Multilayer target tomography method, device and equipment based on polarization illumination

Abstract

The invention provides a multi-layer target tomography method, device and equipment based on polarization illumination. The method comprises the following steps: acquiring an orthogonal polarization image pair; establishing a current Jones matrix based on the current optical axis direction and the current phase delay, and establishing a Jones vector for the corresponding initial polarization incident light by using the cross-polarization image; jointly establishing a current forward propagation model through the current Jones matrix and the current Jones vector; performing parameter updating processing on the current forward propagation model based on the cross-polarization image pair to obtain updated light field data; and carrying out back propagation processing on the updated light field data to obtain a post-layer light field. According to the method, a forward propagation model is established according to the polarization characteristic of a target scattering light field, reverse updating processing is continuously carried out on a Jones matrix through the iteration process of reverse propagation, parallel reconstruction of multiple pieces of target information is finally achieved, and a multi-layer target tomography result is obtained. As the hardware equipment and the lighting state do not need to be calibrated, the tomography efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of computational imaging technology, and in particular to a multi-layer target tomography method, device and equipment based on polarized illumination. Background Art

[0002] Existing deep multi-layer microscopy technology can achieve high-speed parallel imaging and sensing of multiple targets. This technology establishes sample constraints on the light field interpretation process by changing the incident light illumination angle, and models different target layers as different coding surfaces and restores them. However, this technology relies on the change of the incident light illumination angle, which not only requires the introduction of mechanical moving equipment or the use of LEDs to provide illumination at different angles during the experiment, but also requires the calculation and calibration of the state of the illumination light during the reconstruction process, thus increasing the complexity of the solution process of this method.

[0003] For most biological tissues and crystalline materials, their anisotropic structure will cause the polarization information carried by light to change when it is transmitted in the sample (target). After the light is modulated by the sample structure and birefringence properties, the emitted scattered light field will highlight its polarization characteristics. By measuring and interpreting the polarization information of the scattered light field, the information of the sample can be obtained. Therefore, if the modulation effect of the sample on the polarization information of the light scattering field is used to analyze the change process of the polarization information when the light field passes through multi-layer targets, establish new sample constraints, and realize the modeling of light field information under single angle illumination, it will greatly simplify the complexity of the experimental system and improve imaging efficiency.

[0004] Therefore, how to improve the structure and imaging process of the imaging system in the prior art has important application prospects and value in improving detection efficiency. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a multi-layer target tomography method, device and equipment based on polarized illumination.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a multi-layer target tomography method based on polarized illumination, comprising:

[0008] S101, acquiring an orthogonal polarization image pair; the first polarization image and the second polarization image in the orthogonal polarization image pair are a pair of polarization images acquired by a multi-layer target tomography device under fixed polarized light illumination conditions, and the orthogonal polarization image pair contains multiple target information; the multiple target information contains preset coding layer information;

[0009] S102, establishing a current Jones matrix based on the current optical axis direction and the current phase delay, and establishing a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image;

[0010] S103, jointly establishing a current forward propagation model through the current Jones matrix and the Jones vector;

[0011] S104, performing parameter update processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data;

[0012] S105, performing back propagation processing on the updated light field data to obtain a post-layer light field;

[0013] S106, updating the current optical axis direction and the current phase delay in S102 based on the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and using the updated optical axis direction as the current optical axis direction in S102, and using the updated phase delay as the current phase delay in S102;

[0014] S107, repeatedly executing S102-S106 until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets the preset convergence condition;

[0015] S108. When S107 is established, the updated optical axis direction and the updated phase delay corresponding to the most recent execution of S106 are used as the multi-slice target tomography result.

[0016] Optionally, the current Jones matrix is ​​expressed as:

[0017]

[0018] Among them, Js t represents the current Jones matrix of the target at the tth layer, θ represents the current optical axis direction, δ represents the current phase delay, i represents the imaginary unit, and T represents the total number of layers of the target;

[0019] The Jones vector is expressed as:

[0020]

[0021] Among them, E j represents the Jones vector under the jth illumination condition, E x represents the initial polarized incident light of the orthogonal polarization image under the x-axis component, E y represents the initial polarized incident light of the orthogonal polarization image under the y-axis component, and J represents the total number of lighting conditions.

