Display method with three-dimensional display effect and holographic projection display device

Abstract

The invention discloses a display method with a three-dimensional display effect and a holographic projection display device. The method comprises the following steps: dividing an RGB-D image into a foreground area and a background area; pixel points of the foreground area are filled with black, pixel points of the background area are filled into white, and a mask image is obtained; dividing the image into a corresponding foreground image and a background image based on the RGB-D image; filling the vacant part of the background image to obtain a background image; and the foreground image displayed by the first non-transparent screen and the mask image displayed by the transparent screen are superposed to form a superposed image, and the superposed image and the background image displayed by the second non-transparent screen form a holographic projection image through the spectroscope. The embodiment of the invention has the following advantages: the space utilization rate is higher, the occupied transverse space is smaller when images with the same height are presented, and the imaging range is more flexible. The mask image presented by the transparent screen can effectively decouple the foreground and the background image of the corresponding area, and the sense of reality of three-dimensional display is improved.

Description

Technical Field

[0001] The present invention relates to the field of holographic projection, and in particular to a display method with three-dimensional display effect and a display device of holographic projection. Background Art

[0002] 3D display technology allows observers to see the projected object more intuitively, and has high application value in the film, television, advertising and communications industries. Nowadays, with the improvement of hardware functions and the development of artificial intelligence algorithms, holographic projection products of virtual digital people are gradually being used in daily life, including virtual shopping guides, intelligent customer service and chat assistants. These products can simulate human behavior through 3D display technology to bring users a better experience.

[0003] Existing three-dimensional display technology mainly reflects the light emitted by the projection source into space through a transparent plate to achieve a three-dimensional display effect. The technical solutions based on this type of method mainly include pyramid holography and a holographic method in which a 45-degree lens is installed in the vertical direction of the projection source. The pyramid holographic projection product projects the views of the projection source in different directions onto the four faces of a four-sided pyramid. Its characteristic is that different perspectives of the image can be seen in different directions. However, this type of product occupies a large space horizontally and has a low space utilization rate. The holographic method with a 45-degree lens has a poor sense of reality.

[0004] In addition, some products use a short-throw projector to project a flat image onto a transparent screen to achieve a holographic display effect. This type of product has a single projection source, lacks spatial layering information, and the display effect lacks three-dimensionality. Summary of the invention

[0005] The object of the present invention is to provide a display method with three-dimensional display effect and a holographic projection display device, so as to solve the problems existing in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solution: a display method with a three-dimensional display effect, comprising the following steps:

[0007] Get RGB-D image;

[0008] Dividing the RGB-D image into a foreground area and a background area;

[0009] Fill the pixels in the foreground area with black and the pixels in the background area with white to obtain a mask image;

[0010] The RGB-D image is divided into a corresponding foreground image and a background image according to the foreground area and the background area;

[0011] Filling the vacant part of the background image to obtain a background image;

[0012] Displaying the generated foreground image through a first non-transparent screen;

[0013] Displaying the generated background image through a second non-transparent screen;

[0014] Displaying the generated mask image through a transparent screen;

[0015] The superimposed image formed by superimposing the foreground image displayed by the first non-transparent screen and the mask image displayed by the transparent screen is combined with the background image displayed by the second non-transparent screen through a beam splitter to form a holographic projection image.

[0016] Preferably, in the step of “dividing the RGB-D image into a foreground area and a background area”, the RGB-D image is divided into a foreground area and a background area by a clustering algorithm.

[0017] Preferably, in the step of "dividing the RGB-D image into a foreground area and a background area by a clustering algorithm", the frequency histogram of the depth value distribution of the RGB-D image is divided and determined by a Gaussian mixture model to divide it into a foreground area and a background area.

[0018] Preferably, in the step of "dividing the RGB-D image into corresponding foreground images and background images according to the foreground area and the background area", the RGB-D image is divided into a foreground image and a background image by an image segmentation algorithm, wherein the foreground image corresponds to the foreground area, and the background image corresponds to the background area.

