Projection image display method, device, equipment and storage medium

Abstract

The present invention discloses a projection image display method, device, equipment and storage medium, and relates to the field of projection technology. The method comprises: obtaining the projection distance between the projection device and the projection surface; determining the maximum reference brightness value according to the projection distance, so that the maximum reference brightness value is inversely proportional to the projection distance; and mapping the high dynamic range image to be displayed to the image displayable by the projection device according to the maximum reference brightness value. The present invention is based on projection distance detection, and dynamically changes the maximum reference brightness value of the tone mapping algorithm according to the projection distance, thereby avoiding the problem of poor image display caused by the incompatibility of the existing manually selected maximum reference brightness value or the change of the projection distance while the maximum reference brightness value remains unchanged.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection image display method, device, equipment and storage medium. Background Art

[0002] High Dynamic Range Imaging (HDRI or HDR for short) is a set of technologies used to achieve a larger exposure dynamic range (i.e., a larger difference between light and dark) than ordinary digital imaging technology. The purpose of high dynamic range imaging is to correctly represent a wide range of brightness in the real world, from direct sunlight to the darkest shadow. Since HDR technology can show more details in bright and dark areas, the displayed image is closer to what the human eye sees. With the development of projection technology, HDR technology has been widely used in projection equipment to optimize the display effect of projection equipment. Summary of the invention

[0003] In current projection equipment, HDR display is usually based on the premise that the projection distance remains unchanged. If the projection distance changes, the maximum reference brightness value will change, but the hardware capability remains unchanged, resulting in poor dynamic adjustment effect. In view of this, the present invention provides a projection image display method, device, equipment and storage medium to achieve a balance between hardware adaptation and dynamic adjustment range.

[0004] In a first aspect, the present invention provides a projection image display method, comprising:

[0005] Get the projection distance between the projection device and the projection surface;

[0006] Determine a maximum reference brightness value according to the projection distance, so that the maximum reference brightness value is inversely proportional to the projection distance;

[0007] The high dynamic range image to be displayed is mapped into an image displayable by the projection device according to the maximum reference brightness value.

[0008] A possible implementation also includes:

[0009] Get the lumen value, projection surface aspect ratio and projection ratio of the projection device;

[0010] The determining of the maximum reference brightness value according to the projection distance so that the maximum reference brightness value is inversely proportional to the projection distance includes:

[0011] The maximum reference brightness value is determined according to the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface and the projection ratio, so that the maximum reference brightness value is proportional to the lumen value of the projection device and / or the aspect ratio of the projection surface, and inversely proportional to the projection distance and / or the projection ratio.

[0012] In a second aspect, the present invention provides a projection image display device, comprising an image display module, wherein the image display module is configured to perform the following steps:

[0013] Get the projection distance between the projection device and the projection surface;

[0014] Determine a maximum reference brightness value according to the projection distance, so that the maximum reference brightness value is inversely proportional to the projection distance;

[0015] The high dynamic range image to be displayed is mapped into an image displayable by the projection device according to the maximum reference brightness value.

[0016] In a possible implementation, mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value includes:

[0017] Selecting a brightness level that is closest to the maximum reference brightness value and has a brightness value greater than the maximum reference brightness value as the target brightness level, and using the brightness value corresponding to the target brightness level as the mapping maximum threshold value, wherein the projection device has a plurality of brightness levels preset inside, and each brightness level corresponds to a brightness value or a brightness range;

[0018] A fixed value is used as a minimum mapping threshold; or, the minimum mapping threshold is determined according to the maximum reference brightness value and the contrast of the projection device, so that the minimum mapping threshold is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device; or, the minimum mapping threshold is determined according to the detected ambient light brightness, so that the minimum mapping threshold is proportional to the detected ambient light brightness;

[0019] The high dynamic range image to be displayed is mapped into an image displayable by the projection device according to the mapping maximum threshold value and the mapping minimum threshold value.

