Coordinate system correction and unification method of reflective full-polarization imaging system

Abstract

The invention provides a coordinate system correction and unification method for a reflective full-polarization imaging system. The method comprises the following steps: acquiring a muller matrix of an anisotropic column scattering phantom model through the reflective full-polarization imaging system; secondly, judging the state of the photon coordinate system by using the positive and negative of the photon coordinate system mark P, and determining the photon coordinate system as a unified system or a non-unified system; then, judging the specific configuration of the coordinate system by combining the state of the photon coordinate system and the positive and negative of a space coordinate system mark S; and finally, adjusting and correcting the coordinate system to a unified system according to all solutions and mutual conversion relations of the Muller matrix about coordinate system transformation so as to realize accurate decoding of polarization information. The method is suitable for various imaging and measuring systems related to the reflective polarization modulation technology, such as a two-photon full-polarization imaging system, a polarization endoscope and a full-polarization biosensor, effectively solves the coupling problem of a space coordinate system and a photon coordinate system, and improves the credibility and accuracy of information extraction.

Description

Technical Field

[0001] The invention relates to polarization imaging technology, and in particular to a coordinate system correction and unification method for a reflective full polarization imaging system. Background Art

[0002] Compared with traditional non-polarized optical measurement methods, polarization imaging and Mueller matrix polarization measurement methods have been widely used in remote sensing, materials, biomedicine and other fields due to their advantages of high information dimension, non-labeling and non-invasiveness, sensitivity to anisotropic structures, and good compatibility. In the biomedical field, in vivo imaging technology plays a vital role in clinical diagnosis. Since the objects of in vivo measurement are often in vivo or thick tissue samples, a reflective full polarization imaging system is what we need. In the reflective full polarization imaging system, due to the vector properties of polarized light and the non-collinear characteristics of the measurement system, the calculation and measurement of the Mueller matrix and its derived polarization parameters are closely related to the transformation and selection of the coordinate system. Therefore, the coupling effect of the photon coordinate system and the spatial coordinate system will further affect the credibility and accuracy of the subsequent quantitative extraction of polarization information.

[0003] It should be noted that the information disclosed in the above background technology section is only used for understanding the background of the present application, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] The main purpose of the present invention is to overcome the defects existing in the above-mentioned background technology and provide a coordinate system correction and unification method for a reflective full polarization imaging system.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for correcting and unifying the coordinate system of a reflective full polarization imaging system comprises the following steps:

[0007] S1. Obtain the Mueller matrix measurement results of the anisotropic column scattering phantom model based on the reflective full polarization imaging system;

[0008] S2. Use the positive or negative sign of the photon coordinate system symbol P=M(2,2)M(3,3) to determine the state of the photon coordinate system: when P>0, it means that the p-axis directions of the incident light and the outgoing light are consistent, and the photon coordinate system is a unified system; when P<0, it means that the p-axis directions of the incident light and the outgoing light are opposite, and the photon coordinate system is a non-uniform system; thereby determining the current state of the photon coordinate system;

[0009] S3, use the positive or negative value of the space coordinate system mark S = M(1,3) / M(1,2) to determine the state of the space coordinate system, and then combine the state of the photon coordinate system in S2 to determine the state of the coordinate system: when P>0 and S>0, the coordinate system is judged to be the RL coordinate system; when P>0 and S<0, the coordinate system is judged to be the LR coordinate system; when P<0 and S>0, the coordinate system is judged to be the RR coordinate system; when P<0 and S<0, the coordinate system is judged to be the LL coordinate system;

[0010] S4. According to the solution and mutual conversion relationship of the Mueller matrix under different coordinate system transformations, combined with the coordinate system state determined in step S3, the corresponding coordinate system is adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

[0011] Further:

[0012] The reflective full polarization imaging system comprises a light source, a polarizer, a sample, an analyzer and a camera, and the anisotropic column scattering phantom model is used as a sample.

[0013] The anisotropic column scattering phantom model is composed of concentrically arranged filamentary fibers, and can reflect the polarization response of the column scatterer in the azimuth range of 0° to 360° in the imaging plane in a single measurement.

