Projection method, projection device and storage medium

Abstract

The embodiments of the present application disclose a projection method, a projection device, and a storage medium, which projects a display image through a first light source, and then projects a reference image through a second light source at a preset time interval, and then obtains a real-time projection position corresponding to the reference image, and then determines whether there is a difference between the real-time projection position and the target projection position. If so, the optical axis of the projected display image is adjusted so that the real-time projection position approaches the target projection position. In this way, when there is a difference between the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval and the target projection position, the optical axis of the projected display image can be adjusted so that the real-time projection position can approach the target projection position, thereby achieving the adjustment of the projection effect without affecting the projection of the display image, so as to overcome the problem of reduced projection image quality due to pixel offset.

Description

Technical Field

[0001] The present application relates to the field of projection technology, and more specifically, to a projection method, a projection device, and a storage medium. Background Art

[0002] A projector, also known as a projector, is a device that projects images or videos onto a screen. It can connect to computers, VCDs, DVDs, BDs, game consoles, DVs, and other devices through various interfaces to play the corresponding video signals. With the advancement of projection technology, projectors have become widely used in various conferences and teaching settings, bringing great convenience to people's daily lives. However, projectors generate a large amount of heat during operation. This heat can cause the projector's optical engine and lens to deform during operation, resulting in a certain degree of pixel shift in the image projected onto the screen. This can lead to image loss or severe quality degradation, compromising the projection quality and the user's viewing experience. Summary of the Invention

[0003] In view of the above problems, the present application proposes a projection method, a projection device and a storage medium to improve the above problems.

[0004] In a first aspect, an embodiment of the present application provides a projection method, which can be applied to a projection system, and the method includes: projecting a display image through a first light source, and projecting a reference image through a second light source at a preset time interval, the display image and the reference image having the same projection optical axis; obtaining a real-time projection position corresponding to the reference image; determining whether there is a difference between the real-time projection position and the target projection position; if so, adjusting the optical axis of projecting the display image so that the real-time projection position approaches the target projection position.

[0005] In a second aspect, an embodiment of the present application provides a projection method, which can be applied to a projection system, and the method includes: projecting a display image through a first light source, and projecting a reference image through a second light source at a preset time interval, the display image and the reference image having different projection optical axes; obtaining a real-time projection position corresponding to the reference image; determining whether there is a difference between the real-time projection position and the target projection position; if so, adjusting the optical axis of projecting the display image so that the real-time projection position is adapted to the target projection position.

[0006] In a third aspect, an embodiment of the present application provides a projection device, comprising a picture acquisition module, a pixel offset detection module, an adjustment module, one or more processors, and a memory; one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs are configured to execute the method described in the first or second aspect above.

[0007] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which program code is stored, wherein the method described in the first aspect or the second aspect above is executed when the program code is run.

[0008] The present application provides a projection method, projection device and storage medium, which projects a display image through a first light source and then projects a reference image through a second light source at a preset time interval, wherein the display image and the reference image have the same projection optical axis, and then obtains the real-time projection position corresponding to the reference image, and then determines whether there is a difference between the real-time projection position and the target projection position. If so, adjusts the optical axis of the projected display image so that the real-time projection position approaches the target projection position. In this way, when the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval is different from the target projection position, the optical axis of the projected display image can be adjusted so that the real-time projection position can approach the target projection position, thereby achieving the adjustment of the projection effect without affecting the projection of the display image, so as to overcome the problem of reduced projection image quality due to pixel offset. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0010] Figure 1 An example diagram showing pixel offset in a projected image in the prior art is shown.

[0011] Figure 2 A schematic structural diagram of a projection system proposed in an embodiment of the present application is shown.

[0012] Figure 3 A flowchart of a projection method proposed in an embodiment of the present application is shown.

[0013] Figure 4 A schematic structural diagram of a color wheel in an embodiment of the present application is shown.

[0014] Figure 5 A schematic diagram showing the timing of the light modulation device modulating the projection position in an embodiment of the present application is shown.

[0015] Figure 6 A schematic diagram of the light path of the light modulation device provided in an embodiment of the present application for modulating the projection position is shown.

[0016] Figure 7 A schematic diagram showing the positional relationship between the lens corresponding to the image acquisition module and the projection lens corresponding to the projection device in an embodiment of the present application is shown.

[0017] Figure 8 A flowchart of a projection method proposed in another embodiment of the present application is shown.

[0018] Figure 9 Shown Figure 8 Flowchart of the method for step S240 in FIG.

[0019] Figure 10 An example diagram of a projected target test pattern provided by an embodiment of the present application is shown.

[0020] Figure 11 An exemplary diagram showing an implementation method of adjusting the optical axis of a projected display image in an embodiment of the present application is shown.

[0021] Figure 12 Shown with Figure 11 An example diagram of the adjustment implementation principle corresponding to the implementation method in FIG.

[0022] Figure 13 An exemplary diagram showing another implementation of adjusting the optical axis of a projected display image in an embodiment of the present application is shown.

[0023] Figure 14 A flowchart of a projection method proposed in another embodiment of the present application is shown.

[0024] Figure 15 A flowchart of a projection method proposed in yet another embodiment of the present application is shown.

[0025] Figure 16 FIG. 2 shows another example of the projected target test pattern provided by this embodiment.

[0026] Figure 17 FIG. 4 shows another example of the projected target test pattern provided by this embodiment.

[0027] Figure 18 A flowchart of a projection method proposed in yet another embodiment of the present application is shown.

[0028] Figure 19 An example diagram of the principle of determining the target projection position in the case of multiple projection devices provided in an embodiment of the present application is shown.