[0022] Optionally, the current forward propagation model is expressed as:

[0023]

[0024] in, Represents the current light field data of the T-th layer target under the j-th illumination condition, PSF free (d1) represents the free space propagation kernel under the propagation distance d1, d1 represents the distance from the first layer target to the second layer target, PSF free (d T-1 ) represents the propagation distance d T-1 The free space propagation kernel under T-1 Indicates the distance from the target on the T-1th layer to the target on the Tth layer.

[0025] Optionally, performing parameter update processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data includes:

[0026] Based on the amplitude value corresponding to the orthogonal polarization image and the current forward propagation model, the updated light field data is calculated using the following formula:

[0027]

[0028] represents the kth row of Jones vector components corresponding to the updated light field data of the Tth layer target under the jth illumination condition, I jk represents the k-th row Jones vector component corresponding to the light intensity value of the orthogonal polarization image under the j-th illumination condition, represents the kth row of Jones vector components corresponding to the current light field data of the Tth layer target under the jth illumination condition, where I jk The corresponding intensity values ​​are obtained based on the orthogonal polarization images.

[0029] Optionally, the post-layer light field is represented as:

[0030]

[0031] in, represents the kth row of Jones vector components corresponding to the post-layer light field of the tth layer target under the jth illumination condition, represents the k-th row of Jones vector components corresponding to the updated light field data of the t-th layer target under the j-th illumination condition, PSF free (-d t ) represents the propagation distance - d t The free space propagation kernel under t Represents the distance from the target at the tth layer to the target at the t+1th layer.

[0032] Optionally, updating the current optical axis direction and the current phase delay in S102 based on the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and using the updated optical axis direction as the current optical axis direction in S102, and using the updated phase delay as the current phase delay in S102, includes:

[0033] Using the post-layer light field, the current optical axis direction and the current phase delay, the following formula is used for update processing to obtain the non-complex increment of the current optical axis direction and the non-complex increment of the current phase delay:

[0034]

[0035] represents the kth row of Jones vector components corresponding to the post-layer light field of the tth layer target under the jth illumination condition, Indicates before update The partial derivative expression of the element in the kth row and the uth column of the current Jones matrix representing the target of the tth layer with respect to θ is: represents the partial derivative expression of the element in the kth row and the uth column of the current Jones matrix of the tth layer target with respect to δ, Δθ represents the non-complex increment in the current optical axis direction, Δδ represents the non-complex increment in the current phase delay, represents the u-th Jones vector component of the current light field data of the t-1-th layer target under the j-th illumination condition;

[0036] Based on the non-complex increment of the current optical axis direction and the non-complex increment of the current phase delay, the updated optical axis direction and the updated phase delay are calculated using the following formula:

[0037] θ'=θ+α·Δθ;

[0038] δ'=δ+α·Δδ;

[0039] θ' represents the updated optical axis direction, δ' represents the updated phase delay, θ represents the current optical axis direction, δ represents the current phase delay, and α represents the step coefficient;

[0040] The updated optical axis direction is used as the current optical axis direction in S102, and the updated phase delay is used as the current phase delay in S102.

[0041] Optionally, the preset convergence condition is that the non-complex increment corresponding to the updated optical axis direction and the non-complex increment corresponding to the updated phase delay are both smaller than a preset threshold.

[0042] In a second aspect, the present invention provides a multi-layer target tomography device based on polarized illumination, comprising: an acquisition unit, a matrix establishment unit, an update unit, a processing unit, an iteration unit, and a judgment unit;

[0043] The acquisition unit is used to: acquire an orthogonal polarization image pair; the first polarization image and the second polarization image in the orthogonal polarization image pair are a pair of polarization images acquired by a multi-layer target tomography device under fixed polarized light illumination conditions, and the orthogonal polarization image pair contains multiple target information; the multiple target information contains preset coding layer information;

[0044] The matrix establishing unit is used to: establish a current Jones matrix based on the current optical axis direction and the current phase delay, and establish a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image;

[0045] The current forward propagation model is established through the current Jones matrix and Jones vector;

[0046] The updating unit is used to: perform parameter updating processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data;

[0047] The processing unit is used to: perform back propagation processing on the updated light field data to obtain the post-layer light field;

[0048] The updating unit is further used for: performing updating processing based on the current optical axis direction and the current phase delay of the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and using the updated optical axis direction as the current optical axis direction in the matrix establishing unit, and using the updated phase delay as the current phase delay in the matrix establishing unit;

[0049] The iteration unit is used to: control the repeated execution of the operations of the matrix establishment unit, the update unit and the processing unit until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets the preset convergence condition;

[0050] The judging unit is used for: when the preset convergence condition of the iterative unit is satisfied, taking the updated optical axis direction and the updated phase delay of the most recent update executed in the updating unit as the multi-layer target tomography result.