[0014] The anisotropic column scattering phantom model as a sample shows significantly different polarization responses under coordinate system transformation, and its polarization response usually presents a phenomenon of periodic rotation or translation about the azimuth angle.

[0015] In step S3, the azimuth angle investigation range is 0° to 45°.

[0016] In step S4, the following operations are performed to adjust and correct the corresponding coordinate system to a unified system: according to the solution and mutual conversion relationship of the Mueller matrix under different coordinate system transformations, as shown in Eqs. (4) and (5), combined with the coordinate system state determined in step S3, the corresponding coordinate system is adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

[0017] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the coordinate system correction and unification method of the reflective full polarization imaging system.

[0018] A computer program product comprises a computer program, wherein when the computer program is executed by a processor, the coordinate system correction and unification method of the reflective full polarization imaging system is realized.

[0019] The coordinate system correction and unification method of the reflective full polarization imaging system is applied in the imaging and measurement of the reflective polarization modulation technology.

[0020] Furthermore, the coordinate system correction and unification method of the reflective full polarization imaging system is applied to the two-photon full polarization imaging system to improve the decoding capability of the two-photon full polarization imaging system for structural information such as orientation distribution and dichroism of biological molecules, so as to obtain accurate and reliable imaging results.

[0021] The present invention has the following beneficial effects:

[0022] The present invention utilizes an anisotropic column scattering phantom model to propose a coordinate system correction and unification method suitable for a reflective full polarization imaging system, which can effectively and clearly determine the coordinate system state of the current system, and can further realize the conversion and correction of the coordinate system on the basis of maintaining the original state of the system, effectively solving the coupling problem between the spatial coordinate system and the photon coordinate system in the reflective full polarization imaging system, and providing strong technical support for more reliable and accurate information extraction under a unified system.

[0023] The present invention is applicable to imaging and measurement systems involving reflective polarization modulation technology, such as two-photon full polarization imaging systems, polarization endoscopes, full polarization biosensors, etc.

[0024] Other beneficial effects of the embodiments of the present invention will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of all combinations and agreed forms of the space coordinate system and the photon coordinate system according to an embodiment of the present invention.

[0026] Figure 2 Schematic diagram of a reflective full-polarization imaging system according to an embodiment of the present invention and an anisotropic column scattering phantom model composed of concentrically arranged filamentary fibers designed by the present invention.

[0027] Figure 3 It is a schematic diagram of the coordinate system correction and unification method flow based on the anisotropic column scatterer phantom model according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following is a detailed description of the embodiments of the present invention. It should be emphasized that the following description is only exemplary and is not intended to limit the scope and application of the present invention.

[0029] See also Figure 3 The embodiment of the present invention provides a coordinate system correction and unification method for a reflective full polarization imaging system, comprising the following steps:

[0030] S1. Obtain the Mueller matrix measurement results of the anisotropic column scattering phantom model based on the reflective full polarization imaging system;

[0031] S2. Use the positive or negative sign of the photon coordinate system symbol P=M(2,2)M(3,3) to determine the state of the photon coordinate system: when P>0, it means that the p-axis directions of the incident light and the outgoing light are consistent, and the photon coordinate system is a unified system; when P<0, it means that the p-axis directions of the incident light and the outgoing light are opposite, and the photon coordinate system is a non-uniform system; thereby determining the current state of the photon coordinate system;

[0032] S3, use the positive or negative sign of the spatial coordinate system mark S = M (1,3) / M (1,2) to determine the state of the spatial coordinate system, and then combine the state of the photon coordinate system in S2 to determine the state of the coordinate system. When S>0, the spatial coordinate system is Figure 1 The xyz coordinate system (xyz-axes) in (a) corresponds to; when S<0, the spatial coordinate system is Figure 1 When P>0 and S>0, the coordinate system is judged to be the RL coordinate system; when P>0 and S<0, the coordinate system is judged to be the LR coordinate system; when P<0 and S>0, the coordinate system is judged to be the RR coordinate system; when P<0 and S<0, the coordinate system is judged to be the LL coordinate system;

[0033] S4. According to the solution and mutual conversion relationship of the Mueller matrix under different coordinate system transformations, combined with the coordinate system state determined in step S3, the corresponding coordinate system is adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

[0034] The coordinate system correction and unification method of the reflective full-polarization imaging system proposed in the present invention effectively solves the coupling problem of the spatial coordinate system and the photon coordinate system in the imaging system, provides strong technical support for more reliable and accurate information extraction under a unified system, and ensures that the quantitative extraction of polarization information has high reliability and accuracy.

