Single hologram generation method, apparatus and device, and storage medium

Abstract

The invention relates to the field of optical display, and discloses a single hologram generation method, device and equipment and a storage medium, and the method comprises the steps: obtaining the target amplitude distribution of a target image corresponding to each monochromatic channel in three-primary-color channels; by adding a scattering phase term to the target amplitude distribution, determining a target complex amplitude constraint of the target image; carrying out convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate a sequence-superposed initial hologram; and generating a target hologram by using the initial hologram in combination with adaptive constraint and a phase soft quantization method. Through the implementation of the scheme of the invention, the finally output target hologram can realize the display of a full-color image under the illumination of white light mixed by red, green and blue, the information capacity of a single hologram is improved to the maximum extent, and the requirements of multi-wavelength encryption and display are met.

Description

Technical Field

[0001] The present application relates to the field of optical display, and in particular to a method, device, equipment and storage medium for generating a single hologram. Background Art

[0002] Computer-generated holography is a technology that generates computer-generated holograms through numerical calculations. It can record and reproduce the amplitude and phase information of light waves and is the product of the combination of optics and information technology. Traditional holography relies on laser interference recording, while computer-generated holography breaks away from the limitations of physical recording and generates holograms directly on computers through diffraction algorithms, neural networks and other methods, thus greatly expanding its application potential in the fields of modern display and optics.

[0003] At present, the existing methods for generating computer-generated holograms are usually designed for a single wavelength, that is, a single hologram can only form a monochromatic diffraction image of the target size at the expected position under illumination of a single working wavelength. When multi-wavelength illumination (such as white light illumination mixed with red, green and blue) is used, severe chromatic aberration will result. The single-wavelength characteristics of a single hologram significantly limit its information capacity. In color holographic display, in order to achieve color images, it is necessary to switch multiple holograms and assist with equipment such as electronic shutters. Summary of the invention

[0004] The present application provides a single hologram generation method, device, equipment and storage medium, which are used to solve the problem that the hologram generation algorithm in the related art is mainly aimed at a single wavelength working mode and cannot meet the multi-wavelength display requirements.

[0005] The first aspect of the present application provides a single hologram generation method, the single hologram generation method comprising: Obtain the target amplitude distribution of the target image corresponding to each monochrome channel in the three primary color channels; Determining a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution; Perform convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate an initial hologram of sequence superposition; A target hologram is generated by performing adaptive constraints and phase soft quantization on the initial hologram.

[0006] Optionally, in a first implementation of the first aspect of the present application, the step of determining a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution includes: The above target complex amplitude constraint is calculated by the following formula: , in, is the optical vector perpendicular to the diffraction propagation direction of the target image, is the target complex amplitude constraint, is the target amplitude distribution, It is a random scattering phase with scattering properties, i is an imaginary unit, j=R,G,B, representing the three colors of red, green and blue.

[0007] Optionally, in a second implementation of the first aspect of the present application, the step of performing convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram includes: Determine the initial field distribution in the principal plane corresponding to each monochromatic channel; Acquire a first diffraction field distribution of a display surface corresponding to the main plane according to the initial field distribution; wherein the first diffraction field distribution is a diffraction field distribution of a first large iterative cycle; Replacing a first amplitude distribution corresponding to the first diffraction field distribution according to the target complex amplitude to determine a first complex amplitude distribution corresponding to the first amplitude distribution; Reversely propagate the first complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels; Performing sequential superposition on holograms generated corresponding to the first complex amplitude distribution on the main plane to obtain a first hologram; The initial hologram is determined by performing an iterative cycle of a preset number of iterations according to the first hologram.

[0008] Optionally, in a third implementation of the first aspect of the present application, the step of converging all the target complex amplitude constraints and determining first complex amplitude distributions corresponding to all the target complex amplitude constraints respectively includes: The first complex amplitude distribution is calculated by the following formula: , , in, is the magnification of the display surface where the target image is located relative to the main plane, is the wavelength of the incident light, is the propagation distance, is the frequency domain coordinate, is the optical vector of the display surface, is the optical vector of the principal plane, the operator represents the two-dimensional Fourier transform, the operator represents the two-dimensional inverse Fourier transform, represents the first diffraction field distribution calculated by the variable scale diffraction algorithm, represents the target complex amplitude constraint, represents the first complex amplitude distribution after constraint, angle function represents the phase distribution in the complex amplitude distribution, and exp represents the exponential function with the natural constant e as the base.

