Projection curtain light field display gain method and system used under ambient light

Abstract

The invention relates to the technical field of projection display, and discloses a projection curtain light field display gain method and system used under ambient light. According to the method, environment light data, projection curtain data and original output signals of projection equipment are collected in real time, and a dynamic light field distribution model is established after fusion processing. And based on the dynamic light field distribution model, adopting an adaptive genetic algorithm to optimize a compensation weight, generating a light field compensation parameter set, performing reverse compensation processing of brightness gain, contrast and chromaticity offset on an original output signal, and generating an enhanced projection signal. The system comprises a multi-source data acquisition module, a light field feature extraction module, a dynamic compensation calculation module, a signal enhancement processing module and a closed-loop feedback control module, ensures that the projection image keeps an optimal display effect under different ambient light conditions, and remarkably improves the watching experience of audiences.

Description

Technical Field

[0001] The present invention relates to the technical field of projection display, and particularly to a method and system for light field display gain of a projection screen under ambient light. Background Art

[0002] In stereoscopic projection display technology, the stereoscopic images output by projection devices are often significantly affected by ambient light. Especially in environments with complex and variable light, ambient light not only reduces the brightness of the projection image, but also weakens the contrast of the image and causes chromaticity shift, thus affecting the viewing experience of stereoscopic display. Although traditional stereoscopic projection display technology considers the influence of ambient light to a certain extent, most of them adopt fixed compensation methods and are difficult to adapt to the dynamic changes under different ambient light conditions. Especially in stereoscopic display application scenarios that require a high degree of realism and immersion, such as cinemas, exhibitions, virtual reality experiences, etc., the problem of ambient light interference is particularly prominent, and there is an urgent need for a solution that can adapt to ambient light changes in real time and effectively improve the stereoscopic display effect. Summary of the Invention

[0003] Aiming at the above-mentioned existing technical deficiencies, the purpose of the present invention is to provide a method and system for light field display gain of a projection screen under ambient light, and solve the problems of reduced brightness, weakened contrast and chromaticity shift caused by the susceptibility of stereoscopic projection display to ambient light in the prior art.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a method for light field display gain of a projection screen under ambient light, and the method includes: Collect ambient light data, projection screen data and the original output signal of the projection device in real time. The ambient light data includes spectral distribution data, light intensity distribution data and incident angle data, and the projection screen data includes real-time reflectivity parameters and scattering characteristic parameters; Fuse the ambient light data and the projection screen data, eliminate the interference of ambient light noise through time-domain filtering and spatial-domain correction, extract the superimposed light field characteristics formed by the ambient light on the surface of the projection screen, and establish a dynamic light field distribution model; Based on the dynamic light field distribution model, perform iterative calculation of compensation values, construct a three-dimensional compensation matrix including incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameter, optimize the compensation weight through an adaptive genetic algorithm, and generate a light field compensation parameter set for the current ambient light scene; Perform reverse compensation processing on the original output signal according to the light field compensation parameter set, adjust the brightness gain, contrast and chromaticity offset of the output signal, and generate an enhanced projection signal that is negatively correlated with the ambient light interference; The projection device outputs an enhanced projection signal, while establishing a closed-loop feedback mechanism to monitor the compensation effect in real time and update the compensation parameters periodically.

[0005] Preferably, in a possible implementation manner of the first aspect, the process of fusing the ambient light data and the projection screen data includes: Performing time-domain smoothing processing on the light intensity distribution data by using a sliding window mean filter, and combining with a Gaussian spatial domain filter to eliminate high-frequency noise; Performing dynamic calibration on the real-time reflectivity parameter of the projection screen, and separating the superimposed light field characteristics of the ambient light and the projection light through a multi-scale decomposition algorithm; Identifying the scattering characteristic distribution on the surface of the screen based on the region growing algorithm, and establishing a light field propagation path model in combination with the incident angle data; Mapping the light intensity, spectrum, incident angle and reflectivity parameter to a three-dimensional grid coordinate system to generate a dynamic light field distribution model including spatio-temporal correlation.

[0006] Preferably, in a possible implementation manner of the first aspect, the calculation formula of the dynamic light field distribution model is:

[0007] Wherein, is the light intensity on the surface of the screen at position at time , is the reflection characteristic parameter at position , and are respectively the ambient light and the projection light intensity at position at time , is the incident angle of the ambient light, is the position is the scattering characteristic parameter at the position.