[0035] See also Figure 2 In some embodiments, the reflective full polarization imaging system includes a light source, a polarizer, a sample, an analyzer, and a camera, and the anisotropic column scattering phantom model is used as a sample. The anisotropic column scattering phantom model is composed of concentrically arranged filamentary fibers, and can reflect the polarization response of the column scatterer in the azimuth range of 0° to 360° in the imaging plane in a single measurement.

[0036] In some embodiments, in step S3, the azimuth angle investigation range is 0° to 45°.

[0037] In step S4, the following operations are performed to adjust and correct the corresponding coordinate system to a unified system: according to the solution and mutual conversion relationship of the Mueller matrix under different coordinate system transformations, as shown in formulas (4) and (5) below, combined with the coordinate system state determined in step S3, the corresponding coordinate system is adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

[0038] In some embodiments, the coordinate system correction and unification method of the reflective full polarization imaging system is applied in the imaging and measurement of the reflective polarization modulation technology.

[0039] For example, the coordinate system correction and unification method of the reflective full polarization imaging system can be applied to the two-photon full polarization imaging system to improve the decoding ability of the two-photon full polarization imaging system for structural information such as biological molecule orientation distribution and dichroism, so as to obtain accurate and reliable imaging results. The method can also be used for polarization imaging applications such as polarization endoscopes and full polarization biosensors.

[0040] The specific embodiments of the present invention are further described below.

[0041] The overall process of a coordinate system correction and unification method for a reflective full polarization imaging system is as follows: Figure 3 shown.

[0042] All combinations and conventions of space coordinate system and photon coordinate system are summarized as follows Figure 1 The present invention also designs an anisotropic column scattering phantom model composed of concentrically arranged filamentary fibers, such as Figure 2 As shown, it can reflect the polarization response of the cylindrical scatterer in the imaging plane within the azimuth range of 0° to 360° in a single measurement. Since its Mueller matrix imaging result shows a polarization response with obvious differences with respect to the coordinate system transformation, the present invention utilizes its specificity and sensitivity with respect to the coordinate system transformation to design a coordinate system correction and unification method, as shown in FIG. Figure 3 shown.

[0043] like Figure 3 As shown, the coordinate system correction and unification method of the reflective full polarization imaging system of the embodiment of the present invention includes the following steps:

[0044] S1. Mueller images of anisotropic column scattering phantom model obtained based on reflective full polarization imaging system Matrix measurement results;

[0045] S2. Use the positive or negative sign of the photon coordinate system symbol P=M(2,2)M(3,3) to determine the state of the photon coordinate system: when P>0, the photon coordinate system is a unified system; when P<0, the photon coordinate system is a non-uniform system;

[0046] S3, use the sign of the spatial coordinate system S = M (1,3) / M (1,2) to determine the state of the spatial coordinate system: when S>0, the spatial coordinate system is Figure 1 (a) corresponds to; when S<0, the space coordinate system is Figure 1 (b) corresponds to the above. It should be noted that the azimuth angle range here is 0° to 45°;

[0047] S4, according to the complete solution and mutual conversion relationship of Mueller matrix about coordinate system transformation (see Figure 1 and below), the corresponding coordinate systems are adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

[0048] Figure 1 What is shown is all the combinations and conventions of the space coordinate system and the photon coordinate system. The specific conventions are as follows: Figure 1 The xyz coordinate systems in (a) and (b) represent two different spatial coordinate systems (also known as laboratory coordinate systems), and their conventions mainly depend on the observation habits of researchers; the incident plane is the xOz plane; in order to distinguish it from the spatial coordinate system, the present invention uses the spk coordinate system to represent the photon coordinate system of incident light and outgoing light, which essentially corresponds to the concepts and definitions of s-wave, p-wave and light wave normal k in physical optics. For the photon coordinate system of incident light-outgoing light, there are mainly two conventions: (i) The p-axis directions of the incident light and the outgoing light are opposite, that is, a non-uniform system, such as Figure 1 (a i ) and (b i ) as shown; (ii) the p-axis directions of the incident light and the outgoing light are consistent, that is, a unified system, such as Figure 1 (a ii ) and (b ii ). The non-unified system in convention (i) is mainly used in various optical textbooks, while the unified system in convention (ii) is mainly used in many studies related to polarization measurement of biological tissues.

