Edge detection device and edge detection method based on speckle correlation scattering matrix

Abstract

The present application belongs to the field of optical measurement, and discloses an edge detection device and method based on speckle correlation scattering matrix, which comprises: a laser for emitting a first light beam; a spatial light modulator, a signal light modulation area of which receives the first light beam to output a signal light beam, and a reference light modulation area of which receives the first light beam to output a reference light beam; a scattering medium for outputting the scattered signal light beam and reference light beam to an image sensor; and a data processing module, which loads different phase encoding light fields into the spatial light modulator to obtain the intensity of the interference light field of the scattered signal light beam and reference light beam and calculate a transmission matrix; loads a to-be-measured image into the spatial light modulator, and the image sensor collects speckle intensity; and processes the data collected by the image sensor to obtain a speckle correlation scattering matrix, and then calculates an edge information value. The present application does not need to introduce an additional interference optical path to measure the phase of the speckle of the to-be-measured image, thereby avoiding the instability introduced by the additional interference optical path and saving time cost.

Description

Technical Field

[0001] This invention belongs to the field of optical measurement technology, specifically relating to an edge detection device and method based on speckle correlation scattering matrix. Background Technology

[0002] Optical imaging has always been one of the important ways for people to obtain information, especially in biomedical imaging. However, in complex environments such as the atmosphere, ocean, and biological tissues, due to the non-uniform distribution of refractive index, photons no longer propagate in a straight line after being interacted with multiple times by particles of the same order of magnitude as the wavelength of light in the complex environmental medium. Their propagation direction deviates and spreads in all directions. The output light field also becomes more random due to multiple scattering. This phenomenon is called scattering, and the medium that interacts with photons is called a random scattering medium.

[0003] As an important branch of imaging, edge detection has significant applications in image segmentation and recognition. Current technologies for edge detection through scattering media are based on the transfer matrix method. This involves measuring the transfer matrix of the medium, then applying a spiral phase filter to the matrix in the spatial frequency domain. The filtered transfer matrix, combined with speckle light field information of the target image obtained from additional interferometric optical path measurements (including intensity and phase), enables the detection of edge information in the target image.

[0004] Current edge detection technology requires additional speckle phase information because CCD cameras can only measure speckle intensity. This necessitates the introduction of an additional interferometric optical path to measure the speckle phase. This not only makes the experimental optical path cumbersome and time-consuming, but the additional interferometric optical path also introduces system instability.

[0005] Therefore, there is an urgent need in this field for an edge detection device and method based on speckle correlation scattering matrix to solve the above-mentioned technical problems. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to solve the above problems and provide an edge detection device and edge detection method based on speckle correlation scattering matrix.

[0007] To address the aforementioned technical problems, this invention provides an edge detection device based on a speckle correlation scattering matrix, comprising: A laser, used to emit the first beam; A spatial light modulator includes a signal light modulation region and a reference light modulation region, wherein the signal light modulation region is used to receive the first light beam output signal beam, and the reference light modulation region is used to receive the first light beam output reference beam. A scattering medium is used to receive the signal beam, scatter the signal beam, and output a scattered signal beam; the scattering medium is also used to receive the reference beam, scatter the reference beam, and output a scattered reference beam. An image sensor is used to receive the scattered signal beam and the scattered reference beam, and the image sensor acquires the speckle intensity of the image under test; The data processing module controls the spatial light modulator to load different phase-coded light fields, obtains the intensity of the interference light field of the scattered signal beam and the scattered reference beam, performs algorithmic processing on the intensity of the interference light field to obtain the transmission matrix of the scattering medium, controls the spatial light modulator to load the image under test in the signal light modulation area, controls the image sensor to acquire the speckle intensity of the image under test, calculates and processes all the data acquired by the image sensor to obtain the speckle-related scattering matrix, and calculates and processes the speckle-related scattering matrix to obtain edge information values.

[0008] As a further improvement of the present invention, a first prism, a first convex lens, a second convex lens, a total reflection mirror, and a second prism are sequentially arranged between the laser and the spatial light modulator along the optical path direction. The first prism polarizes the first beam and outputs a second beam. The first convex lens expands the second beam and outputs a third beam. The second convex lens collimates the third beam and outputs a fourth beam. The total reflection mirror receives the fourth beam and vertically inputs the fourth beam into the second prism. The second prism receives the fourth beam, splits the fourth beam, and outputs it.