[0019] Preferably, in the step of "filling the missing parts of the background image to obtain the background image", the Diffusion model is used to fill the missing parts of the background image to obtain the background image.

[0020] Preferably, in the step of "the superimposed image formed by superimposing the foreground image displayed by the first non-transparent screen and the mask image displayed by the transparent screen forms a holographic projection image with the mask image displayed by the transparent screen through a beam splitter", the first non-transparent screen and the transparent screen are arranged in parallel, and the angle formed by the transparent screen and the beam splitter is 45°; the angle formed by the second non-transparent screen and the beam splitter is 45°; the transparent screen and the second non-transparent screen are respectively located on both sides of the beam splitter; and the transparent screen is arranged closer to the beam splitter than the first non-transparent screen.

[0021] Preferably, the beam splitter is a plane beam splitter.

[0022] Preferably, the RGB-D image is a projection of the object to be projected.

[0023] An embodiment of the present application discloses a holographic projection display device, comprising: a beam splitter, a first non-transparent screen, a transparent screen, and a second non-transparent screen; the first non-transparent screen and the transparent screen are arranged in parallel, and the angle formed by the transparent screen and the beam splitter is 45°; the angle formed by the second non-transparent screen and the beam splitter is 45°; the transparent screen and the second non-transparent screen are respectively located on both sides of the beam splitter; the transparent screen is arranged closer to the beam splitter than the first non-transparent screen.

[0024] Preferably, the transparent screen is an LCD transparent screen, the beam splitter is a plane beam splitter, and the first non-transparent screen and the second non-transparent screen are LCD screens.

[0025] The embodiments of the present application have the following advantages through the above structure and method:

[0026] 1. Compared with traditional pyramid holographic display products, the space utilization rate of the present invention is better. The aspect ratio of the pyramid projection is about 2:1, and this product can present an aspect ratio of 1:1. When presenting images of the same height, it occupies less lateral space and has a more flexible imaging range.

[0027] 2. Compared with the traditional holographic projection method of placing a 45-degree beam splitter, the present invention can highlight the main body of the picture in combination with the background screen. Different imaging effects can be seen through different viewing angles of the observer. The mask image presented by the LCD transparent screen can effectively decouple the foreground and the background image of the corresponding area, thereby increasing the realism of the three-dimensional display.

[0028] 3. The present invention uses a machine learning-based method to adaptively segment the foreground and background, which is more practical and more real-time.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the working principle of the display method with three-dimensional display effect in the present invention.

[0031] Figure 2 It is a schematic diagram of the structural principle of the holographic projection display device in the present invention.

[0032] Figure 3 The frequency histogram (unit: mm) of the depth value distribution of the original image is exemplarily illustrated.

[0033] Figure 4 The frequency histogram mapped to 8-bit intervals is exemplarily illustrated.

[0034] Figure 5 The frequency histogram after GMM clustering is illustrated as an example.

[0035] Figure 6 The structural principle diagram of the Diffusion model is illustrated by way of example.

[0036] Figure 7 An example of a background image with a gap is shown.

[0037] Figure 8 The figure shows an example of a background image after filling.

[0038] Fig. 9 The figure is a hardware principle block diagram of the holographic projection display device in the present invention.

[0039] The figure markings of the above drawings are: 1. first non-transparent screen; 2. light; 3. transparent screen; 4. spectroscope; 5. second non-transparent screen; 6. observation point. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Reference Figure 1 and Figure 2 As shown, the embodiment of the present application discloses a display method with a three-dimensional display effect, comprising the following steps:

[0045] Get RGB-D image;

[0046] Dividing the RGB-D image into a foreground area and a background area;

[0047] Fill the pixels in the foreground area with black and the pixels in the background area with white to obtain a mask image;

[0048] The RGB-D image is divided into a corresponding foreground image and a background image according to the foreground area and the background area;

[0049] Filling the vacant part of the background image to obtain a background image;

[0050] Displaying the generated foreground image through a first non-transparent screen 1;

[0051] Displaying the generated background image through the second non-transparent screen 5;

[0052] The generated mask image is displayed through the transparent screen 3;

[0053] The superimposed image formed by superimposing the foreground image displayed by the first non-transparent screen 1 and the mask image displayed by the transparent screen 3 is combined with the background image displayed by the second non-transparent screen 5 through a beam splitter 4 to form a holographic projection image.