[0029] Figure 20 A structural block diagram of a projection device for executing a projection method according to an embodiment of the present application is shown.

[0030] Figure 21 A storage unit for storing or carrying program code for implementing a projection method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0032] With the development of projection technology, projectors have become widely used in various conferences and teaching, bringing great convenience to people's daily lives. However, the inventors discovered in their research that the efficiency of converting electricity into light during projector operation is less than 10%, and a large amount of heat is generated during operation. This heat causes some components, especially those in the optical path (such as the projector's optical engine and lens), to undergo thermal deformation. For example, the structural components that secure the display chip in the optical engine and the internal lens and structural components of the lens expand due to heat. This causes a certain degree of pixel shift in the image projected to the screen, which is accompanied by a certain degree of image defocus.

[0033] Among them, when the projector optical engine and lens design can better meet the use requirements, the image defocus problem is not too serious and the image quality is acceptable. However, if the projector optical engine and lens design are average, the image defocus accompanied by pixel offset may cause a significant reduction in projector performance. There are two common usage scenarios where the projector optical engine and lens are greatly affected: 1. When multiple projectors are integrated, the projection images of two adjacent projectors will overlap to a certain extent, such as Figure 1 As shown in the fusion area. Since the projector pixel offset is affected by many factors, such as ambient temperature, light output brightness, and optical machine lens design, the offset between the two projectors is different and has a large degree of non-repeatability. When the fusion area displays static single-pixel width content and the pixel offset is between 1 and 2 pixels, the images in the fusion area of ​​the two projectors will have a certain degree of ghosting, resulting in a serious decline in image quality, such as Figure 1 2. When the image projected by the projector needs to be coordinated with the projection screen, the projection screen is fixed on the projection surface, and the movement of the projected image may cause the image to exceed the screen frame, resulting in the loss of imaging content or serious quality degradation.

[0034] In the existing technology, the method of turning on the projector in advance each time is usually adopted to improve the picture quality, or the method of making the edge of the frame larger than the projected image to allow a 1-2 pixel offset is adopted. Although the degradation of picture quality caused by pixel offset when using the projector can be avoided to a certain extent, the problem of low picture quality and reduced user visual experience still exists.

[0035] Therefore, in order to improve the above-mentioned problem, the present application provides a projection method and a projection device, in which, when the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval is different from the target projection position, the optical axis of the projected display image can be adjusted so that the real-time projection position can approach the target projection position, thereby achieving the adjustment of the projection effect without affecting the projection of the display image, so as to overcome the problem of deterioration in the projection image quality caused by pixel offset.

[0036] The following first introduces the projection system involved in the projection method provided in the embodiment of the present application.

[0037] like Figure 2 FIG. 1 is a schematic diagram of the structure of a projection system 10 provided in an embodiment of the present application. The projection control system 10 includes a projection imaging module 11, an image acquisition module 12, an information processing module 13, and an actuator 14. The projection imaging module 11 is electrically connected to the image acquisition module 12, the image acquisition module 12 is electrically connected to the information processing module 13, and the information processing module 13 is electrically connected to the actuator 14.

[0038] As a method, the projection imaging module 11 is used to project various text materials or audio and video materials that need to be projected, and the specific projection content is not limited. The image acquisition module 12 is used to obtain the real-time projection position corresponding to the reference image. The information processing module 13 is used to determine whether there is a difference between the real-time projection position and the target projection position (which can be a pre-stored target projection position). If there is a difference, the difference between the two is converted into a position adjustment instruction and sent to the actuator 14, so that the actuator 14 can adjust the optical axis of the projected display image according to the position adjustment instruction, so that the real-time projection position approaches the target projection position, that is, the real-time projection position is the same as the target projection position, or the real-time projection position is infinitely close to the target projection position.

[0039] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0040] See also Figure 3 An embodiment of the present application provides a projection method, which is applied to a projection system. The method includes:

[0041] Step S110: projecting a display image via the first light source, and projecting a reference image via the second light source at preset time intervals.

[0042] Optionally, the first light source and the second light source in this embodiment can be light sources emitted by the same projection device, or can be light sources emitted by different projection devices. The first light source and the second light source can be the same light source (which can be understood as the same light source here) or different light sources. For example, in one implementation, the first light source and the second light source can both emit visible light; in another implementation, the first light source can emit visible light, and the second light source can emit infrared light.

[0043] Among them, the display image can be understood as the projection screen projected onto the projection plane (the projection screen is smaller than the projection plane, for example, the projection plane can be a wall, and the projection screen is the area on the wall used to display the projection screen), and the reference image can be understood as a test pattern projected at a preset time interval during the projection of the display image. The test pattern can be used to test whether there is a difference between the position of the projected reference image and the target projection position.

[0044] Optionally, the display image and the reference image in this embodiment may have the same projection optical axis. For example, assuming that the first light source and the second light source are the same light source, the projection optical axis of the display image and the reference image may both be the optical axis of the optical-mechanical part of the projector.

