by the projection device 2 matches the projection screen 1. The projection device comprises a laser light source 100, an optical machine 200, a lens 300, and a projection medium 400. The laser light source 100 provides illumination for the optical machine 200, the optical machine 200 modulates the light beam of the light source and outputs the light beam to the lens 300 for imaging, and the lens 300 projects the light beam to the projection medium 400 to form a projection picture. Since the laser light source 100, the optical machine 200, and the lens 300 are collectively used to emit the projection light to project the projection picture, in some embodiments of the present application, the laser light source 100, the optical machine 200, and the lens 300 are collectively referred to as a light-emitting assembly.

[0044] In some embodiments, the laser light source 100 of the projection device comprises a laser assembly 110 and an optical lens assembly 120. The light beam emitted by the laser assembly 110 can pass through the optical lens assembly 120 to provide illumination for the optical machine. For example, the optical lens assembly 120 requires a high level of environmental cleanliness and airtight sealing, while the chamber in which the laser assembly is installed can be sealed at a lower sealing level to reduce sealing costs.

[0045] In some embodiments, the optical machine 200 of the projection device can be implemented to comprise a blue optical machine, a green optical machine, and a red optical machine, and can further comprise a heat dissipation system and a circuit control system. It should be noted that in some embodiments, the light-emitting component of the projector can also be implemented by an LED light source.

[0046] Figure 3 The circuit architecture of the projection device of some embodiments of the present application is shown. In some embodiments, the projection device can comprise a display control circuit 10, a laser light source 20, at least one laser driver assembly 30, and at least one brightness sensor 40. The laser light source 20 can comprise at least one laser corresponding to the at least one laser driver assembly 30. The at least one means one or more, and the plurality means two or more.

[0047] Based on the circuit architecture, the projection device can be adapted to adjust. For example, by arranging the brightness sensor 40 in the light-emitting path of the laser light source 20, the brightness sensor 40 can detect the first brightness value of the laser light source and send the first brightness value to the display control circuit 10.

[0048] The display control circuit 10 can obtain a second brightness value corresponding to the driving current of each laser, and determine that the laser has a COD fault when the difference between the second brightness value of the laser and the first brightness value of the laser is greater than a difference threshold value; then the display control circuit can adjust the current control signal of the corresponding laser driving component of the laser until the difference is less than or equal to the difference threshold value, thereby eliminating the COD fault of the blue laser; the projection device can timely eliminate the COD fault of the laser, reduce the damage rate of the laser, and improve the image display effect of the projection device.

[0049] Figure 4 The structure schematic diagram of the projection device of some embodiments of the present application is shown.

[0050] In some embodiments, the laser light source 20 in the projection device can include independently arranged blue lasers 201, red lasers 202, and green lasers 203, and the projection device can also be referred to as a three-color projection device. The blue lasers 201, the red lasers 202, and the green lasers 203 are all module lightweight (Mirai Console Loader, MCL) packaged lasers, which have small volumes and are beneficial to compact arrangement of the optical path.

[0051] 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), a RAM (Random Access Memory), a ROM (Read-Only Memory), a first interface to an n-th interface for input / output, a communication bus, and the like.

[0052] In some embodiments, the projection device can be configured with a camera for cooperative operation with the projection device to achieve adjustment and control of the projection process. For example, the camera configured by the projection device 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 obtain the image and the playing content presented by the projection screen corresponding to the projection device, which are projected by the light machine built in the projection device.

[0053] When the projection device moves to a new position, the projection angle and the distance to the projection screen change, which can cause the projection image to deform, and the projection image can be displayed as a trapezoidal image or other distorted image. The controller of the projection device can realize automatic trapezoidal correction based on the image captured by the camera by coupling the angle between the light machine and the projection screen and the correct display of the projection image.

[0054] Figure 5 A system framework schematic diagram for implementing display control by the projection device of some embodiments of the present application is shown.

[0055] In some embodiments, the projection device has the characteristics of long-focus micro projection, and the controller thereof can perform display control on the projected light image through a preset algorithm to realize functions such as automatic trapezoidal correction, automatic entering, automatic obstacle avoidance, automatic focusing, and anti-eye shooting.

[0056] In some embodiments, the projection device is configured with a gyroscope sensor; during movement of the device, the gyroscope sensor can sense the position movement and actively collect movement data; then the collected data is sent to the application service layer through the system framework layer to support the application data required in the user interface interaction and application interaction process, and the collected data can also be used for data calling in the algorithm service implementation of the controller.

[0057] In some embodiments, the projection device is configured with a time-of-flight sensor, and after the time-of-flight sensor collects corresponding data, the data will be sent to the corresponding time-of-flight service in the service layer; after the time-of-flight service obtains the data, the collected data will be sent to the application service layer through the process communication framework, and the data will be used for data calling of the controller, user interface, program application, and the like.

[0058] In some embodiments, the projection device is configured with a camera for collecting images, which can be implemented as a binocular camera, or a depth camera, or a 3D camera, etc.; the camera collected data will be sent to the camera service, and then the camera service will send 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 collected data sent by the camera service, and the controller can call corresponding control algorithms in the algorithm library for different functions to be implemented.

[0059] In some embodiments, data interaction is performed between the process communication framework and the application service, and then the calculation result is fed back to the correction service through the process communication framework; the correction service sends the obtained calculation result to the projection device operating system to generate control signaling, and sends the control signaling to the optical engine control driver to control the optical engine working condition and realize automatic correction of the display image.

[0060] In some embodiments, the user can use the above projection device in a plurality of different scenarios, and in different use scenarios, different projection surfaces can be used as the projection medium 400. For example, some users need to project onto a projection screen, i.e., the projection medium 400 is a projection screen; some users need to project onto a white wall, i.e., the projection medium 400 is a white wall; and some users need to project onto a ceiling, i.e., the projection medium 400 is a ceiling. For ease of description, in the embodiments of the present application, the projection medium 400, the projection surface, the background wall, etc. all refer to a medium for presenting a projection picture, and the projection medium 400, the projection surface, and the background wall have the same meaning and function unless otherwise specified.