[0054] By means of the above method, the space utilization rate of the present invention is better. The present invention can present an aspect ratio of 1:1. When presenting an image of the same height, it occupies less lateral space and has a more flexible imaging range. Compared with the traditional holographic projection method of placing a 45° beam splitter 4, the present invention can highlight the main body of the picture in combination with the background screen. Different imaging effects can be seen through different viewing angles of the observer. The mask image presented by the transparent screen 3 can effectively decouple the foreground and the background images of the corresponding area, thereby increasing the realism of the three-dimensional display.

[0055] Specifically, the display method with three-dimensional display effect disclosed in the embodiment of the present application includes the following steps:

[0056] Step 101: Acquire an RGB-D image;

[0057] Among them, the acquired RGB-D image corresponds to the projected object. It can be understood that the RGB-D image (depth image) is a combination of the RGB three-channel color image and the Depth image. The Depth image is similar to a grayscale image, except that each pixel value is the actual distance between the sensor and the object. The RGB image and the Depth image are registered, so there is a one-to-one correspondence between the pixels.

[0058] Step 103: Divide the RGB-D image into a foreground area and a background area;

[0059] Specifically, the RGB-D image is divided into a foreground area and a background area by a clustering algorithm.

[0060] In statistics, a mixture model is a probability model used to represent the existence of a subpopulation in a population. In other words, a mixture model represents the probability distribution of a measurement result in a population. It is a mixture distribution composed of the probability distributions of several subpopulations. A mixture model does not require the measurement result to provide information about the probability distribution of each subpopulation in order to calculate the probability of the measurement result in the distribution of the population.

[0061] The Gaussian Mixture Model (GMM) is a statistical model used to model a probability distribution that is a mixture of multiple Gaussian distributions. The basic assumption of this model is that the observed data is randomly generated from several Gaussian distributions. In GMM, each Gaussian distribution is called a "component", and the mixture of these components forms the final data distribution.

[0062] GMM has the following main components:

[0063] Gaussian distribution (normal distribution): Each component is a Gaussian distribution that describes the local characteristics of the data. The Gaussian distribution is parameterized by the mean (describing the center of the distribution) and the variance (describing the width of the distribution).

[0064] Mixing coefficients: Each component has a mixing coefficient that represents the weight of that component in the final data distribution. The sum of these mixing coefficients must equal 1.

[0065] Probability density function: The probability density function of GMM is the weighted sum of the individual Gaussian distributions. For a given observation, GMM can calculate the probability that the data point belongs to each component.

[0066] Maximum Likelihood Estimation: Maximum likelihood estimation is often used to determine the parameters of the GMM, including the mean, variance, and mixing coefficients of each component.

[0067] For a one-dimensional Gaussian random variable X, there exists the following probability density function:

[0068]

[0069] Where σ is the standard deviation of X, and μ is the expected value of X.

[0070] When the Gaussian distribution is extended to k dimensions, according to the definition, if the k-dimensional random vector X = [X 1 ,…,X k ] T If the distribution is normal, there exists a symmetric semi-positive definite covariance matrix Σ and an expected value vector μ = [v 1 ,…,v k ] T Satisfies the characteristic function of X. If Σ is non-singular, then this distribution can be described by the following probability density function:

[0071]

[0072] |Σ| is the determinant of the covariance matrix.

[0073] The Gaussian mixture model is an extension of a single Gaussian probability density function. It uses multiple Gaussian probability density functions (normal distribution curves) to accurately quantify the distribution of variables. It decomposes the distribution of variables into several statistical sub-models based on the distribution of Gaussian probability density functions (normal distribution curves). Each sub-model can be regarded as a latent variable of this mixture model.