[0008] Preferably, in a possible implementation manner of the first aspect, the iterative calculation process of the compensation value includes: Calculating the incident light attenuation coefficient according to the spatio-temporal distribution difference between the ambient light and the projection light, performing multi-dimensional interpolation in combination with the scattering characteristic parameter on the surface of the screen to obtain the scattering compensation factor, and simultaneously generating the reflection enhancement parameter through dynamic calibration of the reflectivity parameter; Constructing a three-dimensional compensation matrix including the incident light attenuation coefficient, the scattering compensation factor and the reflection enhancement parameter; Using an adaptive genetic algorithm to optimize the compensation weight, realizing global optimization of the parameter space, and performing layer-by-layer iterative optimization on the three-dimensional compensation matrix; Finally, generating a light field compensation parameter set including multi-dimensional compensation parameters according to the spatial distribution characteristics of the current ambient light scene.

[0009] Preferably, in a possible implementation manner of the first aspect, the calculation of the incident light attenuation coefficient satisfies the following relationship:

[0010] wherein, is the incident light attenuation coefficient at the three-dimensional grid point , is the ambient light intensity at the three-dimensional grid point at time , is the projected light intensity at the three-dimensional grid point at time , is the anti-zero constant, to is the sampling time window; The calculation process of the scattering compensation factor is:

[0011] wherein, is the scattering compensation factor at the three-dimensional grid point , is the intrinsic scattering coefficient of the curtain material, is the scattering parameter at the three-dimensional grid point , is the scattering intensity adjustment factor, represents the square of the two-norm of the ambient light intensity; The reflection enhancement parameter satisfies:

[0012] wherein, is the reflection enhancement parameter at the three-dimensional grid point , is the target reflectivity at the curtain surface , is the reflectivity adjustment coefficient.

[0013] Preferably, in a possible implementation manner of the first aspect, the objective function of the adaptive genetic algorithm is:

[0014] wherein, is the weight matrix, determined by the optical characteristics of the projection device, is the compensation parameter set, is the target light intensity distribution, is the Laplace smoothing operator, generated based on the curtain surface topology, is the penalty coefficient, is The transpose of

[0015] Preferably, in a possible implementation manner of the first aspect, the reverse compensation process includes: Per-pixel adjustment of the luminance gain of the output signal based on the incident light attenuation coefficient, contrast compensation for the high-frequency components of the image according to the scattering compensation factor, and at the same time dynamically expanding the color gamut boundary of the projection signal in combination with the reflection enhancement parameter; Calculating the chromaticity offset using the synergistic effect of the scattering compensation factor and the reflection enhancement parameter, and performing non-linear correction on the color space coordinates of the projection signal; Finally, perform multi-channel fusion processing on the image data after luminance gain adjustment, contrast compensation, and chromaticity correction to generate an enhanced projection signal that is negatively correlated with the ambient light interference.

[0016] Preferably, in a possible implementation manner of the first aspect, the adjustment formula for the chromaticity offset is:

[0017] Where represents the chromaticity offset at the three-dimensional grid point , is the chromaticity adjustment factor, and are respectively the scattering compensation factor and the reflection enhancement parameter of the corresponding grid point, is the non-linear adjustment index, represents the two-norm of the ambient light intensity.

[0018] Preferably, in a possible implementation manner of the first aspect, the implementation of the closed-loop feedback mechanism includes: After the projection signal is output, the actual display effect data on the screen surface is collected in real time through a light sensor; Calculate the peak signal-to-noise ratio and chromaticity difference degree of the compensated image. If the peak signal-to-noise ratio is lower than the threshold or the color difference exceeds the tolerance, trigger parameter update; Periodically re-execute the light field distribution modeling and light field compensation calculation.

[0019] In a second aspect, the present invention provides a projection screen light field display gain system for ambient light, and the system includes: A multi-source data acquisition module for real-time acquisition of ambient light data, projection screen data, and the original output signal of the projection device. The ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data, and the projection screen data includes real-time reflectivity parameters and scattering characteristic parameters; The light field feature extraction module is used to fuse the ambient light data and the projection screen data, eliminate the interference of ambient light noise through time-domain filtering and spatial-domain correction, extract the superimposed light field features formed by the ambient light on the surface of the projection screen, and establish a dynamic light field distribution model; The dynamic compensation calculation module performs iterative calculation of compensation values based on the dynamic light field distribution model, constructs a three-dimensional compensation matrix including the incident light attenuation coefficient, the scattering compensation factor, and the reflection enhancement parameter, optimizes the compensation weight through an adaptive genetic algorithm, and generates a light field compensation parameter set for the current ambient light scene; The signal enhancement processing module performs reverse compensation processing on the original output signal according to the light field compensation parameter set, adjusts the brightness gain, contrast, and chromaticity offset of the output signal, and generates an enhanced projection signal that is negatively correlated with the ambient light interference; The closed-loop feedback control module is used to output the enhanced projection signal by the projection device, and at the same time establish a closed-loop feedback mechanism to monitor the compensation effect in real time and update the compensation parameters periodically.