[0020] In a possible implementation, mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value includes:

[0021] Using the maximum reference brightness value as a mapping maximum threshold value;

[0022] A fixed value is used as a minimum mapping threshold; or, the minimum mapping threshold is determined according to the maximum reference brightness value and the contrast of the projection device, so that the minimum mapping threshold is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device; or, the minimum mapping threshold is determined according to the detected ambient light brightness, so that the minimum mapping threshold is proportional to the detected ambient light brightness;

[0023] The high dynamic range image to be displayed is mapped into an image displayable by the projection device according to the mapping maximum threshold value and the mapping minimum threshold value.

[0024] In a possible implementation, determining the mapping minimum threshold value according to the detected ambient light brightness so that the mapping minimum threshold value is proportional to the detected ambient light brightness includes:

[0025] Setting a minimum reference brightness value, where the minimum reference brightness value is a preset value or is determined according to the maximum reference brightness value and the contrast of the projection device. When the minimum reference brightness value is determined according to the maximum reference brightness value and the contrast of the projection device, the minimum reference brightness value is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device;

[0026] When the detected ambient light brightness is greater than the darkroom ambient brightness, k times the minimum reference brightness value is used as the mapping minimum threshold value, where k is a real number greater than 1 and is proportional to the detected ambient light brightness;

[0027] When the detected ambient light brightness is less than or equal to the darkroom ambient brightness, the minimum reference brightness value is used as the mapping minimum threshold value.

[0028] In a possible implementation, the image display module is further configured to perform the following steps:

[0029] Get the lumen value, projection surface aspect ratio and projection ratio of the projection device;

[0030] The determining of the maximum reference brightness value according to the projection distance so that the maximum reference brightness value is inversely proportional to the projection distance includes:

[0031] The maximum reference brightness value is determined according to the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface and the projection ratio, so that the maximum reference brightness value is proportional to the lumen value of the projection device and / or the aspect ratio of the projection surface, and inversely proportional to the projection distance and / or the projection ratio.

[0032] In a third aspect, the present invention provides a projection device, comprising:

[0033] A light source device for emitting a light beam;

[0034] A spatial light modulator, located at the light output side of the light source device, and used to modulate incident light into image light;

[0035] A projection lens, located at the light-emitting side of the spatial light modulator, and used for imaging the output light of the spatial light modulator;

[0036] A processor is connected to the spatial light modulator, and the processor is used to obtain a projection distance between a projection device and a projection surface; determine a maximum reference brightness value according to the projection distance, so that the maximum reference brightness value is inversely proportional to the projection distance; and map a high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value.

[0037] In a fourth aspect, the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the method described in the first aspect.

[0038] In a fifth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method described in the first aspect.

[0039] In a sixth aspect, the present invention provides a computer program product, comprising a computer-readable code, or a non-volatile computer-readable storage medium carrying a computer-readable code, wherein when the computer-readable code runs in an electronic device, the processor in the electronic device executes the method described in the first aspect.

[0040] It should be noted that the device described in the second aspect, the projection device described in the third aspect, the electronic device described in the fourth aspect, the storage medium described in the fifth aspect and the computer program product described in the sixth aspect are used to execute the method provided in the first aspect above, and thus can achieve the same beneficial effects as the method described in the first aspect, and the present invention will not go into details one by one.

[0041] The present invention obtains the projection distance between the projection device and the projection surface, determines the maximum reference brightness value according to the projection distance, so that the maximum reference brightness value is inversely proportional to the projection distance, and then maps the high dynamic range image to be displayed to the image displayable by the projection device according to the maximum reference brightness value. Based on the projection distance detection, the maximum reference brightness value of the tone mapping algorithm is dynamically changed according to the projection distance, thereby avoiding the problem of poor image display caused by the incompatibility of the existing manually selected maximum reference brightness value or the change of the projection distance while the maximum reference brightness value remains unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of functional modules of a projection device provided by an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention;

[0044] Figure 3 A schematic diagram of a flow chart of a projection image display method provided by an embodiment of the present invention;

[0045] Figure 4 A schematic diagram of a projection scene provided by an embodiment of the present invention;