[0009] As a further improvement of the present invention, a 4f light group and a microscope objective are sequentially arranged between the spatial light modulator and the scattering medium along the optical path direction; The second prism transmits the signal beam to the 4f optical group, the 4f optical group filters the signal beam and outputs a fifth beam, and the microscope objective focuses the fifth beam and outputs it. The second prism transmits the reference beam to the 4f beam group, the 4f beam group filters the reference beam and outputs a sixth beam, and the microscope objective focuses the sixth beam and outputs it.

[0010] As a further improvement of the present invention, a fifth convex lens and a polarizer are sequentially arranged between the scattering medium and the image sensor along the optical path direction; The fifth convex lens converges the scattered modulated beam onto the polarizer, and the polarizer filters out the vertical polarization component of the scattered signal beam and outputs it. The fifth convex lens converges the scattered reference beam onto the polarizer, and the polarizer filters out the vertical polarization component of the scattered reference beam and outputs it.

[0011] As a further improvement of the present invention, the scattering medium is frosted glass.

[0012] The present invention also provides an edge detection method based on speckle correlation scattering matrix, the method comprising: S1: Measure the transmission matrix of the scattering medium using the Hadamard phase-encoded optical field and the four-step phase-shifting method; S2: Acquire speckle intensity, load the image to be tested onto the signal light modulation area of ​​the spatial light modulator, and the image sensor acquires the speckle intensity of the image to be tested; S3: Obtain edge information. Process the filtered transmission matrix and the speckle intensity of the acquired image under test using the speckle correlation scattering matrix to obtain the speckle correlation scattering matrix. Obtain the eigenvector corresponding to the largest eigenvalue of the speckle correlation scattering matrix to obtain the edge information value of the image under test.

[0013] As a further improvement of the present invention, step S1, which uses the Hadamardi method and a four-step phase-shifting method to measure the transfer matrix of the scattering medium, includes: S11: Measure the interference light field intensity of the signal beam and the reference beam when the phase offset is 0, π / 2, 3π / 2, and π respectively: in, Representing the One output channel, Corresponding to the The input light field of the Hadramakkis in the Vygotsky, It is the first of the Hadamard matrix. The vector corresponding to the column, It is the first The reference optical complex amplitude used in each transmission channel for Hermitian conjugation, α represents the phase shift in the four-step phase shift, and the elements of the Hadamardi are 1 or -1; where 1 can represent the complex amplitude. -1 can be represented as complex amplitude ; S12: Solve for different Below : in, It is the first of the Hadamard matrix. The vector corresponding to the column, It is the first The reference optical complex amplitude used in each transmission channel; S13: Solve all The optical transmission matrix under the Hadamazoid structure is formed. Transformed into a matrix under a Cartesian basis using basis vectors. .

[0014] As a further improvement of the present invention, in S13: all solutions are obtained The optical transmission matrix under the Hadamazoid structure is formed. Transformed into a matrix under a Cartesian basis using basis vectors. Following that, it also includes: S14: For the matrix Spiral phase filtering in the spatial frequency domain: in, Represents the transfer matrix Perform a two-dimensional Fourier transform on each row. Represents the spatial frequency domain; S15: Perform a two-dimensional inverse Fourier transform back to the spatial domain to obtain the overall filtered transfer matrix. : in, Represents the transfer matrix Perform a two-dimensional inverse Fourier transform on each row, and then perform spatial filtering to obtain... .

[0015] As a further improvement of the present invention, in S3, the speckle correlation scattering matrix obtained by processing the filtered transmission matrix and the speckle intensity algorithm of the image under test is as follows: in, Corresponding to the filtered transfer matrix The List, Represents the scattered field. Represents speckle intensity. , ,and It is the normalization factor.

[0016] As a further improvement of the present invention, in S3, obtaining the edge information value by finding the eigenvector corresponding to the largest eigenvalue of the speckle correlation scattering matrix specifically involves: obtaining the speckle correlation scattering matrix. The eigenvector corresponding to the largest eigenvalue yields the complex coefficient X of the incident field, and the magnitude of the complex value X is the required edge information value.