[0051] In a third aspect, the present invention provides a multi-layer target tomography device based on polarized illumination, the multi-layer target tomography device based on polarized illumination comprises: a first unit, a second unit and a third unit arranged in sequence;

[0052] The first unit comprises: a coherent light source, a collimating lens and a first polarization modulation device which are arranged in sequence; the center of the coherent light source is aligned with the center of the collimating lens;

[0053] The second unit is provided with a second polarization modulation device; a plurality of targets to be imaged are stacked and arranged between the first unit and the second polarization modulation device along the axial direction, and the centers of the plurality of targets to be imaged are aligned with the center of the collimating lens; the last layer of the plurality of targets to be imaged is set as a coding layer;

[0054] The third unit includes: a detector and a computing device arranged in sequence; the distance between the edge of the coding layer and the detector is 1-5 mm.

[0055] In a fourth aspect, the present invention provides a multi-layer target tomography imaging device based on polarized illumination, comprising: a processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor. When the multi-layer target tomography imaging device based on polarized illumination is running, the processor and the storage medium communicate via the bus, and the processor executes the machine-readable instructions to perform the steps of the multi-layer target tomography imaging method based on polarized illumination as described in the first aspect above.

[0056] The present invention provides a multi-layer target tomography method, device and equipment based on polarized illumination. Among them, a multi-layer target tomography method based on polarized illumination includes: S101, obtaining an orthogonal polarization image pair; the first polarization image and the second polarization image in the orthogonal polarization image pair are a pair of polarization images collected under fixed polarized light illumination conditions using a multi-layer target tomography device, and the orthogonal polarization image pair contains multiple target information; S102, establishing a current Jones matrix based on the current optical axis direction and the current phase delay, and establishing a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image pair; S103, jointly establishing a current forward propagation model through the current Jones matrix and the Jones vector; S104, performing parameter update processing on the current forward propagation model based on the orthogonal polarization image pair to obtain an updated light field data; S105, back-propagating the updated light field data to obtain the post-layer light field; S106, updating the current optical axis direction and the current phase delay in S102 based on the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and using the updated optical axis direction as the current optical axis direction in S102, and using the updated phase delay as the current phase delay in S102; S107, repeatedly executing S102-S106 until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets the preset convergence condition; S108, when S107 is established, using the updated optical axis direction and the updated phase delay corresponding to the most recent execution of S106 as the multi-layer target tomography result. In the present invention, based on a pair of polarized images collected under polarized light illumination conditions, the target information of each single layer is effectively separated from the aliased image information of the multi-layer target. Specifically, the forward propagation model is established based on the polarization characteristics of the target scattered light field, and the Jones matrix is ​​continuously updated inversely through the iterative process of reverse propagation, and finally the parallel reconstruction of multiple target information under single-angle illumination is achieved to obtain the multi-layer target tomography result. Since the present invention does not need to calibrate the hardware equipment and the illumination state, the efficiency of multi-layer target tomography is improved.

[0057] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic flow chart of a multi-layer target tomography method based on polarized illumination provided by an embodiment of the present invention;

[0059] Figure 2 A flowchart of a multi-layer target tomography method based on polarized illumination provided by an embodiment of the present invention;

[0060] Figure 3 A schematic structural diagram of a multi-layer target tomography device based on polarized illumination provided by an embodiment of the present invention;

[0061] Figure 4 A schematic structural diagram of a multi-layer target tomography device based on polarized illumination provided by an embodiment of the present invention;

[0062] Figure 5 A schematic structural diagram of a multi-layer target tomography device based on polarized illumination provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0064] In order to improve the efficiency of multi-layer target tomography, an embodiment of the present invention provides a multi-layer target tomography method based on polarized illumination. Figure 1 A schematic flow chart of a multi-layer target tomography method based on polarized illumination provided by an embodiment of the present invention. Figure 1 As shown, including:

[0065] S101. Acquire an orthogonal polarization image pair.

