CN111722513B - Holographic display method, system, equipment and storage medium based on frequency decomposition - Google Patents
Holographic display method, system, equipment and storage medium based on frequency decomposition Download PDFInfo
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Abstract
The embodiment of the invention relates to the technical field of holographic display, and discloses a holographic display method, a system, equipment and a storage medium based on frequency decomposition. The method comprises the steps of firstly obtaining an image to be displayed; filtering the image to be displayed to obtain target frequency information with preset number; respectively determining corresponding holographic surface complex amplitude distribution information according to the target frequency information; respectively encoding the holographic surface complex amplitude distribution information to obtain a hologram; and loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display the holographic images. Therefore, the embodiment of the invention can perform frequency decomposition action aiming at different modulation characteristics of the spatial light modulator so as to finally improve the quality of the computed holographic reconstruction, and can ensure the high efficiency and the real-time performance in the dimension of computation time while improving the image quality.
Description
Technical Field
The invention relates to the technical field of holographic display, in particular to a holographic display method, a system, equipment and a storage medium based on frequency decomposition.
Background
Holographic display is an ideal three-dimensional display mode which is carried out by utilizing the principles of light interference and diffraction and conforms to the visual characteristics of human eyes.
There are many specific ways of holographic display, for example, conventional optical recording holography, but the conventional optical recording holography can only record the complex amplitude information of the object light in the form of interference fringes by using a holographic dry plate, and is complex for the requirements of optical experimental environment, and it is difficult to realize dynamic large-size three-dimensional display.
It can be seen that conventional optical recording holography has certain limitations.
In recent years, with the continuous improvement of computer software and hardware and the rapid development of hologram display devices, the computer holography technology has become an important means for realizing holographic three-dimensional display. The method is not influenced by the characteristics of the recording medium, and can construct complex or even unrealistic objects.
Therefore, the hologram is obtained by directly adopting a digital processing method, and the method has unique advantages.
However, the computer-generated hologram reconstruction technique is limited by the characteristics of the spatial light modulator, such as the pixel structure and the modulation mode, and not only consumes a lot of time when generating the hologram, but also causes a serious degradation of the reconstructed image quality, and cannot meet the current requirements of people on the three-dimensional display effect.
Therefore, the prior art for computing holographic reconstruction has the technical problems of low computing speed and poor imaging quality.
Disclosure of Invention
In order to solve the technical problems of poor imaging quality and low computing speed of computed holographic display, the embodiment of the invention provides a holographic display method, a system, equipment and a storage medium based on frequency decomposition.
In a first aspect, an embodiment of the present invention provides a holographic display method based on frequency decomposition, including:
acquiring an image to be displayed;
filtering the image to be displayed to obtain target frequency information with preset number;
determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively;
respectively encoding the holographic surface complex amplitude distribution information to obtain holograms;
and loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display a holographic image.
Preferably, the spatial light modulator comprises a reflective phase type spatial light modulator and a transmissive amplitude type spatial light modulator, and the hologram comprises a first hologram and a second hologram;
the loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reproduction to display the hologram images specifically includes:
and loading the first hologram into a reflective phase-type spatial light modulator corresponding to the first hologram, and loading the second hologram into a transmissive amplitude-type spatial light modulator corresponding to the second hologram for joint reconstruction, so as to display a holographic image.
Preferably, the holographic surface complex amplitude distribution information includes first holographic surface complex amplitude distribution information and second holographic surface complex amplitude distribution information;
the encoding the holographic surface complex amplitude distribution information respectively to obtain the hologram specifically includes:
encoding the first holographic surface complex amplitude distribution information in a kinoform encoding mode to obtain a first hologram;
and encoding the second holographic surface complex amplitude distribution information by adopting an amplitude type encoding mode to obtain a second hologram.
Preferably, the determining the corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively specifically includes:
determining a secondary phase factor according to the object plane sampling interval of the image to be displayed;
determining a frequency spectrum surface phase factor according to a preset spatial light modulator pixel interval;
and determining corresponding holographic surface complex amplitude distribution information according to the target frequency information, the secondary phase factor and the frequency spectrum surface phase factor.