[0074] The usage of the GMM algorithm in the present invention is as follows:

[0075] Reference Figure 3 As shown, first, the frequency histogram of the depth value distribution of the original image. Image depth refers to the number of bits used to store each pixel, and is also used to measure the color resolution of the image. Image depth determines the number of colors that each pixel of a color image may have, or the number of gray levels that each pixel of a grayscale image may have. It determines the maximum number of colors that can appear in a color image, or the maximum gray level in a grayscale image. For example, for a monochrome image, if each pixel has 8 bits, the maximum number of gray levels is 2 to the 8th power, that is, 256. The number of pixel bits for the RGB channels of a color image is 4, 4, and 2 respectively, then the maximum number of colors is 2 to the 4+4+2th power, that is, 1024, which means that the depth of the pixel is 10 bits, and each pixel can be one of 1024 colors.

[0076] In the Figure 3 After the depth value of the original image is mapped to the 8-bit space, the frequency histogram is as follows: Figure 4 shown.

[0077] Reference Figure 5As shown, two Gaussian functions (yellow line and green line) are trained by the GMM model, and the points close to the yellow line cluster center are determined as the foreground, and the points close to the green line cluster center are determined as the background. Figure 5 The red line in the figure divides the points on the left into the foreground and the points on the right into the background.

[0078] Step 105: Fill the pixels in the foreground area with black and fill the pixels in the background area with white to obtain a mask image.

[0079] Step 107: dividing the RGB-D image into corresponding foreground image and background image according to the foreground area and the background area;

[0080] The RGB-D image is divided into a foreground image and a background image, wherein the foreground image corresponds to the foreground area, and the background image corresponds to the background area.

[0081] Step 109, filling the blank part of the background image to obtain a background image;

[0082] The Diffusion model (Stable Diffusion) fills the missing parts of the background image to obtain the background image. The core idea of ​​Stable Diffusion is to use a technology called "Diffusion Models" to generate images. The Diffusion Model breaks down the image generation process into multiple steps, and each step uses a denoising autoencoder to process the image. This makes this model perform very well in image generation, and the generation process can be controlled without retraining.

[0083] The network structure of the Stable Diffusion model can be found in Figure 6 .

[0084] The network structure of the Stable Diffusion model mainly consists of three parts:

[0085] (1) First, the input text or image is converted into a specific vector through an encoder

[0086] (2) Diffusion Process gradually diffuses the encoded data into new data vectors

[0087] (3) Convert the result of the diffusion process into image output.

[0088] The effect of the Diffusion model in this application can be roughly compared to Figure 6 and Figure 7 .

[0089] Step 111, displaying the generated foreground image through the first non-transparent screen 1;

[0090] Displaying the generated background image through the second non-transparent screen 5;

[0091] The generated mask image is displayed through the transparent screen 3.

[0092] The superimposed image formed by superimposing the foreground image displayed by the first non-transparent screen 1 and the mask image displayed by the transparent screen 3 is combined with the background image displayed by the second non-transparent screen 5 through a beam splitter 4 to form a holographic projection image.

[0093] Specifically, the first non-transparent screen 1 emits light 2 toward the transparent screen 3, so that the generated foreground image is displayed through the first non-transparent screen 1;

[0094] The second non-transparent screen 5 emits light 2 toward the beam splitter 4, and the generated background image is displayed through the second non-transparent screen 5;

[0095] The transparent screen 3 emits light 2 toward the beam splitter 4 , and the generated mask image is displayed through the transparent screen 3 .

[0096] The first non-transparent screen 1 and the transparent screen 3 are arranged in parallel, and the angle between the transparent screen 3 and the beam splitter 4 is 45°; the angle between the second non-transparent screen 5 and the beam splitter 4 is 45°; the transparent screen 3 and the second non-transparent screen 5 are respectively located on both sides of the beam splitter 4; the transparent screen 3 is arranged closer to the beam splitter 4 than the first non-transparent screen 1. The transparent screen 3 is an LCD transparent screen 3, the beam splitter 4 is a plane beam splitter 4, and the first non-transparent screen 1 and the second non-transparent screen 5 are LCD screens.