[0066] It should be noted that the orthogonal polarization image pair includes a first polarization image and a second polarization image. The first polarization image and the second polarization image are a pair of polarization images collected by a multi-layer target tomography device under fixed polarized light illumination conditions. The orthogonal polarization image pair includes multiple target information, and the multiple target information includes preset coding layer information.

[0067] Specifically, the last layer of the multiple objects to be imaged is set as a coding layer, and information corresponding to the coding layer is preset coding layer information.

[0068] It should be noted that, in the embodiment of the present invention, the first polarization image and the second polarization image correspond to images collected by the second polarization modulation device along the horizontal and vertical directions.

[0069] In addition, in an embodiment of the present invention, the last layer of the target to be imaged is set as a coding layer. It can be understood that by setting the coding layer, the light field information of the blank area of ​​the target to be imaged can be modulated. At the same time, the coding layer can play the role of a high-resolution computational lens to achieve clear imaging of the target to be imaged.

[0070] The process of acquiring orthogonal polarization image pairs based on the multi-layer target tomography device is as follows:

[0071] Step 1: Turn on the coherent light source 1;

[0072] Step 2: Align the coherent light source 1 with the center of the collimating lens 2 so that the light spot of the coherent light source 1 completely covers the target 4;

[0073] Step 3: placing the first polarization modulation device 3 before the target 4 and behind the collimating lens 2;

[0074] Step 4: stack all targets 4 axially and place them at the same lateral position, align them with the center of the collimating lens 2, and set the target spacing;

[0075] Step 5: Place the detector 6 2-3 cm away from the last target, and place the second polarization modulation device 5 between the target 4 and the detector 6;

[0076] Step 6: Turn on the detector 6 to receive the images generated by the first unit and the second unit, and adjust the first unit and the second unit so that the imaging spot is located at the center of the detector target surface;

[0077] Step 7: Rotate the first polarization modulator 3 to generate different polarized illuminations, and rotate the second polarization modulator 5 so that the polarization axis is located at 0 degree and 90 degree to obtain two images containing orthogonal polarization information, which are used as the first polarization image and the second polarization image.

[0078] S102 , establishing a current Jones matrix based on the current optical axis direction and the current phase delay, and establishing a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image.

[0079] Optionally, the current Jones matrix is ​​expressed as:

[0080]

[0081] Among them, Js t represents the current Jones matrix of the target at the tth layer, θ represents the current optical axis direction, δ represents the current phase delay, i represents the imaginary unit, and T represents the total number of layers of the target;

[0082] The Jones vector is expressed as:

[0083]

[0084] Among them, E j represents the Jones vector under the jth illumination condition, E x represents the initial polarized incident light of the orthogonal polarization image under the x-axis component, E y represents the initial polarized incident light of the orthogonal polarization image under the y-axis component, and J represents the total number of lighting conditions.

[0085] S103. Establish the current forward propagation model through the current Jones matrix and Jones vector.

[0086] Optionally, the current forward propagation model is expressed as:

[0087]

[0088] in, Represents the current light field data of the T-th layer target under the j-th illumination condition, PSF free (d1) represents the free space propagation kernel under the propagation distance d1, d1 represents the distance from the first layer target to the second layer target, PSF free (d T-1 ) represents the propagation distance d T-1 The free space propagation kernel under T-1 Indicates the distance from the target on the T-1th layer to the target on the Tth layer.

[0089] S104 , performing parameter update processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data.

[0090] Optionally, S104 may specifically include:

[0091] Based on the amplitude value corresponding to the orthogonal polarization image and the current forward propagation model, the updated light field data is calculated using the following formula:

[0092]

[0093] represents the kth row of Jones vector components corresponding to the updated light field data of the Tth layer target under the jth illumination condition, I jk represents the k-th row Jones vector component corresponding to the light intensity value of the orthogonal polarization image under the j-th illumination condition, represents the kth row of Jones vector components corresponding to the current light field data of the Tth layer target under the jth illumination condition, where I jk The corresponding intensity values ​​are obtained based on the orthogonal polarization images.

[0094] It should be noted that The overall value represents the amplitude value corresponding to the orthogonal polarization image.

[0095] S105 , performing back propagation processing on the updated light field data to obtain a post-layer light field.

