Single hologram generation method, device, equipment and storage medium

Abstract

This application relates to the field of optical display and discloses a single hologram generation method, device, equipment and storage medium. The method includes: obtaining the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels; determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution; performing convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate a sequence superposition initial hologram; using the initial hologram, combined with adaptive constraints and phase soft quantization method to generate the target hologram. Through the implementation of the solution of this application, the final output target hologram can realize full-color image display under white light illumination of a mixture of red, green and blue, maximizing the information capacity of a single hologram and meeting the needs of multi-wavelength encryption and display.

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] Computational holography (CGH) is a technique that generates computer-generated holograms (holograms) through numerical calculations. It can record and reproduce the amplitude and phase information of light waves and is a product of the integration of optics and information technology. While traditional holography relies on laser interferometry for recording, CGH breaks free from the limitations of physical recording and generates holograms directly on a computer through methods such as diffraction algorithms and neural networks, greatly expanding its potential for application in modern display and optics.

[0003] Currently, existing methods for generating computer-generated holograms are typically designed for a single wavelength. This means that a single hologram can only form a monochromatic diffraction image of the target size at the desired location when illuminated by a single operating wavelength. Using multi-wavelength illumination (such as white light, a mixture of red, green, and blue) results in severe chromatic aberration. The single-wavelength nature of a single hologram significantly limits its information capacity. In color holographic displays, achieving color images requires switching between multiple holograms and the assistance of devices 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] A first aspect of the present application provides a method for generating a single hologram, the method comprising:

[0006] Obtain the target amplitude distribution of the target image corresponding to each monochrome channel in the three primary color channels;

[0007] Determining a target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution;

[0008] Perform convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram;

[0009] A target hologram is generated by performing adaptive constraints and phase soft quantization on the initial hologram.

[0010] 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:

[0011] The target complex amplitude constraint is calculated using the following formula:

[0012] ,

[0013] in, is the optical vector perpendicular to the target image diffraction propagation direction, 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.

[0014] 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:

[0015] Determine the initial field distribution in the principal plane corresponding to each monochromatic channel;

[0016] 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;

[0017] replacing a corresponding first amplitude distribution in the first diffraction field distribution according to the target complex amplitude to determine a first complex amplitude distribution corresponding to the first amplitude distribution;

[0018] Reversely propagating the first complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels;

[0019] performing sequential superposition on holograms generated corresponding to the first complex amplitude distribution on the principal plane to obtain a first hologram;

[0020] An iterative cycle of a preset number of iterations is performed according to the first hologram to determine the initial hologram.

[0021] 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 includes:

[0022] The first complex amplitude distribution is calculated by the following formula:

[0023] ,

[0024] ,

[0025] 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.

[0026] 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 method further includes:

[0027] determining a quantization level of a phase value in the initial hologram according to a preset quantization step size and a tolerance value;

[0028] determining a quantized value of the phase value according to the quantization level;

[0029] The quantization level of the phase value is determined according to the quantization value.

[0030] Optionally, in a fifth implementation of the first aspect of the present application, the step of generating a target hologram by adaptively constraining and soft-quantizing the phase of the initial hologram includes:

[0031] performing soft quantization on the initial field distribution according to the quantization level;

[0032] Obtaining 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;

[0033] Converging a second amplitude distribution corresponding to the second diffraction field distribution to determine an adaptive complex amplitude distribution corresponding to the second amplitude distribution;

[0034] Propagating the adaptive complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels;

[0035] Sequentially superimposing the holograms generated corresponding to the adaptive complex amplitude distribution on the main plane to obtain a second hologram;

[0036] An iterative cycle is performed on the second hologram based on the tolerance value to generate the target hologram.

[0037] Optionally, in a sixth implementation of the first aspect of the present application, the method further includes:

[0038] Performing separate imaging on each monochromatic channel of the three primary color channels at different diffraction distances;

[0039] Under the illumination of RGB mixed white light, detect whether there is information crosstalk between each monochromatic channel;

[0040] If there is no information crosstalk between the monochromatic channels, a single hologram is output at the same diffraction distance and the same magnification;

[0041] If information crosstalk exists 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.

[0042] A second aspect of the present application provides a single hologram generation device, the single hologram generation device comprising:

[0043] An acquisition module is used to obtain the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels;

[0044] 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;

[0045] A first generating module is configured to perform convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram;

[0046] The second generating module is used to generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram.

[0047] 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 on the memory, and when the processor executes the computer program, it implements the steps of the single hologram generation method provided in the first aspect of the embodiment of the present application.