[0061] If the user needs to project onto a wall or a ceiling, the user can adjust the projection angle and position of the projection device, etc. by himself, so that the projection device can project an image to different areas until the user finds the best viewing area.

[0062] If the user needs to project onto a specific area, such as a projection screen, the projection device can be caused to project content that coincides with the blank area in the projection screen, so that the user gets the best viewing experience.

[0063] The projection screen is a tool used in movies, offices, home theaters, large meetings, etc. to display images and video files, and can be set to different specifications and sizes according to actual needs. In order to make the display effect more in line with the user's viewing habits, the aspect ratio of the projection screen corresponding to the projection device is usually set to 16:9 or 4:3 to adapt to the image size projected by the projection device. Figure 6 A schematic diagram of a projection screen in some embodiments is shown. As shown in Figure 6 The projection screen can include a frame and an intermediate area, the frame can be a dark edge band, such as a black frame, used to highlight the boundary of the screen, and the intermediate area of the projection screen can be a white screen, which can be used as a projection area to display the image projected by the projection device.

[0064] In order to achieve the best projection effect, the installation position of the projection screen and the projection device can be operated by professional after-sales technical personnel, by setting the projection screen and the projection device at the placement position that achieves the best projection effect during work, so that the image projected by the projection device can be completely in the projection screen, thereby improving the user experience. In the use process, the user can also set the positions of the two by himself, which is not limited in the embodiments of the present application.

[0065] It should be noted that, considering that the process of adjusting the projection device by the user is relatively cumbersome, the projection device can have an automatic curtain-in function. The automatic curtain-in function refers to the projection device being able to automatically determine a projection area in the curtain and project an image into the projection area, thereby avoiding the user manually adjusting the angle and position of the projection device to improve the user's experience. The projection device can be provided with an automatic curtain-in mode, and the user can send an automatic curtain-in instruction to the projection device to make the projection device enter the automatic curtain-in mode, so as to enable the projection device to start the automatic curtain-in function.

[0066] In some embodiments, the user can send an automatic curtain-in instruction to the projection device by operating a specified key of the remote controller. The correspondence between the automatic curtain-in instruction and the remote controller key is bound in advance in the actual application. For example, an automatic curtain-in mode key is provided on the remote controller, and when the user touches the key, the remote controller sends an automatic curtain-in instruction to the projection device, and at this time the projection device can enter the automatic curtain-in mode. When the user touches the key again, the projection device can exit the automatic curtain-in mode.

[0067] In some embodiments, the projection device has a voice control function. The projection device includes a sound collector, which can be a microphone. The user can use the sound collector of the projection device to send an automatic curtain-in instruction to the projection device in a voice input manner to control the projection device to enter the automatic curtain-in mode.

[0068] In some embodiments, a specific button can be provided on the projection device to control whether the projection device enters the automatic curtain-in mode. When the user presses the button, the projection device can enter the automatic mode.

[0069] In some embodiments, the user can use a smart device to control the projection device, for example, use a mobile phone to control the projection device. The user can use the mobile phone to send an automatic curtain-in instruction to the projection device. In the actual application, a control can be provided in the mobile phone, and the control can be used to select whether to perform the automatic curtain-in mode process, thereby sending an automatic curtain-in instruction to the projection device.

[0070] In order to enable the projection device to implement the automatic curtain-in function, the projection device should at least include a light-emitting assembly, a camera 500, and a controller. Figure 7 A component schematic diagram of the projection device in some embodiments is shown.

[0071] The light-emitting component is configured to project content onto the projection surface. Clearly, the projected content includes the user interface and the media assets being played. For example, when a user uses the remote control that comes with the projector to set up the projector, the light-emitting component can project the settings interface onto the projection surface; and when a user uses the projector to watch movies, TV series, or other multimedia resources, the light-emitting component can project the media assets onto the projection surface.

[0072] Camera 500 is configured to capture images, specifically images of the projection surface. Camera 500 can also capture images of the environment surrounding the projection device, thereby obtaining scene images. Camera 500 can acquire images of different objects depending on the intended purpose. For example, when the projection device adjusts its projection angle, camera 500 can capture images of the projection surface to obtain an image including the projected content; when the projection device automatically avoids obstacles, camera 500 can capture images of targets in front of the light-emitting component to obtain sampled images including the obstacle targets.

[0073] In some embodiments, when the projection device enters automatic screen placement mode, it can acquire the placement of the screen to determine the projection area within the screen. Considering that the screen includes a border and a central area, the projection device can identify the screen border. After identifying the screen border, the area within the border, i.e., the white screen area in the center of the screen, can be determined. The projection device can then define this white screen area as the projection area and project images or other content onto that projection area.

[0074] When the projection device automatically enters the screen, the controller can first control the light-emitting component to illuminate the screen area. This can be achieved by projecting a pure white image onto the projection surface, ensuring the white image covers the entire screen. The purpose is to make the screen's border visible in the white image, thus allowing the border to be identified.

[0075] The controller allows the camera to take a picture of the projection surface, capturing an image that includes the white graphic and the entire screen. The acquired image will contain the white graphic area, and the white graphic area will also include the entire screen.

[0076] The controller can identify the image acquired by the camera, acquire the white card region in the image, and acquire the curtain in the white card region, so as to obtain the entire frame of the curtain, including the frames corresponding to the four edges. It should be noted that in order to enable the projection device to accurately identify, the frame of the curtain has a certain thickness, which includes an outer edge and an inner edge. The outer edge can be the edge of the entire curtain, and the inner edge constitutes the outline of the white region in the middle of the curtain. Therefore, the controller can identify the inner edge of the frame of the curtain, and specifically identify the four vertices of the inner edge, that is, the four inner corner points of the frame. The rectangular region formed by the four inner corner points is the white curtain region, which can be used as the projection region of the curtain.