[0096] Optionally, the post-layer light field is represented as:

[0097]

[0098] in, represents the kth row of Jones vector components corresponding to the post-layer light field of the tth layer target under the jth illumination condition, represents the k-th row of Jones vector components corresponding to the updated light field data of the t-th layer target under the j-th illumination condition, PSF free (-d t ) represents the propagation distance - d t The free space propagation kernel under t Represents the distance from the target at the tth layer to the target at the t+1th layer.

[0099] Furthermore, in the embodiment of the present invention, PSF free It can be expressed as follows:

[0100]

[0101] Where d represents the interlayer spacing, n is the refractive index of the interlayer medium, and f x and f y They represent the spatial frequency distribution in the x-axis direction and the spatial frequency distribution in the y-axis direction respectively, λ represents the wavelength, and i represents an imaginary number.

[0102] S106. Update the current optical axis direction and the current phase delay in S102 based on the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and use the updated optical axis direction as the current optical axis direction in S102, and use the updated phase delay as the current phase delay in S102.

[0103] Optionally, S106 may specifically include:

[0104] Using the post-layer light field, the current optical axis direction and the current phase delay, the following formula is used for update processing to obtain the non-complex increment of the current optical axis direction and the non-complex increment of the current phase delay:

[0105]

[0106] represents the kth row of Jones vector components corresponding to the post-layer light field of the tth layer target under the jth illumination condition, Indicates before update The partial derivative expression of the element in the kth row and the uth column of the current Jones matrix representing the target of the tth layer with respect to θ is: represents the partial derivative expression of the element in the kth row and the uth column of the current Jones matrix of the tth layer target with respect to δ, Δθ represents the non-complex increment in the current optical axis direction, Δδ represents the non-complex increment in the current phase delay, represents the u-th Jones vector component of the current light field data of the t-1-th layer target under the j-th illumination condition;

[0107] Based on the non-complex increment of the current optical axis direction and the non-complex increment of the current phase delay, the updated optical axis direction and the updated phase delay are calculated using the following formula:

[0108] θ'=θ+α·Δθ;

[0109] δ'=δ+α·Δδ;

[0110] θ' represents the updated optical axis direction, δ' represents the updated phase delay, θ represents the current optical axis direction, δ represents the current phase delay, and α represents the step coefficient;

[0111] The updated optical axis direction is used as the current optical axis direction in S102, and the updated phase delay is used as the current phase delay in S102.

[0112] Furthermore, in an embodiment of the present invention, The update process is expressed as:

[0113]

[0114] Indicates that The updated result, γ represents the step size coefficient.

[0115] Will Substitute the calculation formula corresponding to S104 and repeat the updating process of the target layer until the update is completed under all polarized illuminations. t (t=1,2,...T) is put into the forward propagation model as input, and then the update process is performed until the current Jones matrix corresponding to the target of each layer meets the preset convergence condition.

[0116] S107 , repeatedly executing S102 - S106 until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets a preset convergence condition.

[0117] Optionally, the preset convergence condition is that the non-complex increment corresponding to the updated optical axis direction and the non-complex increment corresponding to the updated phase delay are both smaller than a preset threshold.

[0118] S108. When S107 is established, the updated optical axis direction and the updated phase delay corresponding to the most recent execution of S106 are used as the multi-slice target tomography result.

[0119] The embodiment of the present invention provides a multi-layer target tomography method based on polarized illumination, including: based on a pair of polarized images collected under polarized light illumination conditions as the focus point, effectively separating the target information of each single layer from the aliased image information of the multi-layer target, specifically, establishing a forward propagation model based on the polarization characteristics of the target scattered light field, and continuously performing reverse update processing on the Jones matrix through the iterative process of reverse propagation, and finally achieving parallel reconstruction of multiple target information to obtain multi-layer target tomography results. Since the present invention does not require calibration of hardware equipment and illumination status, the efficiency of multi-layer target tomography is improved.