[0020] The beneficial effects of the present invention are as follows: By collecting the ambient light data, the projection screen data, and the original output signal of the projection device in real time, and performing fusion processing, a dynamic light field distribution model is established. Based on this model, an adaptive genetic algorithm is used to optimize the compensation weight, a light field compensation parameter set for the current ambient light scene is generated, and reverse compensation processing is performed on the original output signal for the brightness gain, contrast, and chromaticity offset, so as to generate an enhanced projection signal.

[0021] The present invention can not only significantly improve the brightness gain and contrast of the stereoscopic projection display, but also accurately correct the chromaticity offset, ensuring that the stereoscopic projection image can maintain the best display effect under different ambient light conditions. In addition, the closed-loop feedback mechanism established by the present invention can monitor the compensation effect in real time and update the compensation parameters periodically, further improving the stability and adaptability of the stereoscopic display, and bringing a more realistic and immersive stereoscopic viewing experience to the audience. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings without creative efforts based on these drawings.

[0023] Figure 1 This application provides a flow chart of a method for the light field display gain of a projection screen under ambient light.

[0024] Figure 2This application provides a structural diagram of a projection screen light field display gain system for ambient light.

[0025] Explanation of reference numerals: 1 - Multi-source data acquisition module, 2 - Light field feature extraction module, 3 - Dynamic compensation calculation module, 4 - Signal enhancement processing module, 5 - Closed-loop feedback control module. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying 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.

[0027] Embodiment 1: As Figure 1 shown, the present invention provides a projection screen light field display gain method for ambient light, including: Real-time collecting ambient light data, projection screen data, and the original output signal of the projection device. The ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data. The projection screen data includes real-time reflectivity parameters and scattering characteristic parameters.

[0028] In this embodiment, the collection of ambient light data is achieved through a multi-spectral sensor array distributed around the projection screen. The multi-spectral sensor array consists of high-precision light intensity sensors, narrow-band spectral analysis modules, and wide-angle optical lenses, and synchronously collects the ambient light spectral distribution data, dynamic light intensity distribution data, and incident angle data at each position on the surface of the projection screen. Specifically, the spectral distribution data is obtained by the narrow-band spectral analysis module to perform 16-channel discrete sampling on the visible light band of 400 - 700 nm to generate a normalized spectral energy distribution histogram; the light intensity distribution data is linearly measured in a wide dynamic range of 0.01 lux to 100,000 lux through a photosensitive element array combined with an adaptive integration circuit; the incident angle data is calculated by the wide-angle optical lens combined with a spot deformation analysis algorithm to obtain the azimuth angle and elevation angle of the ambient light source, and the angle resolution reaches 0.1°.

[0029] The acquisition of the projection screen data is achieved through a micro reflectivity sensor and a scattering characteristic detection device embedded in the screen substrate. Among them, the real-time reflectivity parameter is dynamically measured by combining pulsed laser ranging with the reflected light intensity ratio method. By periodically emitting 905nm near-infrared laser pulses on the screen surface and receiving their diffuse reflection signals, the real-time reflectivity parameters of each region are calculated according to the Lambertian reflection model, and the measurement frequency is 60Hz; the scattering characteristic parameters are obtained through an internal micro grating array combined with the Mie scattering theory inversion algorithm. The scattering phase function of the microscopic structure on the screen surface is fitted using the multi-angle scattered light intensity distribution data, and the wavelength-related scattering anisotropy factor is extracted.

[0030] The original output signal of the projection device is obtained in real time through the data capture module of the HDMI / SDI interface. The FPGA hardware decoder is used to analyze the brightness, contrast, and RGB color gamut coordinates of the original video stream, and the video stream frame data is aligned with the ambient light and screen data by the timestamp synchronization mechanism.

