De-scattering imaging method based on polarization common-mode dual suppression and related device

Abstract

The invention discloses a de-scattering imaging method based on polarization common-mode dual suppression and a related device, and the method comprises the steps: determining a polarization angle of target reflected light according to a principle that polarization common-mode suppression is generated in an orthogonal polarization detection direction when the similarity of a target region is highest; determining a polarization angle of back scattering light by using a principle that polarization common-mode rejection is generated in an orthogonal polarization detection direction when the similarity of a background region is highest; according to the orthogonal polarization image with the highest similarity in the target area, determining a polarization difference graph of the back scattering light; determining a polarization difference graph of the target reflected light according to the cross-polarization image with the highest similarity in the background region; determining a polarization part of the back scattering light and a polarization part of the target reflected light by using the polarization angle of the target reflected light, the polarization angle of the back scattering light, the polarization difference graph of the target reflected light and the polarization difference graph of the back scattering light based on a calculation rule of a polarization Stokes parameter; selecting any group of cross-polarization images, and performing background region sampling and fitting and image quality feedback iterative optimization to obtain an optimal non-polarization part of back scattering light; and all noise light is removed by using the polarization part of the backscattered light and the non-polarization part of the optimal backscattered light. The method can be suitable for a defogging scene in which multiple types of targets coexist, the image contrast is remarkably improved, and the environmental adaptability is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of polarization imaging, and in particular to a de-scattering imaging method based on polarization common-mode double suppression and a related device. Background Art

[0002] The polarization information of light is another dimension of information independent of the light intensity component. Polarization detectors can increase the dimension of information acquisition and improve the accuracy of target acquisition. Compared with other optical imaging technologies, polarization imaging technology uses the difference in polarization characteristics between target information and noise information to achieve stray light separation, which has the effect of "weakening strong light and strengthening weak light". Polarization differential imaging is a representative imaging method. Whether it is based on rotating polarizers or differential imaging technology based on Stokes vector calculation, its core lies in finding the polarization direction of backscattered light and filtering out noise light through common mode suppression. However, in actual imaging environments, due to the randomness of multiple scattering and the uncertainty of spatial distribution of the polarization state of backscattered light, polarization differential imaging often weakens the target information itself while filtering out noise.

[0003] The basic principle of polarization differential imaging technology is to find the optimal polarization suppression angle by direct or indirect means. At the same time, the development direction of this technology is to adapt to the observation scene where multiple types of targets coexist and realize selective descattering. Xu Jingyan et al. proposed a polarization differential imaging method with weight coefficients (Study on polarization characteristics of background light based on Stokes vector difference method [J]. Acta Physica Sinica, 2023, 24(72)).

[0004] When previous polarization differential imaging methods deal with scenes where reflective targets and diffuse targets coexist, the transmission directions of light reflected from different types of targets are randomized, and the polarization states of signal-to-noise light under strong scattering conditions are diversified after multiple scattering, resulting in inconsistency in the corresponding optimal polarization detection directions. The polarization differential operation will further cause the useful signal and the noise signal to attenuate by the same amplitude, especially the information of diffuse targets is easily lost, and the image quality is only slightly improved. Summary of the invention

[0005] In response to the problems existing in the prior art, the present invention provides a descattering imaging method and related devices based on polarization common-mode dual suppression, which can be applied to defogging scenarios where multiple types of targets coexist, significantly improve image contrast, and have stronger environmental adaptability.

[0006] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0007] According to a first aspect of the present invention, a descattering imaging method based on polarization common mode double suppression is provided, comprising:

[0008] Acquire multiple sets of orthogonal polarization images;

[0009] Delimiting a target area and a background area for each set of orthogonal polarization images, and determining the similarity between the target area and the background area of ​​each set of orthogonal polarization images;

[0010] The polarization angle of the target reflected light is determined by using the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target area similarity is the highest;

[0011] The polarization angle of the backscattered light is determined by using the principle that the orthogonal polarization direction produces polarization common mode suppression when the background area similarity is the highest;

[0012] Determine a polarization difference map of the backscattered light according to the orthogonal polarization images with the highest similarity in the target area;

[0013] Determine the polarization difference map of the target reflected light according to the orthogonal polarization image with the highest similarity in the background area;

[0014] Based on the calculation rule of polarization Stokes parameters, the polarization angle of target reflected light, the polarization angle of backscattered light, the polarization difference diagram of target reflected light and the polarization difference diagram of backscattered light are used to determine the polarization part of backscattered light and the polarization part of target reflected light;

[0015] Select any set of orthogonal polarization images, sample and fit the background area, and iterate and optimize the image quality feedback to obtain the optimal non-polarized part of the backscattered light.