[0077] After determining the projection region, the controller can control the light emitting assembly to project the image and the like to the projection region for the user to view.

[0078] However, in actual application, the complete frame may not be identified in the white card region photographed by the camera, that is, the four frames cannot be identified, which leads to the failure to determine the four inner corner points of the frame and the failure to acquire the projection region. For example, due to the influence of the placement position or angle of the projection device and the like, after the light emitting assembly projects the white card to the projection surface, the white card may not cover the entire curtain, but only a part of the curtain, so that only part of the frame is in the white card region. At this time, only part of the frame can be obtained when the white card region is identified, which leads to the failure to identify all the inner corner points of the frame, for example, only the left frame of the curtain is included in the white card region, so that the inner corner points of the frame cannot be identified. Since the complete four inner corner points cannot be acquired, the projection region cannot be determined.

[0079] Alternatively, due to the influence of the diversity of the curtain, the frame of the curtain itself is not a complete rectangular structure. For example, the curtain can be in the form of a single frame, a double frame, a triple frame, or even a frameless form. Even if the white card projected by the light emitting assembly can cover the entire curtain, the four frames cannot be identified when the frame of the curtain is identified, the four inner corner points cannot be determined, and the projection region cannot be determined.

[0080] For the above-mentioned situation that the projection region cannot be acquired, the projection device cannot accurately project the image into the curtain region, leading to poor user experience.

[0081] In order to accurately project the image into the curtain region, a specific automatic curtain entering method is also provided in some embodiments of the application and applied to the projection device. Figure 8 The interaction flowchart of the components of the projection device in some embodiments is shown in FIG. 1. Figure 8 As shown in FIG. 1, the method comprises the following steps:

[0082] S801, in response to a projection instruction input by a user, a controller controls a light-out component to project a first card to a projection surface, and acquires a first image captured by a camera on the first card on the projection surface. The first card does not contain feature points.

[0083] S802, the controller crops the first card in the first image to obtain a first card image.

[0084] S803, the controller performs a binaryzation process on the first card image, and acquires a white connected region in the first card image based on the binaryzation result.

[0085] S804, the controller locates a to-be-projected region based on the white connected region.

[0086] S805, the controller controls the light-out component to project to-be-projected content to the to-be-projected region.

[0087] In some embodiments, after receiving the projection instruction input by the user, the projection device can implement an automatic curtain-in function by acquiring the to-be-projected region, so as to project the to-be-projected content.

[0088] The controller can first control the light-out component to project the first card to the projection surface. The first card does not contain feature points, and is used to illuminate the curtain to determine the frame of the curtain. In order to avoid the influence of the content in the card on the identification of the frame of the curtain, the first card can be a pure color card, for example, a white card.

[0089] When the first card is projected, the controller can adjust the projection angle of the light-out component to the maximum angle, so that the light-out component can project the image in the maximum range, so that the first card in the projection surface can cover the entire curtain as much as possible, thereby accurately identifying the frame of the curtain.

[0090] After the light-out component projects the first card, the projection surface contains the content of the first card. The controller can control the camera to capture the projection surface, and acquire the image captured by the camera on the first card on the projection surface, which is referred to as the first image in the embodiments of the present application. The first image can contain the content of the first card, and the first card can contain the curtain.

[0091] In some embodiments, in order to avoid the influence of other regions, the controller can crop the first card in the first image to obtain the image corresponding to the first card in the projection surface, which is referred to as the first card image in the embodiments of the present application. The first card image is the first card region in the projection surface, which can reduce the subsequent calculation amount and data processing, and can also exclude the interference of non-light-out regions.

[0092] The controller can perform binarization processing on the first prop image to obtain a binarization result. It should be noted that the purpose of binarization processing is to distinguish black regions and white regions in the image. Since the first prop image is the region corresponding to the first prop, it only contains the curtain region, and the first prop is a white prop, so the first prop image contains a black frame of the curtain, and the other regions are white regions.

[0093] Therefore, in the binarization result, the black part is the frame of the curtain, and the white part can include the white curtain region or the region other than the curtain in the projection surface that is illuminated by the first prop, such as a white wall.

[0094] The controller can divide the first prop image into black regions and white regions according to the binarization result. The black region is the frame region. Considering that the frame of the curtain occupies a small area of the curtain, the entire first prop image can be considered as a white image containing several frames, which can contain one frame, multiple frames, or no frame.

[0095] The controller can obtain all connected regions in the first prop image based on the binarization result, including white connected regions and black connected regions. A connected region refers to a continuous and uninterrupted region that contains only one color. The frame is a black connected region, the white curtain is a white connected region, and the white wall outside the curtain is also a white connected region.

[0096] It should be noted that considering that the first prop projected by the light-emitting assembly can not cover the entire curtain, resulting in the first prop image possibly containing only part of the curtain, the first prop image can contain more than one black connected region and white connected region. When the image contains multiple frame regions, it also contains multiple black connected regions. When the image contains both the white curtain and the white wall, it can also contain multiple white connected regions.

[0097] Figure 9 A schematic diagram of the connected regions of the first prop image in some embodiments is shown. As shown in Figure 9 The first prop image includes one black connected region and one white connected region. The curtain frame is U-shaped, i.e., the curtain only contains the left frame, the right frame, and the lower frame. The left frame, the right frame, and the lower frame of the curtain together form a black connected region, and the region outside the black connected region forms a white connected region.