[0049] Below, Figure 1 (a i ) and the RR coordinate system shown in Figure 1 (a ii ) as an example, the expression form of the Mueller matrix in different photon coordinate systems is determined, as shown in formula (1-4).

[0050]

[0051] Among them, S R in and S R outThey represent the Stokes vectors of the incident and outgoing light respectively that satisfy the right-hand rule; S L out represents the Stokes vector of the outgoing light that does not satisfy the right-hand rule; accordingly, M RR and M RL are the Mueller matrices measured in the RR and RL coordinate systems, respectively. L out S R out It is obtained symmetrically about the s axis, so it satisfies the transformation relationship shown in formula (3), and then M can be obtained RR and M RL The relationship between is shown in formula (4).

[0052]

[0053]

[0054] Where M(i,j) represents the element in the i-th row and j-th column of the Mueller matrix M. From equation (4), we can get M RR and M RL The third and fourth rows of array elements have opposite signs. Figure 1 The transformation of other coordinate systems is similar to the above process. As shown in formula (5), the present invention provides the solution of Mueller matrix with respect to other coordinate system transformations.

[0055]

[0056] Therefore, for all solutions of the Mueller matrix with respect to coordinate system transformation, the 2×2 array in the upper left corner is always unaffected by the spatial coordinate system and the photon coordinate system, while the remaining 12 array elements located in the third row, fourth row, third column and fourth column will produce differential responses with the coordinate system transformation. This differential response will further affect the credibility and accuracy of the subsequent quantitative extraction of polarization information. In particular, for the two-photon full polarization imaging system, the coupling effect of the spatial coordinate system and the photon coordinate system will affect the decoding of structural information such as the orientation distribution and dichroism of biological molecules.

[0057] Figure 2 This is an overall schematic diagram of the reflective full-polarization imaging system and the anisotropic cylindrical scattering phantom.

[0058] For the reflective full polarization imaging system, it mainly includes components such as a light source, a polarizer, a sample, an analyzer and a camera. Among them, the polarizer and the analyzer are usually composed of polarization devices such as polarizers and wave plates. In the present invention, since the anisotropic column scattering phantom model as a sample shows a polarization response with obvious differences under the coordinate system transformation, and its polarization response usually shows a phenomenon of periodic rotation or translation about the azimuth angle, its Mueller matrix array element can be used as a sensitive coordinate system marker for the correction and unification of the coordinate system of the reflective full polarization imaging system.

[0059] In summary, the coordinate system correction and unification method designed in the present invention based on the full-polarization Mueller matrix coordinate system transformation and anisotropic cylindrical scattering phantom model experiment can effectively solve the coupling problem of the spatial coordinate system and the photon coordinate system in the reflective full-polarization imaging system, and provide the premise and support for subsequent more reliable and accurate information extraction.

[0060] An embodiment of the present invention further provides a storage medium for storing a computer program, which at least performs the above method when executed.

[0061] An embodiment of the present invention further provides a control device, comprising a processor and a storage medium for storing a computer program; wherein the processor is configured to execute at least the method described above when executing the computer program.

[0062] An embodiment of the present invention further provides a processor, wherein the processor executes a computer program and at least executes the method described above.

[0063] The storage medium can be implemented by any type of non-volatile storage device, or a combination thereof. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory can be a disk memory or a tape memory. The storage medium described in the embodiments of the present invention is intended to include, but is not limited to, these and any other suitable types of memory.

[0064] In the several embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0065] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0066] In addition, all functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0067] Those skilled in the art can understand that: all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), disks or optical disks, etc. Various media that can store program codes.