[0048] A 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, each step of the single hologram generation method provided in the first aspect of the embodiments of the present application is implemented.

[0049] In summary, according to the single hologram generation method, device, equipment and storage medium provided by 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; the convergence iteration of each monochromatic channel is performed according to the target complex amplitude constraint to generate a sequence superimposed initial hologram; the target hologram is generated by adaptively constraining the initial hologram and performing phase soft quantization. Through the implementation of the present application, the target image is sequentially superimposed and soft 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 target hologram finally outputted can realize full-color image display under multi-wavelength mixed illumination, thereby maximizing the information capacity of a single hologram and meeting the needs of multi-wavelength display. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic flow chart of a method for generating a single hologram provided in an embodiment of the present application;

[0051] Figure 2 A schematic diagram of generating an initial hologram in the single hologram generating method provided in an embodiment of the present application;

[0052] Figure 3 A schematic diagram of generating a target hologram in the single hologram generating method provided in an embodiment of the present application;

[0053] Figure 4 A schematic diagram of the program modules of a single hologram generating device provided in an embodiment of the present application;

[0054] Figure 5 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] 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 embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0056] 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 This is a flow chart of a method for generating a single hologram provided in this embodiment. The method for generating a single hologram includes the following steps:

[0057] Step 110: Obtain the target amplitude distribution of the target image corresponding to each monochromatic channel in the three primary color channels.

[0058] 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, it is necessary to determine its corresponding amplitude distribution, 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 values ​​can be set based on the actual illumination wavelength. After determining the target image, grayscale the target image. By calculating the pixel value distribution of the grayscaled image, the target amplitude distribution of the single color channel can be obtained.

[0059] Step 120 : Determine the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution.

[0060] 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 specific pattern. The amplitude distribution and phase distribution are then combined to form a complex amplitude distribution. The added phase term gives this constraint certain scattering properties, which can effectively reduce the image's depth of focus and significantly reduce information crosstalk between diffraction images at different diffraction distances, while maintaining the desired image quality.

[0061] In an optional implementation of this embodiment, the calculation formula of the target complex amplitude constraint is:

[0062] ,

[0063] 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 random phase change of the light wave after scattering due to the random distribution and property differences of scatterers (such as particles and microstructures).

[0064] Step 130: Perform convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram.

[0065] Specifically, in this embodiment, it should be noted that the convergence iterations for the target complex amplitude constraints of the target images 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 a mathematical transformation (such as a Fourier transform). On the display surface, the amplitude distribution of the target image is replaced with the constrained complex amplitude distribution. The modified complex amplitude is then reverse-propagated from the display surface back to the main plane, and the phase component of the complex amplitude obtained by reverse propagation is retained on the main plane. After each iteration, the complex amplitude distribution is checked to see if it meets the convergence criteria. The convergence criteria can be that the error in the amplitude distribution is less than a certain threshold, or that the stability of the phase distribution reaches a certain level. When the complex amplitude distribution meets the convergence criteria, the iteration process terminates, and a phase distribution corresponding to the amplitude distribution of the target image is obtained. This phase distribution corresponds to a hologram. The holograms of the monochromatic channels are then superimposed to obtain an initial single hologram.

[0066] In an optional implementation of this embodiment, the steps of performing convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram include: determining an initial field distribution in the main plane corresponding to each monochromatic channel; obtaining a first diffraction field distribution of the display surface corresponding to the main plane according to the initial field distribution; replacing the 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 main plane corresponding to each monochromatic channel; sequentially superimposing the holograms generated corresponding to the first complex amplitude distribution on the main plane to obtain a first hologram; and performing an iterative loop for a preset number of iterations based on the first hologram to determine the initial hologram.

[0067] Specifically, in this embodiment, for each monochromatic channel (such as red, green, and blue channels), an initial field distribution is determined on the corresponding principal plane (usually the object plane or the input plane), and the distribution includes amplitude and phase values. The initial field distribution can be a complex-valued field with a random phase and an amplitude that is 1 everywhere. The expression formula corresponding to the initial field distribution can be expressed as:

[0068] ,

[0069] in, "[exp]" represents the generation of an M×N matrix whose elements are random values ​​between 0 and 1, and "exp" represents an exponential function with the natural constant e as its base. Using wave optics principles (such as Fresnel diffraction and Fraunhofer diffraction), the initial field distribution of each monochromatic channel on the principal plane is propagated to the corresponding display surface (typically the viewing or output plane), yielding the first diffraction field distribution. The diffraction field distribution describes the spatial distribution of the electromagnetic field (typically amplitude and phase) during the diffraction process of light and is the specific manifestation of the complex amplitude distribution in diffraction. This diffraction field distribution serves as the starting point for the first large iteration loop. Within the first diffraction field distribution of each monochromatic channel, the first amplitude distribution corresponding to the target image is found. An iterative algorithm (such as the GS algorithm based on a variable-scale diffraction algorithm) is used to converge the first amplitude distribution until it meets the convergence criteria for the target complex amplitude constraint. The phase term derived from the diffraction calculation remains unchanged during the replacement process. After convergence, a first complex amplitude distribution corresponding to the first amplitude distribution is obtained. The first complex amplitude distribution of each monochromatic channel is propagated back from the display surface to its corresponding principal plane. This step is the feedback step in the iterative process, which allows the algorithm to further adjust the first complex amplitude distribution on the principal plane. On the principal plane of each monochromatic channel, a corresponding hologram is generated based on the first complex amplitude distribution. These holograms are then sequentially superimposed in a certain manner (such as weighted summation) to obtain the first hologram. At this point, the hologram has been superimposed from a monochromatic hologram to a color hologram. An iterative algorithm (such as the GS algorithm or other improved algorithms) is further iterated on the first hologram 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.

[0070] Optionally, in the process of converging all target complex amplitude constraints and determining the first complex amplitude distributions corresponding to all target complex amplitude constraints, the first complex amplitude distribution may be calculated using the following formula:

[0071] , (1)

[0072] ,

[0073] 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, the 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. In numerical calculation, the two-dimensional Fourier transform is implemented by discrete fast Fourier transform (FFT).

[0074] Optional, such as Figure 2 As shown, in the first large iteration loop, Spread z 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, keeping the phase distribution unchanged, thus obtaining a monochromatic hologram of the red channel It should be noted that in the first large iteration cycle, formula (1) can be simplified to:

[0075] ,

[0076] 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:

[0077] , (2)

[0078] , (3)

[0079] , (4)

[0080] , (5)

[0081] 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 reverse propagating the desired first complex amplitude distribution back to the main plane.

[0082] Similarly, in the same large iterative loop, for the green channel, Spread z G The distance reaches the G plane and the diffraction field distribution is obtained , keeping the phase information unchanged, replace the entire complex amplitude distribution with the desired first complex amplitude distribution. Back propagate back to the principal plane, replace the amplitude with 1, keeping the phase distribution unchanged:

[0083] ,

[0084] ,

[0085] ,

[0086] ,

[0087] In the same large iteration loop, for the blue channel, Propagate zB distance to reach B plane and get the diffraction field distribution Keeping the phase information unchanged, replace the field distribution with the desired first complex amplitude distribution. Back propagate back to the principal plane, replace the amplitude with 1, keeping the phase distribution unchanged:

[0088] ,

[0089] ,

[0090] ,

[0091] ,

[0092] The 3 holograms obtained 、 、 Perform sequence superposition and complete one iteration:

[0093] ,

[0094] ,

[0095] During the sequence superposition process, , , The coefficients of can be any preset positive number instead of 1. The purpose of setting their coefficients to 1 is to make the three holograms have the same weight. If the weights required for the three holograms are different, the coefficients can be changed according to the requirements. As the input of the next iteration loop. 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.

[0096] Step 140: Generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram.

[0097] Specifically, it should be noted that in the first major cycle, the preliminary hologram is generated only by simple sequence superposition. In order to ensure the fidelity and quality of the final 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 the R plane, the G plane, and the 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 sequentially superimposed. At this point, one iteration is completed. After the second major iterative cycle is completed, the final target hologram is obtained.

[0098] In an optional implementation of this embodiment, before the step of generating a target hologram by soft quantizing the initial hologram, the step further 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; and determining the quantization level of the phase value according to the above quantization value.

[0099] Specifically, in this embodiment, a soft quantization operation is performed on the phase values, dividing them into discrete levels based on the step size and tolerance value (kace). The quantization levels are mapped to integer multiples of the increment value, where each phase is assigned a specific quantization level based on its value relative to the step size and 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:

[0100] ,

[0101] in, is the quantization step size. For each phase value θ at position r in the matrix, the quantization value It is calculated based on the nearest quantization level within the tolerance defined by kace, and its calculation formula is:

[0102] ,

[0103] 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-tune it according to kace. Specifically:

[0104] ,

[0105] The function iterates over 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 is performed on u.

[0106] In an optional implementation of this embodiment, the calculation formula corresponding to the improved Fourier domain adaptive constraint is:

[0107] ,

[0108] 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, its value is in the range of -1 to 1, j=R,G,B, represents 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 loop further improves the fidelity of the constraint process in the loop by improving the target complex amplitude.