[0098] Figure 10 A schematic diagram of the connected regions of the first prop image in some embodiments is shown. As shown in Figure 10As shown, the first image consists of one black connected region and two white connected regions. The length of the curtain border is the same as the length of the image. It can be a case where only the bottom border of the curtain is visible, or it can be a case where only a portion of the bottom border of the curtain is captured. Specifically, the bottom border of the curtain is a black connected region, the area above the bottom border is a white connected region, and the area below the bottom border is also a white connected region.

[0099] Figure 11 A schematic diagram of the connected regions of the first card image in some embodiments is shown. For example... Figure 10 As shown, the first image includes a black connected region and two white connected regions. This can be a case where only the left and bottom borders of the screen are visible, or where only the lower left portion of the screen is captured. The left and bottom borders of the screen together form a black connected region, while the screen borders also divide the image into a rectangular white connected region and an L-shaped white connected region.

[0100] Figure 12 A schematic diagram of the connected regions of the first card image in some embodiments is shown. For example... Figure 10 As shown, the first image includes two black connected regions and three white connected regions. The image includes a top border and a bottom border of the screen. Each border is a black connected region, the area below the bottom border is a white connected region, the area above the top border is a white connected region, and the area between the top and bottom borders is also a white connected region.

[0101] In some embodiments, the controller can acquire white connected regions in the first image card and locate the region to be projected based on the white connected regions.

[0102] The controller can detect the number of white connected regions. When the number of white connected regions is different, different methods can be used to locate the area to be projected.

[0103] In some embodiments, if a single white connected region is detected, the controller can first calculate the area of ​​the first image card, referred to as the area of ​​the first image card in this embodiment, and simultaneously calculate the area of ​​the white connected region, referred to as the area of ​​the white connected region in this embodiment.

[0104] The controller can determine the size relationship between the area of ​​the first image card and the area of ​​the white connected region.

[0105] If the first card image area is equal to the white connected region area, it means that the first card image is a complete white connected region, which does not contain black connected regions, i.e., does not contain the frame of the curtain. At this time, the first card projected by the projection device is completely in the white curtain, which may cover part of the white curtain or just cover the white curtain completely.

[0106] At this time, the controller can directly determine the white connected region as the to-be-projected region, i.e., the region where the first card is projected as the to-be-projected region.

[0107] In some embodiments, if it is detected that there is one white connected region, and the first card image area is equal to the white connected region area, it means that the white connected region is all the white curtain region. However, considering that the image proportion of the to-be-projected content and the size proportion of the white connected region may not be suitable, for example, the image proportion of the to-be-projected content can be 16:9 or 4:3, but the size proportion of the white connected region can be 16:13. If the white connected region is directly determined as the to-be-projected content, after the to-be-projected content is projected to the region, the image may present a poor effect such as stretching, which affects the viewing experience of the user. Therefore, the white connected region can be processed to obtain the to-be-projected region.

[0108] The controller can crop the white connected region according to the first proportion and the second proportion to obtain a first region and a second region. The first proportion can be 16:9, and the second proportion can be 4:3.

[0109] The controller can calculate the first region area and the second region area, and calculate the area difference between the first region area S1 and the second region area S2. An area difference threshold can be preset in the projection device, which can be 1 / 5S1 or 1 / 5S2. The controller can detect the size relationship between the area difference and the area difference threshold.

[0110] If the area difference is less than or equal to the preset area difference threshold, one of the first region and the second region can be determined as the to-be-projected region, which can be determined according to the image proportion of the to-be-projected content.

[0111] If the area difference is greater than the preset area difference threshold, the region with the largest area in the first region and the second region can be determined as the to-be-projected region.

[0112] In some embodiments, if it is detected that there is one white connected region, and the first card image area is greater than the white connected region area, it means that the first card image is not a complete white connected region, which includes several black connected regions, i.e., includes the frame of the curtain. The controller can determine the to-be-projected region according to the black connected regions therein.

[0113] The controller can obtain the edges of the black connected regions in the first card image. The black connected regions can include only one frame or multiple frames. Thus, the controller can identify all edges of each black connected region.

[0114] To improve the viewing experience of the user, the to-be-projected region can be as large as possible. The controller can obtain the largest rectangle that can be formed by the edges of the black connected regions in the white connected region, and determine the largest rectangle as the to-be-projected region.

[0115] In the first card image, the edges of the black connected regions are black line segments, including horizontal lines and vertical lines. After identifying all the horizontal lines and vertical lines in the image, the largest rectangle that can be formed by each line end in the white connected region can be obtained. After obtaining the largest rectangle corresponding to all edges, the controller can select the largest rectangle with the largest area from all the largest rectangles, and determine the rectangle as the to-be-projected region.

[0116] Figure 13 A schematic diagram of the largest rectangle in some embodiments is shown. As shown in FIG. 1A, the curtain includes a U-shaped frame, and the edges of the frame are identified and the largest rectangle is formed in the white connected region, including A1, A2, A3, and A4. The controller can detect the areas of the four rectangles, and select the largest rectangle A1 as the to-be-projected region. Figure 13 In some embodiments, if two white connected regions are detected, the controller can obtain the number of corner points of the two white connected regions, respectively.

[0117] If the number of corner points of the two white connected regions is a preset value, it indicates that the two white connected regions are regions of a preset shape. For example, the preset value can be 4, and if the number of corner points of the two white connected regions is 4, as shown in FIG. 1B, it indicates that the two white connected regions are rectangles, and the image can be displayed.

[0118] Figure 10 The controller can obtain the areas of the two white connected regions, and determine the white connected region with the largest area as the target white connected region. The controller can obtain the to-be-projected region based on the target white connected region.

[0119] In some embodiments, after obtaining the target white connected region, the controller can obtain a target ratio of the target white connected region. It should be noted that, to improve the viewing experience of the user, the size ratio of the to-be-projected region can be as close as possible to the image ratio. An error threshold can be preset in the projection device to detect the error between the target ratio and the image ratio. The error threshold can be 5%.