[0046] Figure 5 A schematic flow chart of another projection image display method provided by an embodiment of the present invention;

[0047] Figure 6 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Although the disclosure in the present invention is introduced according to one or several exemplary examples, it should be understood that each aspect of these disclosures can also constitute a complete technical solution separately. In the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0049] In order to fully understand the present invention, a detailed description will be provided below to illustrate the technical solution of the present invention. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0050] Figure 1 Schematic diagram of functional modules of a projection device provided by an embodiment of the present invention. Figure 1 As shown, the projection device includes an image processor 101 and a projection optical engine 102. Among them:

[0051] The image processor 101 may be a microcontroller, a dedicated image processing chip, etc. The microcontroller may be an ARM chip, a microcontroller unit (MCU), etc. The dedicated image processing chip may be an image signal processor (ISP), a graphics processing unit (GPU), an embedded neural network processor (NPU), etc. The image processor 101 may be used for video decoding, image quality processing, etc.

[0052] The projection optical engine 102 may include a driver chip, a spatial light modulator 204 (see Figure 2) and light source, etc. Among them, the light source may include a laser light source, an LED light source, etc.; the spatial light modulator 204 may be a digital micromirror device (DMD), a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), etc.; the driver chip corresponds to the spatial light modulator 204, for example, the digital micromirror device may be driven by a digital light processing element (DLP). The projection optical machine 102 is used to project the image to be projected into a projection screen.

[0053] In some embodiments, the projection device further includes a central controller 103 with one or more processing cores, which may be a CPU, ARM, MCU or other controller. The central controller 103 is the control center of the projection device, and uses various interfaces and lines to connect various parts of the entire projection device, and can run or execute software programs and / or operating systems stored in the storage module 104, and call data stored in the storage module 104. Optionally, the image processor 101 and the central controller 103 may be integrated into one processor.

[0054] In some embodiments, the projection device further includes a storage module 104 of one or more computer-readable storage media, an input module 105, a communication module 106, a power supply 107 and other components. Those skilled in the art will appreciate that Figure 1 The structure of the projection device shown in the figure does not constitute a limitation on the projection device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0055] The storage module 104 can be used to store software programs and operating systems. The central controller 103 executes various functional applications and data processing by running the software programs and operating systems stored in the storage module 104. The storage module 104 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the projection device, etc. In addition, the storage module 104 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices. Accordingly, the storage module 104 can also include a memory controller to provide the central controller 103 with access to the storage module 104.

[0056] The projection device may further include an input module 105, which may be used to receive input digital or character information and generate remote control, keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control.

[0057] The projection device may further include a communication module 106. In some embodiments, the communication module 106 may include a wireless module. The projection device may perform short-distance wireless transmission through the wireless module of the communication module 106, thereby providing the user with wireless broadband Internet access. For example, the communication module 106 may be used to help the user access streaming media, etc.

[0058] The projection device further includes a power supply 107 for supplying power to various components. In some embodiments, the power supply 107 can be logically connected to the central controller 103 through a power management system, so as to manage charging, discharging, and power consumption through the power management system. The power supply 107 can also include any components such as one or more DC or AC power supplies, recharging systems, power failure detection circuits, power converters or inverters, and power status indicators.

[0059] Figure 2 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention. Figure 2 As shown, the projection device includes a light source device 201, an optical system 202 and an imaging system 203. The light source device 201 includes one or more light sources and optical elements for collimating and combining the light from the light source; the light beam emitted by the light source device 201 is irradiated to the spatial light modulator 204 via the optical system 202, and the spatial light modulator 204 modulates its incident light into image light, and images the image light onto a projection object such as a screen via the imaging system 203. The imaging system 203 is generally a lens system, such as a projection lens.

[0060] In addition, the projection device may further include a light source control module (not shown in the figure), which may control the operation of one or more light sources in the light source device 201 so that the light source device 201 emits light of a specified wavelength band required for generating an image. Further, the light source device 201, the optical system 202 and the imaging system 203 may all be included in the projection optical machine 102 (refer to Figure 1 )middle.