[0017] Compared with existing technologies, the present invention provides an edge detection device and method based on speckle correlation scattering matrix. After measuring the medium transmission matrix using the device, the image sensor acquires speckle intensity information from the image under test. Combined with the transmission matrix, the speckle correlation scattering matrix is ​​calculated, and the eigenvector corresponding to the largest eigenvalue of this matrix is ​​obtained, thus acquiring the edge information of the target image. Compared with existing technologies that require additional interferometric optical paths to measure speckle phase for edge detection, this invention avoids the cumbersome experimental optical path and time wastage caused by introducing an additional interferometric optical path for speckle phase measurement. It also avoids system instability introduced by the additional interferometric optical path, thus improving measurement accuracy. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and not all embodiments. For those skilled in the art, other drawings obtained from these drawings without creative effort are all within the scope of protection of this application.

[0019] Figure 1 This is a schematic diagram of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention; Figure 2 This is a flowchart of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention; Figure 3 This is an architectural diagram of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention; Figure 4 This is a distribution diagram of the signal light modulation region and the reference light modulation region of the spatial light modulator of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention; Figure 5 This is a measurement process diagram of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention, (a) the image to be measured, (b) the speckle of the image to be measured, and (c) the edge of the image to be measured; Figure 6These are the experimental results of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention: (a) theoretical calculation of the edge, and (b) experimental measurement of the edge.

[0020] Explanation of reference numerals in the attached figures: 1 is a laser, 2 is a first prism, 3 is a first convex lens, 4 is a second convex lens, 5 is a total reflection mirror, 6 is a spatial light modulator, 7 is a second prism, 8 is a third convex lens, 9 is a filter aperture, 10 is a fourth convex lens, 11 is a microscope objective, 12 is a scattering medium, 13 is a fifth convex lens, 14 is a polarizer, and 15 is an image sensor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] To make the description of this disclosure more detailed and complete, illustrative descriptions of embodiments and specific examples of the present invention are provided below; however, these are not the only forms of implementing or utilizing the specific embodiments of the present invention. The embodiments cover features of multiple specific embodiments and the methods, steps, and their order for constructing and operating these specific embodiments. However, other specific embodiments may also be used to achieve the same or equivalent functions and step sequences. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0023] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0025] In the description of the embodiments of the present invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The word "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more. Other quantifiers should be understood similarly. The preferred embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of this application can be combined with each other without conflict.

[0026] Please refer to Figures 1-6 This invention provides an edge detection device and method based on speckle correlation scattering matrix. Using existing technology for edge detection and introducing additional interference optical paths to measure the phase of speckle not only makes the experimental optical path cumbersome and time-consuming, but also introduces system instability problems due to the additional interference optical path.

[0027] Specifically, please refer to Figure 1 This invention provides an edge detection device based on a speckle-correlated scattering matrix, comprising a laser 1, a spatial light modulator 6, a scattering medium 12, and an image sensor 15 arranged sequentially along the optical path. Both the spatial light modulator 6 and the image sensor 15 are electrically connected to a data processing module. The edge detection device based on the speckle-correlated scattering matrix measures the medium's transmission matrix, and then the image sensor 15 acquires speckle intensity information from the image under test. Combined with the transmission matrix, the speckle-correlated scattering matrix is ​​calculated, and the eigenvector corresponding to the largest eigenvalue of the speckle-correlated scattering matrix is ​​obtained, thus acquiring the edge information of the image under test. Compared to existing technologies that require additional interference optical paths to measure speckle phase for edge detection, this invention avoids the cumbersome experimental optical path and time wastage caused by the additional interference optical path introduced for speckle phase measurement, and also avoids the instability introduced by the additional interference optical path, thus improving measurement accuracy.

[0028] Specifically, the laser 1 emits a first beam; the signal light modulation region of the spatial light modulator 6 receives the first beam and outputs a signal beam, and the reference light modulation region of the spatial light modulator 6 receives the first beam and outputs a reference beam; the scattering medium 12 receives the signal beam and scatters it, outputting a scattered signal beam; the scattering medium 12 receives the reference beam and scatters it, outputting a scattered reference beam; the image sensor 15 receives the scattered signal beam and the scattered reference beam. In one specific embodiment, the laser wavelength emitted by the laser 1 of the present invention is 532 nm.

