An imaging system based on a light waveguide plate

Abstract

The present invention discloses an imaging system based on a light waveguide plate, specifically related to the field of optical imaging. The light waveguide control module includes a display unit and an optical imaging unit, and the display unit is connected to the imaging module; the display unit is used to generate a light source image, receive signals from the imaging module and convert them into an initial image source; the optical imaging unit includes a light waveguide plate, and the light waveguide plate is used to receive and process the initial light source image and form a medium-free holographic floating imaging through total internal reflection; the light waveguide plate includes a glass substrate containing an air surface and a reflection surface, a metal film layer, and a magnetic material film layer. By recording the internal light path in the light waveguide plate, three-dimensional light field modeling, and user position detection, the pixel light intensity and the light emission angle are dynamically adjusted to eliminate the imaging differences at different observation positions and improve the multi-view consistency.

Description

Technical Field

[0001] The present invention relates to the field of optical imaging technology, and more specifically, to an imaging system based on a light waveguide plate. Background Art

[0002] A light waveguide plate is an optical guiding element, usually made of an optical material, with microstructures or specific channels inside. It can guide the input optical signal to a specified spatial position through total internal reflection or a specific reflection path of light, realizing the control of the spatial distribution of the light field. Media-free holographic floating imaging is a display technology that uses an optical structure to make an image break away from a physical screen and directly float in the air; it does not rely on any physical medium to carry the image, but forms a visible three-dimensional virtual image in the real space through a special optical path design or light field reconstruction principle;

[0003] During the process of media-free holographic floating imaging with a light waveguide plate, due to the difference in the light propagation path, there will be an angular deviation when observers at different spatial positions observe the same image, resulting in an obvious consistency difference in the observed content. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides an imaging system based on a light waveguide plate. Through the internal light path recording of the light waveguide plate, three-dimensional light field modeling, and user position detection, the pixel light intensity and the light emission angle are dynamically adjusted to eliminate the imaging differences at different observation positions, so as to solve the problems proposed in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solution: An imaging system based on a light waveguide plate, comprising: a light waveguide control module and an imaging module; the light waveguide control module includes a display unit and an optical imaging unit, and the display unit is connected to the imaging module; the display unit is used to generate a light source image, receive signals from the imaging module and convert them into an initial image source; the optical imaging unit includes a light waveguide plate;

[0006] The imaging module includes an image optimization module, an optical path transmission module, a spatial modeling module, a parallax detection module, a dynamic correction module, a consistency evaluation module, and an adaptive output module;

[0007] The image optimization module is used to obtain an image signal, convert it into a two-dimensional light source image, and optimize it through an image preprocessing algorithm;

[0008] The optical path transmission module is used to enter the optimized light source image into the light waveguide plate through the display unit, and record the light propagation paths of each channel in the light waveguide plate to form a preliminary floating imaging light field;

[0009] The spatial modeling module establishes a three-dimensional light field model based on a spatial reconstruction algorithm and records the spatial distribution characteristics of parallax;

[0010] The parallax detection module detects the spatial positions of each user based on the spatial distribution characteristics of parallax, calculates the parallax error at each position, and forms an error data set;

[0011] The dynamic correction module adjusts the image pixel light intensity and outgoing direction of the display unit based on the error data set according to the consistency of observations at different positions to obtain an adjusted image;

[0012] The consistency evaluation module evaluates the image consistency of each viewing angle based on the adjusted image and generates feedback parameters for adjusting the light source image to control the output of the display unit;

[0013] The adaptive output module outputs a consistency floating imaging image with parallax adaptive compensation based on the feedback parameters.

[0014] In a preferred embodiment, the image preprocessing algorithm includes gray correction, sharpness enhancement, and edge enhancement;

[0015] The gray correction includes adjusting the gray value at each pixel position (x, y) through a non-linear gray mapping function f g to make the image gray level evenly distributed; representing the pixel gray level at (x, y) after gray correction through I g (x, y);

[0016]

[0017] where I ori (x, y) represents the pixel gray value at the two-dimensional plane coordinate position (x, y) in the original image; is the non-linear correction parameter;

[0018] The sharpness enhancement uses a sharpening algorithm based on the second-order Laplacian operator to perform spatial sharpening on the gray level of each pixel; assuming I s (x, y) represents the pixel gray level at the position (x, y) in the image after sharpness enhancement;

[0019]

[0020] where k s is the sharpness enhancement coefficient, and the sharpness enhancement coefficient is used to control the strength of the sharpening effect; is the second-order spatial derivative of the image gray level;

[0021] The edge enhancement is processed based on a non-linear edge enhancement operator (Edge(·)); representing through I opt(x, y) represents the pixel grayscale at the position (x, y) of the final optimized image after all preprocessing is completed;

[0022] I opt (x, y) = I s (x, y) + k e ·Edge[I s (x, y)];

[0023] where Edge[·] represents a non - linear edge detection function; k e is the edge enhancement intensity coefficient.