Preferably, the determining a secondary phase factor according to the object plane sampling interval of the image to be displayed specifically includes:
and determining a secondary phase factor according to the object plane sampling interval of the image to be displayed, the wavelength of the first laser and the first diffraction distance.
Preferably, before determining the secondary phase factor according to the object plane sampling distance of the image to be displayed, the frequency decomposition-based holographic display method further includes:
and carrying out discretization sampling processing on the image to be displayed so as to obtain the object plane sampling interval.
Preferably, the discretizing sampling processing is performed on the image to be displayed to obtain an object plane sampling interval, and specifically includes:
and carrying out discretization sampling treatment according to the preset pixel interval of the spatial light modulator, the wavelength of the second laser, the second diffraction distance and the holographic surface resolution to obtain the object surface sampling interval of the image to be displayed.
In a second aspect, an embodiment of the present invention provides a holographic display system based on frequency decomposition, including:
the image input module is used for acquiring an image to be displayed;
the filtering processing module is used for carrying out filtering processing on the image to be displayed so as to obtain target frequency information with preset number;
the complex amplitude distribution determining module is used for determining corresponding holographic surface complex amplitude distribution information according to the target frequency information;
the encoding module is used for encoding the holographic surface complex amplitude distribution information respectively to obtain holograms;
and the holographic display module is used for loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reproduction so as to display the holographic image.
In a third aspect, an embodiment of the present invention provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the computer program to implement the steps of the frequency decomposition based holographic display method according to the first aspect of the present invention.
In a fourth aspect, an embodiment of the present invention provides a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the frequency decomposition-based holographic display method provided in the first aspect of the present invention.
According to the frequency decomposition-based holographic display method, system, equipment and storage medium provided by the embodiment of the invention, an image to be displayed is obtained firstly; filtering the image to be displayed to obtain target frequency information with preset number; determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively; respectively encoding the holographic surface complex amplitude distribution information to obtain holograms; and loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display a holographic image. Therefore, the embodiment of the invention can perform frequency decomposition action aiming at different modulation characteristics of the spatial light modulator so as to finally improve the quality of the computed holographic reconstruction, and can ensure the high efficiency and the real-time performance in the dimension of computation time while improving the image quality.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
FIG. 1 is a flowchart of a holographic display method based on frequency decomposition according to an embodiment of the present invention;
FIG. 2 is a flowchart of a holographic display method based on frequency decomposition according to another embodiment of the present invention;
FIG. 3 is a flowchart of a holographic display method based on frequency decomposition according to still another embodiment of the present invention;
FIG. 4 is a flow chart of a holographic display method based on frequency decomposition according to another embodiment of the present invention;
FIG. 5 is a flow chart of the operation of an experimental apparatus according to another embodiment of the present invention;
FIG. 6 is a schematic structural diagram of a holographic display system based on frequency decomposition according to an embodiment of the present invention;
fig. 7 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a flowchart of a holographic display method based on frequency decomposition according to an embodiment of the present invention, as shown in fig. 1, the method includes:
and S1, acquiring the image to be displayed.
And S2, filtering the image to be displayed to obtain target frequency information with preset number.
It can be understood that the computer-generated hologram reconstruction technique is limited by the characteristics of the pixel structure and the modulation mode of the spatial light modulator, and cannot meet the current requirements of people for three-dimensional imaging quality. In order to improve the three-dimensional imaging quality, the embodiment of the invention can perform frequency decomposition on different modulation characteristics of the spatial light modulator so as to finally improve the quality of computed holographic reconstruction; moreover, the image quality is improved, and meanwhile, the high efficiency and the real-time performance in the dimension of the calculation time can be guaranteed.
Specifically, an image to be displayed may be input first, and the image to be displayed may be filtered to obtain a plurality of frequency information.
For example, the preset number may be 2, and the number of divisions of the frequency information is not limited herein, but the divided target frequency information corresponds to a spatial light modulator to be used, so as to perform frequency resolution action for different modulation characteristics of the spatial light modulator.
The target frequency information is frequency information in different frequency ranges.
And S3, determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively.
Then, for each target frequency information, corresponding hologram surface complex amplitude distribution information is determined, and for each target frequency information, one hologram surface complex amplitude distribution information is correspondingly present.