[0097] The first non-transparent screen 1 outputs a foreground image toward the transparent screen 3, and the transparent screen 3 outputs a mask image toward the plane beam splitter 4. After passing through the transparent screen 3, the foreground image is superimposed with the mask image to form a superimposed image. After passing through the plane beam splitter 4, part (e.g., 50%) of the superimposed image is output toward the observation point 6.

[0098] The second non-transparent screen 5 outputs the background image toward the plane beam splitter 4 , and a portion (eg 50%) of the background image is output toward the observation point 6 .

[0099] After the partial superimposed image and the partial background image are combined, a holographic projection image is formed.

[0100] Compared with the existing three-dimensional display method and device, the present invention has the following advantages:

[0101] 1. Compared with the existing method of displaying three-dimensional images on a single screen, the present invention uses two screens to display the foreground and the background respectively, and the image of the foreground screen is presented in front of the observation point 6 by the beam splitter 4, which can better show the three-dimensional effect of the image.

[0102] 2. The present invention uses a transparent LCD screen to enable the observation point 6 to receive background light in a specific area (the light of the background image of the first non-transparent screen 1, that is, the light of the first non-transparent screen 1), thereby overcoming the problem of image blur caused by the superposition of light 2 when imaging the foreground and background.

[0103] 3. The present invention is based on a machine learning algorithm, which can reduce dependence on manual operations and improve the practicability of the present invention in actual scenarios.

[0104] Reference Figure 2 As shown, an embodiment of the present application discloses a holographic projection display device, comprising: a beam splitter 4, a first non-transparent screen 1, a transparent screen 3, and a second non-transparent screen 5; the first non-transparent screen 1 and the transparent screen 3 are arranged in parallel, and the angle formed by the transparent screen 3 and the beam splitter 4 is 45°; the angle formed by the second non-transparent screen 5 and the beam splitter 4 is 45°; the transparent screen 3 and the second non-transparent screen 5 are respectively located on both sides of the beam splitter 4; the transparent screen 3 is arranged closer to the beam splitter 4 than the first non-transparent screen 1.

[0105] Preferably, the transparent screen 3 is an LCD transparent screen 3, the beam splitter 4 is a plane beam splitter 4, and the first non-transparent screen 1 and the second non-transparent screen 5 are LCD screens. The first non-transparent screen 1, the second non-transparent screen 5 and the LCD transparent screen 3 have the same size and are all square. When viewed from a frontal angle, the beam splitter 4 overlaps with the transparent screen 3 and the first non-transparent screen 1; when viewed from a top-down angle, the beam splitter 4 overlaps with the second non-transparent screen 5, so that the image of the second non-transparent screen 5 is presented at the position of the transparent screen 3 in a 1:1 ratio.

[0106] like Fig. 9 As shown, of course, in order to achieve better control, the holographic projection display device may include an image processing chipset, an LCD transparent screen 3, two conventional LCD screens (a first non-transparent screen 1, a second non-transparent screen 5), a beam splitter 4, a backlight, a button, an Ethernet module, a WiFi module and a power supply circuit, etc. The holographic projection display device can present the projected image in space with a three-dimensional effect.

[0107] In particular, the second non-transparent screen 5 and the transparent screen 3 can be almost fitted (for example, the spacing distance can be less than 5 mm, such as 0-5 mm), and the second non-transparent screen 5 and the transparent screen 3 are installed at 90° to each other. The spacing between the transparent screen 3 and the first non-transparent screen 1 can be about 6 cm.

[0108] The second non-transparent screen 5 and the transparent screen 3 are both at an angle of 45 degrees to the beam splitter 4, so that the image of the second non-transparent screen 5 is presented 1:1 at the position of the transparent screen 3. Since the first non-transparent screen 1 is located at the rear, its image is smaller than the image of the second non-transparent screen 5 (when observed at the observation point), so it is necessary to perform proportional debugging (for example, by writing a Python script for debugging) after the device is installed, and enlarge the image of the first non-transparent screen 1 so that the pixels of the foreground image and the background image just overlap.