[0120] In some embodiments, after obtaining the target white connected region, the controller can obtain a target ratio of the target white connected region. It should be noted that, to improve the viewing experience of the user, the size ratio of the to-be-projected region can be as close as possible to the image ratio. An error threshold can be preset in the projection device to detect the error between the target ratio and the image ratio. The error threshold can be 5%.

[0121] ​The controller can first calculate a first error of the target ratio and the first ratio, and a second error of the target ratio and the second ratio. Taking the first ratio as an example, the error is calculated as follows: the difference between the target ratio and the first ratio is obtained. And the ratio of the difference and the first ratio is calculated, which is the error of the target ratio and the first ratio. For example, the target ratio is 16:10, and the first ratio is 16:9. The difference is 1 / 16, and the ratio of the difference and the first ratio is 1 / 9, that is, the first error is 1 / 9.

[0122] If at least one of the second errors of the first error is less than or equal to a preset error threshold, the first error can be less than or equal to the error threshold, the second error can be less than or equal to the error threshold, or both errors can be less than or equal to the error threshold. The controller can then determine the target white connected region as the to-be-projected region.

[0123] If the first error and the second error are both greater than the preset error threshold, the controller can crop the target white connected region according to the first ratio and the second ratio respectively to obtain a third region and a fourth region. The controller can determine the region with the largest area in the third region and the fourth region as the to-be-projected region.

[0124] If only one white connected region has a number of corner points equal to a preset number, it means that only one white connected region is a region of a preset shape, such as Figure 11 As shown, one white connected region is a rectangle, and one white connected region is in the shape of L. The controller can determine the white connected region as the to-be-projected region.

[0125] In some embodiments, if three white connected regions are detected, the controller can obtain the positional relationship of the three white connected regions. The three white connected regions can be arranged left and right, or arranged up and down. As shown in the image Figure 12 The three white connected regions are arranged up and down. Based on the positional relationship, the controller can determine the white connected region in the middle position as the to-be-projected region.

[0126] If the number of white connected regions is greater than three, the white connected region in the middle position can also be determined as the to-be-projected region.

[0127] In some embodiments, considering that the maximum number of curtain frames is four, the frame can cut the first card image into three white connected regions at most.

[0128] If the number of white connected regions is greater than four, it means that there can be some obstacles or some content on the white wall forms a black connected region, causing interference. The controller can select the white connected region with the largest area as the to-be-projected region.

[0129] The controller can also control the light-emitting assembly to adjust a projection angle and other parameters, re-project the first card, and repeat the above steps to re-acquire the to-be-projected region.

[0130] In some embodiments, after the to-be-projected region is acquired, the controller can control the light-emitting assembly to project the to-be-projected content to the to-be-projected region.

[0131] To be able to project the image to the to-be-projected region, the controller can first determine the projection relationship between the projection surface and the projection device. In the embodiments of the present application, the projection relationship refers to the projection relationship of the projection device projecting the image to the projection surface, that is, the mapping relationship between the content projected by the light-emitting assembly of the projection device and the projection surface. After the projection relationship between the projection surface and the projection device is determined, the projection device can determine the position information of the projection region in the projection surface, so as to project the to-be-projected content to the to-be-projected region for the user to view.

[0132] The projection device can project a second card in the projection surface, and determine the position information of the projection surface according to the second card. According to the position information of the projection surface, the projection relationship between the projection surface and the projection device can be further determined.

[0133] It should be noted that the embodiments of the present application can construct the conversion matrix of the projection surface in the world coordinate system and the light-emitting assembly coordinate system based on the binocular camera, and the conversion matrix is the homography relationship between the projection image in the projection surface and the playing card played by the light-emitting assembly. The homography relationship is also called the projection relationship, and the homography relationship can be used to realize the arbitrary projection conversion between the projection image and the playing card.

[0134] In some embodiments, to acquire the mapping relationship, the controller can first control the light-emitting assembly to project the second card to the projection surface. After the second card is projected, the controller can also control the camera to capture the second card displayed in the projection surface to obtain a second image.

[0135] The second card can include a plurality of feature points, and therefore the second image captured by the camera can also include all the feature points in the second card. The position information of the projection surface can be determined through the feature points. It should be noted that for a plane, when the positions of three points in the plane are determined, the position information of the plane can be determined. Therefore, to determine the position information of the projection surface, the positions of at least three points in the projection surface need to be determined, that is, at least three feature points need to be included in the second card. According to the at least three feature points, the position information of the projection surface can be determined.

[0136] In some embodiments, the second card can include a pattern and color feature preset by the user. The second card can be a checkerboard card, which is set as a black-and-white checkerboard, as shown inFigure 14 As shown in FIG. 6, the feature points contained in the checkerboard card are the corner points of the rectangle. The pattern in the second card can also be set as a circular ring card, including a circular ring pattern, such as Figure 15 As shown in FIG. 7, the feature points contained in the circular ring card are the corresponding solid points on the circular rings. In some embodiments, the second card can also be set as a combination of the above two types of patterns, or as other patterns with identifiable feature points.

[0137] In some embodiments, after the light-emitting assembly projects the second card onto the projection surface, the controller can control the camera to capture the second card to obtain a second image, so as to obtain the positions of the feature points.

[0138] Specifically, the camera can be a binocular camera, and one camera is arranged on each side of the light-emitting assembly. By capturing the second card through the binocular camera, one image is captured by the left camera and another image is captured by the right camera.

[0139] The controller can perform image recognition processing on the two images to obtain first coordinates of the feature points in any one of the images. In the embodiments of the present application, the first coordinates refer to the coordinate information of the feature points in the image coordinate system corresponding to the second image.

[0140] The image coordinate system refers to a coordinate system with the center of the image as the coordinate origin and the X and Y axes parallel to the two sides of the image. The image coordinate system in the embodiments of the present application can be set as follows: for the projection region preset by the user, the center point of the projection region can be set as the origin, the horizontal direction as the X axis, and the vertical direction as the Y axis. The high image coordinate system can be set in advance according to the preset projection region.