[0009] Optionally, in a fourth implementation of the first aspect of the present application, before the step of generating a target hologram by adaptively constraining the initial hologram and performing phase soft quantization, the step further includes: Determining a quantization level of a phase value in the initial hologram according to a preset quantization step size and a tolerance value; Determining a quantized value of the phase value according to the quantization level; The quantization level of the phase value is determined according to the quantization value.

[0010] Optionally, in a fifth implementation of the first aspect of the present application, the step of generating a target hologram by adaptively constraining the initial hologram and performing phase soft quantization includes: Soft quantizing the initial field distribution according to the quantization level; Acquire a second diffraction field distribution according to the initial field distribution after soft quantization; wherein the second diffraction field distribution is the diffraction field distribution of the second largest iterative cycle; Converging a second amplitude distribution corresponding to the second diffraction field distribution, and determining an adaptive complex amplitude distribution corresponding to the second amplitude distribution; Propagate the adaptive complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels; Sequentially superimposing the holograms generated corresponding to the adaptive complex amplitude distribution on the main plane to obtain a second hologram; The second hologram is iterated based on the tolerance value to generate the target hologram.

[0011] Optionally, in a sixth implementation of the first aspect of the present application, the method further includes: Performing separate imaging on each monochromatic channel of the three primary color channels at different diffraction distances; Under the illumination of RGB mixed white light, detect whether there is information crosstalk between each monochrome channel; If there is no information crosstalk between the monochromatic channels, a single hologram is output at the same diffraction distance with the same magnification; If there is information crosstalk between the monochromatic channels, the step of determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution is performed.

[0012] A second aspect of the present application provides a single hologram generation device, the single hologram generation device comprising: An acquisition module is used to acquire the target amplitude distribution of the target image corresponding to each monochrome channel in the three primary color channels; A determination module, configured to determine a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution; A first generating module, used for performing convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate an initial hologram of sequence superposition; The second generating module is used to generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram.

[0013] A third aspect of an embodiment of the present application provides an electronic device, comprising a memory and a processor, wherein the processor is used to execute a computer program stored in the memory, and when the processor executes the computer program, it implements each step of the single hologram generation method provided in the first aspect of the embodiment of the present application.

[0014] The fourth aspect of the embodiments of the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the single hologram generation method provided in the first aspect of the embodiments of the present application are implemented.

[0015] In summary, according to a single hologram generation method, device, equipment and storage medium provided by the scheme of the present application, the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels is obtained; the target complex amplitude constraint of the target image is determined by adding a scattering phase term to the target amplitude distribution; each monochromatic channel is converged and iterated according to the target complex amplitude constraint to generate a sequence superimposed initial hologram; the target hologram is generated by adaptively constraining and softly quantizing the initial hologram. Through the implementation of the scheme of the present application, the target image is sequentially superimposed and softly quantized according to the desired target complex amplitude constraints corresponding to the imaging of each monochromatic channel in the three primary color channels, so that the target hologram finally outputted can realize full-color image display under multi-wavelength mixed illumination, maximizing the information capacity of a single hologram and meeting the needs of multi-wavelength display. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a flow chart of a method for generating a single hologram provided in an embodiment of the present application; Figure 2 A schematic diagram of generating an initial hologram in a single hologram generating method provided in an embodiment of the present application; Figure 3 A schematic diagram of generating a target hologram in a single hologram generating method provided in an embodiment of the present application; Figure 4A schematic diagram of a program module of a single hologram generating device provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0018] In order to solve the problem that the hologram generation algorithm in the related art is mainly aimed at the single-wavelength working mode and cannot meet the multi-wavelength display requirements, the embodiment of the present application provides a single hologram generation method, such as Figure 1 The schematic diagram of the flow chart of the single hologram generation method provided in this embodiment includes the following steps: Step 110: Obtain the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels.

[0019] Specifically, it can be understood that the target amplitude distribution describes the brightness or intensity distribution of each pixel in the image. In digital image processing, the amplitude usually corresponds to the grayscale value of the image. Therefore, determining the target amplitude distribution is actually determining the grayscale distribution of the image. In this embodiment, for the target image generated by each color channel, its corresponding amplitude distribution needs to be determined, wherein the monochrome image of each channel can be set to different sizes, located at different positions, and at different diffraction distances. The wavelengths corresponding to the three channels are (where j=R,G,B, representing red, green, and blue), the specific wavelength value can be set according to the actual illumination wavelength. After determining the target image, the target image is grayed, and the target amplitude distribution of the monochrome channel can be obtained by calculating the pixel value distribution of the grayed image.