[0031] The ambient light data and the projection screen data are fused and processed. The ambient light noise interference is eliminated through time-domain filtering and spatial domain correction, the superimposed light field characteristics formed by the ambient light on the projection screen surface are extracted, and a dynamic light field distribution model is established.

[0032] In this embodiment, first, the light intensity distribution data is smoothed in the time domain. A moving average calculation is performed on the time-series light intensity data using a sliding window mean filter with a window length of 5 frames to eliminate the pulse noise generated by instantaneous strong light interference. Subsequently, combined with the standard deviation of the Gaussian spatial filter, a spatial convolution operation is performed on the light intensity data. The three-dimensional Gaussian kernel function is used to suppress the spatial high-frequency noise components and improve the signal-to-noise ratio of the light intensity data.

[0033] When dynamically calibrating the real-time reflectivity parameters of the projection screen, a three-layer wavelet decomposition is performed on the superimposed light field using the Haar wavelet basis, and the characteristic components of the ambient light and the projection light are separated in the frequency domain dimension. Specifically, the steady-state component of the ambient light is reconstructed through the low-frequency subband coefficients, and the dynamic details of the projection light are extracted using the high-frequency subband coefficients. At the same time, combined with the region growing algorithm, a spatial clustering analysis is performed on the scattering characteristics of the screen surface: the region with a standard deviation of the scattering parameter less than 0.05 is used as the seed point, and the adjacent grids with similar scattering characteristics are gradually merged through the eight-neighborhood expansion strategy, and finally a partition topology map containing anisotropic scattering characteristics is formed.

[0034] In the stage of modeling the light field propagation path, the incident angle parameter and the normal vector of the screen surface are geometrically projected and calculated. The ray tracing algorithm is used to simulate the reflection path of the ambient light on the screen surface to generate a dynamic light field distribution model:

[0035] Among them, is the surface light intensity of the time curtain at position ; is the reflection characteristic parameter at position ; and are respectively the ambient light and projection light intensity at position at time ; they are obtained from adjacent sensor data through the bilinear interpolation algorithm. is the incident angle of the ambient light, ; is the scattering characteristic parameter at position . This model realizes parameter refreshing every 50 ms through the dynamic update mechanism, and characterizes the non-linear superposition effect of ambient light and projection light on the curtain surface.

[0036] Based on the dynamic light field distribution model, iterative calculation of compensation values is carried out, a three-dimensional compensation matrix including the incident light attenuation coefficient, scattering compensation factor and reflection enhancement parameter is constructed, and the compensation weight is optimized through the adaptive genetic algorithm to generate a set of light field compensation parameters for the current ambient light scene.

[0037] In this embodiment, the iterative calculation process of compensation values is carried out based on the spatio-temporal correlation data output by the dynamic light field distribution model. First, the incident light attenuation coefficient is calculated according to the spatio-temporal distribution difference between ambient light and projection light, specifically realized through the light intensity ratio relationship of each spatio-temporal node in the three-dimensional grid coordinate system. For each three-dimensional grid point , its incident light attenuation coefficient is calculated to satisfy the following relational expression:

[0038] Among them, is the incident light attenuation coefficient at the three-dimensional grid point , is the ambient light intensity at the three-dimensional grid point at time , is the projection light intensity at the three-dimensional grid point at time , is the anti-zero constant, to is the sampling time window. The time window is set to the sliding sampling period of the last 100 ms, and the ambient light intensity and the projection light intensity are obtained through the bilinear interpolation module in the dynamic light field distribution model. The anti-zero constant is set to , which is used to avoid numerical instability caused by the denominator approaching zero. This coefficient characterizes the degree of suppression of ambient light on projection light. When the proportion of ambient light intensity increases, the value approaches 0, triggering a higher-intensity brightness compensation requirement.

[0039] The calculation process of the scattering compensation factor integrates the intrinsic characteristics of the curtain material and dynamic measurement data. For each grid point , the scattering compensation factor is generated by an exponential decay function:

[0040] where is the scattering compensation factor at the three-dimensional grid point , is the intrinsic scattering coefficient of the curtain material, is the scattering parameter at the three-dimensional grid point , is the scattering intensity adjustment factor, represents the square of the two-norm of the ambient light intensity. The curtain intrinsic scattering coefficient is preset to 0.82 through the material spectral database. The scattering parameter is measured in real time by the built-in micro grating array. The scattering intensity adjustment factor is adaptively adjusted to a dynamic value within the range of 0.75 - 1.25 according to the curtain surface topology. The two-norm square term in the formula is obtained by calculating the square of the modulus length of the intensity vector of the ambient light in the RGB three channels, enabling the scattering compensation factor to effectively suppress the composite interference of multi-spectral ambient light.