[0029] Furthermore, the data processing module controls the spatial light modulator 6 to load different phase-coded light fields. Correspondingly, the image sensor 15 receives the scattered signal beam and the scattered reference beam under different phase-coded light fields, thereby obtaining the intensity of the interference light field of the scattered signal beam and the scattered reference beam. The data processing module calculates the transmission matrix of the scattering medium from the data collected by the image sensor 15. The data processing module controls the spatial light modulator 6 to load the image to be tested in the signal light modulation area. The data processing module controls the image sensor 15 to collect the speckle intensity of the image to be tested. Combining the transmission matrix of the scattering medium, the data processing module performs algorithmic processing on all the data collected by the image sensor 15 to obtain the speckle-related scattering matrix. The edge information value is calculated from the speckle-related scattering matrix.

[0030] As a further improvement of the present invention, a first prism 2, a first convex lens 3, a second convex lens 4, a total reflection mirror 5, and a second prism 7 are sequentially arranged along the optical path between the laser emitter and the spatial light modulator 6. The first prism 2 polarizes the first beam and outputs a second beam. The first convex lens 3 expands the second beam and outputs a third beam. The second convex lens 4 collimates the third beam and outputs a fourth beam. The total reflection mirror 5 receives the fourth beam and vertically inputs it into the second prism 7. The second prism 7 receives the fourth beam, splits it, and outputs it. Specifically, the first prism 2 is used to polarize the first beam to obtain horizontally linearly polarized light. Preferably, the first prism 2 is a Glan prism. The first convex lens 3 and the second convex lens 4 form a collimation and beam-expanding system to expand and collimate the incident beam to obtain a beam of a preset width.

[0031] As a further improvement of the present invention, a 4f light group and a microscope objective 11 are sequentially arranged between the spatial light modulator 6 and the scattering medium 12 along the optical path direction; the second prism 7 transmits the signal beam to the 4f light group, the 4f light group filters the signal beam and outputs a fifth beam, and the microscope objective 11 focuses and outputs the fifth beam; the second prism 7 transmits the reference beam to the 4f light group, the 4f light group filters the reference beam and outputs a sixth beam, and the microscope objective 11 focuses and outputs the sixth beam. Specifically, the 4f optical group includes a third convex lens 8, a filter aperture 9, and a fourth convex lens 10 arranged sequentially along the optical path. The 4f optical group performs diffraction order filtering on the incident beam. The filter aperture 9 extracts the +1 order light, which is collimated by the fourth convex lens 10 and then enters the microscope objective 11. The microscope objective 11 focuses the incident beam. Preferably, the focal length f of the third convex lens 8 and the fourth convex lens 10 is 100 mm, and the numerical aperture NA of the microscope objective 11 is 0.25.

[0032] As a further improvement of the present invention, a fifth convex lens 13 and a polarizer 14 are sequentially arranged between the scattering medium 12 and the image sensor 15 along the optical path direction. The fifth convex lens 13 focuses the scattered signal beam onto the polarizer 14, and the polarizer 14 filters out the vertical polarization component of the scattered signal beam and outputs it. The fifth convex lens 13 collects and focuses the scattered reference beam onto the polarizer 14, and the polarizer 14 filters out the vertical polarization component of the scattered reference beam and outputs it. Specifically, the fifth convex lens 13 is used to collect and focus the beam scattered by the scattering medium 12. Due to the depolarization effect of the scattering medium 12, when a beam with a horizontal polarization direction is incident, the outgoing scattered light has not only a horizontal polarization component but also a vertical polarization component. The polarizer 14 is used to filter out the speckle intensity of the vertical polarization component in the scattered signal beam and the scattered reference beam.

[0033] As a further improvement of the present invention, the scattering medium 12 shall meet the usage conditions of the speckle correlation scattering matrix method: its transmission matrix satisfies the orthogonality of column vectors, and the scattered field scattered by it satisfies the complex Gaussian random distribution. Preferably, the scattering medium 12 is frosted glass.