[0024] In a preferred embodiment, after the image is optimized by the image preprocessing algorithm, the two - dimensional optimized image I opt (x, y) will enter the inside of the waveguide plate through the display unit for multiple reflections to form the preliminary light field structure required for floating imaging; record the light propagation path data in each channel of the preliminary light field structure to describe the floating light field structure; use L i to represent the total propagation path length of the i - th ray after passing through the waveguide plate;

[0025]

[0026] where N i is the number of reflections experienced by the i - th ray in the micro - channels of the waveguide plate; d i,n represents the geometric size of the channel passed by the i - th ray after the n - th reflection; θ i,n represents the spatial angle of emergence of the i - th ray after the n - th reflection; α is the light energy attenuation coefficient of the micro - channel material.

[0027] In a preferred embodiment, the three - dimensional light field model is established based on the spatial reconstruction algorithm, and the spatial distribution characteristics of the parallax are recorded, including: using the spatial reconstruction algorithm according to the obtained preliminary light field structure to construct the three - dimensional light field model F 3D (x, y, z); the spatial reconstruction algorithm includes the NeRF light field reconstruction method based on ray tracing or neural network; in the case of L i , a three - dimensional spatial light field reconstruction function Ψ is used to reconstruct the three - dimensional spatial light field;

[0028]

[0029] where α i is the weight coefficient of the contribution of each ray to the overall three - dimensional light field; K is the total number of rays recorded in the waveguide plate.

[0030] In a preferred embodiment, based on the three-dimensional light field model established by the spatial modeling module, the imaging module obtains the coordinate positions of each observer in space in real time through the parallax detection module, measures the three-dimensional spatial positions of each user through the position sensor, thereby determining the viewing angles of each observer, performs error detection on the coordinate positions of each observer in space, calculates the difference between the actual image light intensity and the ideal image light intensity at each position in space, and defines it as the spatial parallax error; calculates the visual difference degree between the actually seen three-dimensional floating image and the ideal imaging at the spatial position point (u, v, w) of the j-th user through D j (u, v, w);

[0031]

[0032] where is the spatial area range where the j-th user actually views the floating image; G 实际 (u ′ , v ′ , w ′ ) is the three-dimensional light intensity distribution of the current actual spatial imaging; G 目标 (u ′ , v ′ , w ′ ) is the light intensity distribution of the target spatial floating imaging in the ideal state without parallax; Z j (u ′ , v ′ , w ′ ) is the spatial sensitivity weight function; (u ′ , v ′ , w ′ ) are the three-dimensional coordinate positions in space.

[0033] In a preferred embodiment, the dynamic correction module performs pixel-level correction according to the overall spatial parallax error of each user's location, adjusts the light ray angles and intensities emitted by each pixel of the image, so that users at different positions can see a consistent floating image;

[0034]

[0035] where P 调节 (m, n) represents the light intensity output of the (m, n)-th pixel after dynamic parallax correction; P 基础 (m, n) represents the basic pixel light intensity emitted by the display unit before parallax adjustment; represents the multiplication operation for K observing users; m and n respectively represent the horizontal and vertical coordinates of the pixels of the two-dimensional image; η j (m, n) is the parallax correction weight coefficient of the j-th user for the (m, n)-th pixel; ρ jis the spatial parallax error value for the j-th user; D j is the spatial distance between the line-of-sight center of the j-th user and the current pixel; δ j (m,n) is the sensitivity of the position change of the j-th user to the light intensity output of the pixel (m,n);

[0036] The consistency of the dynamically corrected floating image is evaluated by the consistency evaluation module from multiple user perspectives; the horizontal azimuth angle and vertical azimuth angle of the observer's line of sight are represented by α and β, and K(α,β) is constructed to represent the quantization value of the image consistency difference degree when the observer observes from different positions in space;

[0037]

[0038] where G 参考 (u,v) is the standard image light intensity of the ideal reference perspective; Q 频谱 (ρ,θ) is the spatial spectrum weight function; T(α,β) is the spatial observation area at different observation angles; represents the actual distribution of the image after dynamic parallax correction in the spatial frequency domain; is the spatial spectrum distribution of the reference image in the ideal state, ρ and τ are the spectrum space coordinates, and τ is used to represent the vertical spectrum axis of the standard reference image spectrum.