[0045] Optionally, the projection system in this embodiment may include a color wheel, wherein the color wheel can receive light from the light source and sequentially emit three-color sequential light such as red, green and blue. Figure 4 The color wheel in this embodiment is briefly described as follows:

[0046] like Figure 4 As shown, the color wheel 50 is located on the optical path of the light source light emitted by the light source. The color wheel 50 includes at least two segmented areas 51. The period from when the light spot formed by the light source light emitted by the light source irradiates the color wheel 50 from the beginning of crossing two adjacent segmented areas 51 to the end of crossing the two segmented areas 51 is a spoke period. The area irradiated by the light spot in a spoke period constitutes a spoke area 52. A spoke area 52 is divided into two spoke areas (such as Figure 15 511 in the figure), the two spoke areas are located in two adjacent segmented areas 51, and the area outside the spoke area 52 included in the two adjacent segmented areas 51 constitutes a non-spoke area 513. In this manner, the preset time interval can be the time interval between the rotation of the color wheel cycle to the spoke area, that is, the second light source can project the reference image within the time interval between the rotation of the color wheel cycle to the spoke area.

[0047] In a specific application scenario, assuming that the first light source emits visible light and the second light source emits infrared light, the step of projecting a reference image at a preset time interval through the second light source may be: when the color wheel rotates to the spoke area corresponding to the color wheel, the visible light source is turned off and an infrared test pattern is projected. For example, the stray light of visible light is brighter, and the signal-to-noise ratio of the projection position of the projected image captured by a visible light camera is poor, resulting in poor calculation accuracy of the latest projection position of the displayed image. In this case, the visible light camera can be replaced with an infrared camera, and the infrared signal actively transmitted by the projector is used as the information collected by the image acquisition module. Optionally, a filter can be added before the camera to filter out wavelengths other than the infrared light projected by the projector, and the infrared signal can be displayed within the aforementioned preset time interval. For example, the time it takes for the DMD to process the spoke can be used to display the infrared signal.

[0048] For example, in a specific application scenario, such as Figure 5 As shown, the image displayed in the non-spoke area 61 is in a modulated state, and the image displayed in the spoke area 62 is in a non-modulated state. As a method, the power of the visible light source in the spoke area can be turned off, while the power of the infrared light source is turned on. In this way, an infrared test pattern can be projected in the spoke area to achieve adjustment of the projection lens in the spoke area.

[0049] Among them, see Figure 6 , showing the Figure 5 The light path diagram corresponding to the projection process is as follows: Figure 6 As shown, the light source module includes infrared light and visible light, which are combined into the same light path by wavelength combination through a dichroic plate 63. Optionally, Figure 6 The infrared light in the figure shown uses a separate infrared light source, and the wavelength can be 850nm or 940nm. Optionally, in actual implementation, the infrared light can also be realized by laser fluorescence, that is, a laser with a shorter wavelength than the infrared light is used to excite the infrared phosphor, and the short wavelength can be a blue laser or other laser. The light emitted by the light source module is relayed to the display chip DMD through the optical machine module, and the light modulated by the display chip is projected onto the screen through the lens module. It should be noted that in this embodiment, a single-chip DMD, a dual-chip or triple-chip DMD, or a single-chip, dual-chip, triple-chip LCD, or LCoS can all be implemented using the same principle, which will not be repeated here.

[0050] Optionally, as another embodiment, when the color wheel rotates to the spoke area corresponding to the color wheel, the visible light source is not turned off, and test patterns of other light sources (for example, visible light sources) are projected. In this way, the projection lens can be adjusted according to the test patterns of other light sources. The specific modulation principle and modulation process can be referred to the description in the aforementioned embodiments and will not be repeated here.

[0051] It should be noted that in this embodiment, the image acquisition module is installed in a position that is less affected by temperature changes caused by the projector's power on and off process. For example, it can be fixed on the entire bottom plate of the projection device and is not directly connected to the optical machine and lens.

[0052] like Figure 7 As shown, the projection ratio of the lens corresponding to the image acquisition module and the projection ratio of the projection lens of the projection device in the zoom state satisfy the formula: The field of view angle of the lens corresponding to the image acquisition module and the field of view angle of the projection lens of the projection device in the zoom state satisfy the formula: Among them, TR camera Characterizes the projection ratio of the lens corresponding to the image acquisition module, Characterizes the maximum throw ratio of the projection lens of the projection device in the zoom state, FOV camera Characterizes the field of view angle of the lens corresponding to the image acquisition module, Characterizes the maximum field of view angle of the projection lens of the projection device in the zoom state.

[0053] Optionally, the image capture module may capture an image with a resolution capable of distinguishing a single pixel of the image when the projection lens of the projection device is at a minimum field of view. The angular resolution of the lens corresponding to the image capture module satisfies the following formula: in, It represents the minimum field of view of the projection lens of the projection device in the zoom state. N represents the number of pixels on the side with more pixels.

[0054] Optionally, the pixel resolution of the lens corresponding to the image acquisition module is greater than the pixel resolution of the projection lens of the projection device. The pixel size of the acquisition chip corresponding to the image acquisition module should be small enough: assuming that the pixel size of the projection display chip is a projector , then the pixel side length on the projected image is P projector =a projector *M projector When the projector lens zooms to the maximum projection ratio, the magnification of the corresponding collector lens corresponds to its minimum value. At this time, the pixel size of the picture acquisition module is Since the pixel size and resolution of the display chip are determined, the image magnification of the projection device is proportional to its field of view, which can be obtained as follows:

[0055] Optionally, the actuator in the embodiment of the present application may be a voice coil motor or piezoelectric ceramics to execute the commands issued by the information processing module.

[0056] Optionally, the update frequency of the image position may comprehensively consider the time frequency of large changes in the image position, the response frequency of the information acquisition module and the information processing module, and the response frequency of the actuator that can perform actions.

[0057] It is understood that there is a time interval between different image frames of the projected image. As a method, this embodiment can project a characteristic pattern within the interval between different image frames, and then use this characteristic pattern as the target test pattern. The specific process of projecting the target test pattern and adjusting the projection position in this embodiment can be referred to the description of the previous embodiment and will not be repeated here.