[0041] The reflection enhancement parameter is calculated using the hyperbolic tangent function to achieve non-linear adjustment, and its expression is:

[0042] where the target reflectivity is set to 0.95 according to the ideal reflection characteristics of the curtain material, and the reflectivity adjustment coefficient is calibrated to 0.3 through experiments. When the ambient light intensity exceeds the projection light intensity, the function output value approaches , so that the reflection enhancement parameter reaches the theoretical maximum value ; when the projection light dominates, the output value approaches , and the parameter value drops to , realizing dynamic two-way adjustment of the reflection characteristics.

[0043] After calculating each compensation parameter, the system constructs a three-dimensional compensation matrix containing , , . The dimension of this matrix is consistent with the spatial resolution (1920×1080) and the temporal sampling depth (10-frame buffer) of the dynamic light field distribution model. This matrix integrates three types of parameters into a unified data structure through tensor splicing technology, and each grid point corresponds to a parameter vector containing 24-bit floating-point numbers.

[0044] In the parameter optimization stage, an improved adaptive genetic algorithm is adopted, and its objective function is defined as:

[0045] Among them, is the weight matrix, which is determined by the optical characteristics of the projection device, is the compensation parameter set, is the target light intensity distribution, is the Laplacian smoothing operator, which is generated based on the topological structure of the curtain surface, is the penalty coefficient, is transpose. The weight matrix is determined by the optical modulation transfer function of the projection device and contains the RGB channel gain coefficients of each pixel point; the compensation parameter set is the vectorized representation of the three-dimensional compensation matrix; the target light intensity distribution is generated according to the CIE 1931 chromaticity specification of the international display measurement standard; the Laplacian smoothing operator is constructed based on the curvature data of the curtain surface, and its matrix element is assigned according to the reciprocal of the geodesic distance between adjacent grid points, and the penalty coefficient is dynamically adjusted within the range of 0.1 - 10 according to the signal-to-noise ratio.

[0046] When the algorithm is implemented, the initial population size is set to 200 individuals, and each individual gene is composed of the normalized values of the compensation parameters. The selection operation adopts the tournament mechanism, and the top 20% of the individuals with fitness in each generation of the population are selected to enter the mating pool. The crossover probability is adaptively adjusted between 0.6 - 0.9 according to the population diversity index, and the mutation operation adopts the Gaussian perturbation strategy, and the standard deviation linearly decays from 0.1 to 0.01 as the number of iterations increases. After each generation of evolution is completed, the system performs layer-by-layer iterative optimization on the three-dimensional compensation matrix, that is, the parameters of the X-Y plane are preferentially optimized in the spatial dimension, and then the temporal consistency correction is performed along the time axis direction. When the change amplitude of the objective function value is less than for 5 consecutive generations.When the maximum number of iterations is reached or 100 iterations are completed, the algorithm terminates and outputs the optical field compensation parameter set. This parameter set is finally encapsulated into a binary data packet containing the spatial coordinate mapping relationship and timestamp marking for the signal enhancement processing module to call.

[0047] Perform reverse compensation processing on the original output signal according to the optical field compensation parameter set, adjust the brightness gain, contrast, and chromaticity offset of the output signal, and generate an enhanced projection signal that is negatively correlated with the ambient light interference.

[0048] In this embodiment, the system first adjusts the brightness gain of each pixel of the original output signal through the incident light attenuation coefficient stored in the three-dimensional compensation matrix For each three-dimensional grid point , based on value, perform non-linear mapping on the brightness components of the RGB channels, and use a piecewise exponential function to achieve the coordinated adjustment of dark area enhancement and highlight suppression. Among them, the adjustment amplitude of the brightness gain of dark area pixels increases logarithmically with the decrease of value, while the adjustment slope of the highlight area is limited by the Sigmoid function to prevent overexposure.