[0039] In a preferred embodiment, based on the quantization value of the consistency difference degree calculated by the consistency evaluation module from multiple user perspectives, the consistency evaluation module generates feedback adjustment parameters for controlling the pixel output of the display unit;

[0040]

[0041] where Y 反馈 (m,n) is the feedback adjustment parameter for the pixel (m,n); D 频谱差 (ρ,θ;m,n) is the difference degree between the pixel (m,n) and the ideal situation in the spatial frequency domain; (ρ,θ) is the polar coordinate representing the frequency domain; R max is the maximum value of the radius of the spatial spectrum analysis; Q 调整因子 (ρ,θ;m,n) represents the adjustment weight factor for the pixel (m,n), and the importance of the difference at the position (ρ,θ) to the final display adjustment decision; 2π is the complete angular range covered by the integral in the angular dimension of the spatial frequency domain;

[0042] According to the generated Y 反馈 (m,n), the imaging module regulates the light-emitting state of each pixel of the display unit and outputs a consistent floating image; formulate T 输出(m, n) is the complex optical field expression of the floating image after parallax compensation for the final output of the (m, n)th pixel;

[0043] T 输出 (m, n) = P 调节 (m, n)·exp[-j·(η m,n +Y 反馈 (m, n)·δ m,n )];

[0044] Where P 调节 (m, n) is the pixel light intensity determined after parallax correction; Y 反馈 (m, n) represents the feedback display adjustment parameter; j is the imaginary unit; η m,n is the initial setting value of the basic phase of the (m, n)th pixel; Y 反馈 (m, n) represents the fine phase adjustment control parameter of the (m, n)th pixel based on parallax evaluation feedback; δ m,n is the sensitivity coefficient of the phase adjustment of the (m, n)th pixel.

[0045] In a preferred embodiment, the optical waveguide plate is used to receive and process the initial light source image and form a medium-free holographic floating imaging through total internal reflection; the optical waveguide plate includes a glass substrate containing an air surface and a reflective surface, a second metal film layer, a magnetic material film layer, a first metal film layer, and a filtering layer; the included angle between adjacent two layers of the glass substrate containing an air surface and a reflective surface, the second metal film layer, the magnetic material film layer, the first metal film layer, and the filtering layer is 35 - 55 degrees.

[0046] Technical effects and advantages of the present invention:

[0047] 1. By recording the internal light path in the optical waveguide plate, three-dimensional optical field modeling, and user position detection, dynamically adjust the pixel light intensity and the light ray exit angle, eliminate the imaging differences at different observation positions, and improve the multi-view consistency;

[0048] 2. Adopt preprocessing algorithms such as gray correction, sharpness enhancement, and edge enhancement to improve the clarity of the input image, reduce the attenuation and noise in optical transmission, and enhance the stability of the final floating imaging;

[0049] 3. By real-time monitoring of the user position, calculating the parallax error, and dynamically adjusting the pixel light intensity and direction, ensure that the images are consistent when different users observe at different angles, and enhance the adaptability;

[0050] 4. Use spatial spectrum analysis to evaluate the imaging consistency, optimize the light source output based on the feedback parameters, enable the system to adaptively adjust, and enhance the visual accuracy and dynamic adaptation ability of the floating image;

[0051] 5. By recording the light propagation path, compensating for the microchannel structure error of the optical waveguide plate, and reducing the impact of manufacturing deviation on the imaging quality. Description of the Drawings

[0052] Figure 1 It is a schematic diagram of the system module of the present invention;

[0053] Figure 2 It is a schematic diagram of the optical waveguide plate structure of the present invention;

[0054] Legend Explanation

[0055] 1. Magnetic material film layer; 2. First metal film layer; 3. Second metal film layer; 4. Glass substrate; 5. Filter layer. Detailed Embodiments

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] Referring to the attached drawings of the specification Figure 1 and Figure 2 , an imaging system based on an optical waveguide plate according to an embodiment of the present invention includes: an optical waveguide control module and an imaging module; the optical waveguide control module includes a display unit and an optical imaging unit, and the display unit is connected to the imaging module; the display unit is used to generate a light source image, receive a signal from the imaging module and convert it into an initial image source;

[0058] The optical imaging unit includes an optical waveguide plate, and the optical waveguide plate is used to receive and process the initial light source image and form a medium-free holographic floating imaging through total internal reflection; the optical waveguide plate includes a glass substrate 4 with an air surface and a reflection surface, a second metal film layer 3, a magnetic material film layer 1, a first metal film layer 2, and a filter layer 5; the included angle between adjacent two layers of the glass substrate 4 with an air surface and a reflection surface, the second metal film layer 3, the magnetic material film layer 1, the first metal film layer 2, and the filter layer 5 is 35 - 55 degrees;

[0059] Wherein, the included angle between adjacent two layers refers to the reflection angle / refraction angle formed between the light and each functional layer or interface during the propagation process of the light inside the optical waveguide plate; the "included angle" referred to here is not the geometric stacking angle between the film layers, but the propagation angle of the light, similar to the "optical path design angle" in the prior art, and its influences are: optical path length, the number of stray lights, imaging clarity and consistency;