[0016] The polarized portion of the backscattered light and the unpolarized portion of the optimal backscattered light are used to remove any noise light.

[0017] In a possible implementation manner of the first aspect, demarcating the target area and the background area for each group of orthogonal polarization images is specifically:

[0018] The histogram equalization method is used to scale the grayscale values ​​of each group of orthogonal polarization images, expand the difference between the pixels in the target area and the background area, and delineate the target area and the background area.

[0019] In a possible implementation manner of the first aspect, the polarization angle of the target reflected light is determined by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target region similarity is the highest, specifically:

[0020] α=|P(θ)-45°|

[0021] Where α is the polarization angle of the target reflected light; P(θ) is the analyzer angle of the orthogonal polarization image when the similarity of the target area is the highest.

[0022] In a possible implementation manner of the first aspect, the principle of using the orthogonal polarization analysis direction to generate polarization common mode suppression when the background region similarity is the highest is used to determine the polarization angle of the backscattered light, specifically:

[0023]

[0024] Where β is the polarization angle of the backscattered light; is the analyzer angle of the orthogonal polarization image when the similarity of the background area is the highest.

[0025] In a possible implementation manner of the first aspect, determining the polarization difference map of the backscattered light according to the orthogonal polarization images with the highest similarity in the target area is specifically:

[0026] I pd-B =I θ -I θ+90°

[0027] In the formula, I pd-B I is the polarization difference diagram of the backscattered light; θ with I θ+90° The orthogonal polarization images together represent the target area with the highest similarity.

[0028] In a possible implementation manner of the first aspect, determining the polarization difference map of the target reflected light according to the orthogonal polarization image with the highest similarity in the background area is specifically:

[0029]

[0030] In the formula, I pd-D is the polarization difference diagram of the target reflected light; and The orthogonal polarization images together represent the background region with the highest similarity.

[0031] In a possible implementation manner of the first aspect, the polarization angle of the target reflected light, the polarization angle of the backscattered light, the polarization difference map of the target reflected light, and the polarization difference map of the backscattered light are used to determine the polarization portion of the backscattered light and the polarization portion of the target reflected light, specifically:

[0032]

[0033]

[0034] In the formula, B P I is the polarization part of the backscattered light; pd-B is the polarization difference diagram of the backscattered light; D P I is the polarization part of the target reflected light; pd-Dis the polarization difference diagram of the target reflected light; α is the polarization angle of the target reflected light; β is the polarization angle of the backscattered light.

[0035] In a possible implementation manner of the first aspect, the non-polarized part of the backscattered light is obtained by sampling the background area, fitting, and iterative optimization through image quality feedback, specifically:

[0036] A Gaussian surface fitting function based on the least squares method is used to fit and reconstruct the background area of ​​any set of orthogonal polarization images to remove the interference of the polarization part, and the non-polarized part of the initial backscattered light is obtained;

[0037] B NP =f gas-fit (IB P -D P ) background

[0038] The adjustment coefficient is introduced, and based on the UIQM image quality feedback algorithm, the non-polarized part of the initial backscattered light is iteratively optimized to obtain the optimal non-polarized part of the backscattered light:

[0039] B NP '=εB NP (if UIQM=UIQM max )

[0040] In the formula, B NP is the non-polarized part of the initial backscattered light; ε is the adjustment coefficient; B P is the polarization part of the backscattered light; D P is the polarized part of the target reflected light; I is the intensity image obtained by summing each set of orthogonal polarization images; f gas-fit () background is the Gaussian surface fitting function based on the least squares method; B NP ' is the unpolarized part of the optimal backscattered light.