[0020] Step 120: Determine a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution.

[0021] Specifically, after determining the target amplitude distribution corresponding to the target image of each channel, a phase term is added to it to form a complex amplitude constraint, thereby obtaining the target complex amplitude constraint corresponding to the target object. For example, for the amplitude distribution of the red channel, a corresponding random phase distribution can be generated. This phase distribution can be a uniformly distributed random number or a phase function with a certain specific pattern. Then, the amplitude distribution and the phase distribution are combined to form a complex amplitude distribution. The added phase term gives the constraint certain scattering characteristics, which can effectively reduce the depth of focus of the image and significantly reduce the information crosstalk between diffraction images at different diffraction distances, while maintaining the quality of the expected image.

[0022] In an optional implementation of this embodiment, the calculation formula of the target complex amplitude constraint is: , in, is the optical vector perpendicular to the diffraction propagation direction of the target image, is the target complex amplitude constraint, is the target amplitude distribution, is the random scattering phase, i is an imaginary unit, and the target complex amplitude constraint is expressed as the expected complex amplitude distribution of the hologram during the iteration process. It can be understood that the random scattering phase refers to the randomness of the phase change of the light wave after scattering due to the random distribution and property differences of the scatterers (such as particles, microstructures, etc.) during the random scattering process.

[0023] Step 130: perform convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate an initial hologram of sequence superposition.

[0024] Specifically, in this embodiment, it should be noted that the convergence iteration of the target complex amplitude constraint of the target image in different monochromatic channels can be performed simultaneously or one by one. During the iteration process, the complex amplitude of the target image on the main plane needs to be propagated to the display surface through mathematical transformation (such as Fourier transform), and the amplitude distribution of the target image on the display surface is replaced with the constrained complex amplitude distribution, and the modified complex amplitude is reversely propagated from the display surface back to the main plane, and the phase part of the complex amplitude obtained by reverse propagation is retained on the main plane. After each iteration, it is checked whether the complex amplitude distribution meets the convergence standard. The convergence standard can be that the error of the amplitude distribution is less than a certain threshold, or the stability of the phase distribution reaches a certain degree. When the complex amplitude distribution meets the convergence standard, the iteration process is terminated. At this time, a phase distribution corresponding to the amplitude distribution of the target image is obtained, and this phase distribution corresponds to a hologram. Then, the holograms of each monochromatic channel are superimposed to obtain an initial single hologram.

[0025] In an optional implementation of the present embodiment, the steps of performing convergence iterations on each monochromatic channel according to a target complex amplitude constraint to generate a sequence-superimposed initial hologram include: determining an initial field distribution in a principal plane corresponding to each monochromatic channel; obtaining a first diffraction field distribution of a display surface corresponding to the principal plane according to the initial field distribution; replacing a first amplitude distribution corresponding to the first diffraction field distribution according to the target complex amplitude to determine a first complex amplitude distribution corresponding to the first amplitude distribution; reversely propagating the first complex amplitude distribution back to the principal plane corresponding to each monochromatic channel; sequentially superimposing holograms generated corresponding to the first complex amplitude distribution on the principal plane to obtain a first hologram; and performing an iterative loop for a preset number of iterations according to the first hologram to determine the initial hologram.

[0026] Specifically, in this embodiment, for each monochromatic channel (such as red, green, and blue channels), an initial field distribution is determined on the corresponding main plane (usually the object plane or the input plane), and the distribution includes amplitude and phase values, wherein the initial field distribution can be a complex-valued field with a random phase and an amplitude of 1 everywhere, and the expression formula corresponding to the initial field distribution can be expressed as: , in, Indicates the generation of an M×N matrix, where all matrix elements are random values ​​between 0 and 1, and exp represents an exponential function with the natural constant e as the base. Using the principles of wave optics (such as Fresnel diffraction, Fraunhofer diffraction, etc.), the initial field distribution of each monochromatic channel on the main plane is propagated to the corresponding display surface (usually the observation plane or the output plane) to obtain the first diffraction field distribution, where the diffraction field distribution is an expression describing the distribution of the electromagnetic field (usually amplitude and phase) in space during the diffraction process of light, and is the specific manifestation of the complex amplitude distribution in the diffraction phenomenon. This diffraction field distribution is the starting point of the first large iteration cycle. In the first diffraction field distribution of each monochromatic channel, the first amplitude distribution corresponding to the target image is found, and the first amplitude distribution is converged using an iterative algorithm (such as the GS algorithm based on the variable scale diffraction algorithm) until the convergence criterion of the target complex amplitude constraint is met, and the phase term obtained by the diffraction calculation during the replacement process remains unchanged. After convergence, the first complex amplitude distribution corresponding to the first amplitude distribution is obtained, and the first complex amplitude distribution of each monochrome channel is back-propagated from the display surface to its corresponding main plane. This step is a feedback step in the iterative process, which allows the algorithm to further adjust the first complex amplitude distribution on the main plane. On the main plane of each monochrome channel, a corresponding hologram is generated according to the first complex amplitude distribution. Then, these holograms are sequentially superimposed in a certain way (such as weighted summation) to obtain a first hologram, at which time the hologram has been superimposed from a monochrome hologram to a color hologram. The first hologram is further iterated using an iterative algorithm (such as the GS algorithm or other improved algorithms) until a preset number of iterations is reached or a certain convergence criterion is met. Each iteration adjusts the hologram according to the target complex amplitude constraint. Through continuous iteration, the performance of the hologram is optimized and the quality of the online image is improved.