[0058] Step S120: Acquire the real-time projection position corresponding to the reference image.

[0059] The real-time projection position corresponding to the reference image can be understood as the position of the reference image when it is projected onto the projection plane. As an implementation method, the projection plane and projection distance can be obtained (the specific principle and process for obtaining the projection distance can be referred to in related technologies and will not be repeated here). The real-time projection position corresponding to the reference image is obtained based on the projection plane and vertex coordinates. As another implementation method, the projection frequency of the reference image projected by the second light source can be obtained, and the real-time projection position corresponding to the reference image is obtained based on the projection frequency.

[0060] Step S130: determining whether there is a difference between the real-time projection position and the target projection position.

[0061] The target projection position can be understood as the position of a pre-stored projected display image. Optionally, the position coordinates of the real-time projection position can be compared with the position coordinates of the target projection position to determine whether there is a difference between the real-time projection position and the target projection position. Optionally, if the position coordinates of the real-time projection position are different from the position coordinates of the target projection position, it can be determined that there is a difference between the real-time projection position and the target projection position; if the position coordinates of the real-time projection position are the same as the position coordinates of the target projection position, it can be determined that there is no difference between the real-time projection position and the target projection position.

[0062] Step S140: adjusting the optical axis for projecting the display image so that the real-time projection position approaches the target projection position.

[0063] As one approach, if a difference is determined between the real-time projection position and the target projection position, it can be determined that the projected display image has pixel offset. In this approach, the pixel offset can be avoided by adjusting the optical axis of the projected display image so that the real-time projection position approaches the target projection position. For example, the offset direction and amount of the display image on the projection plane can be calculated based on the projection plane and the measured projection distance, so that the optical axis of the projected display image can be adjusted based on the offset direction and amount.

[0064] Optionally, if there is no difference between the position coordinates of the real-time projection position and the target projection position, the determination process may be terminated.

[0065] The present application provides a projection method, which projects a display image through a first light source, and then projects a reference image through a second light source at a preset time interval, wherein the display image and the reference image have the same projection optical axis, and then obtains the real-time projection position corresponding to the reference image, and then determines whether there is a difference between the real-time projection position and the target projection position. If so, adjust the optical axis of the projected display image so that the real-time projection position approaches the target projection position. In this way, when the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval is different from the target projection position, the optical axis of the projected display image can be adjusted so that the real-time projection position can approach the target projection position, thereby achieving the adjustment of the projection effect without affecting the projection of the display image, so as to overcome the problem of decreased projection image quality caused by pixel offset.

[0066] See also Figure 8 Another embodiment of the present application provides a projection method, applied to a projection system, the method comprising:

[0067] Step S210: projecting a display image via a first light source, and projecting a reference image via a second light source at preset time intervals.

[0068] Step S220: Obtaining the real-time projection position corresponding to the reference image.

[0069] Step S230: determining whether there is a difference between the real-time projection position and the target projection position.

[0070] Step S240: obtaining an offset parameter corresponding to the difference according to the target test pattern.

[0071] The reference image in this embodiment may be a target test pattern, and the specific content of the target test pattern (e.g., pattern style and number of patterns) may be set according to actual needs. For example, the shape of the target test pattern may be a triangle, a positive direction, a rectangle, etc., and the pattern content of the target test pattern may be stripes or a checkered pattern, etc., without specific limitation. The outline size of the target test pattern may be equal to the outline of the projected image, or the outline size of the target test pattern may be smaller than the outline of the projected image.

[0072] As one approach, if a discrepancy is determined between the real-time projection position and the target projection position, an offset parameter corresponding to the discrepancy can be obtained based on the target test pattern. Optionally, the offset parameter and offset amount here can be understood as the offset direction and amount of the real-time projection position relative to the target projection position. The specific process for obtaining the offset parameter is described below.

[0073] See also Figure 9 As one approach, step S240 may include:

[0074] Step S241: Acquire a first coordinate corresponding to the target projection position.

[0075] Optionally, the target projection position may be a vertex of the projection screen, and the first coordinate may be the position coordinate of the vertex. As an embodiment, the pre-stored target projection position may be obtained from the information processing module of the aforementioned projection system, and then the first coordinate corresponding to the target projection position may be obtained.

[0076] Step S242: Acquire a second coordinate corresponding to the real-time projection position based on the target test pattern.

[0077] Among them, the second coordinate is the coordinate of the current projection position. As an implementation method, the second coordinate corresponding to the real-time projection position can be obtained based on the target test pattern. For example, the projection distance of the target test pattern can be obtained, and then the second coordinate corresponding to the real-time projection position can be obtained based on the projection distance and the vertex of the target test pattern.

[0078] For example, in a specific application scenario, see Figure 10 , shows an example diagram of the projected target test pattern provided by an embodiment of the present application, such as Figure 10 As shown, the vertices of the projection screen 21 are A0, B0, C0, and D0 respectively, and the coordinates corresponding to the vertices A0, B0, C0, and D0 are X0=[X A0 ,X B0 ,X C0 ,X D0 ],Y0=[y A0 ,y B0 ,yC0 ,y D0 ], the vertices of the target test pattern 22 are A, B, C, and D respectively. Optionally, assuming that the projection distance of the target test pattern 22 is d, the coordinates X0 corresponding to the vertices A0, B0, C0, and D0 can be combined to obtain [X A0 ,X B0 ,X C0 ,X D0 ],Y0=[y A0 ,y B0 ,y C0 ,y D0 ] and the projection distance d to calculate the coordinates of vertices A, B, C, and D, respectively, X = [X A ,X B ,X C ,X D ],Y=[y A ,y B ,y C ,y D ], the second coordinate corresponding to the real-time projection position can be obtained. The specific calculation principle and calculation process can refer to the relevant technology and will not be repeated here.