And S4, respectively encoding the holographic surface complex amplitude distribution information to obtain the holograms.
For example, the encoding may be performed according to the modulation modes of different spatial light modulators to generate a plurality of computed holograms.
And S5, loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display the holographic image.
Each hologram can then be loaded into a different respective spatial light modulator to reconstruct a reconstructed image in space.
The spatial light modulators respectively corresponding to different target frequency information may be different types of spatial light modulators.
In addition, the execution subject of the embodiment of the invention is an electronic device. The electronic device may include a spatial light modulator or may not include a spatial light modulator, and only data transmission exists with the spatial light modulator, for example, the electronic device loads holograms into the spatial light modulators corresponding to the holograms, respectively.
Among them, the Spatial Light Modulator (SLM) is a core device of a system based on the liquid crystal micro display technology, such as real-time optical information processing, optical interconnection, and optical computing. The SLM may change the amplitude, intensity, phase, polarization, and wavelength of the spatial light distribution under control of electrical or other signals. The reading mode of the reading light can be divided into a reflection type and a transmission type; according to the input control signal, the optical addressing (OA-SLM) and the electric addressing (EA-SLM) can be divided; according to the type of modulation mode, there are a phase type, an amplitude type, and a complex amplitude type.
Further, with the current computer-generated hologram reconstruction technology, in the hologram display based on the spatial light modulator, an ideal image can be completely reconstructed only in a specific area, and the calculation of a higher order diffraction image and complex information not only requires a lot of time in generating a hologram but also brings about a serious degradation in the quality of a reconstructed image.
The algorithms for computing the holographic improvement quality at the present stage include an iterative optimization algorithm based on a single-phase spatial light modulator, a complex amplitude optimization algorithm based on a dual-amplitude spatial light modulator, and the like. However, these approaches often require a large amount of optimization time or complex experiments of joint alignment at the pixel level to reproduce the desired image, and it is difficult to achieve real-time and high-quality three-dimensional display simultaneously.
Therefore, the embodiment of the invention provides a method for improving the reconstruction quality of the computed hologram based on frequency decomposition aiming at different modulation characteristics of the spatial light modulator, and can ensure high efficiency and real-time performance on the dimension of computation time while improving the image quality.
Furthermore, the embodiment of the invention does not need to carry out iterative solution on the calculation hologram, so that the complex amplitude real-time display can be realized, and meanwhile, the quality of the reproduced image can be improved.
The holographic display method based on frequency decomposition provided by the embodiment of the invention comprises the steps of firstly obtaining an image to be displayed; filtering the image to be displayed to obtain target frequency information with preset number; determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively; respectively encoding the holographic surface complex amplitude distribution information to obtain holograms; and loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display a holographic image. Therefore, the embodiment of the invention can perform frequency decomposition action aiming at different modulation characteristics of the spatial light modulator so as to finally improve the quality of the computed holographic reconstruction, and can ensure the high efficiency and the real-time performance in the dimension of computation time while improving the image quality.
Fig. 2 is a flowchart of a holographic display method based on frequency decomposition according to another embodiment of the present invention, which is based on the embodiment shown in fig. 1.
In this embodiment, the spatial light modulator includes a reflective phase-type spatial light modulator and a transmissive amplitude-type spatial light modulator, and the hologram includes a first hologram and a second hologram.
It is understood that, in the embodiment of the present invention, 2 spatial light modulators are taken as an example to exemplify a scene, and similarly, 2 pieces of target frequency information, 2 pieces of holographic surface complex amplitude distribution information, 2 pieces of holograms and the like also exist.
The S5 specifically includes:
and S51, loading the first hologram into a reflective phase-type spatial light modulator corresponding to the first hologram, and loading the second hologram into a transmissive amplitude-type spatial light modulator corresponding to the second hologram for joint reconstruction, so as to display a holographic image.
Specifically, if the laser is used as a reference light source to illuminate the screen of the spatial light modulator, corresponding voltages can be applied to the liquid crystal lattice of the spatial light modulator according to the gray scale value corresponding to the light intensity or phase of each pixel point in the computed hologram, so as to reproduce a three-dimensional image, i.e., the holographic image.
The first hologram corresponds to a reflective phase type spatial light modulator, and the second hologram corresponds to a transmissive amplitude type spatial light modulator.