[0027] Optionally, in the process of converging all target complex amplitude constraints and determining first complex amplitude distributions corresponding to all target complex amplitude constraints, the first complex amplitude distribution may be calculated by the following formula: , (1) , in, is the magnification of the display surface where the target image is located relative to the main plane, is the wavelength of the incident light, is the propagation distance, is the frequency domain coordinate, is the optical vector of the display surface, is the optical vector of the principal plane, the operator represents the two-dimensional Fourier transform, the operator represents the two-dimensional inverse Fourier transform, represents the first diffraction field distribution calculated by the variable scale diffraction algorithm, represents the target complex amplitude constraint, represents the first complex amplitude distribution after constraint, angle function represents the phase distribution in the complex amplitude distribution, exp represents the exponential function with the natural constant e as the base, and in numerical calculation, the two-dimensional Fourier transform is realized by discrete fast Fourier transform (FFT).

[0028] Optional, such as Figure 2 As shown, in the first large iteration cycle, Spread R The distance reaches the R plane (i.e. the display surface), and the diffraction field distribution is obtained Keeping the phase information unchanged, the field distribution is replaced by the desired first complex amplitude distribution, and then reversely propagated back to the main plane, replacing the amplitude with 1 and keeping the phase distribution unchanged, thus obtaining a monochrome hologram of the red channel. It should be noted that in the first large iteration cycle, formula (1) can be simplified to: , Among them, u represents the initial target image, is the number of pixels in the horizontal or vertical direction, is the pixel size of the input surface, is the pixel size of the output surface, i.e., the image surface, i.e., the above-mentioned monochrome hologram The evolution process can be expressed as: , (2) , (3) , (4) , (5) Among them, in formula (2) is the pixel size of the main plane, is the pixel size of the R plane in the red channel, N is the number of pixels in the horizontal or vertical direction, and formulas (4) and (5) represent the hologram obtained after the desired first complex amplitude distribution is reversely propagated back to the main plane.

[0029] Similarly, in the same large iteration loop, for the green channel, Spread G The distance reaches the G plane and the diffraction field distribution is obtained , keep the phase information unchanged, replace the entire complex amplitude distribution with the desired first complex amplitude distribution. Backward propagation back to the main plane, replace the amplitude with 1, and keep the phase distribution unchanged: , , , , In the same large iteration loop, for the blue channel, After propagating zB distance to reach plane B, we get the diffraction field distribution Keeping the phase information unchanged, replace the field distribution with the desired first complex amplitude distribution. Backward propagation back to the principal plane, replace the amplitude with 1, keeping the phase distribution unchanged: , , , , The three holograms obtained , , Perform sequence superposition and complete one iteration: , , During the sequence superposition process, , , The coefficients of can be any preset positive number other than 1. The purpose of setting their coefficients to 1 is to make the three holograms have the same weight. If the three holograms require different weights, the coefficients can be changed as needed. As the input of the next iteration cycle. Set the number of iterations, or set the evaluation index, and get the value after all iterations are completed. This is the initially optimized hologram. The generation steps are as follows Figure 2 shown.

[0030] Step 140: Generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram.

[0031] Specifically, it should be noted that in the first large cycle, the preliminary hologram is generated only by simple sequence superposition. In order to ensure the fidelity and quality of the finally generated holographic image, the preliminary hologram needs to be further optimized. Therefore, in this embodiment, the phase value of the preliminary hologram is soft-quantized. Through soft quantization, the preliminary hologram obtains a more stable diffraction field distribution when it reaches the target plane (including R plane, G plane and B plane). Then, the improved Fourier domain adaptive constraint is used as a new constraint to constrain the complex amplitude distribution in the diffraction field distribution, and three optimized holograms are obtained and sequenced. Superposition is performed, and one iteration is completed. After the second large iterative cycle is completed, the final target hologram is obtained.