[0049] In the contrast compensation stage, the system dynamically enhances the high-frequency components of the image according to the scattering compensation factor Decompose the original image into low-frequency subbands and high-frequency subbands through two-dimensional discrete wavelet transform, and apply a gain coefficient that is positively correlated with the value to the high-frequency detail components. This gain coefficient satisfies non-linear relationship, where is the calibrated adjustment index (typical value is 1.2 - 1.5), so that regions with large differences in scattering characteristics can obtain differential contrast compensation effects. At the same time, combined with the reflection enhancement parameter dynamically expand the color gamut boundary of the projection signal, by translating the RGB color gamut coordinates towards the edge direction of the CIE 1931 color space, and the expansion amount is dynamically determined by the product of and the current color gamut coverage rate, ensuring that wide color gamut display characteristics can still be maintained under ambient light interference.

[0050] The calculation of the chromaticity offset is achieved through the synergistic effect of the scattering compensation factor and the reflection enhancement parameter , and its adjustment formula is:

[0051] Where, represents the chromaticity offset at the three-dimensional grid point , is the chromaticity adjustment factor, and are the scattering compensation factor and the reflection enhancement parameter corresponding to the grid points, respectively, is the non-linear adjustment index, represents the two-norm of the ambient light intensity, is the chromaticity adjustment factor calibrated by the device (typical value 0.8 - 1.2), is the non-linear adjustment index (value range 1.0 - 2.0). The two-norm of the ambient light intensity strengthens the coupling effect of the scattering and reflection characteristics on chromaticity correction through the exponential operation of the two-parameter product term. At the same time, the intensity ratio of the ambient light and the projection light is introduced as a dynamic adjustment term, so that the chromaticity offset can adapt to the ambient light interference intensity. The calculated chromaticity offset acts on the CIELAB color space, and the and channels of the original projection signal are coordinate-translated through a non-linear transformation matrix to correct the chromaticity distortion caused by ambient light absorption.

[0052] After completing the independent correction in each dimension, the system uses multi-channel fusion technology to synthesize the processed brightness, contrast, and chromaticity data. During the fusion process, cross-interference between compensation dimensions is eliminated through the weighted least squares algorithm, and the weight matrix is dynamically adjusted according to the confidence of the compensation parameters. The finally generated enhanced projection signal ensures compliance with the physical limitations of the target display device through a gamut clipping module and is output to the optical engine of the projection device with a 12-bit quantization accuracy, forming a high-quality display image negatively correlated with the ambient light interference.

[0053] The projection device outputs an enhanced projection signal, and at the same time establishes a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

[0054] In this embodiment, the actual light field distribution data on the surface of the compensated projection screen is collected in real time through a high-sensitivity optoelectronic sensor array distributed at the edge of the projection screen. The sensor array consists of a 16-bit analog-to-digital converter and a wide-dynamic-range photodiode, and synchronously captures the brightness, chromaticity, and spectral characteristics at each spatial position at a sampling frequency of 200 Hz. After the collected data is preprocessed, the peak signal-to-noise ratio (PSNR) and chromaticity difference degree of the compensated image are calculated in parallel using the structural similarity index (SSIM) and the CIEDE2000 color difference formula. Among them, the PSNR is dynamically evaluated by comparing the mean square error between the original projection signal and the feedback light field in the YUV color space, and the chromaticity difference degree is calculated using the Euclidean distance in the CIE 1976 Lab* color space, while the influence coefficient of the sensitivity of the ambient light to specific wavelengths is weighted and considered.

[0055] When it is monitored that the PSNR is lower than the preset 30 dB or the chromaticity difference degree exceeds When an alarm is triggered, a three - level parameter update mechanism is automatically activated: First, the time - domain filtering window in the light field distribution model is dynamically shrunk, and the sampling period of the moving window mean filtering is compressed from 100 ms to 50 ms to improve the response speed; Subsequently, a fast genetic algorithm is enabled to locally optimize the compensation parameter set, reducing the population size to 50 individuals and adopting an elitist retention strategy to accelerate convergence; Finally, the optimized compensation parameters are injected into the signal processing pipeline through an incremental update method to ensure a smooth transition of the projected image. For normal operating conditions without an alarm trigger, the system establishes a periodic full - parameter update mechanism, re - executing the complete light field distribution modeling and compensation calculation process every 5 seconds. During the update process, a double - buffer technique is used to achieve atomic replacement of the compensation parameters, avoiding image flickering or tearing phenomena.

[0056] Embodiment 2: As Figure 2 shown, the present invention provides a light field display gain system for a projection screen under ambient light, including: A multi - source data acquisition module 1, which is used to collect ambient light data, projection screen data, and the original output signal of the projection device in real time. The ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data, and the projection screen data includes real - time reflectivity parameters and scattering characteristic parameters.