[0120] In order to explain the implementation process of the method of the present invention in detail, Figure 2 A flowchart of a multi-layer target tomography method based on polarized illumination provided by an embodiment of the present invention. Figure 2 As shown, first, a 1 / 4 wave plate is rotated at a fixed angle at intervals of 0 to 180 degrees to obtain polarized illumination, and two images are collected under single polarized light illumination to obtain an orthogonal polarized image pair. Then, the detector plane light field information is updated according to the orthogonal polarized image pair, during which the initial guess (initial optical axis direction and initial phase delay) of each layer of the target is set and the light field wavefront information is obtained according to the forward propagation model, and the light field information after the target layer is updated according to the plane light field information and the light field wavefront information is back-propagated back to each layer of the target (obtaining the layer-post light field), and then the target information and the light field information before the target layer are updated according to the formula of the above embodiment (obtaining the updated optical axis direction and the updated phase delay), and the updated optical axis direction is used as the initial optical axis direction, and the updated phase delay is used as the initial phase delay; and the above processing is repeated until the Jones matrix corresponding to each layer of the target in the orthogonal polarized image pair meets the preset convergence condition, and finally the multi-layer target tomography result is obtained.

[0121] The method provided in the embodiment of the present invention can be applied to an electronic device. Specifically, the electronic device can be: a desktop computer, a portable computer, an intelligent mobile terminal, a server, etc., which is not limited in the embodiment of the present invention.

[0122] Corresponding to a multi-layer target tomography method based on polarized illumination, Figure 3 A schematic diagram of the structure of a multi-layer target tomography device based on polarized illumination provided by an embodiment of the present invention. Figure 3 As shown, the multi-layer target tomography device includes: a first unit A, a second unit B and a third unit C arranged in sequence;

[0123] The first unit A comprises: a coherent light source 1, a collimating lens 2 and a first polarization modulation device 3 which are arranged in sequence; the center of the coherent light source 1 is aligned with the center of the collimating lens 2;

[0124] The second unit B is provided with a second polarization modulation device 5; a plurality of targets 4 to be imaged are stacked axially between the first unit A and the second polarization modulation device 5, and the centers of the plurality of targets 4 to be imaged are aligned with the center of the collimating lens 2; the last layer of the plurality of targets to be imaged is set as a coding layer;

[0125] The third unit C comprises: a detector 6 and a computing device 7 which are arranged in sequence; the distance between the edge of the coding layer and the detector 6 is 1-5 mm.

[0126] Furthermore, in another embodiment, a polarization camera may be used to integrate the functions of the second polarization modulation device 5 and the detector 6 to reduce the design complexity of the multi-layer target tomography imaging device.

[0127] Based on the same inventive concept, an embodiment of the present invention further provides a multi-layer target tomography device based on polarized illumination. Figure 4 A schematic diagram of the structure of a multi-layer target tomography device based on polarized illumination provided by an embodiment of the present invention. Figure 4 As shown, it includes: an acquisition unit 401, a matrix establishment unit 402, an update unit 403, a processing unit 404, an iteration unit 405 and a judgment unit 406;

[0128] The acquisition unit 401 is used to: acquire an orthogonal polarization image pair; the first polarization image and the second polarization image in the orthogonal polarization image pair are a pair of polarization images collected by a multi-layer target tomography device under fixed polarized light illumination conditions, and the orthogonal polarization image pair contains multiple target information, and the multiple target information contains preset coding layer information;

[0129] The matrix establishing unit 402 is used to: establish a current Jones matrix based on the current optical axis direction and the current phase delay, and establish a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image;

[0130] The current forward propagation model is established through the current Jones matrix and Jones vector;

[0131] The updating unit 403 is used to: perform parameter updating processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data;

[0132] The processing unit 404 is used to: perform back propagation processing on the updated light field data to obtain a post-layer light field;

[0133] The updating unit 403 is further used to: perform updating processing based on the current optical axis direction and the current phase delay of the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and use the updated optical axis direction as the current optical axis direction in the matrix establishing unit, and use the updated phase delay as the current phase delay in the matrix establishing unit;

[0134] The iteration unit 405 is used to control the repeated execution of the operations of the matrix establishment unit, the updating unit and the processing unit until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets the preset convergence condition;

[0135] The judging unit 406 is used for: when the preset convergence condition of the iterative unit is satisfied, taking the updated optical axis direction and the updated phase delay of the most recent update performed in the updating unit as the multi-slice target tomography result.

[0136] Figure 5 A schematic structural diagram of a multi-layer target tomography device based on polarized illumination provided by an embodiment of the present invention includes: a processor 710, a storage medium 720 and a bus 730, wherein the storage medium 720 stores machine-readable instructions executable by the processor 710, and when the multi-layer target tomography device based on polarized illumination is running, the processor 710 communicates with the storage medium 720 via the bus 730, and the processor 710 executes the machine-readable instructions to execute the steps of the above method embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0137] The storage medium may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk storage. Optionally, the storage medium may also be at least one storage device located away from the aforementioned processor.