[0060] The reason for choosing an angle of 35°-55° is that in an optical waveguide plate, to ensure that light undergoes stable total internal reflection between the glass substrate (refractive index n≈1.5, denoted as n in the formula) 高 ) and air (refractive index n≈1.0, denoted as n in the formula) 低 ), the theoretical critical angle is approximately 41.8°. From the formula: where arcsin is the arcsine function; θ c is the critical angle, which refers to the minimum incident angle required for total internal reflection when light travels from a material with a high refractive index to a material with a low refractive index, and is the angle between the light ray and the normal;

[0061] If there is any reflection path with an angle lower than 41.8°, light will undergo partial penetration and transmission, resulting in light loss, stray light, and imaging failure. The purpose of choosing 35° as the lower limit of the angle is not to let light enter directly at this angle, but to consider: the adjustment range of the incident angle brought by the geometric tilt angle of the layer arrangement; in a complex multi-layer structure, the deviation angle of the actual reflection path of light will fluctuate by 5°-10° due to microstructural perturbations and material inhomogeneities;

[0062] If the angle is designed to be 35°, in the reflection geometry, it can ensure that the actual reflection angle is close to or higher than the critical angle. Even if there are microscopic defects or errors in the material, the total internal reflection condition is still satisfied;

[0063] Therefore, 35° represents a "safe lower limit" angle design redundancy range within a certain material refractive index range, and at the same time avoids the problem of light leakage caused by process fluctuations;

[0064] In the application of a 55° angle, as the angle increases, the incident angle of light between the film layers also increases. Although total internal reflection is easier to satisfy, it will bring three negative impacts:

[0065] Too long light path: The larger the angle, the geometrically longer the path that light travels in the waveguide, increasing light energy attenuation and delay;

[0066] Too many reflection times: A longer path means an increase in the number of reflections required for a single pixel to form an image, resulting in increased stray light, ghost images, and interference waves;

[0067] Limited spatial exit angle: At the limit angle, the exit direction is more concentrated at the waveguide boundary, easily causing poor imaging concentration and a narrow viewing angle. Especially in multi-view floating imaging, there will be inconsistent parallax.

[0068] According to the principles of geometric optics and the theory of multi-layer reflection, when the angle is close to or exceeds 55°, the reflection path of light in the optical waveguide plate is lengthened, resulting in an increase in the number of reflections, which easily causes stray light interference and the concentration of the outgoing direction, thereby reducing the imaging stability and multi-view consistency;

[0069] Therefore, 55° is selected as the upper limit value, which represents the physical angle at which the optical waveguide plate structure can maintain relatively low loss, multi-view consistency, and control stray light under the current glass refractive index and reflector reflectivity;

[0070] To sum up, the angle range of 35° - 55° is the structural design interval determined by comprehensively considering multi-dimensional factors such as material refractive index, total reflection critical conditions, optical path stability, reflection times control, and floating image consistency, and it is also the theoretical data that can be deduced based on common knowledge; among them, 35° is used to ensure the safety redundancy lower limit of total reflection, and 55° is used to control the feasible upper limit of reflection diffusion and stray light interference, with clear physical basis and engineering practice feasibility.

[0071] The imaging module includes an image optimization module, an optical path transmission module, a space modeling module, a parallax detection module, a dynamic correction module, a consistency evaluation module, and an adaptive output module;

[0072] The image optimization module is used to obtain an image signal, convert it into a two-dimensional light source image, and then optimize it through an image preprocessing algorithm; the image preprocessing algorithm includes gray correction, sharpness enhancement, and edge enhancement;

[0073] The optical path transmission module is used to enter the optimized light source image into the optical waveguide plate through the display unit, and record the light propagation paths of each channel in the optical waveguide plate to form a preliminary floating imaging light field;

[0074] The space modeling module establishes a three-dimensional light field model based on a space reconstruction algorithm and records the spatial distribution characteristics of parallax;

[0075] The parallax detection module detects the spatial position of each user based on the spatial distribution characteristics of parallax, calculates the parallax error at each position, and forms an error data set;

[0076] The dynamic correction module adjusts the image pixel light intensity and outgoing direction of the display unit according to the error data set based on the consistency of observations at different positions to obtain an adjusted image;

[0077] The consistency evaluation module evaluates the image consistency of each view based on the adjusted image and generates feedback parameters for adjusting the light source image to control the output of the display unit;

[0078] The adaptive output module outputs a consistent floating imaging image with parallax adaptive compensation based on the feedback parameters.