[0041] According to a second aspect of the present invention, a descattering imaging method based on polarization common mode double suppression is provided, comprising:

[0042] An acquisition module, used for acquiring multiple groups of orthogonal polarization images;

[0043] A similarity determination module is used to define a target area and a background area for each set of orthogonal polarization images, and determine the similarity of the target area and the similarity of the background area of ​​each set of orthogonal polarization images;

[0044] The target reflected light polarization angle determination module is used to determine the polarization angle of the target reflected light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target area similarity is the highest;

[0045] A module for determining the polarization angle of backscattered light, for determining the polarization angle of backscattered light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the background area similarity is the highest;

[0046] A target polarization difference map determination module is used to determine a polarization difference map of backscattered light based on the orthogonal polarization images with the highest similarity in the target area;

[0047] A backscattered light polarization difference map determination module is used to determine the polarization difference map of the target reflected light based on the orthogonal polarization image with the highest similarity in the background area;

[0048] A polarization part determination module is used to determine the polarization part of the backscattered light and the polarization part of the target reflected light based on the calculation rule of the polarization Stokes parameter, using the polarization angle of the target reflected light, the polarization angle of the backscattered light, the polarization difference map of the target reflected light and the polarization difference map of the backscattered light;

[0049] The module for determining the non-polarized part of the optimal backscattered light is used to select any set of orthogonal polarization images, and obtain the non-polarized part of the optimal backscattered light by sampling the background area, fitting and optimizing;

[0050] The noise light removal module is used to remove all noise light by using the polarized part of the backscattered light and the non-polarized part of the optimal backscattered light.

[0051] According to a third aspect of the present invention, there is provided a device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the descattering imaging method based on polarization common-mode double suppression is implemented.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] The present invention provides a descattering imaging method based on polarization common-mode dual suppression. Starting from the difference in polarization characteristics between target reflected light and backscattered light, the method uses dual polarization common-mode suppression to achieve accurate estimation of the polarized part and the non-polarized part of the backscattered light. Combined with the image quality feedback iterative optimization algorithm, the denoising effect is remarkable. Taking into account the convergence of the polarization distribution of reflected light from reflective targets and diffuse targets, the special dimensional information of polarization is utilized to the maximum extent. The method is easy to operate and does not require prior information. Therefore, it can be applied to complex scenes where multiple types of targets coexist. It has stronger environmental adaptability and can meet the needs of target enhancement and restoration in a strong scattering environment. It has broad application prospects.

[0054] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the specific implementation modes of the present invention, the drawings required for use in the description of the specific implementation modes will be briefly introduced below. Obviously, the drawings described below are some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0056] Figure 1 This is a flow chart of a de-scattering imaging method based on polarization common-mode double suppression according to an embodiment of the present invention;

[0057] Figure 2 Polarization direction decomposition diagram of target and background scattered light polarization common mode double suppression;

[0058] Figure 3 Schematic diagram of the composition of the active polarization imaging system in turbid water environment;

[0059] Figure 4 is a diagram of the descattering process of an embodiment;

[0060] Figure 5 A comparison diagram of the dehazed image restored by the embodiment and the images restored by other methods.

[0061] In the figure: 1. laser light source, 2. beam expander, 3. polarization generator, 4. scattering medium container, 5. detection target, 6. polarization analyzer, 7. image acquisition device, 8. image processing and storage module, 9. image display device. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] like Figure 1 As shown, an embodiment of the present invention provides a de-scattering imaging method based on polarization common mode double suppression, which specifically includes the following steps:

[0064] Step 1: Acquire multiple sets of orthogonal polarization images.

[0065] It should be understood that, among the multiple groups of orthogonal polarization images, each group of orthogonal polarization images includes two images in orthogonal polarization directions, namely, an image in a 0° polarization direction and an image in a 90° polarization direction, or any two images in perpendicular polarization directions.