[0141] The coordinate information of the feature points in the second image can be determined according to the image coordinate system.

[0142] For the same feature point, its position in the image captured by the left camera and its position in the image captured by the right camera can be different. The coordinates of the feature point in the camera coordinate system of any one of the left and right cameras can be determined through the two positions of the same feature point in the two images. In the embodiments of the present application, the second coordinates are used to represent the coordinate information of the feature points in the camera coordinate system.

[0143] In the embodiments of the present application, the camera coordinate system is specifically a direct coordinate system established with the light point of the camera as the center, the optical axis as the Z axis, and the plane parallel to the projection surface as the XOY plane.

[0144] For the binocular camera, the second coordinates of the feature points in the camera coordinate system corresponding to any one of the cameras can be determined, and the left camera is taken as an example for introduction in the embodiments of the present application.

[0145] Specifically, the second coordinate information of the feature point in the camera coordinate system of the left camera can be determined according to the position information of the feature point in the two images captured by the left and right cameras, and is set as:

[0146] P(x,y,z)

[0147] In some embodiments, after the second coordinate of the feature point in the camera coordinate system of the left camera is obtained, the controller can convert the second coordinate into a third coordinate. The third coordinate refers to the coordinate information of the feature point in the light-emitting assembly coordinate system.

[0148] In the embodiments of the present application, the light-emitting assembly coordinate system is a direct coordinate system established with the light point of the light-emitting assembly as the center, the optical axis as the Z axis, and the plane parallel to the projection surface as the XOY plane. It should be noted that the light-emitting assembly coordinate system and the camera coordinate system can be converted into each other, so the coordinates of the feature point in the camera coordinate system can be converted into the coordinates of the feature point in the light-emitting assembly coordinate system. Specifically, the coordinates of the feature point can be converted between the two coordinate systems according to the extrinsic parameters between the light-emitting assembly and the camera. The extrinsic parameters between the light-emitting assembly and the camera are device parameters marked on the device shell or the instruction manual of the projection device when the projection device is manufactured, and are usually set based on the function, assembly, manufacturing, and parts of the projection device, and are applicable to all projection devices of the same model, and can include a rotation matrix and a translation matrix between the light-emitting assembly and the camera.

[0149] According to the extrinsic parameters between the light-emitting assembly and the camera, the conversion relationship between the light-emitting assembly coordinate system and the camera coordinate system can be determined, and the coordinates of the feature point in the light-emitting assembly coordinate system can be further obtained. The conversion formula is as follows:

[0150] P′(x′,y′,z′)=RRR*P+TTT (1)

[0151] Wherein:

[0152] P′(x′,y′,z′) is the coordinates of the feature point in the light-emitting assembly coordinate system.

[0153] RRR is the rotation matrix between the light-emitting assembly and the camera, and TTT is the translation matrix between the light-emitting assembly and the camera.

[0154] In some embodiments, after the coordinates of the feature point in the light-emitting assembly coordinate system are obtained, the projection surface equation in the light-emitting assembly coordinate system can be determined.

[0155] It should be noted that at least three coordinate information of points is required to determine the position information of a plane. Therefore, the controller can obtain the first positions of at least three feature points in the at least second image, and determine the coordinate information in the camera coordinate system according to the first positions of the feature points. Further, the coordinate information in the camera coordinate system can be converted into coordinate information in the light emitting component coordinate system.

[0156] After determining the coordinate information of the at least three feature points in the light emitting component coordinate system, the controller can fit the coordinates of the feature points to obtain a projection surface equation of the projection surface in the light emitting component coordinate system. The projection surface equation can be expressed as:

[0157] z=ax+by+c (2)

[0158] or the following formula:

[0159]

[0160] In some embodiments, after determining the projection surface equation of the projection surface in the light emitting component coordinate system, the controller can obtain a conversion matrix between the light emitting component coordinate system and the world coordinate system according to the projection surface equation, and the conversion matrix is used to represent the projection relationship.

[0161] In the embodiments of the present application, the world coordinate system is set as: taking the image coordinate system as the XOY plane, that is, the projection surface is the XOY plane, and the origin is the center point of the projection area set by the user in advance. The Z axis is set in the direction perpendicular to the projection surface to establish the space coordinate system.

[0162] When obtaining the conversion matrix between the light emitting component coordinate system and the world coordinate system, the controller can determine the representation of the projection surface in the world coordinate system and the representation of the projection surface in the light emitting component coordinate system, respectively.

[0163] Specifically, the controller can first determine the unit normal vector of the projection surface in the world coordinate system.

[0164] Since the projection surface itself is the XOY plane of the world coordinate system, the unit normal vector of the projection surface in the world coordinate system can be expressed as:

[0165] m=(0,0,1)*T (4)

[0166] The controller can also obtain the unit normal vector of the projection surface in the light emitting component coordinate system according to the projection surface equation of the projection surface in the light emitting component coordinate system, and the unit normal vector of the projection surface in the light emitting component coordinate system can be expressed as the formula:

[0167]

[0168] According to the unit normal vectors of the projection surface in the two coordinate systems, a conversion matrix between the light emitting component coordinate system and the world coordinate system can be obtained, and the mutual relationship is expressed as the following formula:

[0169] m = R1 * n (6)

[0170] Wherein, R1 represents the conversion matrix between the light emitting component coordinate system and the world coordinate system. The conversion matrix can represent the mapping relationship between the content projected by the light emitting component and the projection surface.

[0171] After the mapping relationship is determined, the controller can realize the conversion of the coordinates of a certain point between the world coordinate system and the light emitting component coordinate system.