[0109] In an optional implementation of this 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 an 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; and iterating the second hologram based on the tolerance value to generate the target hologram.

[0110] Specifically, in this embodiment, the soft quantization operation of the initial field distribution has been described in the above embodiment. Similarly, 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 to obtain the second diffraction field distribution , keeping the phase information unchanged, replace the second amplitude distribution of the field distribution with the desired adaptive constraint, that is, use 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 monochromatic channel from the display surface back to its corresponding main plane. On the main plane of each monochromatic channel, generate the corresponding hologram according to the adaptive complex amplitude distribution. The specific expression is:

[0111] , (6)

[0112] , (7)

[0113] , (8)

[0114] , (9)

[0115] , (10)

[0116] 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. Formulas (9) and (10) represent the second hologram obtained by backpropagating the diffraction field distribution of the red channel from the display surface back to its corresponding principal plane.

[0117] 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 loop. After a set number of iterations, the loop ends. During the loop process, the value of kace needs to be increased in each loop, and the above operation is repeated. When kace=1 (that is, the maximum value) and all loops are completed, the final target hologram is obtained.

[0118] Similarly, when kace=0.1, the G channel is processed. Spread z 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. Backpropagate back to the principal plane, replace the amplitude with 1, and keep the phase distribution unchanged:

[0119] ,

[0120] ,

[0121] ,

[0122] ,

[0123] ,

[0124] When kace=0.1, the B channel is processed. Spread z 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. Backpropagate back to the principal plane, replace the amplitude with 1, and keep the phase distribution unchanged:

[0125] ,

[0126] ,

[0127] ,

[0128] ,

[0129] ,

[0130] The holograms of the three channels R, G, and B 、 、 Perform sequence superposition and complete one iteration:

[0131] ,

[0132] ,

[0133] During the sequence superposition process, , , The coefficients of can be any preset positive number instead of 1. The purpose of setting their coefficients to 1 is to make the three holograms have the same weight. If the weights required for the three holograms are different, the coefficients can be changed according to the requirements. 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.

[0134] In an optional implementation of this 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.

[0135] Specifically, in this embodiment, the phase image corresponding to the optimized target hologram is loaded onto the spatial light modulator. R ,λ G ,λB 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 and with the same magnification, so that and , a color diffraction image can be designed, meaning a single hologram carries color image information. If there is information crosstalk between the images, it means that the image convergence iteration has not achieved the expected effect, and the target image needs to be iterated again to achieve the desired result.

[0136] 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 lighting methods for holographic display.

[0137] 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 at the refresh rate of the spatial light modulator to maximize the temporal resolution. 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 an electronic shutter or other timing synchronization devices, which simplifies the hardware requirements.

[0138] Based on the embodiment 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; the convergence iteration of each monochromatic channel is performed 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 soft 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.

[0139] Figure 4 The present invention provides a single hologram generation device, which can be used to implement the single hologram generation method in the above embodiment. Figure 2 、 4 As shown, the single hologram generating device mainly includes:

[0140] 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;

[0141] a determination module 20 for determining a target complex amplitude constraint of a target image by adding a scattering phase term to the target amplitude distribution;

[0142] The first generation module 30 is used to perform convergence iteration on each monochromatic channel according to the target complex amplitude constraint to generate a sequence superimposed initial hologram;

[0143] The second generating module 40 is configured to generate a target hologram by performing soft quantization on the initial hologram.

[0144] In an optional implementation of this embodiment, the first generation module is specifically used to: determine an initial field distribution in the main plane corresponding to each monochromatic channel; obtain a first diffraction field distribution of the display surface corresponding to the main plane based on the initial field distribution; wherein the first diffraction field distribution is the diffraction field distribution of the first large iterative cycle; converge the first amplitude distribution corresponding to the first diffraction field distribution based on the target complex amplitude, and determine the first complex amplitude distribution corresponding to the first amplitude distribution; propagate the first complex amplitude distribution back to the main plane corresponding to each monochromatic channel; sequentially superimpose the holograms generated corresponding to the first complex amplitude distribution on the main plane to obtain a first hologram; and perform an iterative cycle of a preset number of iterations based on the first hologram to determine the initial hologram.

[0145] Furthermore, in an optional implementation of this embodiment, the determination module is further configured to: determine the quantization level of the phase value in the initial hologram according to a preset quantization step size 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 quantization value.

[0146] Furthermore, in an optional implementation of this embodiment, the second generation module is specifically used to: soft-quantize the initial field distribution according to the quantization level; obtain a second diffraction field distribution based on 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.