[0066] For example, by electrically controlling the rotation of the polarizer imaging detector, with the angles of the PSA being 45° and 135° to the incident polarization direction as the center, multiple sets of orthogonal polarization images can be obtained by adjusting the angles of the PSA at certain angle intervals. min-1 …I min-n ] and [I max-1 …I max-n ]. Multiple sets of orthogonal polarization images [I min-1 …I min-n ] and [I max-1 …I max-n ], mainly considering the reflection type target and the diffuse type target in the orthogonal detection at a specific angle will appear: D θ -D θ+90° = 0, backscattered light will also appear and

[0067] Step 2: Delineate the target area and the background area for each set of orthogonal polarization images, and calculate the similarity of the target area and the similarity of the background area for each set of orthogonal polarization images.

[0068] Preferably, the histogram equalization method is used to scale the grayscale values ​​of each group of orthogonal polarization images, expand the difference between the pixels in the target area and the pixels in the background area, and delineate the target area and the background area. That is, the histogram equalization method is used to pre-process each group of orthogonal polarization images to delineate the target area and the background area. It should be noted that histogram equalization is an image processing technology used to enhance the contrast of an image. By adjusting the grayscale histogram of the image, the grayscale value distribution is made more uniform, thereby improving the visual effect of the image.

[0069] For example, the similarity between the target region and the background region can be measured by calculating the structural similarity index (SSIM) of the two regions. When the SSIM is maximum, it means that the grayscale distribution of the two images is similar, which indirectly indicates that the spatial distribution of the electric field components is similar.

[0070] Step 3: Determine the polarization angle of the target reflected light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target area similarity is the highest.

[0071] That is, based on the principle that polarization common mode suppression occurs when the similarity of the target area is the highest, the orthogonal polarization image with the highest similarity of the target area is selected to determine the polarization angle of the target reflected light.

[0072] In this implementation, the polarization angle of the target reflected light is determined as follows:

[0073] α=|P(θ)-45°|

[0074] Where α is the polarization angle of the target reflected light; P(θ) is the analyzer angle of the orthogonal polarization image when the similarity of the target area is the highest.

[0075] Step 4: Determine the polarization angle of the backscattered light by utilizing the principle that the orthogonal polarization detection directions produce polarization common mode suppression when the background area similarity is the highest.

[0076] Similarly, based on the principle that polarization common mode suppression occurs when the similarity of the background area is the highest, the orthogonal polarization image with the highest similarity of the background area is selected to determine the polarization angle of the backscattered light.

[0077] In this embodiment, the polarization angle of the backscattered light is determined as follows:

[0078]

[0079] Where β is the polarization angle of the backscattered light; is the analyzer angle of the orthogonal polarization image when the similarity of the background area is the highest.

[0080] By determining the polarization angle of the target reflected light and the polarization angle of the backscattered light, the polarization direction that can maximally suppress the noise (backscattered light) while retaining the target information is found.

[0081] Step 5: Determine the polarization difference map of the backscattered light based on the orthogonal polarization image with the highest similarity in the target area.

[0082] In this implementation manner, the target polarization difference map is determined as follows:

[0083] I pd-B =I θ -I θ+90°

[0084] In the formula, I pd-B I is the polarization difference diagram of the backscattered light; θ with I θ+90° The orthogonal polarization images with the highest similarity jointly represent the target area.

[0085] Step 6: Determine the polarization difference image of the target reflected light based on the orthogonal polarization image with the highest similarity in the background area.

[0086] In this implementation, the backscattered light polarization difference map is determined as follows:

[0087]

[0088] In the formula, I pd-D is the polarization difference diagram of the target reflected light; and The orthogonal polarization images with the highest similarity jointly represent the background area.

[0089] That is, based on dual-polarization common-mode suppression, the directions of target and backscattered light polarization common-mode suppression are found respectively, and the target polarization difference map and the backscattered light polarization difference map can be obtained through two polarization difference operations.

[0090] Step 7: Based on the calculation rule of Stokes parameters, the polarization angle of the target reflected light, the polarization angle of the backscattered light, the polarization difference diagram of the target reflected light and the polarization difference diagram of the backscattered light are used to determine the polarization portion of the backscattered light and the polarization portion of the target reflected light.