[0172] For a certain target region in the projection surface that has been determined, the coordinate representation of the target region in the world coordinate system can be determined according to the position information of the target region in the projection surface. The controller can convert the coordinate representation in the world coordinate system into the coordinate representation in the light emitting component coordinate system according to the conversion matrix, so as to determine the position information of the target region for the projection device, and then the image can be directly projected into the target region.

[0173] Therefore, the controller can obtain the position information of the to-be-projected region based on the mapping relationship, that is, the coordinate representation of the to-be-projected region in the light emitting component coordinate system. According to the position information, the controller can control the light emitting component to project the to-be-projected content into the to-be-projected region, so that the user can watch.

[0174] The embodiments of the present application also provide a projection method applied to a projection device, and the method comprises:

[0175] Step 1601, in response to a projection instruction input by a user, a light emitting component is controlled to project a first picture card to a projection surface, and a first image of the first picture card photographed by a camera on the projection surface is obtained.

[0176] Step 1602, the first picture card in the first image is cropped to obtain a first picture card image.

[0177] Step 1603, the first picture card image is subjected to a binaryzation processing, and a white connected region in the first picture card image is obtained based on a binaryzation result.

[0178] Step 1604, a to-be-projected region is located based on the white connected region.

[0179] Step 1605, the light emitting component is controlled to project to-be-projected content to the to-be-projected region.

[0180] In some embodiments, the to-be-projected region is located based on the white connected region, comprising:

[0181] If it is detected that there is one white connected region, the area of the first card image and the area of the white connected region are calculated; if the area of the first card image is equal to the area of the white connected region, the white connected region is determined as the to-be-projected region.

[0182] In some embodiments, after the area of the first card image and the area of the white connected region are calculated, the following steps are included:

[0183] If it is detected that there is one white connected region, the area of the first card image and the area of the white connected region are calculated. If the area of the first card image is equal to the area of the white connected region, the white connected region is cropped according to the first ratio and the second ratio respectively to obtain a first region and a second region. The area of the first region and the area of the second region are calculated, and the area difference between the area of the first region and the area of the second region is calculated. If the area difference is less than or equal to a preset area difference threshold, the first region or the second region is determined as the to-be-projected region; if the area difference is greater than the preset area difference threshold, the region with the largest area in the first region and the second region is determined as the to-be-projected region.

[0184] In some embodiments, after the area of the first card image and the area of the white connected region are calculated, the following steps are included: if the area of the first card image is greater than the area of the white connected region, the edge of the black connected region in the first card image is obtained; the largest rectangle that can be formed by the edge in the white connected region is obtained, and the largest rectangle is determined as the to-be-projected region.

[0185] In some embodiments, the to-be-projected region is located based on the white connected region, including:

[0186] If it is detected that there are two white connected regions, the number of corner points of the two white connected regions is obtained. If the number of corner points of the two white connected regions is a preset number, the area of the two white connected regions is obtained, and the white connected region with the largest area is determined as the target white connected region. The to-be-projected region is obtained based on the target white connected region. If only one white connected region has a number of corner points equal to the preset number, the white connected region with the number of corner points equal to the preset number is determined as the to-be-projected region.

[0187] In some embodiments, the to-be-projected region is obtained based on the target white connected region, including:

[0188] The target proportion of the target white connected region is obtained. A first error between the target proportion and the first proportion is calculated, and a second error between the target proportion and the second proportion is calculated. If the first error and / or the second error is less than or equal to a preset error threshold, the target white connected region is determined as the to-be-projected region. If the first error and the second error are both greater than the preset error threshold, the target white connected region is cropped according to the first proportion and the second proportion respectively to obtain a third region and a fourth region; and the region with the largest area in the third region and the fourth region is determined as the to-be-projected region.

[0189] In some embodiments, the to-be-projected region is located based on the white connected regions, including: based on detecting that the number of white connected regions is greater than or equal to three, obtaining a positional relationship of the white connected regions; and based on the positional relationship, determining a white connected region at a middle position as the to-be-projected region.

[0190] In some embodiments, before the light emitting component is controlled to project the to-be-projected content to the to-be-projected region, the method further includes:

[0191] The second image is obtained by the camera capturing the second graphic card on the projection surface. The second graphic card contains the feature points. The mapping relationship between the content projected by the light emitting component and the projection surface is obtained based on the second image.

[0192] The light emitting component is controlled to project the to-be-projected content to the to-be-projected region, including: obtaining position information of the to-be-projected region based on the mapping relationship; and controlling the light emitting component to project the to-be-projected content to the to-be-projected region based on the position information.

[0193] In some embodiments, the mapping relationship between the content projected by the light emitting component and the projection surface is obtained based on the second image, including: obtaining a first coordinate of the feature points of the second graphic card in an image coordinate system corresponding to the second image; obtaining a second coordinate of the feature points in a camera coordinate system based on the first coordinate; converting the second coordinate into a third coordinate of the feature points in a light emitting component coordinate system; obtaining a projection surface equation of the projection surface in the light emitting component coordinate system based on the third coordinate; and obtaining a conversion matrix of the light emitting component coordinate system and a world coordinate system based on the projection surface equation, the conversion matrix being used to represent the mapping relationship.

[0194] The same or similar parts among various embodiments in the specification are referred to each other, and will not be described here again.

[0195] Those skilled in the art can clearly understand that the technical solutions in the embodiments of the present application can be implemented by means of software plus necessary universal hardware platforms. Based on such understanding, the technical solutions in the embodiments of the present application can be embodied in the form of a software product, and the computer software product can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a plurality of instructions to cause a computer device (which can be a personal computer, a server, or a network device, and the like) to execute the methods of the various embodiments or some parts of the embodiments of the present application.

[0196] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

[0197] For the convenience of explanation, the above description has been made in combination with specific embodiments. However, the above exemplary discussion is not intended to exhaust or 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 to better explain 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 use considerations.