[0034] In one specific installation method, firstly, the spatial light modulator 6 is fixed, and the image sensor 15 is installed on the right side of the spatial light modulator, so that the optical axis of the image sensor 15 passes through the center of the control light area of ​​the spatial light modulator. Then, a second prism 7, a third lens, a filter aperture 9, a fourth lens, a microscope objective 11, a scattering medium 12, a fifth convex lens 13, and a polarizer 14 are installed between the spatial light modulator 6 and the image sensor 15, ensuring that the second prism 7, the third convex lens 8, the filter aperture 9, the fourth convex lens 10, the microscope objective 11, the scattering medium 12, the fifth lens, and the polarizer 14 are coaxially installed. Then, a total reflection mirror 5 with a 45° tilt is installed above the second prism 7, and a second convex lens 4, a first convex lens 3, and a laser 1 are installed sequentially on the reflected light path of the total reflection mirror 5, so that all the light emitted by the laser 1 is reflected onto the second prism 7.

[0035] The arrangement of the modules in the system described above is only an example of this embodiment. Those skilled in the art can make further arrangements according to actual conditions, and this invention does not limit the scope of the invention.

[0036] This invention also provides an edge detection method based on speckle correlation scattering matrix; please refer to [link to relevant documentation]. Figure 2-5 The method includes: S1: Measure the transmission matrix of scattering medium 12 using the Hadamard phase-encoded optical field and the four-step phase-shifting method; It should be noted that this embodiment uses an incident mode number N=32. 32. Using a macro-pixel approach, each incident mode or incident channel corresponds to 16. The system consists of 16 spatial light modulators (6 pixels), each with a pixel size of 8μm. Please refer to [reference needed]. Figure 4 The reference light modulation area and signal light modulation area of ​​the spatial light modulator 6 are located in the same optical arm. The rectangular area in the middle of the spatial light modulator 5 is the dynamic signal light modulation area, while the part inside the circle and outside the rectangular area is the static reference light modulation area. Preferably, the proportions of the reference light modulation area and the signal light modulation area in the entire light-transmitting area of ​​the spatial light modulator 6 are 35% and 65%, respectively. The optical path is adjusted so that the size of a single speckle is comparable to the pixel of the image sensor 15, and the output is selected as M=512. 512 pixels are used as the output mode sampling number. Then the transfer matrix... The Hadamard matrix is ​​used to measure the optical transmission matrix because the pixels of the Hadamard matrix at the same modulus are 1 or -1, where 1 can represent the complex amplitude Aexp(j0) and -1 can represent the complex amplitude Aexp(jπ). Both have the same amplitude and A = 1, with a phase difference of π. This not only separates the intensity information from the phase information, but also allows all elements on the spatial light modulator 6 to be transparent, retaining the maximum intensity of the input beam. This ensures that sufficient energy is available for subsequent transmission through the scattering medium 12, reducing the experiment's sensitivity to noise.

[0037] S2: Acquire speckle intensity, load the image to be tested into the signal light modulation area of ​​the spatial light modulator 6, and the image sensor 15 acquires the speckle intensity of the image to be tested.

[0038] It should be noted that the hologram of the image to be detected is loaded into the signal light region of the spatial light modulator 6, and the size is also N=32. 32 macropixels. Correspondingly, the speckle intensity value is measured at the image sensor 15.

[0039] S3: Obtain edge information. Process the filtered transmission matrix and the detected speckle intensity using the algorithm to obtain the speckle correlation scattering matrix. Obtain the eigenvector corresponding to the largest eigenvalue of the speckle correlation scattering matrix to obtain the edge information value.

[0040] As a further improvement of the present invention, step S1, measuring the transfer matrix of the scattering medium 12 using the Hadamard method and the four-step phase shift method includes: S11: Measure the interference light field intensity of the signal beam and the reference beam when the phase offset is 0, π / 2, 3π / 2, and π respectively: in, Representing the One output channel, Corresponding to the The incident light field of the Haddamaki It is the first of the Hadamard matrix. The vector corresponding to the column, It is the first The reference optical complex amplitude used in each transmission channel for Hermitian conjugation, α represents the phase shift in the four-step phase shift, and the elements of the Hadamardi are 1 or -1; where 1 can represent the complex amplitude. -1 can be represented as complex amplitude ; S12: Solve for different Below : , in, It is the first of the Hadamard matrix. The vector corresponding to the column, It is the first The reference optical complex amplitude used in each transmission channel; S13: Solve all Composed of the Hadamard optical transmission matrix Transformed into a matrix under a Cartesian basis using basis vectors. .