[0079] The image preprocessing algorithm includes gray correction, sharpness enhancement, and edge enhancement;

[0080] The gray correction includes adjusting the gray value of each pixel position (x, y) through a non-linear gray mapping function f g to make the gray distribution of the image uniform; representing the pixel gray value at (x, y) after gray correction by I g (x, y);

[0081]

[0082] where I ori (x, y) represents the pixel gray value at the two-dimensional plane coordinate position (x, y) in the original image; is a non-linear correction parameter, and its value range is between 0.4 and 2.5. By selecting different gamma values, the gray distribution balance of different regions of the image is achieved.

[0083] The sharpness enhancement adopts a sharpening algorithm based on the second-order Laplacian operator to perform spatial sharpening on the gray value of each pixel; assuming I s (x, y) represents the pixel gray value at the position (x, y) in the image after sharpness enhancement;

[0084]

[0085] where k s is the sharpness enhancement coefficient, and the sharpness enhancement coefficient is used to control the strength of the sharpening effect; is the second-order spatial derivative of the image gray value, and the second-order spatial derivative of the image gray value is used to locate the image detail and texture feature regions;

[0086] The edge enhancement is processed based on a non-linear edge enhancement operator (Edge(·)); representing the pixel gray value at the position (x, y) in the final optimized image after all preprocessing by I opt (x, y);

[0087] I opt (x, y) = I s (x, y) + k e ·Edge[I s (x, y)];

[0088] where Edge[·] represents a non-linear edge detection function, and the non-linear edge detection function includes being calculated using the Canny or Sobel operator; k e is the edge enhancement intensity coefficient, and the edge enhancement intensity coefficient is used to determine the obviousness of the edge enhancement effect.

[0089] After the image is optimized by the image preprocessing algorithm, the two-dimensional optimized image I opt (x, y) will enter the inside of the light waveguide plate through the display unit and be reflected multiple times to form the preliminary light field structure required for floating imaging; since the inside of the light waveguide plate is a large number of parallel microchannel structures, each microchannel will affect the light transmission path due to the slight differences in the process processing accuracy, and record the light propagation path data in each microchannel of the preliminary light field structure to describe the floating light field structure; through L i to represent the total length of the propagation path of the i-th ray after passing through the light waveguide plate;

[0090]

[0091] where N i is the number of reflections experienced by the i-th ray in the microchannels of the light waveguide plate; d i,n represents the geometric size of the microchannel passed by the i-th ray after the n-th reflection; θ i,n represents the spatial angle at which the i-th ray exits after the n-th reflection; α is the light energy attenuation coefficient of the microchannel material, and the light energy attenuation coefficient of the microchannel material is used to represent the intensity loss of the light after reflection.

[0092] The three-dimensional light field model is established based on the spatial reconstruction algorithm, and the spatial distribution characteristics of the parallax are recorded, including: using the spatial reconstruction algorithm according to the obtained preliminary light field structure to construct the three-dimensional light field model F 3D (x, y, z), F 3D (x, y, z) also represents the light field intensity at the position of the three-dimensional space coordinates (x, y, z); the spatial reconstruction algorithm includes the NeRF light field reconstruction method based on ray tracing or neural network; in the case of L i adopt the three-dimensional space light field reconstruction function Ψ to reconstruct the three-dimensional space light field;

[0093]

[0094] where the three-dimensional space light field reconstruction function Ψ[·] is a function obtained through neural network training or multi-view ray tracing; α i is the weight coefficient of the contribution of each ray to the overall three-dimensional light field; K is the total number of rays recorded in the light waveguide plate.

[0095] The imaging module is based on the three-dimensional light field model established by the spatial modeling module. It obtains the coordinate positions of each observer in space in real time through the parallax detection module, and measures the three-dimensional spatial positions of each user through a position sensor, which includes but is not limited to an infrared stereo camera or a depth sensor, so as to determine the viewing angles of each observer. Error detection is performed on the coordinate positions of each observer in space, and the difference between the actual image light intensity and the ideal image light intensity at each position in space is calculated, which is defined as the spatial parallax error; It is planned that D j D(u, v, w) represents the overall spatial parallax error of the position of the j-th user, and the visual difference degree between the actual three-dimensional floating image and the ideal imaging seen by the j-th user at the spatial position point (u, v, w) is calculated through D j (u, v, w);

[0096]

[0097] where is the spatial area range where the j-th user actually views the floating image; G 实际 (u ′ , v ′ , w ′ ) is the three-dimensional light intensity distribution of the current actual spatial imaging; G 目标 (u ′ , v ′ , w ′ ) is the light intensity distribution of the target spatial floating imaging in the ideal state without parallax; Z j (u ′ , v ′ , w ′ ) is the spatial sensitivity weight function, which is used to reflect the influence degree of the parallax error of the j-th user at the position (u ′ , v ′ , w ′ ). The more sensitive the position is, the higher its value; (u ′ , v ′ , w ′ ) is the three-dimensional spatial coordinate position, which corresponds to the relative position of the display device.