[0057] A light field feature extraction module 2, which is used to perform fusion processing on the ambient light data and the projection screen data, eliminate ambient light noise interference through time - domain filtering and spatial domain correction, extract the superimposed light field features formed by the ambient light on the projection screen surface, and establish a dynamic light field distribution model.

[0058] A dynamic compensation calculation module 3, which performs iterative calculation of compensation values based on the dynamic light field distribution model, constructs a three - dimensional compensation matrix including an incident light attenuation coefficient, a scattering compensation factor, and a reflection enhancement parameter, optimizes the compensation weights through an adaptive genetic algorithm, and generates a light field compensation parameter set for the current ambient light scene.

[0059] A signal enhancement processing module 4, which performs reverse compensation processing on the original output signal according to the light field compensation parameter set, adjusts the brightness gain, contrast, and chromaticity offset of the output signal, and generates an enhanced projection signal that is negatively correlated with the ambient light interference.

[0060] A closed - loop feedback control module 5, which is used to output the enhanced projection signal by the projection device, and at the same time establish a closed - loop feedback mechanism to monitor the compensation effect in real time and update the compensation parameters periodically.

[0061] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for enhancing the light field display of a projection screen under ambient light, characterized in that, The method includes: Collecting ambient light data, projection screen data, and the original output signal of the projection device in real time. The ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data. The projection screen data includes real-time reflectivity parameters and scattering characteristic parameters; Performing fusion processing on the ambient light data and the projection screen data, eliminating ambient light noise interference through time-domain filtering and spatial-domain correction, extracting the superimposed light field characteristics formed by the ambient light on the projection screen surface, and establishing a dynamic light field distribution model; Performing iterative calculation of compensation values based on the dynamic light field distribution model, constructing a three-dimensional compensation matrix including incident light attenuation coefficient, scattering compensation factor, and reflection enhancement parameter, optimizing the compensation weight through an adaptive genetic algorithm, and generating a light field compensation parameter set for the current ambient light scenario; Performing reverse compensation processing on the original output signal according to the light field compensation parameter set, adjusting the brightness gain, contrast, and chromaticity offset of the output signal, and generating an enhanced projection signal that is negatively correlated with the ambient light interference; The projection device outputs the enhanced projection signal, and at the same time establishes a closed-loop feedback mechanism to monitor the compensation effect in real time and periodically update the compensation parameters.

2. The projection screen light field display gain method for use under ambient light according to claim 1, characterized in that The process of performing fusion processing on the ambient light data and the projection screen data includes: Performing time-domain smoothing processing on the light intensity distribution data using a sliding window mean filter, and combining with a Gaussian spatial filter to eliminate high-frequency noise; Performing dynamic calibration on the real-time reflectivity parameters of the projection screen, and separating the superimposed light field characteristics of the ambient light and the projection light through a multi-scale decomposition algorithm; Identifying the scattering characteristic distribution on the screen surface based on the region growing algorithm, and establishing a light field propagation path model in combination with the incident angle data; Mapping the light intensity, spectrum, incident angle, and reflectivity parameters to a three-dimensional grid coordinate system to generate a dynamic light field distribution model including spatio-temporal correlation.

3. The method for enhancing the light field display gain of a projection screen under ambient light according to claim 2, wherein The calculation formula of the dynamic light field distribution model is: Among them, is the surface light intensity of the time curtain at position . is the reflection characteristic parameter at position . and are respectively the ambient light and projection light intensity at position at time . is the incident angle of the ambient light, and is the scattering characteristic parameter at position .

4. The method for the light field display gain of a projection screen under ambient light as claimed in claim 1, wherein, The iterative calculation process of the compensation value includes: Calculating the incident light attenuation coefficient according to the spatio-temporal distribution difference between the ambient light and the projection light, performing multi-dimensional interpolation based on the scattering characteristic parameters on the screen surface to obtain the scattering compensation factor, and at the same time generating the reflection enhancement parameter through dynamic calibration of the reflectivity parameter; Constructing a three-dimensional compensation matrix including the incident light attenuation coefficient, the scattering compensation factor, and the reflection enhancement parameter; Using an adaptive genetic algorithm to optimize the compensation weight, realizing global optimization of the parameter space, and performing layer-by-layer iterative optimization on the three-dimensional compensation matrix; Finally, generating a light field compensation parameter set including multi-dimensional compensation parameters according to the spatial distribution characteristics of the current ambient light scenario.