[0061] Figure 3 This is a flowchart of a projection image display method provided by an embodiment of the present invention. The projection image display method can be implemented by the central controller 103 running or executing the software program and / or operating system stored in the storage module 104, or by the image processor 101 executing corresponding instructions. Figure 3 As shown, the projection image display method includes the following contents:

[0062] S1001. Obtain the projection distance between the projection device and the projection surface.

[0063] Projection equipment is usually equipped with a distance sensor, which can be used to obtain the projection distance between the projection equipment and the projection surface. Figure 4 , the projection device P1 displays the image to the projection object such as the screen and the wall through the projection lens, forming a projection surface A1B1C1D1, where A1B1 and C1D1 are the long sides of the projection surface, and B1C1 and A1D1 are the wide sides of the projection surface. When the projection device P1 is a front projection, the projection distance between the projection device and the projection surface can be obtained based on TOF (Time of flight), and the data obtained by TOF is the projection distance d.

[0064] S1002. Determine a maximum reference brightness value according to the projection distance, such that the maximum reference brightness value is inversely proportional to the projection distance.

[0065] In the embodiment of the present invention, the maximum reference brightness value changes accordingly with a change in the projection distance. Specifically, the maximum reference brightness value decreases accordingly with a longer projection distance, and increases accordingly with a shorter projection distance, such as Nmax=f(1 / D), where Nmax represents the maximum reference brightness value, f(x) represents the operation function, and D represents the projection distance.

[0066] S1003: Map the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value.

[0067] When HDR technology is applied to a projection device, it is usually necessary to map the HDR original image into an image that can be displayed by the projection device through a tone mapping algorithm. The embodiment of the present invention dynamically changes the maximum reference brightness value of the tone mapping algorithm based on the projection distance, thereby avoiding the problem of poor image display caused by the incompatibility of the existing manually selected maximum reference brightness value or the change of the projection distance while the maximum reference brightness value remains unchanged.

[0068] When performing tone mapping, it is necessary to determine the maximum mapping threshold NMapmax and the minimum mapping threshold NMapmin. According to NMapmax, NMapmin and the brightness mapping algorithm, the HDR original image is mapped to an image that can be displayed by the projection device. The specific tone mapping algorithm can refer to the relevant prior art, and the embodiment of the present invention will not be introduced in detail. The following only exemplarily introduces the method for determining the maximum mapping threshold NMapmax and the minimum mapping threshold NMapmin.

[0069] Method 1:

[0070] 1.1) The projection device has i fixed brightness levels preset inside, corresponding to brightness values ​​N1, ..., Ni respectively; compare Nmax with (N1, ..., Ni), select the brightness level closest to Nmax and with a brightness value greater than Nmax, assuming it is level j, then the corresponding brightness value is Nj, and Nj is used as the maximum mapping threshold value NMapmax. When mapping, consider maximizing the hardware capabilities of the projection device, and the maximum reference brightness value changes accordingly.

[0071] In some embodiments, each brightness level may correspond to a brightness range. In this case, the maximum brightness value in the brightness range corresponding to the j-level target level may be selected as the mapping maximum threshold value NMapmax, or the median value (the average of the minimum brightness value and the maximum brightness value) in the brightness range corresponding to the j-level target level may be selected as the mapping maximum threshold value NMapmax. The embodiments of the present invention do not limit this.

[0072] 1.2) A fixed value is used as the minimum mapping threshold NMapmin, for example, NMapmin is set to a constant 0.1; or NMapmin is calculated according to the contrast c of the projection device and the maximum reference brightness value Nmax, so that the minimum mapping threshold is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device, such as NMapmin=Nmax / c.

[0073] Method 2:

[0074] 2.1) The maximum reference brightness value Nmax is used as the mapping maximum threshold value NMapmax.

[0075] 2.2) A fixed value is used as the minimum mapping threshold NMapmin, for example, NMapmin is set to a constant 0.1; or NMapmin is calculated according to the contrast c of the projection device and the maximum reference brightness value Nmax, so that the minimum mapping threshold is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device, such as NMapmin=Nmax / c.