[0098] The dynamic correction module performs pixel-level correction according to the overall spatial parallax error of the position of each user, adjusts the light angle and intensity emitted by each pixel of the image, so that users at different positions can see a consistent floating image;

[0099]

[0100] where P 调节 (m, n) represents the light intensity output of the (m, n)-th pixel after dynamic parallax correction; P基础 (m, n) represents the base pixel intensity emitted by the display unit before parallax adjustment; Π is the product operation, and the product operation is used to emphasize the comprehensive correction effect in the case of multiple users; represents the product operation on K observed users; m and n respectively represent the horizontal and vertical coordinates of the pixels in the two-dimensional image; η j (m, n) is the parallax correction weight coefficient of the j-th user for the pixel (m, n), which represents the influence degree of the user's position on pixel adjustment; ρ j is the spatial parallax error value of the j-th user; D j is the spatial distance between the line-of-sight center of the j-th user and the current pixel; δ j (m, n) is the sensitivity of the position change of the j-th user to the light intensity output of the pixel (m, n);

[0101] The consistency of the floating image after dynamic correction is evaluated by the consistency evaluation module from multiple user perspectives; α and β represent the horizontal azimuth angle and vertical azimuth angle of the observer's line of sight, and K(α, β) is constructed to represent the quantization value of the image consistency difference degree when the observer observes from different positions in space;

[0102]

[0103] where G 参考 (u, v) is the standard image intensity of the ideal reference perspective; Q 频谱 (ρ, θ) is the spatial spectrum weight function, and the spatial spectrum weight function is used to represent the influence degree of spectrum characteristics on visual consistency; T(α, β) is the spatial observation area at different observation angles; represents the actual distribution of the image after dynamic parallax correction in the spatial frequency domain, and ρ and σ are the spatial frequency coordinates in the frequency domain; is the spatial spectrum distribution of the reference image in the ideal state, ρ and τ are the spectrum space coordinates, and τ is used to represent the vertical spectrum axis of the standard reference image spectrum to avoid conflict with the foregoing parameters; T represents the entire field of view involved in evaluating image consistency; in the numerator part of the formula of K(α, β), it represents the spectrum distribution difference of the adjusted image at different observation perspectives, and the denominator part is the reference normalization factor, that is, the spatial light intensity integral of the ideal image. The above formula is used to evaluate the consistency quality of the floating image from each user perspective and feedback the consistency evaluation data.

[0104] Based on the quantization value of the consistency difference degree calculated by the consistency evaluation module from multiple user perspectives, the consistency evaluation module generates feedback adjustment parameters for controlling the pixel output of the display unit;

[0105]

[0106] where Y 反馈 (m,n) is the feedback adjustment parameter for the pixel (m,n); D 频谱差 (ρ,θ; m,n) is the degree of difference between the pixel (m,n) and the ideal situation in the spatial frequency domain; (ρ,θ) are the polar coordinates representing the frequency domain; R max is the maximum value of the radius of the spatial frequency analysis, and the maximum value of the radius of the spatial frequency analysis represents the frequency spectrum evaluation range; Q 调整因子 (ρ,θ; m,n) represents the adjustment weight factor for the pixel (m,n), and the importance of the difference at the position (ρ,θ) to the final display adjustment decision; 2π is the complete angle range covered by the integral in the angular dimension of the spatial frequency domain; the above formula realizes the comprehensive evaluation of errors in different frequency ranges through integration, obtains the adjustment feedback data set, and guides the next output of the display unit;

[0107] According to the generated Y 反馈 (m,n), the imaging module regulates the light-emitting state of each pixel of the display unit and outputs a consistent floating image; It is proposed that T 输出 (m,n) is the complex optical field expression of the floating image after parallax compensation finally output by the (m,n)th pixel, which reflects the intensity and phase information of the light wave;

[0108] T 输出 (m,n) = P 调节 (m,n)·exp[-j·(η m,n + Y 反馈 (m,n)·δ m,n )];

[0109] where P 调节 (m,n) is the pixel light intensity determined after parallax correction; Y 反馈 (m,n) represents the feedback display adjustment parameter, and the feedback display adjustment parameter is used to adjust the spatial frequency characteristics of the light wave emitted by the pixel in real time; the introduction of the exponential function in the above formula describes the phase change of the light wave; j is the imaginary unit; η m,n is the initial setting value of the basic phase of the (m,n)th pixel; Y 反馈 (m,n) represents the fine phase adjustment control parameter of the (m,n)th pixel based on parallax evaluation feedback; δ m,n is the sensitivity coefficient of the phase adjustment of the (m,n)th pixel.