The holographic display method based on frequency decomposition provided by the embodiment of the invention can use a reflection type phase spatial light modulator and a transmission type amplitude spatial light modulator to carry out combined reproduction.
On the basis of the above embodiment, preferably, the holographic surface complex amplitude distribution information includes first holographic surface complex amplitude distribution information and second holographic surface complex amplitude distribution information.
The S4 specifically includes:
and S41, encoding the first holographic surface complex amplitude distribution information by adopting a kinoform encoding mode to obtain a first hologram.
And S42, encoding the second hologram surface complex amplitude distribution information by adopting an amplitude type encoding mode to obtain a second hologram.
The encoding operation refers to a type of operation behavior of converting the complex amplitude of the hologram surface into transmittance function distribution for different types of spatial light modulators in the acquisition process of the computed hologram.
It will be appreciated that the scene is still exemplified with 2 spatial light modulators. Specifically, there will be 2 target frequency information, 2 holographic surface complex amplitude distribution information.
The first holographic surface complex amplitude distribution information can adopt a kinoform coding mode adapted to a reflective phase type spatial light modulator, and the second holographic surface complex amplitude distribution information can adopt an amplitude type coding mode adapted to a transmissive amplitude type spatial light modulator.
Specifically, the encoding process can be expressed as the following encoding formula,
wherein, Th(u, v) denotes a first hologram, Tl(u, v) represents a second hologram;
representing phase information in the first holographic surface complex amplitude distribution information, Al(u,v)、
Respectively representing amplitude information and phase information in the second holographic surface complex amplitude distribution information.
Therefore, the embodiment of the invention can adopt different encoding operations aiming at different holographic surface complex amplitudes.
Fig. 3 is a flowchart of a holographic display method based on frequency decomposition according to another embodiment of the present invention, which is based on the embodiment shown in fig. 2.
In this embodiment, the S3 specifically includes:
and S31, determining a secondary phase factor according to the object plane sampling distance of the image to be displayed.
Specifically, the object plane sampling interval of the image to be displayed refers to the sampling size of the input image, and can be denoted as (Δ x, Δ y), and the x-y axis is taken as an example here for expression.
And S32, determining a frequency spectrum surface phase factor according to the preset space light modulator pixel spacing.
The preset spatial light modulator pixel pitch refers to a pixel pitch of the spatial light modulator, and may be denoted as (Δ u, Δ v).
And S33, determining corresponding holographic surface complex amplitude distribution information according to the target frequency information, the secondary phase factor and the frequency spectrum surface phase factor.
In a specific implementation, the target frequency information, the secondary phase factor, and the spectral surface phase factor may be combined to determine the holographic surface complex amplitude distribution information corresponding to the target frequency information.
On the basis of the foregoing embodiment, preferably, the determining a secondary phase factor according to the object plane sampling interval of the image to be displayed specifically includes:
and determining a secondary phase factor according to the object plane sampling interval of the image to be displayed, the wavelength of the first laser and the first diffraction distance.
Wherein the first laser wavelength can be designated as λ and the first diffraction distance can be designated as z. As for the first diffraction distance, the diffraction distance may be determined by an application environment or experimental conditions.
Specifically, the secondary phase factor may be as follows,
wherein exp represents an exponential function with a natural constant e as a base in the complex variable function; i is an imaginary unit; (x, y) represents the spatial coordinates of the object plane, x being the abscissa and y being the ordinate.
On the basis of the foregoing embodiment, preferably, the determining a spectral surface phase factor according to a preset spatial light modulator pixel pitch specifically includes:
and determining a frequency spectrum surface phase factor according to the preset pixel interval of the spatial light modulator, the wavelength of the first laser and the first diffraction distance.
Specifically, the spectral plane phase factor can be as follows,
wherein (Δ u, Δ v) represents a preset spatial light modulator pixel pitch; (u, v) represents spectral plane space coordinates.
Further, as for the operation of determining the corresponding hologram surface complex amplitude distribution information based on the target frequency information, the secondary phase factor, and the spectral surface phase factor, respectively, a complex amplitude distribution determination formula shown below may be applied,
wherein, Uh(U, v) denotes first holographic surface complex amplitude distribution information, Ul(u, v) represents second hologram surface complex amplitude distribution information; o ish(x,y)、Ol(x, y) represents target frequency information.