[0032] In an optional implementation of the present embodiment, before the step of generating a target hologram by soft quantizing the initial hologram, it also includes: determining the quantization level of the phase value in the initial hologram according to a preset quantization step and a tolerance value; determining the quantization value of the phase value according to the quantization level; determining the quantization level of the phase value according to the above quantization value.

[0033] Specifically, in this embodiment, a soft quantization operation is performed on the phase values, dividing them into discrete levels according to the step size and the tolerance value (kace). The quantization levels are mapped to integer multiples of the increment value, where each phase is assigned a specific quantization level according to its value relative to the step size and the tolerance. Let θ represent the phase to be quantized, Z represent the number of quantization steps, and kace represent the tolerance factor. The step height can be expressed as: , in, is the quantization step size. For each phase value θ at position r in the matrix, the quantized value It is calculated based on the nearest quantization level within the tolerance defined by kace, and its calculation formula is: , This quantization is adjusted by a tolerance value kace. If the phase θ is within the tolerance window around the quantization level n, then Given a close The value of and fine-tuning according to kace. Specifically: , The function iterates all phase elements in the input matrix and performs quantization on each phase element to obtain a more stable diffraction field distribution. Indicates that soft quantization operation is performed on u.

[0034] In an optional implementation of this embodiment, the calculation formula corresponding to the improved Fourier domain adaptive constraint is: , in, is the energy scaling factor, SW represents the signal area, that is, the diffraction field area occupied by the target image, is the scaling factor, whose value is in the range of -1 to 1, j=R,G,B, representing the three colors of red, green and blue. It should be noted that The adaptive constraint corresponding to the target complex amplitude constraint in the first large cycle further improves the fidelity of the constraint process in the cycle by improving the target complex amplitude.

[0035] In an optional implementation of the present embodiment, the step of generating a target hologram by soft quantizing the initial hologram includes: soft quantizing the initial field distribution according to the quantization level; obtaining a second diffraction field distribution according to the softly quantized initial field distribution; converging the second amplitude distribution corresponding to the second diffraction field distribution, and determining the adaptive complex amplitude distribution corresponding to the second amplitude distribution; propagating the adaptive complex amplitude distribution back to the main plane corresponding to each monochromatic channel; sequentially superimposing the holograms generated corresponding to the adaptive complex amplitude distribution on the main plane to obtain a second hologram; iterating the second hologram based on the tolerance value to generate a target hologram.

[0036] Specifically, in this embodiment, the soft quantization operation of the initial field distribution has been described in the above embodiment. Figure 3 As shown, taking the R plane as an example, when kace=0.1, the R channel is processed and the hologram After soft quantization optimization, propagate z R The distance is diffracted to the R plane, and the second diffraction field distribution is obtained , keeping the phase information unchanged, replacing the second amplitude distribution of the field distribution with the desired adaptive constraint, that is, using the improved Fourier domain adaptive constraint to constrain the second amplitude distribution (i.e. converge), thereby obtaining the adaptive complex amplitude distribution corresponding to the second amplitude distribution, and backpropagating the adaptive complex amplitude distribution of each monochrome channel from the display surface back to its corresponding main plane, and generating the corresponding hologram on the main plane of each monochrome channel according to the adaptive complex amplitude distribution. The specific expression is: , (6) , (7) , (8) , (9) , (10) Among them, formula (6) is for the hologram , formulas (7) and (8) represent the diffraction field distribution including the adaptive complex amplitude distribution on the display surface obtained by constraining the improved Fourier domain adaptive constraint, and formulas (9) and (10) represent the second hologram obtained by back-propagating the diffraction field distribution of the red channel from the display surface back to its corresponding principal plane.

[0037] These holograms are sequentially superimposed in a certain way (such as weighted summation) to obtain the second hologram, and the second hologram is used as the input of the next iterative cycle. After a set number of iterations, the cycle ends. During the loop process, the value of kace needs to be increased in each loop. The above operation is repeated. When kace=1 (i.e. the maximum value) and all loops are completed, the final target hologram is obtained.