[0110] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An imaging system based on a light waveguide plate, comprising: Optical waveguide control module, imaging module; the optical waveguide control module includes a display unit and an optical imaging unit, and the display unit is connected to the imaging module; the display unit is used to generate a light source image, receive signals from the imaging module and convert them into an initial image source; the optical imaging unit includes an optical waveguide plate; It is characterized in that: The imaging module includes an image optimization module, an optical path transmission module, a spatial modeling module, a parallax detection module, a dynamic correction module, a consistency evaluation module, and an adaptive output module; The image optimization module is used to obtain an image signal, convert it into a two-dimensional light source image, and optimize it through an image preprocessing algorithm; The optical path transmission module is used to enter the optimized light source image into the optical waveguide plate through the display unit, and record the light propagation paths of each channel in the optical waveguide plate to form a preliminary floating imaging light field; The spatial modeling module establishes a three-dimensional light field model based on a spatial reconstruction algorithm and records the spatial distribution characteristics of parallax; The parallax detection module detects the spatial position of each user based on the spatial distribution characteristics of parallax, calculates the parallax error at each position, and forms an error data set; The dynamic correction module adjusts the image pixel light intensity and the outgoing direction according to the error data set based on the consistency of observations at different positions to obtain an adjusted image; The consistency evaluation module evaluates the image consistency of each viewing angle according to the adjusted image, and generates feedback parameters for adjusting the light source image to control the output of the display unit; The adaptive output module outputs a consistent floating imaging image with parallax adaptive compensation based on the feedback parameters.

2. The imaging system based on an optical waveguide plate according to claim 1, characterized in that: The image preprocessing algorithm includes gray correction, sharpness enhancement, and edge enhancement; The gray-scale correction includes adjusting the gray-scale value at each pixel position (x, y) through a non-linear gray-scale mapping function f g to make the gray-scale of the image evenly distributed; representing the pixel gray-scale at (x, y) after gray-scale correction by I g (x, y). where I ori (x, y) represents the pixel gray value at the two-dimensional plane coordinate position (x, y) in the original image; is a non-linear correction parameter; The sharpness enhancement adopts a sharpening algorithm based on the second-order Laplacian operator to perform spatial sharpening processing on the gray scale of each pixel; It is assumed that I s (x, y) represents the pixel gray scale of the image after sharpness enhancement at the position (x, y). where k s is the sharpness enhancement coefficient, which is used to control the strength of the sharpening effect; is the second-order spatial derivative of the image grayscale; The edge enhancement is processed based on a non-linear edge enhancement operator (Edge(·)); through I opt (x, y) represents the pixel gray value of the finally optimized image at the position (x, y) after all preprocessing is completed; I opt (x,y) = I s (x,y) + k e ·Edge[I s (x, y)]; where Edge[·] represents a non-linear edge detection function; k e is the edge enhancement intensity coefficient.

3. The imaging system based on an optical waveguide plate according to claim 2, characterized in that: After the image is optimized by the image preprocessing algorithm, the two-dimensional optimized image I opt (x, y) will enter the inside of the light waveguide plate through the display unit for multiple reflections to form the preliminary light field structure required for floating imaging; record the light propagation path data in each channel of the preliminary light field structure to describe the floating light field structure; through L i is used to represent the total propagation path length of the i-th ray after passing through the light waveguide plate; where N i is the number of reflections experienced by the i-th ray in the microchannel of the optical waveguide plate; d i,n represents the geometric size of the channel passed by the i-th ray after the n-th reflection; θ i,n represents the spatial angle at which the i-th ray exits after the n-th reflection; α is the light energy attenuation coefficient of the microchannel material.

4. The imaging system based on an optical waveguide plate according to claim 3, characterized in that: The three-dimensional light field model is established based on the space reconstruction algorithm to record the spatial distribution characteristics of parallax, including: constructing the three-dimensional light field model F 3D (x, y, z) according to the obtained preliminary light field structure by using the space reconstruction algorithm; the space reconstruction algorithm includes the NeRF light field reconstruction method based on ray tracing or neural network; in the case of based on L i a three-dimensional spatial light field reconstruction function Ψ is used to reconstruct the three-dimensional spatial light field; where α i is the weight coefficient of the contribution of each ray to the overall three-dimensional light field; K is the total number of rays recorded in the optical waveguide plate.