[0079] Step S243: Obtaining the offset direction and offset amount of the second coordinate relative to the first coordinate based on a specified rule.

[0080] Optionally, the specified rule in this embodiment can be the formula [X, Y] = M*[X0, Y0] + V, where [X, Y] represents the coordinates of the vertices of the target test pattern, M represents the scaling factor of the current projection screen relative to the pre-stored initial projection screen, V represents the amount of pixel translation of the current projection screen, and [X0, Y0] represents the coordinates of the vertices of the projection screen.

[0081] As a way, the offset direction and offset of the second coordinate relative to the first coordinate can be calculated based on the formula [X, Y] = M*[X0, Y0] + V. For example, after obtaining the coordinates [X0, Y0] and [X, Y], the offset direction and offset of the second coordinate relative to the first coordinate can be calculated based on the formula V = [1,1,1,1]′*[δ X ,δ y ] First calculate the translation amount (i.e. the amount of pixel translation of the current projection image) V, and then calculate the scaling factor M based on V and the formula [X, Y] = M*[X0, Y0] + V, where [δ X ,δ y ] represents the change in the offset of the current projection image relative to the initial projection image in the x and y directions. Optionally, the offset direction of the second coordinate relative to the first coordinate can be determined based on the scaling factor, and the offset of the second coordinate relative to the first coordinate can be determined based on the translation amount.

[0082] Optionally, the offset direction and offset amount obtained above may be used as offset parameters corresponding to the pixel offset, so that the projection position may be adjusted based on the offset parameters.

[0083] Step S250: adjusting the optical axis for projecting the display image according to the offset parameter, so that the real-time projection position approaches the target projection position.

[0084] As a method, the lens of the projection lens can be shifted according to the offset parameter to adjust the optical axis of the projected display image, that is, the projection position can be adjusted by shifting the lens of the projection lens based on the offset parameter. Specifically, a certain lens in the projection lens can be shifted. For example, in a specific application scenario, please refer to Figure 11 , shows an example diagram of adjusting the optical axis of the projected display image based on the offset parameter, as shown in Figure 11 As shown, the projection lens 23 includes a lens 231, a lens 232 and a lens 233. Optionally, the above-mentioned offset parameters can be used as follows: Figure 11 Adjusting the lens 232 in the direction of the arrow (which can be horizontally left or right) deflects the central axis of the projected image, allowing the entire projected image to shift, thereby adjusting the pixel offset of the projected position. Optionally, a lens shift of a few microns can result in a 1-2 pixel shift of the projected image. By adjusting the optical axis of the projected display image by translating the lens of the projection lens, the real-time projection position can be brought infinitely close to the target projection position, thereby reducing pixel offset.

[0085] Among them, such as Figure 12 As shown, coils A and B can be connected to the same circuit, and coils C and D can be connected to the same circuit. When current flows through the circuit, the magnetic field generated by the coils interacts with the permanent magnets near the coils to push the coils to move. The coils are fixed to the positioning device of the lens 23. The movement of the coils can push the movement of the lens, so that a certain lens in the projection lens can be translated in this way.

[0086] As another embodiment, Figure 13 As shown, a parallel plate with a certain angle θ to the optical axis can be added to the imaging light path during the projection process, so that the optical axis is offset to a certain extent, and the overall translation of the projected image pixels is achieved by rotating the angle of the parallel plate. It should be noted that in this embodiment, the parallel plate can be rotated according to the aforementioned offset parameters. For the specific rotation implementation process, please refer to the relevant technology and will not be repeated here.

[0087] The present embodiment is described below with an example:

[0088] Optionally, in this embodiment, a visible light camera can be used to capture the projected image. Assuming that the pixel resolution of the display chip DMD of the projection device is 1920*1080, the pixel size is 5.4um, and the projection ratio range of the projector zoom lens is 1.2 to 2.0:1, the capture camera can be selected according to the following criteria: (1) The FOV of the camera lens needs to be larger than the FOV corresponding to the projection ratio of 1.2:1, that is, the half angle is (2) The camera's pixel resolution is not less than 1920*1080, and the camera's pixel size is not greater than Among them, a voice coil motor (VCM) can be used as an actuator to drive a lens in the lens to adjust the overall translation of the image, and the zoom of the image can be adjusted by moving this lens along the optical axis.

[0089] A projection method provided by the present application realizes that when the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval is different from the target projection position, the offset direction and offset amount corresponding to the pixel offset are obtained according to the projected target test pattern, and the optical axis of the projected display image is adjusted based on the offset direction and offset amount, thereby realizing the adjustment of the projection effect without affecting the image projection process, so as to overcome the problem of reduced projection image quality caused by pixel offset.

[0090] See also Figure 14 Another embodiment of the present application provides a projection method, applied to a projection system, the method comprising:

[0091] Step S310: projecting a display image via a first light source, and projecting a reference image via a second light source at preset time intervals.

[0092] Step S320: Acquire the real-time projection position corresponding to the reference image.

[0093] Step S330: Determine whether there is a difference between the real-time projection position and the target projection position.

[0094] Step S340: Obtain the resolution level corresponding to the target test pattern.