5. The method for enhancing the light field display gain of a projection screen under ambient light according to claim 4, wherein The calculation of the incident light attenuation coefficient satisfies the following relationship: Among them, is the incident light attenuation coefficient at the three-dimensional grid point , is the ambient light intensity at the three-dimensional grid point at time, is the projected light intensity at the three-dimensional grid point at time, is the anti-zero constant, to is the sampling time window; The calculation process of the scattering compensation factor is: Among them, is the scattering compensation factor at the three-dimensional grid point , is the intrinsic scattering coefficient of the curtain material is the scattering parameter at the three-dimensional grid point , is the scattering intensity adjustment factor represents the square of the two-norm of the ambient light intensity; The reflection enhancement parameter satisfies: Among them, the reflection enhancement parameter at the three-dimensional grid point, is the target reflectivity at the curtain surface, and is the reflectivity adjustment coefficient.

6. The method for enhancing the light field display gain of a projection screen under ambient light according to claim 5, wherein, The objective function of the adaptive genetic algorithm is: Among them, is the weight matrix, determined by the optical characteristics of the projection device, is the compensation parameter set, is the target light intensity distribution, is the Laplacian smoothing operator, generated based on the topological structure of the curtain surface, is the penalty coefficient, is the transpose of.

7. The projection screen light field display gain method for use under ambient light according to claim 5, wherein The reverse compensation processing includes: Performing pixel-by-pixel adjustment of the brightness gain of the output signal based on the incident light attenuation coefficient, performing contrast compensation on the high-frequency components of the image according to the scattering compensation factor, and at the same time dynamically expanding the gamut boundary of the projection signal in combination with the reflection enhancement parameter; Calculating the chromaticity offset using the synergistic effect of the scattering compensation factor and the reflection enhancement parameter, and performing non-linear correction on the color space coordinates of the projection signal; Finally, the image data after brightness gain adjustment, contrast compensation, and chromaticity correction is subjected to multi-channel fusion processing to generate an enhanced projection signal that is negatively correlated with ambient light interference.

8. The method for the light field display gain of the projection screen under ambient light according to claim 7, wherein The adjustment formula for the chromaticity offset is as follows: Among them, represents the chromaticity offset at the three-dimensional grid point, is the chromaticity adjustment factor, and are the scattering compensation factor and the reflection enhancement parameter of the corresponding grid point respectively, is the non-linear adjustment index, represents the two-norm of the ambient light intensity.

9. The method for enhancing the light field display gain of a projection screen under ambient light according to claim 1, wherein The implementation of the closed-loop feedback mechanism includes: After the projection signal is output, the actual display effect data on the surface of the projection screen is collected in real time by an optical sensor; Calculate the peak signal-to-noise ratio and chromaticity difference of the compensated image. If the peak signal-to-noise ratio is lower than the threshold or the color difference exceeds the tolerance, parameter update is triggered; Periodically re-execute the optical field distribution modeling and optical field compensation calculation.

10. A projection screen light field display gain system for ambient light, characterized in that, The system includes: A multi-source data acquisition module for collecting ambient light data, projection screen data, and the original output signal of the projection device in real time. The ambient light data includes spectral distribution data, light intensity distribution data, and incident angle data. The projection screen data includes real-time reflectivity parameters and scattering characteristic parameters; An optical field feature extraction module for fusing the ambient light data and the projection screen data, eliminating ambient light noise interference through time-domain filtering and spatial-domain correction, extracting the superimposed optical field features formed by the ambient light on the surface of the projection screen, and establishing a dynamic optical field distribution model; A dynamic compensation calculation module for performing iterative calculation of compensation values based on the dynamic optical field distribution model, constructing a three-dimensional compensation matrix including the incident light attenuation coefficient, scattering compensation factor, and reflection enhancement parameter, optimizing the compensation weight through an adaptive genetic algorithm, and generating an optical field compensation parameter set for the current ambient light scenario; A signal enhancement processing module for performing reverse compensation processing on the original output signal according to the optical field compensation parameter set, adjusting the brightness gain, contrast, and chromaticity offset of the output signal, and generating an enhanced projection signal that is negatively correlated with ambient light interference; A closed-loop feedback control module for outputting the enhanced projection signal by the projection device, and at the same time establishing a closed-loop feedback mechanism to monitor the compensation effect in real time and update the compensation parameters periodically.

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