[0147] In an optional implementation of this 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 the monochromatic channels under the illumination of RGB mixed white light. The output module is used to output a single hologram at the same diffraction distance and with the same magnification if there is no information crosstalk between the monochromatic channels. The control module is used to perform the step of determining the target complex amplitude constraint of the target image by adding a scattering phase term to the target amplitude distribution if there is information crosstalk between the monochromatic channels.

[0148] According to the single hologram generation device provided by 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; the convergence iteration of each monochromatic channel is performed 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 present application, the target image is sequentially superimposed and soft 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, thereby maximizing the information capacity of a single hologram and meeting the needs of multi-wavelength display.

[0149] Figure 5 An electronic device provided in an embodiment of the present application can be used to implement the single hologram generation method in the aforementioned embodiment, mainly comprising:

[0150] Memory 501, processor 502, and computer program 503 stored in memory 501 and executable on processor 502. Memory 501 and processor 502 are connected via communication. When processor 502 executes computer program 503, the single hologram generation method described in the aforementioned embodiment is implemented. The number of processors may be one or more.

[0151] The memory 501 can be a high-speed random access memory (RAM) memory or a non-volatile memory such as a disk drive. The memory 501 is used to store executable program code. The processor 502 is coupled to the memory 501 .

[0152] Furthermore, the embodiment of the present application also provides a computer-readable storage medium, which can be provided in the electronic device in the above embodiments. The computer-readable storage medium can be the above Figure 5 Memory in the illustrated embodiment.

[0153] The computer-readable storage medium stores a computer program that, when executed by a processor, implements the single hologram generation method described in the aforementioned embodiment. Furthermore, the computer-readable storage medium may be a USB flash drive, a mobile hard drive, a read-only memory (ROM), RAM, a magnetic disk, or an optical disk, among other media capable of storing program code.

[0154] Those skilled in the art will 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.

[0155] 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, 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 and includes several instructions for enabling 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, and other media that can store program code.

[0156] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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 includes: calculating the target complex amplitude constraint by the following formula: ， in, is the optical vector perpendicular to the target image diffraction propagation direction, is the target complex amplitude constraint, is the target amplitude distribution, is a random phase with scattering properties, i is the imaginary unit, j =R,G,B, represents the three colors red, green and blue; Performing convergence iterations on each of the monochromatic channels according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram, including: determining an initial field distribution in a principal plane corresponding to each monochromatic channel; obtaining a first diffraction field distribution on a display surface corresponding to the principal plane according to the initial field distribution; wherein the first diffraction field distribution is the diffraction field distribution of the first largest iterative 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 propagating the first complex amplitude distribution back to the principal plane corresponding to each of the monochromatic channels; sequentially superimposing holograms generated corresponding to the first complex amplitude distribution on the principal plane to obtain a first hologram; and performing an iterative cycle of a preset number of iterations based on the first hologram to determine the initial hologram; Generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram; 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 The function represents the phase distribution in the complex amplitude distribution, exp Represents an exponential function with the natural constant e as its base.

2. The single hologram generation method according to claim 1, 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.

3. The single hologram generation method according to claim 2, characterized in that: The step of generating a target hologram by performing adaptive constraint and phase soft quantization on the initial hologram comprises: performing phase soft quantization on the initial field distribution according to the quantization level; Obtaining 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; performing adaptive constraints on 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 monochromatic channel; Sequentially superimposing the holograms generated corresponding to the adaptive complex amplitude distribution on the main plane to obtain a second hologram; An iterative cycle is performed on the second hologram based on the tolerance value to generate the target hologram.

4. 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 monochromatic channel; If there is no information crosstalk between the monochromatic channels, a single hologram is output; If information crosstalk exists 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.

5. A single hologram generating device, characterized in that: The single hologram generating device is used to implement the single hologram generating method according to claim 1, and the single hologram generating device includes: An acquisition module is used to obtain the target amplitude distribution of the target image corresponding to each monochromatic 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 is configured to perform convergence iteration on each of the monochromatic channels according to the target complex amplitude constraint to generate a sequence-superimposed initial hologram; The second generating module is used to generate a target hologram by performing adaptive constraints and phase soft quantization on the initial hologram.

6. An electronic device, characterized in that: Comprising a memory and a processor, wherein: The processor is configured to execute a computer program stored in the memory; When the processor executes the computer program, the steps of the single hologram generation method according to any one of claims 1 to 4 are implemented.

7. 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 of the single hologram generation method according to any one of claims 1 to 4 are implemented.

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