[0076] In some embodiments, the mapping minimum threshold NMapmin may be determined according to the detected ambient light brightness Nc, so that the mapping minimum threshold is proportional to the detected ambient light brightness Nc, and the detail brightness is dynamically adjusted when the ambient light becomes darker. An example is as follows:

[0077] A minimum reference brightness value Rn is set. Rn may be a fixed value, such as 0.1, or may be determined according to a maximum reference brightness value Nmax and a contrast ratio c of the projection device, such as Rn=Nmax / c.

[0078] When Nc is greater than Nd, the mapping minimum threshold NMapmin=Rn*k, where k is a real number greater than 1 and is proportional to Nc, such as NMapmin=Rn*(1+ln(Nc-Nd+1)), where Nd is the ambient brightness of the darkroom;

[0079] When Nc is less than or equal to Nd, the mapping minimum threshold NMapmin=Rn.

[0080] In some embodiments, when tone mapping is performed, in addition to considering the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface, and the projection ratio may also be considered to further improve the image display effect. Figure 5 As shown, the projection image display method includes the following contents:

[0081] S2001. Obtain the projection distance between the projection device and the projection surface.

[0082] S2002, obtaining the lumen value, projection surface aspect ratio and projection ratio of the projection device, wherein projection ratio=projection surface width / projection distance.

[0083] S2003, determining a maximum reference brightness value according to the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface, and the projection ratio, such that the maximum reference brightness value is proportional to the lumen value of the projection device and / or the aspect ratio of the projection surface, and inversely proportional to the projection distance and / or the projection ratio. The specific calculation formula may be: Nmax = (FL / (MR 2 D 2 )), where F represents the aspect ratio of the projection surface, L represents the lumen value of the projection device, M represents the number of brightness samples of the projection surface, R represents the projection ratio, and D represents the projection distance.

[0084] S2004: Map the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value.

[0085] Steps S2001 and S2004 may refer to the above-mentioned steps S1001 and S1003, which will not be described in detail here.

[0086] An embodiment of the present invention also provides a projection image display device, including an image display module, which is used to perform the following steps: obtaining the projection distance between the projection device and the projection surface; determining a maximum reference brightness value based on the projection distance, so that the maximum reference brightness value is inversely proportional to the projection distance; and mapping the high dynamic range image to be displayed into an image that can be displayed by the projection device based on the maximum reference brightness value.

[0087] In an optional example, those skilled in the art will appreciate that the above-mentioned device can be specifically integrated into an electronic device, which can be a terminal, a server, or other device. Among them, the terminal can be a projector, a smart TV, a laser TV, a mobile phone, a tablet computer, a smart Bluetooth device, a laptop computer, a desktop computer, or other devices; the server can be a single server or a server cluster composed of multiple servers. In some embodiments, the server can also be implemented in the form of a terminal. In some embodiments, the device can also be integrated into multiple electronic devices. For example, the projection image display device can be integrated into a terminal and a server, and the terminal and the server jointly implement the projection image display method of the present invention. The device can be used to execute the various processes and / or steps of the above method. To avoid repetition, it will not be repeated here.

[0088] It should be understood that the device here is embodied in the form of a functional module. The term "module" here may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (such as a shared processor, a proprietary processor or a group processor, etc.) and a memory for executing one or more software or firmware programs, a merged logic circuit and / or other suitable components that support the described functions. The above-mentioned device has the function of implementing the corresponding steps in the above-mentioned method; the above-mentioned functions can be implemented by hardware, or by hardware executing the corresponding software implementation. The hardware or software includes one or more modules corresponding to the above-mentioned functions. In an embodiment of the present invention, the device may also be a chip or a chip system, for example: a system on chip (SoC). The present invention is not limited here.