Claims

1. A projection device, characterized in that, include: The light-emitting component is configured to project the content onto the projection surface; The camera is configured to capture images in the projection surface; The controller is configured as follows: In response to a projection command input by the user, the light-emitting component is controlled to project the first image card onto the projection surface, and the camera captures a first image of the first image card on the projection surface. The first image card in the first image is cropped to obtain the first image card image; The first image card is binarized, and the first image card is divided based on the binarization result to obtain a white connected region and a black connected region; the black connected region is used to represent the curtain border, and the white connected region includes the white curtain region; Detect the number of the white connected regions; If the number of white connected regions is a first value, then the area of ​​the white connected regions is obtained, and the area to be projected is located based on the area of ​​the white connected regions and the black connected regions. If the number of white connected regions is the second value, then obtain the number of corner points of the white connected regions, and locate the area to be projected based on the number of corner points; The light-emitting component is controlled to project the content to be projected onto the projection area.

2. The projection device according to claim 1, characterized in that, If the number of white connected regions is a first value, the controller is further configured to: Based on the detection that there is one white connected region, calculate the area of ​​the first image card and the area of ​​the white connected region; If the area of ​​the first image card is equal to the area of ​​the white connected region, the white connected region is determined as the region to be projected.

3. The projection device according to claim 1, characterized in that, If the number of white connected regions is a first value, the controller is further configured to: Based on the detection that there is one white connected region, calculate the area of ​​the first image card and the area of ​​the white connected region; If the area of ​​the first image card is equal to the area of ​​the white connected region, the white connected region is cropped according to the first ratio and the second ratio respectively to obtain the first region and the second region; Calculate the area of ​​the first region and the area of ​​the second region, and calculate the area difference between the first region and the second region. If the area difference is less than or equal to a preset area difference threshold, then the first region or the second region is determined as the region to be projected. If the area difference is greater than a preset area difference threshold, then the area with the largest area in the first region and the second region is determined as the region to be projected.

4. The projection device according to claim 3, characterized in that, After the controller calculates the area of ​​the first image card and the area of ​​the white connected region, it is further configured to: If the area of ​​the first image card is greater than the area of ​​the white connected region, obtain the edge of the black connected region in the first image card; Obtain the largest rectangle that the edges can form in the white connected region, and determine the largest rectangle as the region to be projected.

5. The projection device according to claim 1, characterized in that, If the number of white connected regions is the second value, the controller is further configured to: Based on the detection that there are two white connected regions, the number of corner points of the two white connected regions is obtained; If the number of corner points in two white connected regions is a preset value, obtain the area of ​​the two white connected regions, and determine the white connected region with the largest area as the target white connected region; obtain the region to be projected based on the target white connected region. If only one white connected region has a preset number of corner points, then the white connected region with the preset number of corner points is determined as the region to be projected.

6. The projection device according to claim 5, characterized in that, The controller is configured to obtain the region to be projected based on the target white connected region, and is also configured to: Obtain the target proportion of the target white connected region; Calculate the first error between the target ratio and the first ratio, and calculate the second error between the target ratio and the second ratio; If the first error and / or the second error is less than or equal to a preset error threshold, then the target white connected region is determined as the region to be projected. If both the first error and the second error are greater than a preset error threshold, the target white connected region is cropped according to the first ratio and the second ratio respectively to obtain the third region and the fourth region; the region with the largest area in the third region and the fourth region is determined as the region to be projected.

7. The projection device according to claim 1, characterized in that, After the controller performs the detection of the number of white connected regions, it is further configured to: Based on the detection of three or more white connected regions, the positional relationship of the white connected regions is obtained; Based on the aforementioned positional relationship, the white connected region located in the middle is determined as the region to be projected.

8. The projection device according to claim 1, characterized in that, Before the controller executes the command to control the light-emitting component to project the content to be projected onto the projection area, it is further configured to: The light-emitting component is controlled to project the second image card onto the projection surface, and a second image of the second image card on the projection surface is acquired by the camera, wherein the second image card contains feature points; Based on the second image, obtain the mapping relationship between the content projected by the light-emitting component and the projection surface; The controller is configured to control the light-emitting component to project the content to be projected onto the projection area, and is also configured to: The location information of the region to be projected is obtained based on the mapping relationship; Based on the location information, the light-emitting component is controlled to project the content to be projected onto the projection area.

9. The projection device according to claim 8, characterized in that, The controller is configured to perform the mapping relationship between the content projected by the light-emitting component and the projection surface based on the second image, and is further configured to: Obtain the first coordinates of the feature points of the second image card in the image coordinate system corresponding to the second image; Based on the first coordinates, obtain the second coordinates of the feature point in the camera coordinate system; The second coordinate is converted into the third coordinate of the feature point in the coordinate system of the light-emitting component; The equation of the projection surface in the coordinate system of the light-emitting component is obtained based on the third coordinate. Based on the projection plane equation, the transformation matrix between the optical component coordinate system and the world coordinate system is obtained, and the transformation matrix is ​​used to characterize the mapping relationship.

10. A projection method, characterized in that, Applied to a projection device, the projection device including a light-emitting component, a camera, and a controller, the projection method includes: In response to a projection command input by the user, the light-emitting component is controlled to project the first image card onto the projection surface, and the camera captures a first image of the first image card on the projection surface. The first image card in the first image is cropped to obtain the first image card image; The first image card is binarized, and the first image card is divided based on the binarization result to obtain a white connected region and a black connected region; the black connected region is used to represent the curtain border, and the white connected region includes the white curtain region; Detect the number of the white connected regions; If the number of white connected regions is a first value, then the area of ​​the white connected regions is obtained, and the area to be projected is located based on the area of ​​the white connected regions and the black connected regions. If the number of white connected regions is the second value, then obtain the number of corner points of the white connected regions, and locate the area to be projected based on the number of corner points; The light-emitting component is controlled to project the content to be projected onto the projection area.

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