Three-dimensional measurement method and system based on fusion of linear polarization image and grayscale image

Abstract

The present disclosure relates to a three-dimensional measurement method and system for fusing a linear polarization image with a grayscale image, including: obtaining a polarization phase-shifted stripe image and a black-and-white Gray code image captured by a polarization camera, and extracting a phase-shifted image and a Gray code image therefrom; segmenting the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restoring them to their original resolution through bilinear interpolation processing; obtaining a linear polarization phase-shifted image, a linear polarization average light intensity image, and a grayscale average light intensity image based on the phase-shifted sub-images after bilinear interpolation processing; performing threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image through the Otsu method to obtain a depolarized region mask; complementary fusing the pixels marked as depolarized regions and normal polarization regions on the mask to obtain a high dynamic range phase-shifted image, and generating three-dimensional data in combination with the Gray code image. The disclosed method can realize three-dimensional measurement in complex high dynamic range scenes with multiple materials.

Description

Technical Field

[0001] The present disclosure relates to the field of computer vision, and in particular to a three-dimensional measurement method and system for fusing linear polarization images with grayscale images. Background Art

[0002] In recent years, fringe projection profilometry has been widely used in industrial manufacturing, biomedicine, cultural relic protection, virtual reality and other fields due to its non-contact, high-speed and high-precision characteristics. However, with the diversification of application scenarios, the environment for three-dimensional measurement has become increasingly complex, especially the problems of highlights and underexposure. Highlights are easily generated on metal or smooth surfaces, resulting in the loss of fringe data and the appearance of ripples and holes in the reconstructed point cloud; while dark objects often cause excessive noise and loss of details due to underexposure. In actual measurements, these two situations often exist at the same time. Therefore, a more adaptable high dynamic range imaging method is urgently needed to solve these problems.

[0003] Existing high-dynamic-range 3D measurement technologies, such as multi-exposure fusion, projection intensity adjustment, polarizer filtering, photometric stereo, and deep learning-based methods, all have their limitations. For example, multi-exposure fusion requires a large number of image reconstructions, which is inefficient; adjusting projection intensity requires preprocessing based on different scenes, which is inefficient; polarizer filtering can cause image darkening and reduce the signal-to-noise ratio; photometric stereo increases the light source when suppressing highlights, reducing the field of view; and end-to-end deep learning-based methods require a large amount of training data, which is time-consuming and has limited generalization performance. To address these issues, a new 3D measurement technology is needed that can simultaneously measure high- and low-exposure areas in a single exposure without compromising measurement accuracy to meet the rapidly evolving needs of 3D measurement. Summary of the Invention

[0004] To solve the problems of traditional polarization methods in high dynamic range scenes, such as the reduction of the overall signal-to-noise ratio of the image when eliminating highlights, the unavailability of polarization information due to depolarization, and the lack of reconstruction due to insufficient scene exposure.

[0005] According to one aspect of the present disclosure, a three-dimensional measurement method for fusing a linear polarization image with a grayscale image is provided, comprising:

[0006] S10, acquiring a polarization phase-shifted fringe image and a black-and-white Gray code image captured by a polarization camera, and extracting a phase-shifted image and a Gray code image from the polarization phase-shifted fringe image and the black-and-white Gray code image;

[0007] S20, segmenting the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restoring the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation;

[0008] S30, obtaining a linear polarization degree phase shift image, a linear polarization degree average light intensity image, and a grayscale average light intensity image based on the phase shift sub-image after the bilinear interpolation processing;

[0009] S40, performing threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask;

[0010] S50 , according to the depolarization region mask, complementary fuse the pixels marked as the depolarization region by the mask and the pixels marked as the normal polarization region by the mask to obtain a high dynamic range phase-shift image, and generate three-dimensional data in combination with the Gray code image.

[0011] Preferably, the phase-shifted sub-images at each angle are restored to their original resolution by bilinear interpolation, which is expressed as:

[0012] ,

[0013] ,

[0014] ,

[0015] Where, 、 and Represent the polarization images with polarization angles of 45°, 90°, and 135°, respectively. i is the vertical pixel coordinate, i -1 is i The pixel position of the pixel above, i +1 for i The next pixel position of the pixel, j is the horizontal axis, j -1 is j One pixel to the left, j +1 for j One pixel to the right.

[0016] Preferably, based on the phase-shifted sub-image after bilinear interpolation processing, a linear polarization degree phase-shifted image, a linear polarization degree average light intensity image and a grayscale average light intensity image are obtained, including:

[0017] Based on the interpolated phase-shift sub-image, the linear polarization phase-shift image is obtained by Stokes vector calculation;

[0018] Calculate the average value of multiple frames of linear polarization phase shift images to obtain a linear polarization average light intensity image;

[0019] The average value of the phase-shifted sub-images at each angle is calculated to obtain the grayscale average light intensity image.