[0041] As a further improvement of the present invention, in S13: all solutions are obtained Composed of the Hadamard optical transmission matrix Transformed into a matrix under a Cartesian basis using basis vectors. Following that, it also includes: S14: For the matrix Spiral phase filtering in the spatial frequency domain: ; in, Represents the transfer matrix Perform a two-dimensional Fourier transform on each row. Representing the spatial frequency domain, spatial filtering is performed to obtain... , S15: Perform a two-dimensional inverse Fourier transform back to the spatial domain to obtain the overall filtered transfer matrix. : .

[0042] As a further improvement of the present invention, in S3, the speckle correlation scattering matrix obtained by processing the filtered transmission matrix and the acquired speckle intensity algorithm of the image to be tested is as follows: in, Corresponding to the filtered transfer matrix The List, Represents the scattered field. It is the speckle intensity. , ,and It is the normalization factor. The multiplication between subvectors in the above formula is the multiplication between their corresponding elements, and the multiplication between subvectors is the Hadamard product.

[0043] As a further improvement of the present invention, in S3, obtaining the edge information value by finding the eigenvector corresponding to the largest eigenvalue of the speckle correlation scattering matrix specifically involves: obtaining the speckle correlation scattering matrix. The eigenvector corresponding to the largest eigenvalue yields the complex coefficient X of the incident field, and the magnitude of the complex value X is the required edge information value.

[0044] For further details, please see Figure 5-6 , Figure 5 (a) is a test image of the present invention. Figure 5 (b) is the speckle pattern obtained by scattering the image under test through a scattering medium 12 made of 120-mesh frosted glass. Figure 5 (c) The edge of the image to be tested is calculated by the speckle correlation scattering matrix method; Figure 6 These are experimental results of the edge detection device and method based on speckle correlation scattering matrix provided in the embodiments of the present invention. Figure 6 The embodiments in the example achieved a value of 0.9 or higher. Figure 6 (a) Theoretical edge calculation, (b) experimental edge measurement. The correlation between the image enhancement information and the theoretical image enhancement information was measured using the Pearson correlation coefficient, which reached 0.9380, meaning that the method proposed in this invention can accurately detect the edges of the image to be tested.

[0045] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0046] The above embodiments merely illustrate preferred implementations of the present invention, and their descriptions are quite specific and detailed. However, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. An edge detection method based on speckle correlation scattering matrix, characterized in that, include: S1: The transfer matrix of the scattering medium is measured using the Hadamard phase-encoded optical field and the four-step phase-shifting method; include S11: Measure the interference light field intensity of the signal beam and the reference beam when the phase offset is 0, π / 2, 3π / 2, and π respectively. in, Representing the One output channel, Corresponding to the The input light field of the Hadramakkis in the Vygotsky, It is the first of the Hadamard matrix. The vector corresponding to the column, It is the first The reference optical complex amplitude used in each transmission channel for Hermitian conjugation, α represents the phase shift in the four-step phase shift, and the elements of the Hadamardi are 1 or -1; where 1 can represent the complex amplitude. -1 can be represented as complex amplitude ; S12: Solve for different Below : in, It is the first of the Hadamard matrix. The vector corresponding to the column, It is the first The reference optical complex amplitude used in each transmission channel for Hermetic conjugation; S13: Solve all The optical transmission matrix under the Hadamazoid structure is formed. Transformed into a matrix under a Cartesian basis using basis vectors. ; S2: Load the image to be tested into the signal light modulation area of ​​the spatial light modulator, and the image sensor acquires the speckle intensity of the image to be tested; S3: The speckle correlation scattering matrix is ​​obtained by processing the filtered transfer matrix and the speckle intensity of the acquired image under test using an algorithm. in, Corresponding to the filtered transfer matrix The List, Represents the scattered field. Represents speckle intensity. , ,and It is a normalization factor; The edge information value of the image under test is obtained by finding the eigenvector corresponding to the largest eigenvalue of the speckle correlation scattering matrix.