Specifically, for the complex amplitude distribution determination formula, if the target frequency information includes the first frequency information and the second frequency information, the different frequency information is multiplied by the secondary phase factor, then fourier transform is performed, and then the result of the fourier transform is multiplied by the spectral surface phase factor to obtain the holographic surface complex amplitude distribution information of the different frequency information.
In addition, for the complex amplitude distribution determination formula, the holographic surface complex amplitude distribution information of different frequency information can be obtained by inputting different frequency information in the modes of angular spectrum calculation and the like, and meanwhile, the size of the reproduced image can be ensured to be unchanged.
Wherein the frequency range of the first frequency information is different from the frequency range of the second frequency information.
The first frequency information may be high frequency information, and the second frequency information may be low frequency information. Similarly, the first hologram and the first holographic surface complex amplitude distribution information both correspond to high frequency information, and the second hologram and the second holographic surface complex amplitude distribution information both correspond to low frequency information.
Fig. 4 is a flowchart of a holographic display method based on frequency decomposition according to another embodiment of the present invention, which is based on the embodiment shown in fig. 3.
In this embodiment, before S31, the method for displaying a hologram based on frequency decomposition further includes:
s301, performing discretization sampling processing on the image to be displayed to obtain an object plane sampling interval.
It will be appreciated that to determine the sample size of the input image, the discretized sampling process is performed such that the object plane sampling spacing conforms to the nyquist sampling theorem and the spatial light modulator pixel characteristics.
The sampling operation refers to a kind of operation behavior that can be performed on a continuous function due to the limited information capacity of a physical device when the computer holography is recorded, stored and processed.
On the basis of the foregoing embodiment, preferably, the discretizing sampling processing is performed on the image to be displayed to obtain an object-plane sampling interval, and specifically includes:
and carrying out discretization sampling treatment according to the preset pixel interval of the spatial light modulator, the wavelength of the second laser, the second diffraction distance and the holographic surface resolution to obtain the object surface sampling interval of the image to be displayed.
More specifically, an object plane sampling interval determination formula shown below may be employed,
wherein (Δ x, Δ y) represents an object plane sampling interval to be obtained, (Δ u, Δ v) represents a preset spatial light modulator pixel interval, λ represents a second laser wavelength, z represents a second diffraction distance, and (M × N) represents a holographic plane resolution.
The first laser wavelength and the second laser wavelength are only distinguished by names under the use scene, and the first laser wavelength can be equal to the second laser wavelength. Other similar situations, and so on.
Further, the preset number may be 2, and the 2 pieces of target frequency information may be the first frequency information and the second frequency information, respectively.
Further, the image to be displayed may be filtered to obtain a preset number of target frequency information.
Wherein, as for the filtering processing operation, the image-oriented filtering operation is a processing operation of a frequency domain or a spatial domain based on a computer technology or an optical element on an image.
The input is typically images and the output is the relevant attributes extracted from these images, such as edges, frequencies, contours, and attributes of the designated objects. The filtering means includes a linear filter and a nonlinear filter.
Specifically, with this filter processing operation, a filter function may be set to perform a filter processing action.
For example, the image to be displayed may be denoted as O (x, y), and if 2 spatial light modulators are taken as an example of a scene, the high-frequency information O may be dividedh(x, y) and low frequency information Ol(x,y)。
The filter function is as follows,
wherein, Oh(x, y) represents high frequency information, Ol(x, y) represents low frequency information;
which represents the positive fourier transform of the signal,
denotes the inverse Fourier transform, Fh(x,y)、Fl(x, y) are a high frequency filter function and a low frequency filter function, respectively.
Further, the preset number may be 2, and the 2 pieces of target frequency information may be high frequency information and low frequency information, respectively.
The high frequency information and the low frequency information may be divided by a preset threshold of the filter function, for example, 5% of the gaussian filter radius. Of course, different input images may have their filtering functions and thresholds adjusted accordingly.