[0095] Optionally, in order to ensure the accuracy of the adjusted projection image, the pixels of the test pattern in this embodiment may correspond to multiple densities. As a method, resolution levels corresponding to different densities may be set and stored. For example, the denser the pixels, the lower the resolution level may be set, or the denser the pixels, the higher the resolution level may be set according to actual conditions, and so on. There is no specific limitation. In this case, after obtaining the target test pattern, the resolution level corresponding to the target test pattern may be obtained so that the degree of adjustment of the picture may be determined according to the resolution level.

[0096] Step S350: Acquire adjustment parameters that match the resolution level.

[0097] For example, if the target test pattern is stripes, and the currently acquired resolution level is the lowest resolution level, in this case, the stripes are dense, the image is out of focus, and the vertex position of the target test pattern may not be accurately detected. Optionally, a rough adjustment can be made to the projection image (for example, a test pattern with a larger projection width or projection accuracy can be selected to adjust the projection image), and the adjustment amount corresponding to the rough adjustment can be used as an adjustment parameter that matches the current resolution level. Optionally, after the rough adjustment, a test pattern with a smaller projection width or projection accuracy can be selected to make fine adjustments to the projection image. Optionally, the adjustment process from coarse adjustment to fine adjustment can be implemented periodically according to actual conditions.

[0098] Optionally, in this embodiment, the accuracy of the projected image is adjusted through different degrees of adjustment. The accuracy adjustment can be for the entire area of ​​the projected image, or for a partial area of ​​the projected image. For example, if the projected content in the projected image is located in a corner of the projection screen, then only the accuracy of the projected image in that corner can be adjusted.

[0099] Step S360: using the adjustment parameter as an offset parameter corresponding to the difference.

[0100] As a method, the above adjustment parameters can be used as offset parameters corresponding to pixel offset.

[0101] Step S370: adjusting the optical axis for projecting the display image according to the offset parameter so that the real-time projection position approaches the target projection position.

[0102] A projection method provided by the present application realizes step-by-step precision adjustment of the optical axis of the projected display image based on the obtained offset parameters when there is a difference between the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval and the target projection position. This allows the projection effect to be adjusted without affecting the image projection process, thereby overcoming the problem of decreased projection image quality due to pixel offset.

[0103] See also Figure 15 Another embodiment of the present application provides a projection method, applied to a projection system, the method comprising:

[0104] Step S410: projecting a display image via a first light source, and projecting a reference image via a second light source at preset time intervals.

[0105] Step S420: Acquire the real-time projection position corresponding to the reference image.

[0106] Step S430: Determine whether there is a difference between the real-time projection position and the target projection position.

[0107] Step S440: Acquire the identification pattern content of the target test pattern.

[0108] Optionally, changes in the projection lens may cause changes in different directions or different mirror images of the projected image, thereby affecting the projection effect or quality of the projected image. As a way to improve this problem, this embodiment can use a second light source to project target test patterns with different pattern contents at preset time intervals to achieve precision adjustment of the projected image in various position directions.

[0109] In this embodiment, if the projection image is taken as the entire projection area (such as Figure 10 As shown), target test patterns with different pattern contents can be projected alternately on the projection screen; if the projection screen is divided into multiple areas, target test patterns with different pattern contents can be projected on different areas respectively, for example, Figure 16 As shown, the projection screen includes area A, area B, area C and area D, wherein the pattern content of the target test pattern corresponding to area A is vertical stripes, the pattern content of the target test pattern corresponding to area B is horizontal stripes, the pattern content of the target test pattern corresponding to area C is squares, and the pattern content of the target test pattern corresponding to area D is mosaic-style squares. By setting the pattern contents of the target test patterns corresponding to areas A, B, C and D to be different, it is possible to achieve precision adjustment of the projected image in various position directions through different target test patterns, that is, gradually achieve fine adjustment.

[0110] As one approach, after obtaining the target test pattern, the pattern content of the target test pattern may be obtained so that the adjustment accuracy of the projected image may be determined according to the pattern content.

[0111] Optionally, when dividing the projection screen into multiple areas, using target test patterns with different pattern contents to adjust the projection image separately may increase the amount of calculation to a certain extent, thereby affecting the projection effect. As a way to improve this problem, Figure 17 As shown, it can be Figure 16 Based on the above, an image mask with a certain tolerance is superimposed on the projected image, so that the data calculation in the area where the mask is located can be ignored during the calculation process, thereby reducing the amount of image processing calculations and improving the projection effect. The specific location and area of ​​the mask superimposed on the projected image are not limited.

[0112] Step S450: Acquire the adjustment direction corresponding to the content of the identification pattern.

[0113] Optionally, different pattern contents may correspond to different adjustment directions, which can also be understood as different pattern contents corresponding to different precision adjustment directions. Different pattern contents and corresponding adjustment directions can be pre-configured and stored as a mapping relationship. For example, in the above example, the target test pattern in the area where vertex A is located has vertical stripes, and the corresponding adjustment direction is the horizontal precision direction. The target test pattern in the area where vertex B is located has horizontal stripes, and the corresponding adjustment direction is the vertical precision direction. In this way, the adjustment direction corresponding to the pattern content of the current target test pattern can be obtained.

[0114] Step S460: using the adjustment direction as an offset parameter corresponding to the difference.

[0115] Step S470: adjusting the optical axis for projecting the display image according to the offset parameter so that the real-time projection position approaches the target projection position.

[0116] This application provides a projection method that implements step-by-step precision adjustment of the optical axis of a projected display image based on acquired offset parameters when the real-time projection position corresponding to a reference image projected by a second light source at preset time intervals differs from the target projection position. This method allows adjustment of the projection effect without affecting the image projection process, overcoming the problem of reduced projected image quality caused by pixel offset. Adjusting the projection position in different directions using patterns with different content can improve the accuracy of the adjusted image.