[0109] When the relative height or relative front-to-back distance between the second non-transparent screen 5 and the first non-transparent screen 1 changes, the image sizes of the two screens need to be adjusted in equal proportions for recalibration; the transparent screen is always parallel to the first non-transparent screen 1 and overlaps with its display area at a front-view angle, and the distance from the first non-transparent screen 1 is always the same as the horizontal distance from the second non-transparent screen 5 to the first non-transparent screen 1. The beam splitter always follows the transparent screen at a 45-degree angle, so that it always keeps the top-view angle overlapped with the second non-transparent screen 5, and the front-view angle overlapped with the first non-transparent screen 1 and the transparent screen.

[0110] Preferably, a background light may be provided above the transparent screen 3 and the first non-transparent screen 1. The background light may be powered on and emit light continuously after the device is turned on, thereby providing backlight for the transparent screen 3.

[0111] The display device of holographic projection in the embodiment of the present application can refer to the above description and will not be repeated here.

[0112] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A display method with three-dimensional display effect, characterized in that: The following steps are involved: Get RGB-D image; Dividing the RGB-D image into a foreground area and a background area; Fill the pixels in the foreground area with black and the pixels in the background area with white to obtain a mask image; The RGB-D image is divided into a corresponding foreground image and a background image according to the foreground area and the background area; Filling the vacant part of the background image to obtain a background image; Displaying the generated foreground image through a first non-transparent screen; Displaying the generated background image through a second non-transparent screen; Displaying the generated mask image through a transparent screen; The superimposed image formed by superimposing the foreground image displayed by the first non-transparent screen and the mask image displayed by the transparent screen is combined with the background image displayed by the second non-transparent screen through a beam splitter to form a holographic projection image.

2. The display method according to claim 1, characterized in that: In the step of “dividing the RGB-D image into a foreground area and a background area”, the RGB-D image is divided into a foreground area and a background area by a clustering algorithm.

3. The display method according to claim 2, characterized in that: In the step of "dividing the RGB-D image into a foreground area and a background area by a clustering algorithm", the frequency histogram of the depth value distribution of the RGB-D image is divided and determined by a Gaussian mixture model to divide it into a foreground area and a background area.

4. The display method according to claim 1, characterized in that: In the step of "dividing the RGB-D image into corresponding foreground images and background images according to the foreground area and the background area", the RGB-D image is divided into a foreground image and a background image by an image segmentation algorithm, wherein the foreground image corresponds to the foreground area, and the background image corresponds to the background area.

5. The display method according to claim 4, characterized in that: In the step of "filling the missing parts of the background image to obtain the background image", the Diffusion model fills the missing parts of the background image to obtain the background image.

6. The display method according to claim 1, characterized in that: In the step "the superimposed image formed by superimposing the foreground image displayed by the first non-transparent screen and the mask image displayed by the transparent screen forms a holographic projection image with the mask image displayed by the transparent screen through a beam splitter", the first non-transparent screen and the transparent screen are arranged in parallel, and the angle formed by the transparent screen and the beam splitter is 45°; the angle formed by the second non-transparent screen and the beam splitter is 45°; the transparent screen and the second non-transparent screen are respectively located on both sides of the beam splitter; and the transparent screen is arranged closer to the beam splitter than the first non-transparent screen.

7. The display method according to claim 6, characterized in that: The beam splitter is a plane beam splitter.

8. The display method according to claim 1, characterized in that: The RGB-D image is a projection of the object to be projected.

9. A holographic projection display device, characterized in that: include: A beam splitter, a first non-transparent screen, a transparent screen, and a second non-transparent screen; The first non-transparent screen and the transparent screen are arranged in parallel, and the angle formed by the transparent screen and the beam splitter is 45°; the angle formed by the second non-transparent screen and the beam splitter is 45°; the transparent screen and the second non-transparent screen are respectively located on both sides of the beam splitter; the transparent screen is arranged closer to the beam splitter than the first non-transparent screen.

10. The holographic projection display device according to claim 9, characterized in that: The transparent screen is an LCD transparent screen, the beam splitter is a plane beam splitter, and the first non-transparent screen and the second non-transparent screen are LCD screens.

Images