Therefore, the high-frequency and low-frequency holographic surface distribution of the target image can be respectively calculated, and the target image is loaded in the spatial light modulators with different modulation types to carry out combined complex amplitude display, so that the bottleneck that the complex amplitude of the traditional calculation holographic display is difficult to display in real time is broken through, and meanwhile, system and algorithm noises can be inhibited.
Fig. 5 is a flowchart illustrating an operation of an experimental apparatus according to another embodiment of the present invention, as shown in fig. 5, the experimental apparatus includes a laser 1, a beam expanding collimator 2, a polarizer 3, a beam splitter 4, a spatial light modulator 5, a mirror 6, a computer 7, a receiving screen 8, a beam splitter 9, a beam splitter 10, a spatial light modulator 11, and a computer 12.
It can be seen that there are three beam splitters, two spatial light modulators and two computers.
Wherein, the receiving screen can be replaced by a Charge-coupled Device (CCD).
Wherein, the first hologram corresponding to the high-frequency information can be recorded as a high-frequency hologram Th(u, v), the second hologram corresponding to the low frequency information can be recorded as a low frequency hologram Tl(u,v)。
In particular, during the experiment, the low-frequency hologram T can be controlled using the computer 7l(u, v) are loaded into the spatial light modulator 5 and the computer 12 controls the high frequency hologram Th(u, v) are loaded into the spatial light modulator 11 for joint rendering.
The spatial light modulator 5 is of a transmissive amplitude type, and the spatial light modulator 11 is of a reflective phase type.
Finally, the peak signal-to-noise ratio and structural similarity of the input image and the reconstructed image can be analyzed by comparison, such as diffraction and reconstruction calculations involving images of different frequencies.
Compared with the traditional method, the method provided by the embodiment of the invention has the advantage that the quality of the reconstructed image shows better effect.
Fig. 6 is a schematic structural diagram of a holographic display system based on frequency decomposition according to an embodiment of the present invention, as shown in fig. 6, the system includes: an image input module 301, a filter processing module 302, a complex amplitude distribution determination module 303, an encoding module 304 and a holographic display module 305;
an image input module 301, configured to obtain an image to be displayed;
a filtering processing module 302, configured to perform filtering processing on the image to be displayed to obtain target frequency information of a preset number;
a complex amplitude distribution determining module 303, configured to determine, according to the target frequency information, corresponding holographic surface complex amplitude distribution information respectively;
the encoding module 304 is configured to encode the holographic surface complex amplitude distribution information to obtain holograms;
and the holographic display module 305 is configured to load the holograms into the spatial light modulators corresponding to the holograms respectively for joint reconstruction, so as to display a holographic image.
The holographic display system based on frequency decomposition provided by the embodiment of the invention firstly obtains an image to be displayed; filtering the image to be displayed to obtain target frequency information with preset number; determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively; respectively encoding the holographic surface complex amplitude distribution information to obtain holograms; and loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display a holographic image. Therefore, the embodiment of the invention can perform frequency decomposition action aiming at different modulation characteristics of the spatial light modulator so as to finally improve the quality of the computed holographic reconstruction, and can ensure the high efficiency and the real-time performance in the dimension of computation time while improving the image quality.
The system embodiment provided in the embodiments of the present invention is for implementing the above method embodiments, and for details of the process and the details, reference is made to the above method embodiments, which are not described herein again.
Fig. 7 is a schematic entity structure diagram of an electronic device according to an embodiment of the present invention, and as shown in fig. 7, the electronic device may include: a processor (processor)401, a communication Interface (communication Interface)402, a memory (memory)403 and a bus 404, wherein the processor 401, the communication Interface 402 and the memory 403 complete communication with each other through the bus 404. The communication interface 402 may be used for information transfer of an electronic device. Processor 401 may call logic instructions in memory 403 to perform a method comprising:
acquiring an image to be displayed;
filtering the image to be displayed to obtain target frequency information with preset number;
determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively;
respectively encoding the holographic surface complex amplitude distribution information to obtain holograms;
and loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display a holographic image.