[0117] See also Figure 18Another embodiment of the present application provides a projection method, which can be applied to a projection system. This embodiment differs from the previous embodiment in that it is applicable to scenarios where multiple projectors need to be spliced ​​together and pixel offset compensation is required. The implementation process and implementation principles of other steps in this embodiment can refer to the relevant descriptions in the previous embodiment and will not be repeated here. The method includes:

[0118] Step S510: projecting a display image via a first light source, and projecting a reference image via a second light source at preset time intervals.

[0119] Optionally, the display image and the reference image in this embodiment have different projection optical axes.

[0120] Step S520: Acquire the real-time projection position corresponding to the reference image.

[0121] Optionally, the projection system in this embodiment may further include a projection device, and the target projection position may be a position of the projection device after thermal stabilization or a designated position on the projection surface. As an implementation method, the designated position may be a fixed position on the projection screen. For example, a fixed infrared scattering point may be placed on the projection screen to determine the fixed position on the projection screen. As another method, such as Figure 19 As shown, if the projection device consists of multiple projectors, one projector can be identified as a main projector, numbered P0, and its pixel offset does not need to be automatically compensated; a projector spliced ​​with the main projector is identified as a secondary projector, numbered P1, and its pixel offset can be automatically compensated based on the projection image of the previous projector P0 spliced ​​with it. At this time, the reference position point of the projector can be selected within the fusion area with P0; similarly, another projector spliced ​​with projector P1 can be identified as a secondary projector, numbered P2, and its pixel offset can be automatically compensated based on the projection image of the previous projector P1 spliced ​​with it. At this time, the reference position point of the projector can be selected within the fusion area with projector P1, and so on, to achieve fusion of multiple projectors.

[0122] Step S530: Determine whether there is a difference between the real-time projection position and the target projection position.

[0123] Step S540: If yes, adjust the optical axis for projecting the display image so that the real-time projection position is adapted to the target projection position.

[0124] As a method, if it is determined that there is a difference between the real-time projection position and the target projection position, the optical axis of the projected display image can be adjusted so that the real-time projection position can be adapted to the target projection position. Here, it can be understood that the real-time projection position and the target projection position can be approached to a preset relative position, wherein the preset relative position can be understood as follows: Figure 19 The location of the fusion region shown in .

[0125] The present application provides a projection method that implements step-by-step precision adjustment of the optical axis of the projected display image based on the obtained offset parameters when the real-time projection position corresponding to the reference image projected by a second light source at preset time intervals differs from the target projection position. This allows adjustment of the projection effect without affecting the image projection process, thereby overcoming the problem of reduced projection image quality due to pixel offset. In the case of multiple projectors being spliced ​​and fused, pixel offset compensation can be performed on an adjacent, rear-end projector by automatically compensating for the projected image of the previous projector P1, thereby improving the accuracy of pixel offset compensation.

[0126] The following will be combined Figure 20 A projection device provided in this application is described.

[0127] See also Figure 20 Based on the above-mentioned projection method, embodiments of the present application also provide another projection device 100 capable of executing the aforementioned projection method. Projection device 100 includes one or more (only one is shown in the figure) processors 102 coupled to each other, a memory 104, an image acquisition module 11, a pixel offset detection module 12, and an adjustment module 13 for adjusting the pixel offset of the projected image. The memory 104 stores a program capable of executing the contents of the above-mentioned embodiments, and the processor 102 can execute the program stored in the memory 104.

[0128] The processor 102 may include one or more processing cores. The processor 102 utilizes various interfaces and circuits to connect various components within the projection device 100. It executes instructions, programs, code sets, or instruction sets stored in the memory 104, as well as accesses data stored in the memory 104, to perform various functions of the projection device 100 and process data. Optionally, the processor 102 may be implemented using at least one of the following hardware forms: a digital signal processing (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA). The processor 102 may integrate one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), and a modem. The CPU primarily processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing display content; and the modem handles wireless communications. It is understood that the modem may not be integrated into the processor 102 and may be implemented separately via a communication chip.

[0129] The memory 104 may include a random access memory (RAM) or a read-only memory (ROM). The memory 104 may be used to store instructions, programs, codes, code sets, or instruction sets. The memory 104 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a video image projection and playback function), instructions for implementing the above-mentioned various method embodiments, etc. The data storage area may also store data (such as audio and video data, chat history data), etc. created by the projection device 100 during use.

[0130] The image acquisition module 11 is used to obtain the real-time projection position corresponding to the reference image. Optionally, the image acquisition module in this embodiment can be a module inside the projection device, or a device that has external communication with the projection device.

[0131] The pixel offset detection module 12 is configured to determine whether there is a difference between the real-time projection position and the target projection position. The adjustment module 13 is configured to determine that a pixel offset exists if a difference is determined between the real-time projection position and the target projection position. The adjustment module 13 is configured to adjust the optical axis of the projected display image to bring the real-time projection position closer to the target projection position, such that the adjusted real-time projection position is identical to the target projection position, or to bring the adjusted real-time projection position infinitely close to the target projection position.

[0132] Please refer to Figure 21 , which shows a block diagram of a computer-readable storage medium provided in an embodiment of the present application. The computer-readable medium 600 stores program code, which can be called by a processor to execute the method described in the above method embodiment.