[0068] Alternatively, if the above-mentioned integrated unit of the present invention is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

[0069] The methods disclosed in the several method embodiments provided by the present invention can be arbitrarily combined without conflict to obtain new method embodiments.

[0070] The features disclosed in several product embodiments provided by the present invention can be arbitrarily combined without conflict to obtain new product embodiments.

[0071] The features disclosed in several method or device embodiments provided by the present invention can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0072] 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 those skilled in the art of the present invention, several equivalent substitutions or obvious variations can be made without departing from the concept of the present invention, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A coordinate system correction and unification method for a reflective full polarization imaging system, characterized in that: The following steps are involved: S1. Obtain the Mueller matrix measurement results of the anisotropic column scattering phantom model based on the reflective full polarization imaging system; S2. Use the positive or negative sign of the photon coordinate system symbol P=M(2,2)M(3,3) to determine the state of the photon coordinate system: when P>0, it means that the p-axis directions of the incident light and the outgoing light are consistent, and the photon coordinate system is a unified system; when P<0, it means that the p-axis directions of the incident light and the outgoing light are opposite, and the photon coordinate system is a non-uniform system; thereby determining the current state of the photon coordinate system; S3, use the positive or negative value of the space coordinate system mark S = M(1,3) / M(1,2) to determine the state of the space coordinate system, and then combine the state of the photon coordinate system in S2 to determine the state of the coordinate system: when P>0 and S>0, the coordinate system is judged to be the RL coordinate system; when P>0 and S<0, the coordinate system is judged to be the LR coordinate system; when P<0 and S>0, the coordinate system is judged to be the RR coordinate system; when P<0 and S<0, the coordinate system is judged to be the LL coordinate system; S4. According to the solution and mutual conversion relationship of the Mueller matrix under different coordinate system transformations, combined with the coordinate system state determined in step S3, the corresponding coordinate system is adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

2. The coordinate system correction and unification method of the reflective full polarization imaging system according to claim 1, characterized in that: The reflective full polarization imaging system comprises a light source, a polarizer, a sample, an analyzer and a camera, and the anisotropic column scattering phantom model is used as a sample.

3. The coordinate system correction and unification method of the reflective full polarization imaging system according to claim 2, characterized in that: The anisotropic column scattering phantom model is composed of concentrically arranged filamentary fibers, and can reflect the polarization response of the column scatterer in the azimuth range of 0° to 360° in the imaging plane in a single measurement.

4. The coordinate system correction and unification method of the reflective full polarization imaging system according to claim 2 or 3, characterized in that: The anisotropic column scattering phantom model as a sample shows significantly different polarization responses under coordinate system transformation, and its polarization response usually presents a phenomenon of periodic rotation or translation about the azimuth angle.

5. The coordinate system correction and unification method of the reflective full polarization imaging system according to any one of claims 1 to 4, characterized in that: In step S3, the azimuth angle investigation range is 0° to 45°.

6. The coordinate system correction and unification method of the reflective full polarization imaging system according to any one of claims 1 to 5, characterized in that: In step S4, the following operations are performed to adjust and correct the corresponding coordinate system to a unified system: according to the solution and mutual conversion relationship of the Mueller matrix under different coordinate system transformations, combined with the coordinate system state determined in step S3, the corresponding coordinate system is adjusted and corrected to a unified system, thereby achieving further decoding of the polarization information therein.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the coordinate system correction and unification method of the reflective full polarization imaging system according to any one of claims 1 to 6 is implemented.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the coordinate system correction and unification method of the reflective full polarization imaging system according to any one of claims 1 to 6 is implemented.

9. Application of the coordinate system correction and unification method of the reflective full polarization imaging system described in claim 1 in imaging and measurement of reflective polarization modulation technology.

10. The use according to claim 9, characterized in that The coordinate system correction and unification method of the reflective full polarization imaging system is applied to the two-photon full polarization imaging system to improve the decoding capability of the two-photon full polarization imaging system for structural information such as orientation distribution and dichroism of biological molecules, so as to obtain accurate and reliable imaging results.

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