In addition, the logic instructions in the memory 403 may be implemented in the form of software functional units and stored in a computer readable storage medium when the software functional units are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the above-described method embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program is implemented by a processor to perform the method provided by the foregoing embodiments, for example, including:
acquiring an image to be displayed;
filtering the image to be displayed to obtain target frequency information with preset number;
determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively;
respectively encoding the holographic surface complex amplitude distribution information to obtain holograms;
and loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display a holographic image.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (9)
1. A method of holographic display based on frequency decomposition, comprising:
acquiring an image to be displayed;
filtering the image to be displayed to obtain target frequency information with preset number;
determining corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively;
respectively encoding the holographic surface complex amplitude distribution information to obtain holograms;
loading the holograms into spatial light modulators corresponding to the holograms respectively for joint reconstruction so as to display holographic images;
the spatial light modulator comprises a reflective phase type spatial light modulator and a transmissive amplitude type spatial light modulator, and the hologram comprises a first hologram and a second hologram;
the loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reproduction to display the hologram images specifically includes:
and loading the first hologram into a reflective phase-type spatial light modulator corresponding to the first hologram, and loading the second hologram into a transmissive amplitude-type spatial light modulator corresponding to the second hologram for joint reconstruction, so as to display a holographic image.
2. The frequency-decomposition based holographic display method of claim 1, wherein the holographic surface complex amplitude distribution information comprises first holographic surface complex amplitude distribution information, second holographic surface complex amplitude distribution information;
the encoding the holographic surface complex amplitude distribution information respectively to obtain the hologram specifically includes:
encoding the first holographic surface complex amplitude distribution information in a kinoform encoding mode to obtain a first hologram;
and encoding the second holographic surface complex amplitude distribution information by adopting an amplitude type encoding mode to obtain a second hologram.
3. The holographic display method based on frequency decomposition according to claim 2, wherein the determining the corresponding holographic surface complex amplitude distribution information according to the target frequency information respectively specifically includes:
determining a secondary phase factor according to the object plane sampling interval of the image to be displayed;
determining a frequency spectrum surface phase factor according to a preset spatial light modulator pixel interval;
and determining corresponding holographic surface complex amplitude distribution information according to the target frequency information, the secondary phase factor and the frequency spectrum surface phase factor.
4. The holographic display method based on frequency decomposition according to claim 3, wherein the determining a quadratic phase factor according to the object plane sampling distance of the image to be displayed specifically comprises:
and determining a secondary phase factor according to the object plane sampling interval of the image to be displayed, the wavelength of the first laser and the first diffraction distance.
5. The method for holographic display based on frequency decomposition according to claim 3, wherein before determining the quadratic phase factor according to the object plane sampling distance of the image to be displayed, the method for holographic display based on frequency decomposition further comprises:
and carrying out discretization sampling processing on the image to be displayed so as to obtain the object plane sampling interval.
6. The holographic display method based on frequency decomposition according to claim 5, wherein the discretizing sampling processing on the image to be displayed to obtain an object plane sampling interval specifically comprises:
and carrying out discretization sampling treatment according to the preset pixel interval of the spatial light modulator, the wavelength of the second laser, the second diffraction distance and the holographic surface resolution to obtain the object surface sampling interval of the image to be displayed.
7. A holographic display system based on frequency decomposition, comprising:
the image input module is used for acquiring an image to be displayed;
the filtering processing module is used for carrying out filtering processing on the image to be displayed so as to obtain target frequency information with preset number;
the complex amplitude distribution determining module is used for determining corresponding holographic surface complex amplitude distribution information according to the target frequency information;
the encoding module is used for encoding the holographic surface complex amplitude distribution information respectively to obtain holograms;
the holographic display module is used for loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reproduction so as to display holographic images;
the spatial light modulator comprises a reflective phase type spatial light modulator and a transmissive amplitude type spatial light modulator, and the hologram comprises a first hologram and a second hologram;
the loading the holograms into the spatial light modulators corresponding to the holograms respectively for joint reproduction to display the hologram images specifically includes:
and loading the first hologram into a reflective phase-type spatial light modulator corresponding to the first hologram, and loading the second hologram into a transmissive amplitude-type spatial light modulator corresponding to the second hologram for joint reconstruction, so as to display a holographic image.
8. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor, when executing the program, carries out the steps of the frequency decomposition based holographic display method of any of claims 1 to 6.
9. A non-transitory computer readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the frequency decomposition based holographic display method of any of claims 1 to 6.
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