[0038] Similarly, when kace=0.1, the G channel is processed. Spread G The distance reaches the G plane and the diffraction field distribution is obtained Keeping the phase information unchanged, replace the amplitude distribution of the field distribution with the desired adaptive constraint. Backward propagation back to the principal plane, replace the amplitude with 1, keeping the phase distribution unchanged: , , , , , When kace=0.1, the B channel is processed. Spread B Distance reaches B plane, and the diffraction field distribution is obtained Keeping the phase information unchanged, replace the amplitude distribution of the field distribution with the desired adaptive constraint. Backward propagation back to the principal plane, replace the amplitude with 1, keeping the phase distribution unchanged: , , , , , The holograms of the three channels R, G, and B , , Perform sequence superposition and complete one iteration: , , During the sequence superposition process, , , The coefficients of can be any preset positive number other than 1. The purpose of setting their coefficients to 1 is to make the three holograms have the same weight. If the three holograms require different weights, the coefficients can be changed as needed. As the input of the next iteration, after a set number of iterations, the loop ends. Increase the value of kace and repeat the above operation. When kace=1 (i.e. the maximum value) and all cycles are completed, the final target hologram is determined, corresponding to Figure 3 H in.

[0039] In an optional implementation of the present embodiment, it also includes: separately imaging each monochromatic channel of the three primary color channels at different diffraction distances; detecting whether there is information crosstalk between the monochromatic channels under the illumination of RGB mixed white light; if there is no information crosstalk between the monochromatic channels, outputting a single hologram with the same magnification at the same diffraction distance; if there is information crosstalk between the monochromatic channels, executing the step of determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution.

[0040] Specifically, in this embodiment, the corresponding phase image of the optimized target hologram is loaded onto the spatial light modulator. R , G , B Under the illumination of RGB mixed white light synthesized by laser of different wavelengths, , , At three different diffraction distances, red, green, and blue monochrome images with magnifications of m1, m2, and m3 are generated respectively. For example, the red channel only encodes the pure red word "red", and the green and blue channels have no information. The green channel only encodes the pure green word "green", and the red and blue channels have no information. The blue channel only encodes the pure blue word "blue", and the red and green channels have no information. Under the illumination of RGB mixed white light, red "red", green "green" and blue "blue" of different sizes can be projected at different positions in space to detect whether there is information crosstalk between the images (such as other colors appearing in the monochrome image). If there is no information crosstalk between the images, a single hologram is output at the same diffraction distance with the same magnification, so that and , it can be designed as a color diffraction image, that is, a single hologram carries color image information. If there is information crosstalk between the images, it means that the convergence iteration of the image has not achieved the expected effect, and the target image needs to be iterated again to make the final target hologram achieve the expected effect.

[0041] It should be noted that the present application is not limited to uniform parallel light illumination display, and can be adapted to a variety of light beam types to achieve holographic display, including but not limited to Gaussian beam illumination, Bessel beam illumination, spherical wave illumination and other illumination methods for holographic display.

[0042] In an optional implementation of this embodiment, since the target hologram can carry information of three channels, R, G, and B, at the same time, a single-frame phase-type hologram can generate a full-color holographic image under mixed white light illumination. This feature makes the method for generating the target hologram also applicable to the production of color holographic videos. The generated color holographic video can be played with the maximum temporal resolution at the refresh rate of the spatial light modulator. For example, for a phase-type spatial light modulator with a refresh rate of 60Hz, the color holographic video can be designed to run at a maximum playback rate of 60Hz. Compared with the traditional time-sequential single-color channel playback method, the method of the present application increases the temporal resolution by 3 times. On the other hand, it does not rely on electronic shutters or other timing synchronization devices, which simplifies hardware requirements.

[0043] Based on the implementation scheme of the above application, the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels is obtained; the target complex amplitude constraint of the target image is determined by adding a scattering phase term to the target amplitude distribution; each monochromatic channel is converged and iterated according to the target complex amplitude constraint to generate a sequence superimposed initial hologram; the target hologram is generated by soft quantization of the initial hologram. Through the implementation of the scheme of this application, the target image is sequentially superimposed and softly quantized according to the desired target complex amplitude constraint corresponding to the imaging of each monochromatic channel in the three primary color channels, so that the final output target hologram can realize full-color image display under multi-wavelength mixed illumination, maximizing the information capacity of a single hologram and meeting the needs of multi-wavelength display.

[0044] Figure 4 A single hologram generation device is provided in an embodiment of the present application, and the single hologram generation device can be used to implement the single hologram generation method in the above-mentioned embodiment. Figure 2 , 4 As shown, the single hologram generating device mainly includes: An acquisition module 10 is used to acquire the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels; A determination module 20, configured to determine a target complex amplitude constraint of a target image by adding a scattering phase term to a target amplitude distribution; The first generation module 30 is used to perform convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate an initial hologram of sequence superposition; The second generating module 40 is used to generate a target hologram by performing soft quantization on the initial hologram.