[0138] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0139] It should be noted that the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention.

[0140] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0141] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other changes of the above disclosed embodiments by viewing the drawings and the disclosed content. In the description of the present invention, the term "comprising" does not exclude other components or steps, "one" or "an" does not exclude multiple situations, and the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited. In addition, certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0142] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A multi-layer target tomography method based on polarized illumination, characterized in that: include: S101, acquiring an orthogonal polarization image pair; the first polarization image and the second polarization image in the orthogonal polarization image pair are a pair of polarization images acquired by a multi-layer target tomography device under fixed polarized light illumination conditions, and the orthogonal polarization image pair contains multiple target information; the multiple target information contains preset coding layer information; S102, establishing a current Jones matrix based on the current optical axis direction and the current phase delay, and establishing a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image pair; S103, jointly establishing a current forward propagation model through the current Jones matrix and the Jones vector; S104, performing parameter update processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data; S105, performing back propagation processing on the updated light field data to obtain a post-layer light field; S106, updating the current optical axis direction and the current phase delay in S102 based on the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and using the updated optical axis direction as the current optical axis direction in S102, and using the updated phase delay as the current phase delay in S102; S107, repeatedly executing S102-S106 until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets a preset convergence condition; S108. When S107 is established, the updated optical axis direction and the updated phase delay corresponding to the most recent execution of S106 are used as the multi-slice target tomography result.

2. The multi-layer target tomography method based on polarized illumination according to claim 1, characterized in that: The current Jones matrix is ​​expressed as: Among them, Js t represents the current Jones matrix of the target at the tth layer, θ represents the current optical axis direction, δ represents the current phase delay, i represents the imaginary unit, and T represents the total number of layers of the target; The Jones vector is expressed as: Among them, E j represents the Jones vector under the jth illumination condition, E x represents the initial polarized incident light of the orthogonal polarization image under the x-axis component, E y represents the initial polarized incident light of the orthogonal polarization image under the y-axis component, and J represents the total number of lighting conditions.

3. The multi-layer target tomography method based on polarized illumination according to claim 2, characterized in that: The current forward propagation model is expressed as: in, Represents the current light field data of the T-th layer target under the j-th illumination condition, PSF free (d1) represents the free space propagation kernel under the propagation distance d1, d1 represents the distance from the first layer target to the second layer target, PSF free (d T-1 ) represents the propagation distance d T-1 The free space propagation kernel under T-1 represents the distance from the target on the T-1th layer to the target on the Tth layer, d T Indicates the distance from the target in the Tth layer to the detector.

4. The multi-layer target tomography method based on polarized illumination according to claim 1, characterized in that: The performing parameter updating processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data includes: Based on the amplitude value corresponding to the orthogonal polarization image and the current forward propagation model, the updated light field data is calculated using the following formula: represents the kth row of Jones vector components corresponding to the updated light field data of the Tth layer target under the jth illumination condition, I jk represents the k-th row Jones vector component corresponding to the light intensity value of the orthogonal polarization image under the j-th illumination condition, represents the kth row of Jones vector components corresponding to the current light field data of the Tth layer target under the jth illumination condition, where the I jk The intensity value corresponding to the orthogonal polarization image is obtained.

5. The multi-layer target tomography method based on polarized illumination according to claim 1, characterized in that: The light field after the layer is expressed as: in, represents the kth row of Jones vector components corresponding to the post-layer light field of the tth layer target under the jth illumination condition, represents the k-th row of Jones vector components corresponding to the updated light field data of the t-th layer target under the j-th illumination condition, PSF free (-d t ) represents the propagation distance - d t The free space propagation kernel under t Represents the distance from the target at the tth layer to the target at the t+1th layer.