[0089] An embodiment of the present invention further provides an electronic device, Figure 6 Schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Figure 6 As shown, the device 300 includes a processor 301, a memory 302 and a communication interface 303, wherein the processor 301, the memory 302 and the communication interface 303 communicate with each other via a bus 304, and the memory 302 stores instructions executable by the processor 301, and the instructions are loaded and executed by the processor 301 to control the communication interface 303 to send signals and / or receive signals.

[0090] It should be understood that the device 300 can be specifically the projection device in the above embodiment, or the function of the projection device in the above embodiment can be integrated in the device 300, and the device 300 can be used to execute the various steps and / or processes corresponding to the projection device in the above embodiment. Optionally, the memory 302 may include a read-only memory and a random access memory, and provide instructions and data to the processor 301. A part of the memory 302 may also include a non-volatile random access memory. For example, the memory 302 may also store information about the device type. The processor 301 can be used to execute the instructions stored in the memory 301, and when the processor 301 executes the instructions, the processor 301 can execute the corresponding various steps and / or processes in the above method embodiments.

[0091] It should be understood that in the embodiments of the present invention, the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0092] In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in a processor or an instruction in the form of software. The steps of the method disclosed in conjunction with the embodiment of the present invention can be directly embodied as being executed by a hardware processor, or can be executed by a combination of hardware and software modules in a processor. The software module can be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor executes the instructions in the memory, and completes the steps of the above method in conjunction with its hardware. To avoid repetition, it will not be described in detail here.

[0093] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0094] It should be understood that in various embodiments of the present invention, the size of the sequence number of each process does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention. The modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network modules, and some or all of the modules may be selected according to actual needs to achieve the purpose of the embodiment of the present invention.

[0095] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, a module or component can be divided into multiple modules or components, or multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0096] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0097] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A projection image display method, characterized in that: include: Get the projection distance between the projection device and the projection surface; When the projection device is a front projection, the projection distance between the projection device and the projection surface is obtained based on TOF; Get the lumen value, projection surface aspect ratio and projection ratio of the projection device; The maximum reference brightness value is determined according to the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface and the projection ratio, so that the maximum reference brightness value is proportional to the lumen value of the projection device and / or the aspect ratio of the projection surface, and inversely proportional to the projection distance and / or the projection ratio; Nmax=(FL / (MR 2 D 2 )), where F represents the aspect ratio of the projection surface, L represents the lumen value of the projection device, M represents the number of brightness samples of the projection surface, R represents the projection ratio, and D represents the projection distance; Mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value, comprising: A brightness level that is closest to the maximum reference brightness value and has a brightness value greater than the maximum reference brightness value is selected as the target brightness level, and a brightness value corresponding to the target brightness level is used as a mapping maximum threshold value, wherein the projection device has a plurality of brightness levels preset inside, and each brightness level corresponds to a brightness value or a brightness range; a mapping minimum threshold value is determined according to the detected ambient light brightness, so that the mapping minimum threshold value is proportional to the detected ambient light brightness; and a high dynamic range image to be displayed is mapped into an image that can be displayed by the projection device according to the mapping maximum threshold value and the mapping minimum threshold value.

2. A projection image display method according to claim 1, characterized in that: Mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value comprises: A fixed value is used as a minimum mapping threshold; or, the minimum mapping threshold is determined according to the maximum reference brightness value and the contrast of the projection device, so that the minimum mapping threshold is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device.

3. A projection image display method according to claim 1, characterized in that: Mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value comprises: Using the maximum reference brightness value as a mapping maximum threshold value; A fixed value is used as a minimum mapping threshold; or, the minimum mapping threshold is determined according to the maximum reference brightness value and the contrast of the projection device, so that the minimum mapping threshold is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device; or, the minimum mapping threshold is determined according to the detected ambient light brightness, so that the minimum mapping threshold is proportional to the detected ambient light brightness; The high dynamic range image to be displayed is mapped into an image displayable by the projection device according to the mapping maximum threshold value and the mapping minimum threshold value.