[0045] In an optional implementation of the present embodiment, the first generation module is specifically used to: determine an initial field distribution in a principal plane corresponding to each monochromatic channel; obtain a first diffraction field distribution of a display surface corresponding to the principal plane according to the initial field distribution; wherein the first diffraction field distribution is a diffraction field distribution of a first large iterative cycle; converge a first amplitude distribution corresponding to the first diffraction field distribution according to a target complex amplitude, and determine a first complex amplitude distribution corresponding to the first amplitude distribution; propagate the first complex amplitude distribution back to the principal plane corresponding to each monochromatic channel; perform sequential superposition of holograms generated corresponding to the first complex amplitude distribution on the principal plane to obtain a first hologram; perform an iterative cycle of a preset number of iterations according to the first hologram to determine an initial hologram.

[0046] Further, in an optional implementation of this embodiment, the determination module is further used to: determine the quantization level of the phase value in the initial hologram according to a preset quantization step and a tolerance value; determine the quantization value of the phase value according to the quantization level; and determine the quantization level of the phase value according to the above quantization value. According to the single hologram generation device provided by the present application scheme, Furthermore, in an optional implementation of the present embodiment, the second generation module is specifically used to: soft-quantize the initial field distribution according to the quantization level; obtain the second diffraction field distribution according to the softly quantized initial field distribution; wherein the second diffraction field distribution is the diffraction field distribution of the second largest iterative cycle; converge the second amplitude distribution corresponding to the second diffraction field distribution, and determine the adaptive complex amplitude distribution corresponding to the second amplitude distribution; propagate the adaptive complex amplitude distribution back to the main plane corresponding to each monochromatic channel; sequentially superimpose the holograms generated corresponding to the adaptive complex amplitude distribution on the main plane to obtain a second hologram; iterate the second hologram based on the tolerance value to generate a target hologram.

[0047] In an optional implementation of the present embodiment, the single hologram generation device further includes: an imaging module, a detection module, an output module, and a control module. The imaging module is used to: separately image each monochromatic channel of the three primary color channels at different diffraction distances. The detection module is used to: detect whether there is information crosstalk between each monochromatic channel under the illumination of RGB mixed white light. The output module is used to: if there is no information crosstalk between each monochromatic channel, then output a single hologram with the same magnification at the same diffraction distance. The control module is used to: if there is information crosstalk between each monochromatic channel, then execute the step of determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution.

[0048] According to the single hologram generation device provided by the scheme of the present application, the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels is obtained; the target complex amplitude constraint of the target image is determined by adding a scattering phase term to the target amplitude distribution; each monochromatic channel is converged and iterated according to the target complex amplitude constraint to generate a sequence superimposed initial hologram; the target hologram is generated by soft quantization of the initial hologram. Through the implementation of the scheme of the present application, the target image is sequentially superimposed and softly quantized according to the desired target complex amplitude constraint corresponding to the imaging of each monochromatic channel in the three primary color channels, so that the final output target hologram can realize full-color image display under multi-wavelength mixed illumination, maximizing the information capacity of a single hologram and meeting the needs of multi-wavelength display.

[0049] Figure 5 An electronic device provided in an embodiment of the present application. The electronic device can be used to implement the single hologram generation method in the aforementioned embodiment, mainly comprising: A memory 501, a processor 502, and a computer program 503 stored in the memory 501 and executable on the processor 502. The memory 501 and the processor 502 are connected via communication. When the processor 502 executes the computer program 503, the single hologram generation method in the aforementioned embodiment is implemented. The number of processors may be one or more.

[0050] The memory 501 may be a high-speed random access memory (RAM) memory, or a non-volatile memory (non-volatile memory), such as a disk memory. The memory 501 is used to store executable program codes, and the processor 502 is coupled to the memory 501 .

[0051] Furthermore, the present application also provides a computer-readable storage medium, which may be provided in the electronic device in the above embodiments. Figure 5 Memory in the illustrated embodiment.

[0052] The computer readable storage medium stores a computer program, and when the program is executed by the processor, the single hologram generation method in the aforementioned embodiment is implemented. Furthermore, the computer storable medium can also be a U disk, a mobile hard disk, a read-only memory (ROM), a RAM, a magnetic disk or an optical disk, and other media that can store program codes.