[0133] The computer-readable storage medium 600 can be an electronic memory such as a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), an EPROM, a hard disk, or a ROM. Alternatively, the computer-readable storage medium 600 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 600 has storage space for program code 610 for executing any of the method steps described above. These program codes can be read from or written to one or more computer program products. The program code 610 can be compressed, for example, in a suitable form.

[0134] In summary, the present application provides a projection method, a projection device, and a storage medium, which projects a display image through a first light source, and then projects a reference image through a second light source at a preset time interval, wherein the display image and the reference image have the same projection optical axis, and then obtains the real-time projection position corresponding to the reference image, and then determines whether there is a difference between the real-time projection position and the target projection position. If so, adjust the optical axis of the projected display image so that the real-time projection position approaches the target projection position. In this way, when the real-time projection position corresponding to the reference image projected by the second light source at a preset time interval is different from the target projection position, the optical axis of the projected display image can be adjusted so that the real-time projection position can approach the target projection position, thereby achieving the adjustment of the projection effect without affecting the projection of the display image, so as to overcome the problem of decreased projection image quality due to pixel offset.

[0135] 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 of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A projection method, said method being applied to a projection system, characterized in that: The method comprises: Projecting a display image through a first light source, and projecting a reference image through a second light source at preset time intervals, wherein the display image and the reference image have the same projection optical axis, the second light source is infrared light, and the reference image is an infrared image; Obtaining a real-time projection position corresponding to the reference image; Determining whether there is a difference between the real-time projection position and the target projection position; If so, the optical axis for projecting the display image is adjusted so that the real-time projection position approaches the target projection position.

2. The method according to claim 1, characterized in that The reference image is a target test pattern, and adjusting the optical axis for projecting the display image includes: acquiring an offset parameter corresponding to the difference according to the target test pattern; An optical axis for projecting the display image is adjusted according to the offset parameter.

3. The method according to claim 2, characterized in that The adjusting the optical axis for projecting the display image according to the offset parameter comprises: The lens of the projection lens is translated according to the offset parameter to adjust the optical axis of projecting the display image.

4. The method according to claim 2, characterized in that The acquiring, according to the target test pattern, an offset parameter corresponding to the difference comprises: Acquire a first coordinate corresponding to the target projection position; acquiring a second coordinate corresponding to the real-time projection position based on the target test pattern; The offset direction and offset amount of the second coordinate relative to the first coordinate are obtained based on a specified rule.

5. The method according to claim 2, characterized in that The acquiring, according to the target test pattern, an offset parameter corresponding to the difference comprises: Obtaining a resolution level corresponding to the target test pattern; Obtaining adjustment parameters that match the resolution level; The adjustment parameter is used as an offset parameter corresponding to the difference.

6. The method according to claim 2, characterized in that The acquiring, according to the target test pattern, an offset parameter corresponding to the difference comprises: Obtaining identification pattern content of the target test pattern; Obtaining an adjustment direction corresponding to the content of the identification pattern; The adjustment direction is used as an offset parameter corresponding to the difference.

7. The method according to claim 1, characterized in that The projection system includes a color wheel, and the preset time interval is the time interval for the color wheel to periodically rotate to a spoke area.

8. The method according to claim 7, characterized in that The projection system further includes a projection device, and the target projection position includes a position of the projection device after thermal stabilization or a designated position on a projection surface.

9. The method according to claim 8, characterized in that The projection system further includes a picture acquisition module, and the projection ratio of the lens corresponding to the picture acquisition module and the projection ratio of the projection lens of the projection device in a zoom state satisfy the formula: The field of view angle of the lens corresponding to the image acquisition module and the field of view angle of the projection lens of the projection device in the zoom state satisfy the formula: ; Among them, the Characterizes the projection ratio of the lens corresponding to the image acquisition module, Characterizes the maximum throw ratio of the projection lens of the projection device in the zoom state, Characterizes the field of view angle of the lens corresponding to the image acquisition module, Characterizes the maximum field of view angle of the projection lens of the projection device in the zoom state.

10. The method according to claim 9, characterized in that The image resolution of the image captured by the image acquisition module can distinguish a single pixel of the imaging image when the projection lens of the projection device is at the minimum field of view. The angular resolution of the corresponding lens of the image acquisition module satisfies the following formula: , Among them, the It represents the minimum field angle of the projection lens of the projection device in the zoom state, and N represents the number of pixels on the side with more pixels.

11. The method according to claim 9, characterized in that The pixel resolution of the lens corresponding to the image acquisition module is greater than the pixel resolution of the projection lens of the projection device.

12. The method according to any one of claims 1 to 11, characterized in that The first light source and the second light source are the same light source or different light sources.

13. The method according to claim 12, characterized in that The first light source emits visible light, and the second light source emits infrared light.

14. A projection method, said method being applied to a projection system, characterized in that: The method comprises: Projecting a display image through a first light source, and projecting a reference image through a second light source at preset time intervals, wherein the display image and the reference image have different projection optical axes, the second light source is infrared light, and the reference image is an infrared image; Obtaining a real-time projection position corresponding to the reference image; Determining whether there is a difference between the real-time projection position and the target projection position; If so, the optical axis for projecting the display image is adjusted so that the real-time projection position is adapted to the target projection position.

15. A projection device, characterized in that: It includes a picture acquisition module, a position difference detection module, an adjustment module, one or more processors and a memory; One or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs are configured to execute the method of any one of claims 1 to 13 or claim 14.

16. A computer-readable storage medium, characterized in that The computer-readable storage medium stores program code, wherein when the program code is executed by a processor, the method according to any one of claims 1 to 13 or claim 14 is executed.

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