[0091] That is [I pd-B ,I pd-D After the four parameters [α, β] are obtained, the polarization part of the backscattered light and the polarization part of the target reflected light are determined. In this embodiment, the polarization part of the backscattered light and the polarization part of the target reflected light are determined as follows:

[0092]

[0093]

[0094] In the formula, B P I is the polarization part of the backscattered light; pd-B is the polarization difference diagram of the backscattered light; D P I is the polarization part of the target reflected light; pd-D is the polarization difference diagram of the target reflected light; α is the polarization angle of the target reflected light; β is the polarization angle of the backscattered light.

[0095] Step 8: Select any set of orthogonal polarization images, sample the background area, perform fitting and iterative optimization based on image quality feedback to obtain the optimal non-polarized part of the backscattered light.

[0096] That is, the non-polarized component of the post-optimal backscattered light is extracted from the background area so as to facilitate subsequent noise removal.

[0097] In this implementation, the non-polarized part of the backscattered light is obtained by sampling the background area and performing fitting and image quality feedback iterative optimization, as follows:

[0098] Firstly, a Gaussian surface fitting function based on the least square method is used to fit and reconstruct the background area of ​​any set of orthogonal polarization images to remove the interference of the polarization part, and obtain the non-polarized part of the initial backscattered light;

[0099] B NP =f gas-fit (IB P -D P ) background

[0100] Finally, since the non-polarized part of the initial backscattered light is obtained by fitting reconstruction, an adjustment coefficient is introduced. Based on the image quality feedback algorithm of the underwater image quality measure (UIQM), the non-polarized part of the initial backscattered light is iteratively optimized to obtain the optimal non-polarized part of the backscattered light:

[0101] B NP '=εB NP (if UIQM=UIQM max ).

[0102] In the formula, B NP is the non-polarized part of the initial backscattered light; ε is the adjustment coefficient; B P is the polarization part of the backscattered light; I is the intensity image obtained by summing each set of orthogonal polarization images; f gas-fit () background is the Gaussian surface fitting function based on the least squares method; B NP ' is the unpolarized part of the optimal backscattered light.

[0103] Step 9: Use the polarized part of the backscattered light and the non-polarized part of the optimal backscattered light to remove the noise light, thereby obtaining a clear image.

[0104] That is to say, the polarized part of the backscattered light and the non-polarized part of the optimal backscattered light are used to remove the noise light in the image. While retaining the target information, the noise caused by the backscattered light is removed to the greatest extent, thereby improving the contrast and clarity of the image.

[0105] The present invention is described in detail below in conjunction with embodiments.

[0106] The theoretical basis of the present invention is:

[0107] When active polarization detection is used to image underwater targets, the light information received by the detector can be divided into two parts: one is the backscattered light B from the medium, and the other is the reflected light D from the target. The total light intensity received by the detector can be expressed as:

[0108] I(x,y)=D(xy)+B(x,y)

[0109] Where (x, y) represents the pixel position in the image.

[0110] based on Figure 2 Based on the principle of polarization common mode double suppression in the present embodiment, a descattering imaging method based on polarization common mode double suppression is as follows:

[0111] By rotating the angle of the polarizer PSA, we can first obtain orthogonal polarization images at 45° and 135°, respectively. Based on this, with a change interval of 1°, a total of 30 sets of orthogonal polarization images are obtained, which are recorded as:

[0112] I || =[I 30° ,I 31° ,I 32° …I 60° ]

[0113] I⊥=[I 120° ,I 121° ,I 122° …I 150° ]

[0114] The obtained orthogonal polarization images are first subjected to histogram equalization operation to define the target area range, and the SSIM structural similarity parameters (similarity) of the target areas of 30 groups of orthogonal polarization images are calculated to find the polarization angle θ corresponding to the maximum similarity value.

[0115] At this time, the polarization angle of the target light is α = θ-45°, and the polarization difference image is I pd-D , further derivation:

[0116]

[0117] According to the decomposition of medium light in different polarization directions, we can get:

[0118] The background area of ​​30 sets of orthogonal polarization images is delineated, and the SSIM of the background area is calculated. The direction of the common-mode suppression of the backscattered light polarization is found without considering the attenuation of the target information. The judgment method is similar to that of the target light. At this time, the direction of the polarization angle β of the polarized part in the backscattered light is determined.