2. The edge detection method based on speckle correlation scattering matrix as described in claim 1, characterized in that, In S13: Solve all The optical transmission matrix under the Hadamazoid structure is formed. Transformed into a matrix under a Cartesian basis using basis vectors. Following that, it also includes: S14: For the matrix Spiral phase filtering in the spatial frequency domain: in, Represents the transfer matrix Perform a two-dimensional Fourier transform on each row. Represents the spatial frequency domain; S15: Perform a two-dimensional inverse Fourier transform back to the spatial domain to obtain the overall filtered transfer matrix. : in, Represents the transfer matrix Perform a two-dimensional inverse Fourier transform on each row, and then perform spatial filtering to obtain... .

3. The edge detection method based on speckle correlation scattering matrix as described in claim 1, characterized in that, In step S3, obtaining the edge information value by finding the eigenvector corresponding to the largest eigenvalue of the speckle correlation scattering matrix specifically involves: obtaining the speckle correlation scattering matrix. The eigenvector corresponding to the largest eigenvalue yields the complex coefficient X of the incident field, and the magnitude of the complex value X is the required edge information value.

4. An edge detection device based on a speckle correlation scattering matrix, implementing the edge detection method based on a speckle correlation scattering matrix as described in claim 1, characterized in that, include: A laser, used to emit the first beam; A spatial light modulator includes a signal light modulation region and a reference light modulation region, wherein the signal light modulation region is used to receive the first light beam output signal beam, and the reference light modulation region is used to receive the first light beam output reference beam. A scattering medium is used to receive the signal beam, scatter the signal beam, and output a scattered signal beam; the scattering medium is also used to receive the reference beam, scatter the reference beam, and output a scattered reference beam. An image sensor is used to receive the scattered signal beam and the scattered reference beam, and the image sensor acquires the speckle intensity of the image under test; The data processing module controls the spatial light modulator to load different phase-coded light fields, obtains the intensity of the interference light field of the scattered signal beam and the scattered reference beam, performs algorithmic processing on the intensity of the interference light field to obtain the transmission matrix of the scattering medium, controls the spatial light modulator to load the image under test in the signal light modulation area, controls the image sensor to acquire the speckle intensity of the image under test, calculates and processes all the data acquired by the image sensor to obtain the speckle-related scattering matrix, and calculates and processes the speckle-related scattering matrix to obtain edge information values.

5. The edge detection device based on speckle correlation scattering matrix as described in claim 4, characterized in that, Between the laser emitter and the spatial light modulator, a first prism, a first convex lens, a second convex lens, a total reflection mirror, and a second prism are sequentially arranged along the optical path. The first prism polarizes the first beam and outputs a second beam. The first convex lens expands the second beam and outputs a third beam. The second convex lens collimates the third beam and outputs a fourth beam. The total reflection mirror receives the fourth beam and vertically inputs it into the second prism. The second prism receives the fourth beam, splits it, and outputs it.

6. The edge detection device based on speckle correlation scattering matrix as described in claim 5, characterized in that, A 4f light group and a microscope objective are sequentially arranged between the spatial light modulator and the scattering medium along the optical path; The second prism transmits the signal beam to the 4f optical group, the 4f optical group filters the signal beam and outputs a fifth beam, and the microscope objective focuses the fifth beam and outputs it. The second prism transmits the reference beam to the 4f beam group, the 4f beam group filters the reference beam and outputs a sixth beam, and the microscope objective focuses the sixth beam and outputs it.

7. The edge detection device based on speckle correlation scattering matrix as described in claim 4, characterized in that, A fifth convex lens and a polarizer are sequentially arranged between the scattering medium and the image sensor along the optical path; The fifth convex lens converges the scattered modulated beam onto the polarizer, and the polarizer filters out the vertical polarization component of the scattered signal beam and outputs it. The fifth convex lens converges the scattered reference beam onto the polarizer, and the polarizer filters out the vertical polarization component of the scattered reference beam and outputs it.

8. The edge detection device based on speckle correlation scattering matrix as described in claim 4, characterized in that, The scattering medium is frosted glass.

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