4. A projection image display method according to claim 1 or 3, characterized in that: The step of determining the mapping minimum threshold value according to the detected ambient light brightness, so that the mapping minimum threshold value is proportional to the detected ambient light brightness, includes: Setting a minimum reference brightness value, where the minimum reference brightness value is a preset value or is determined according to the maximum reference brightness value and the contrast of the projection device. When the minimum reference brightness value is determined according to the maximum reference brightness value and the contrast of the projection device, the minimum reference brightness value is proportional to the maximum reference brightness value and inversely proportional to the contrast of the projection device; When the detected ambient light brightness is greater than the darkroom ambient brightness, k times the minimum reference brightness value is used as the mapping minimum threshold value, where k is a real number greater than 1 and is proportional to the detected ambient light brightness; When the detected ambient light brightness is less than or equal to the darkroom ambient brightness, the minimum reference brightness value is used as the mapping minimum threshold value.

5. A projection image display device, characterized in that: It includes an image display module, and the image display module is used to perform the following steps: Obtain the projection distance between the projection device and the projection surface; when the projection device is a front projection, obtain the projection distance between the projection device and the projection surface based on TOF; Get the lumen value, projection surface aspect ratio and projection ratio of the projection device; The maximum reference brightness value is determined according to the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface and the projection ratio, so that the maximum reference brightness value is proportional to the lumen value of the projection device and / or the aspect ratio of the projection surface, and inversely proportional to the projection distance and / or the projection ratio; Nmax=(FL / (MR 2 D 2 )), where F represents the aspect ratio of the projection surface, L represents the lumen value of the projection device, M represents the number of brightness samples of the projection surface, R represents the projection ratio, and D represents the projection distance; Mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value, comprising: A brightness level that is closest to the maximum reference brightness value and has a brightness value greater than the maximum reference brightness value is selected as the target brightness level, and a brightness value corresponding to the target brightness level is used as a mapping maximum threshold value, wherein the projection device has a plurality of brightness levels preset inside, and each brightness level corresponds to a brightness value or a brightness range; a mapping minimum threshold value is determined according to the detected ambient light brightness, so that the mapping minimum threshold value is proportional to the detected ambient light brightness; and a high dynamic range image to be displayed is mapped into an image that can be displayed by the projection device according to the mapping maximum threshold value and the mapping minimum threshold value.

6. A projection device, characterized in that: include: A light source device for emitting a light beam; A spatial light modulator, located at the light output side of the light source device, and used to modulate incident light into image light; A projection lens, located at the light-emitting side of the spatial light modulator, and used for imaging the output light of the spatial light modulator; A processor connected to the spatial light modulator, the processor is used to obtain the projection distance between the projection device and the projection surface; when the projection device is a front projection, the projection distance between the projection device and the projection surface is obtained based on TOF; Used to obtain the lumen value, projection surface aspect ratio and projection ratio of the projection device; For determining a maximum reference brightness value according to the projection distance, the lumen value of the projection device, the aspect ratio of the projection surface and the projection ratio, so that the maximum reference brightness value is proportional to the lumen value of the projection device and / or the aspect ratio of the projection surface, and inversely proportional to the projection distance and / or the projection ratio; Nmax=(FL / (MR 2 D 2 )), where F represents the aspect ratio of the projection surface, L represents the lumen value of the projection device, M represents the number of brightness samples of the projection surface, R represents the projection ratio, and D represents the projection distance; Used to map a high dynamic range image to be displayed into an image displayable by the projection device according to the maximum reference brightness value, comprising: selecting a brightness level that is closest to the maximum reference brightness value and has a brightness value greater than the maximum reference brightness value as a target brightness level, and using a brightness value corresponding to the target brightness level as a mapping maximum threshold value, wherein the projection device has a plurality of brightness levels preset inside, and each brightness level corresponds to a brightness value or a brightness range; determining a mapping minimum threshold value according to the detected ambient light brightness, so that the mapping minimum threshold value is proportional to the detected ambient light brightness; and mapping the high dynamic range image to be displayed into an image displayable by the projection device according to the mapping maximum threshold value and the mapping minimum threshold value.

7. An electronic device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the method according to any one of claims 1 to 4.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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