5. The imaging system based on an optical waveguide plate according to claim 4, characterized in that: The imaging module is based on the three-dimensional light field model established by the spatial modeling module. It obtains the coordinate positions of each observer in space in real time through the parallax detection module, measures the three-dimensional spatial positions of each user through position sensors, thereby determining the viewing angles of each observer, detecting errors for the coordinate positions of each observer in space, calculating the difference between the actual image light intensity and the ideal image light intensity at each position in space, and defining it as the spatial parallax error; formulate D j D(u, v, w) represents the overall spatial parallax error of the position of the j-th user. Through D j D(u, v, w), calculate the degree of visual difference between the actually seen three-dimensional floating image and the ideal imaging at the spatial position point (u, v, w) of the j-th user; where is the spatial region range where the j-th user actually views the floating image; G 实际 (u′, v′, w′) is the three-dimensional light intensity distribution of the current actual space imaging; G 目标 (u′, v′, w′) is the light intensity distribution of the target space floating imaging in the ideal state without parallax; Z j (u′, v′, w′) is the spatial sensitivity weight function; (u′, v′, w′) is the spatial three-dimensional coordinate position.

6. The imaging system based on an optical waveguide plate according to claim 5, characterized in that: The dynamic correction module performs pixel-level correction according to the overall spatial parallax error of the position of each user, adjusts the light angle and intensity of each pixel of the image, so that users at different positions can see a consistent floating image; Among which P 调节 (m,n) represents the light intensity output of the (m,n)-th pixel after dynamic parallax correction; P 基础 (m,n) represents the basic pixel light intensity emitted by the display unit before parallax adjustment; represents the multiplication operation for K observed users; m and n respectively represent the horizontal and vertical coordinates of the pixels in the two-dimensional image; η j (m, n) is the parallax correction weight coefficient of the j-th user for the (m,n)-th pixel; ρ j is the spatial parallax error value of the j-th user; D j is the spatial distance between the line-of-sight center of the j-th user and the current pixel; δ j (m,n) is the sensitivity of the position change of the j-th user to the light intensity output of the pixel (m,n); Evaluate the consistency of the floating image after dynamic correction from multiple user perspectives; use α and β to represent the horizontal azimuth angle and vertical azimuth angle of the observer's line of sight, and construct K(α,β) to represent the quantization value of the image consistency difference degree when the observer observes from different positions in space; where G 参考 (u, v) is the standard image intensity of the ideal reference perspective; Q 频谱 (ρ, θ) is the spatial spectrum weight function; T(α, β) is the spatial observation region at different viewing angles; represents the actual distribution of the image after dynamic parallax correction in the spatial frequency domain; is the spatial spectrum distribution of the reference image in the ideal state, ρ and τ are the spectrum space coordinates, and τ is used to represent the vertical spectrum axis of the standard reference image spectrum.

7. The imaging system based on an optical waveguide plate according to claim 6, characterized in that: Based on the quantization value of the consistency difference degree calculated by the consistency evaluation module from multiple user perspectives, generate feedback adjustment parameters for controlling the pixel output of the display unit through the consistency evaluation module; where Y 反馈 (m,n) is the feedback adjustment parameter for pixel (m,n); D 频谱差 (ρ,θ; m,n) is the degree of difference between pixel (m,n) and the ideal situation in the spatial frequency domain; (ρ,θ) is the polar coordinate representing the frequency spectrum domain; R max is the maximum value of the radius for spatial frequency spectrum analysis; Q 调整因子 (ρ,θ;m,n) represents the adjustment weight factor for the pixel (m,n), indicating the importance of the difference at the position (ρ,θ) for the final display adjustment decision; 2π is the complete angular range covered by the integral in the angular dimension of the spatial frequency spectrum domain; According to the generated Y 反馈 (m,n), the imaging module regulates the light-emitting state of each pixel of the display unit and outputs a consistent floating image; formulate T 输出 (m,n) is the complex optical field expression of the floating image after parallax compensation finally output by the (m,n)th pixel; T 输出 (m,n) = P 调节 (m,n)·exp[-j·(η m,n +Y 反馈 (m,n)·δ m,n )]; Among which P 调节 (m,n) is the pixel light intensity determined after parallax correction; Y 反馈 (m,n) represents the feedback display adjustment parameter; j is the imaginary unit; η m,n is the initial setting value of the basic phase of the (m,n)th pixel; Y 反馈 (m,n) represents the fine phase adjustment control parameter of the (m,n)th pixel based on parallax evaluation feedback; δ m,n is the sensitivity coefficient of the phase adjustment of the (m,n)th pixel.

8. The imaging system based on an optical waveguide plate according to any one of claims 1-7, characterized in that: The optical waveguide plate is used to receive and process an initial light source image and form a medium-free holographic floating imaging through total internal reflection; the optical waveguide plate includes a glass substrate (4) containing an air surface and a reflection surface, a second metal film layer (3), a magnetic material film layer (1), a first metal film layer (2), and a filtering layer (5); the included angle between adjacent two layers of the glass substrate (4) containing an air surface and a reflection surface, the second metal film layer (3), the magnetic material film layer (1), the first metal film layer (2), and the filtering layer (5) is 35-55 degrees.

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