[0119] Since the backscattered light is divided into polarized part and non-polarized part, after the polarized part B is determined, the non-polarized part undergoes multiple scattering, so it can be based on B NP =f gas-fit (IB P -D P ) background Sure;

[0120] Introducing an iterative optimization algorithm based on UIQM image quality feedback with an adjustment coefficient: D = IB P -εB NP (if UIQM=UIQM max ), and finally obtain clear target information.

[0121] like Figure 3As shown, it is an active polarization imaging system in a turbid water environment. The device is an example of the imaging device diagram of the method proposed in the present invention. The laser light source 1 enters the polarization generator 3 after passing through the beam expander 2, generates a horizontal polarized light beam, and illuminates the target 5 in the turbid water body. The polarization analyzer 6 is fixed in front of the reflected light signal, and the polarization information is captured by the image acquisition device 7. The image processing and storage module 8 collects camera data, and the image is processed and stored using the method proposed in the present invention. The processed target image is displayed in real time on the image display device 9. The glass water tank with black light-absorbing cloth on the four walls is used as a scattering medium container 4, and a high-transmittance quartz wall is used as an incident window on the incident side. Skim milk and deionized water are mixed to form a scattering water body with a turbidity of 30NTU. In the experiment, a metal ruler and a bionic fish are used as targets. The steel ruler is made of metal and has a smooth surface, which is a reflective target. The surface of the bionic fish is covered with scales and is rough. The two are combined to form a composite scene. The detection distance is set to 80cm, and the method proposed in the present invention is used for processing.

[0122] like Figure 4 As shown, 601 is passed Figure 3 Multiple groups of orthogonal polarization images acquired by the active polarization imaging system: 602 and 603 are schematic diagrams of the target area and the background area after area division; 604 is the differential image of the backscattered light after common-mode suppression of the target light, and 605 is the differential image of the target light after common-mode suppression of the backscattered light; 606 is the polarized part of the backscattered light obtained by calculation; 607 is the non-polarized part of the backscattered light obtained by calculation, and 608 is the target information image after noise removal restored by the present invention.

[0123] like Figure 5By comparing the results of intensity imaging, polarization differential imaging, and the results after processing with the method of the present invention, it can be found that the contrast and clarity of the restored image by the method of the present invention are higher than those of other methods, and descattering is achieved for both reflective steel rulers and diffuse types, while traditional polarization differential imaging leads to the loss of target information. Based on the inconsistency of common-mode suppression of polarization of the target and background, the present invention accurately solves the backscattering noise through two polarization differences to obtain a clear target image. The polarization characteristics of the target reflected light are utilized. Compared with the previous polarization differential imaging technology that only focuses on backscattered light, the accurate estimation of medium scattered light is achieved for the first time from the perspective of common-mode suppression of polarization of target reflected light, and the restoration accuracy is higher. It has good adaptability to turbid medium observation scenes where diffuse and reflective targets coexist, and is close to practical applications. It is a defogging imaging system that is simple to operate and highly feasible. Specifically, it focuses on the observation scenarios where reflective and diffuse targets coexist in turbid media. By determining two sets of orthogonal polarization analysis directions, dual polarization common-mode suppression of target information and backscattering information is achieved respectively. The polarization part of the backscattered light is indirectly inverted and solved. The background light in the non-target area is used as the boundary constraint, and the non-polarized part of the backscattered light is fitted and reconstructed. The image quality feedback mechanism is introduced to maximize the descattering effect. Compared with the traditional polarization difference noise solution, it is more accurate and can be applied to dehazing scenarios where multiple types of targets coexist. The image contrast is significantly improved and the environmental adaptability is stronger.

[0124] In another embodiment of the present invention, a de-scattering imaging method based on polarization common mode double suppression is provided, which is used to implement the de-scattering imaging method based on polarization common mode double suppression, and specifically includes:

[0125] The acquisition module is used to acquire multiple groups of orthogonal polarization images.

[0126] The similarity determination module is used to define a target area and a background area for each group of orthogonal polarization images, and determine the similarity of the target area and the similarity of the background area of ​​each group of orthogonal polarization images.