6. The multi-layer target tomography method based on polarized illumination according to claim 1, characterized in that: The current optical axis direction and the current phase delay in S102 are updated based on the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and the updated optical axis direction is used as the current optical axis direction in S102, and the updated phase delay is used as the current phase delay in S102, including: The post-layer light field, the current optical axis direction and the current phase delay are used to perform update processing through the following formula to obtain a non-complex increment of the current optical axis direction and a non-complex increment of the current phase delay: represents the kth row of Jones vector components corresponding to the post-layer light field of the tth layer target under the jth illumination condition, Indicates before update The partial derivative expression of the element in the kth row and the uth column of the current Jones matrix representing the target of the tth layer with respect to θ is: represents the partial derivative expression of the element in the kth row and the uth column of the current Jones matrix of the tth layer target with respect to δ, Δθ represents the non-complex increment in the current optical axis direction, Δδ represents the non-complex increment in the current phase delay, represents the u-th Jones vector component of the current light field data of the t-1-th layer target under the j-th illumination condition; Based on the non-complex increment of the current optical axis direction and the non-complex increment of the current phase delay, the updated optical axis direction and the updated phase delay are calculated using the following formula: θ'=θ+α·Δθ; δ'=δ+α·Δδ; θ' represents the updated optical axis direction, δ' represents the updated phase delay, θ represents the current optical axis direction, δ represents the current phase delay, and α represents the step coefficient; The updated optical axis direction is used as the current optical axis direction in S102, and the updated phase delay is used as the current phase delay in S102.

7. The multi-layer target tomography method based on polarized illumination according to claim 1, characterized in that: The preset convergence condition is that the non-complex increment corresponding to the updated optical axis direction and the non-complex increment corresponding to the updated phase delay are both smaller than a preset threshold.

8. A multi-layer target tomography device based on polarized illumination, characterized in that: include: An acquisition unit, a matrix creation unit, an update unit, a processing unit, an iteration unit, and a judgment unit; The acquisition unit is used to: acquire an orthogonal polarization image pair; the first polarization image and the second polarization image in the orthogonal polarization image pair are a pair of polarization images acquired by a multi-layer target tomography device under fixed polarized light illumination conditions, and the orthogonal polarization image pair contains multiple target information; the multiple target information contains preset coding layer information; The matrix establishing unit is used to: establish a current Jones matrix based on the current optical axis direction and the current phase delay, and establish a Jones vector using the initial polarized incident light corresponding to the orthogonal polarization image pair; Establishing a current forward propagation model by using the current Jones matrix and the Jones vector; The updating unit is used to: perform parameter updating processing on the current forward propagation model based on the orthogonal polarization image pair to obtain updated light field data; The processing unit is used to: perform back propagation processing on the updated light field data to obtain a post-layer light field; The updating unit is further used for: performing updating processing based on the current optical axis direction and the current phase delay of the post-layer light field to obtain an updated optical axis direction and an updated phase delay, and using the updated optical axis direction as the current optical axis direction in the matrix establishing unit, and using the updated phase delay as the current phase delay in the matrix establishing unit; The iteration unit is used to control the operations of the matrix establishment unit, the update unit and the processing unit to be repeatedly executed until the current Jones matrix corresponding to each layer of the target in the orthogonal polarization image pair meets the preset convergence condition; The judgment unit is used for: when the preset convergence condition of the iteration unit is satisfied, taking the updated optical axis direction and the updated phase delay when the update is performed most recently in the update unit as the multi-slice target tomography result.

9. A multi-layer target tomography device based on polarized illumination, characterized in that: The multi-layer target tomography device based on polarized illumination comprises: a first unit, a second unit and a third unit arranged in sequence; The first unit comprises: a coherent light source, a collimating lens and a first polarization modulation device which are arranged in sequence; the center of the coherent light source is aligned with the center of the collimating lens; The second unit is provided with a second polarization modulation device; a plurality of targets to be imaged are stacked and arranged between the first unit and the second polarization modulation device along the axial direction, and the centers of the plurality of targets to be imaged are all flush with the center of the collimating lens; the last layer of the plurality of targets to be imaged is set as a coding layer; The third unit includes: a detector and a computing device arranged in sequence; the distance between the edge of the coding layer and the detector is 1-5 mm.

10. A multi-layer target tomography device based on polarized illumination, characterized in that: include: A processor, a storage medium and a bus, wherein the storage medium stores machine-readable instructions executable by the processor, and when the multi-layer target tomography imaging device based on polarization illumination is running, the processor communicates with the storage medium through the bus, and the processor executes the machine-readable instructions to perform the steps of the multi-layer target tomography imaging method based on polarization illumination as described in any one of claims 1 to 7.

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