[0053] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0054] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0055] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for generating a single hologram, characterized in that: include: Obtain the target amplitude distribution of the target image corresponding to each monochrome channel in the three primary color channels; Determining a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution; Perform convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate an initial hologram of sequence superposition; A target hologram is generated by performing adaptive constraints and phase soft quantization on the initial hologram.

2. The single hologram generation method according to claim 1, characterized in that: The step of determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution comprises: The above target complex amplitude constraint is calculated by the following formula: ， in, is the optical vector perpendicular to the diffraction propagation direction of the target image, is the target complex amplitude constraint, is the target amplitude distribution, It is a random phase with scattering properties, i is an imaginary unit, j=R,G,B, representing the three colors of red, green and blue.

3. The single hologram generation method according to claim 1, characterized in that: The step of performing convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram comprises: Determine the initial field distribution in the principal plane corresponding to each monochromatic channel; Acquire a first diffraction field distribution of a display surface corresponding to the main plane according to the initial field distribution; wherein the first diffraction field distribution is a diffraction field distribution of a first large iteration cycle of the channel; replacing a first amplitude distribution corresponding to the first diffraction field distribution according to the target complex amplitude constraint to determine a first complex amplitude distribution corresponding to the first amplitude distribution; Reversely propagate the first complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels; Performing sequential superposition on holograms generated corresponding to the first complex amplitude distribution on the main plane to obtain a first hologram; The initial hologram is determined by performing an iterative cycle of a preset number of iterations according to the first hologram.

4. The single hologram generation method according to claim 3, characterized in that: The step of replacing the first amplitude distribution corresponding to the first diffraction field distribution according to the target complex amplitude constraint to determine a first complex amplitude distribution corresponding to the first amplitude distribution includes: The first complex amplitude distribution is calculated by the following formula: ， ， in, is the magnification of the display surface where the target image is located relative to the main plane, is the wavelength of the incident light, is the propagation distance, is the frequency domain coordinate, is the optical vector of the display surface, is the optical vector of the principal plane, the operator represents the two-dimensional Fourier transform, the operator represents the two-dimensional inverse Fourier transform, represents the first diffraction field distribution calculated by the variable scale diffraction algorithm, represents the target complex amplitude constraint, represents the first complex amplitude distribution after constraint, angle function represents the phase distribution in the complex amplitude distribution, and exp represents the exponential function with the natural constant e as the base.

5. The single hologram generation method according to claim 3, characterized in that: Before the step of generating a target hologram by adaptively constraining the initial hologram and performing phase soft quantization, the method further includes: Determining a quantization level of a phase value in the initial hologram according to a preset quantization step size and a tolerance value; Determining a quantized value of the phase value according to the quantization level; The quantization level of the phase value is determined according to the quantization value.

6. The single hologram generation method according to claim 5, characterized in that: The step of generating a target hologram by adaptively constraining the initial hologram and performing phase soft quantization comprises: Performing phase soft quantization on the initial field distribution according to the quantization level; Acquire a second diffraction field distribution according to the initial field distribution after phase soft quantization; wherein the second diffraction field distribution is the diffraction field distribution of the second largest iterative cycle; Adaptively constraining a second amplitude distribution corresponding to the second diffraction field distribution to determine an adaptive complex amplitude distribution corresponding to the second amplitude distribution; Back-propagating the adaptive complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels; Sequentially superimposing the holograms generated corresponding to the adaptive complex amplitude distribution on the main plane to obtain a second hologram; The second hologram is iterated based on the tolerance value to generate the target hologram.

7. The single hologram generation method according to claim 1, characterized in that: The method further comprises: Performing separate imaging on each monochromatic channel of the three primary color channels at different diffraction distances; Under the illumination of RGB mixed white light, detect whether there is information crosstalk between each monochrome channel; If there is no information crosstalk between the monochromatic channels, a single hologram is output; If there is information crosstalk between the monochromatic channels, the step of determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution is performed.

8. A single hologram generating device, characterized in that: The single hologram generating device comprises: An acquisition module is used to acquire the target amplitude distribution of the target image corresponding to each monochrome channel in the three primary color channels; A determination module, configured to determine a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution; A first generating module, used for performing convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate an initial hologram of sequence superposition; The second generating module is used to generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram.

9. An electronic device, characterized in that: The device comprises a memory and a processor, wherein: The processor is used to execute the computer program stored in the memory; When the processor executes the computer program, the steps in the single hologram generation method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps in the single hologram generation method according to any one of claims 1 to 7 are implemented.

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