[0127] The target reflected light polarization angle determination module is used to determine the polarization angle of the target reflected light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target area similarity is the highest.

[0128] The module for determining the polarization angle of backscattered light is used to determine the polarization angle of backscattered light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the background area similarity is the highest.

[0129] The target polarization difference map determination module is used to determine the polarization difference map of the backscattered light according to the orthogonal polarization images with the highest similarity in the target area.

[0130] The backscattered light polarization difference map determination module is used to determine the polarization difference map of the target reflected light based on the orthogonal polarization image with the highest similarity in the background area.

[0131] The polarization part determination module is used to determine the polarization part of the backscattered light and the polarization part of the target reflected light based on the calculation rule of the polarization Stokes parameter, using the polarization angle of the target reflected light, the polarization angle of the backscattered light, the polarization difference diagram of the target reflected light and the polarization difference diagram of the backscattered light.

[0132] The module for determining the non-polarized part of the optimal backscattered light is used to select any group of orthogonal polarization images, and obtain the non-polarized part of the optimal backscattered light by sampling the background area, fitting and optimizing.

[0133] The noise light removal module is used to remove all noise light by using the polarized part of the backscattered light and the non-polarized part of the optimal backscattered light.

[0134] All relevant contents of each step involved in the aforementioned embodiment of a de-scattering imaging method based on polarization common-mode dual suppression can be referred to the functional description of the functional module corresponding to a de-scattering imaging device based on polarization common-mode dual suppression in the embodiment of the present invention, and will not be repeated here. The division of modules in the embodiment of the present invention is schematic, which is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present invention can be integrated into a processor, or it can exist physically separately, or two or more modules can be integrated into one module. The above-mentioned integrated module can be implemented in the form of hardware or in the form of software functional modules.

[0135] In another embodiment of the present invention, a computer device is provided, the computer device including a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of a descattering imaging method based on polarization common-mode dual suppression.

[0136] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It can be understood that the computer-readable storage medium here can include both built-in storage media in the computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the above-mentioned embodiment regarding a descattering imaging method based on polarization common-mode dual suppression.

[0137] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0138] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0139] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0140] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0141] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials 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 described specific features, structures, materials or characteristics 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 and the features of the different embodiments or examples, without contradiction.

[0142] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A de-scattering imaging method based on polarization common mode double suppression, characterized in that: include: Acquire multiple sets of orthogonal polarization images; Delimiting a target area and a background area for each set of orthogonal polarization images, and determining the similarity between the target area and the background area of ​​each set of orthogonal polarization images; The polarization angle of the target reflected light is determined by using the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target area similarity is the highest; The polarization angle of the backscattered light is determined by using the principle that the orthogonal polarization direction produces polarization common mode suppression when the background area similarity is the highest; Determine a polarization difference map of the backscattered light according to the orthogonal polarization images with the highest similarity in the target area; Determine the polarization difference map of the target reflected light according to the orthogonal polarization image with the highest similarity in the background area; Based on the calculation rule of polarization Stokes parameters, the polarization angle of target reflected light, the polarization angle of backscattered light, the polarization difference diagram of target reflected light and the polarization difference diagram of backscattered light are used to determine the polarization part of backscattered light and the polarization part of target reflected light; Select any set of orthogonal polarization images, sample and fit the background area, and iterate and optimize the image quality feedback to obtain the optimal non-polarized part of the backscattered light. The polarized portion of the backscattered light and the unpolarized portion of the optimal backscattered light are used to remove any noise light.

2. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The target area and the background area are delineated for each group of orthogonal polarization images, specifically: The histogram equalization method is used to scale the grayscale values ​​of each group of orthogonal polarization images, expand the difference between the pixels in the target area and the background area, and delineate the target area and the background area.

3. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The principle of using the orthogonal polarization analysis direction to produce polarization common mode suppression when the target area similarity is the highest to determine the polarization angle of the target reflected light is specifically: α=|P(θ)-45°| Where α is the polarization angle of the target reflected light; P(θ) is the analyzer angle of the orthogonal polarization image when the similarity of the target area is the highest.

4. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The principle of using the orthogonal polarization detection direction to produce polarization common mode suppression when the background area similarity is the highest to determine the polarization angle of the backscattered light is specifically: Where β is the polarization angle of the backscattered light; is the analyzer angle of the orthogonal polarization image when the similarity of the background area is the highest.

5. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The polarization difference map of the backscattered light is determined according to the orthogonal polarization image with the highest similarity in the target area, specifically: I pd-B =I θ -I θ+90° In the formula, I pd-B I is the polarization difference diagram of the backscattered light; θ with I θ+90° The orthogonal polarization images together represent the target area with the highest similarity.

6. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The polarization difference map of the target reflected light is determined according to the orthogonal polarization image with the highest similarity in the background area, specifically: In the formula, I pd-D is the polarization difference diagram of the target reflected light; and The orthogonal polarization images together represent the background region with the highest similarity.

7. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The method of determining the polarization portion of the backscattered light and the polarization portion of the target reflected light by using the polarization angle of the target reflected light, the polarization angle of the backscattered light, the polarization difference diagram of the target reflected light and the polarization difference diagram of the backscattered light is specifically as follows: In the formula, B P I is the polarization part of the backscattered light; pd-B is the polarization difference diagram of the backscattered light; D P I is the polarization part of the target reflected light; pd-D is the polarization difference diagram of the target reflected light; α is the polarization angle of the target reflected light; β is the polarization angle of the backscattered light.

8. The de-scattering imaging method based on polarization common mode double suppression according to claim 1, characterized in that: The non-polarized part of the backscattered light is obtained by sampling the background area, fitting, and iterative optimization through image quality feedback, specifically: A Gaussian surface fitting function based on the least squares method is used to fit and reconstruct the background area of ​​any set of orthogonal polarization images to remove the interference of the polarization part, and the non-polarized part of the initial backscattered light is obtained; B NP =f gas-fit (I-B P -D P ) background The adjustment coefficient is introduced, and based on the UIQM image quality feedback algorithm, the non-polarized part of the initial backscattered light is iteratively optimized to obtain the optimal non-polarized part of the backscattered light: B NP '=εB NP (if UIQM=UIQM max ) In the formula, B NP is the unpolarized part of the initial backscattered light; ε is the adjustment coefficient; B P is the polarization part of the backscattered light; D P is the polarized portion of the light reflected from the target; I is the intensity image obtained by summing each set of orthogonal polarization images; f gas-fit () background is the Gaussian surface fitting function based on the least squares method; B NP ' is the unpolarized part of the optimal backscattered light.

9. A de-scattering imaging method based on polarization common mode double suppression, characterized in that: include: An acquisition module, used for acquiring multiple groups of orthogonal polarization images; A similarity determination module is used to define a target area and a background area for each set of orthogonal polarization images, and determine the similarity of the target area and the similarity of the background area of ​​each set of orthogonal polarization images; The target reflected light polarization angle determination module is used to determine the polarization angle of the target reflected light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the target area similarity is the highest; A module for determining the polarization angle of backscattered light, for determining the polarization angle of backscattered light by utilizing the principle that the orthogonal polarization analysis directions produce polarization common mode suppression when the background area similarity is the highest; A target polarization difference map determination module is used to determine a polarization difference map of backscattered light based on the orthogonal polarization images with the highest similarity in the target area; A backscattered light polarization difference map determination module is used to determine the polarization difference map of the target reflected light based on the orthogonal polarization image with the highest similarity in the background area; A polarization part determination module is used to determine the polarization part of the backscattered light and the polarization part of the target reflected light based on the calculation rule of the polarization Stokes parameter, using the polarization angle of the target reflected light, the polarization angle of the backscattered light, the polarization difference map of the target reflected light and the polarization difference map of the backscattered light; The module for determining the non-polarized part of the optimal backscattered light is used to select any set of orthogonal polarization images, and obtain the non-polarized part of the optimal backscattered light by sampling the background area, fitting and optimizing; The noise light removal module is used to remove all noise light by using the polarized part of the backscattered light and the non-polarized part of the optimal backscattered light.

10. A device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the descattering imaging method based on polarization common-mode double suppression as described in any one of claims 1 to 8 is implemented.

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