[0020] Preferably, the linear polarization degree phase shift image is obtained by Stokes vector calculation, which is expressed as:

[0021] ,

[0022] ,

[0023] Where, represents the total intensity of light, Represents the intensity difference between the horizontally polarized component and the vertically polarized component of light, It represents the intensity difference between the +45° polarization component and the -45° polarization component of light. is the sub-image captured by the polarization camera at 0° angle, This is the sub-image captured by the polarization camera at a 45° angle. is the sub-image captured by the polarization camera at a 90° angle, This is the sub-image captured by the polarization camera at an angle of 135°. represents the linear polarization phase shift image, n A natural number not less than 0 represents the number of steps of the phase shift image.

[0024] Preferably, the average value of multiple frames of linear polarization degree phase shift images is calculated to obtain a linear polarization degree average light intensity image; the average value of each angle phase shift sub-image is calculated to obtain a grayscale average light intensity image, which is expressed as:

[0025] ,

[0026] ,

[0027] Where, is the linear polarization average intensity image, is the grayscale average light intensity image, is the phase shift image at 0° polarization angle, N is the number of phase shift steps.

[0028] Preferably, threshold segmentation is performed on the linear polarization average light intensity image and the grayscale average light intensity image by Otsu's method to obtain a depolarization area mask, comprising:

[0029] Extracting pixel areas with a linear polarization degree greater than 0.8 from the linear polarization degree average light intensity image and treating them as high polarization areas;

[0030] The pixel values ​​of the linear polarization average light intensity image and the grayscale average light intensity image in the high polarization area are set to zero;

[0031] The linear polarization average light intensity image and the grayscale average light intensity image are threshold segmented after the pixel values ​​are set to zero using the Otsu method to obtain the depolarization area mask.

[0032] Preferably, the pixels marked as depolarized areas on the mask are complementary fused with the pixels marked as normal polarized areas on the mask to obtain a high dynamic range phase-shifted image, which is expressed as:

[0033] ,

[0034] Where, represents the fused high dynamic range phase shift image, k =0,45,90,135 represent four different polarization angles, is the depolarization area mask, represents the linear polarization phase shift image, n A natural number not less than 0.

[0035] According to one aspect of the present disclosure, a three-dimensional measurement system for fusing a linear polarization image with a grayscale image is provided, comprising:

[0036] A phase-shift image and Gray code image acquisition module acquires the polarization phase-shift fringe image and the black-and-white Gray code image captured by the polarization camera, and extracts the phase-shift image and the Gray code image from the polarization phase-shift fringe image and the black-and-white Gray code image;

[0037] A bilinear interpolation processing module segments the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restores the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation processing;

[0038] A polarization feature calculation module is configured to obtain a linear polarization degree phase shift image, a linear polarization degree average light intensity image, and a grayscale average light intensity image based on the phase shift sub-image processed by bilinear interpolation;

[0039] a depolarization region mask extraction module, which performs threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask;

[0040] The three-dimensional data generation module complementarily fuses the pixels marked as depolarized areas with the pixels marked as normal polarized areas according to the depolarized area mask to obtain a high dynamic range phase-shifted image, and generates three-dimensional data in combination with the Gray code image.

[0041] According to one aspect of the present disclosure, an electronic device is provided, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to: execute the above-mentioned three-dimensional measurement method of fusing a linear polarization image with a grayscale image.

[0042] According to one aspect of the present disclosure, a computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the three-dimensional measurement method of fusing a linear polarization image with a grayscale image is implemented.

[0043] Compared with the prior art, the beneficial effects of the present disclosure are:

[0044] 1) This paper combines polarization phase-shifted fringe images with a polarization camera to avoid the mechanical errors caused by traditional polarization methods for adjusting the optical path, and can achieve high dynamic range scene reconstruction with only a single exposure.

[0045] 2) This disclosure uses an adaptive threshold segmentation algorithm based on the Otsu method to accurately extract the depolarized area, thereby providing a solid foundation for the complementary fusion of linear polarization images and grayscale images.

[0046] 3) By complementary fusing the linear polarization image and the grayscale image, the present disclosure obtains a high dynamic range image that has the dual advantages of grayscale phase shift and linear polarization phase shift. It can suppress highlights and enhance dark areas of the image while avoiding the influence of depolarization, so that the depolarized area can achieve the high quality effect of grayscale phase shift.

[0047] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0048] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present disclosure and, together with the specification, are used to explain the technical solutions of the present disclosure.

[0050] Figure 1 A flow chart of a three-dimensional measurement method for fusing a linear polarization image with a grayscale image is shown;

[0051] Figure 2 A schematic diagram of a three-dimensional measurement system for fusing a linear polarization image with a grayscale image in an example of the present disclosure is shown;

[0052] Figure 3 A structural block diagram of a three-dimensional measurement system for fusing linear polarization images and grayscale images in an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0053] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0054] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0055] The term "and / or" herein simply describes an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent the existence of three situations: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0056] In addition, numerous specific details are provided in the following detailed description to better illustrate the present disclosure. Those skilled in the art will appreciate that the present disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art are not described in detail in order to highlight the main points of the present disclosure.

[0057] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0058] Example 1

[0059] Based on the above idea, the present invention proposes a three-dimensional measurement method by fusing linear polarization image and grayscale image. Figure 1 A flow chart of a three-dimensional measurement method for fusing a linear polarization image with a grayscale image is shown. The method comprises:

[0060] S10, acquiring a polarization phase-shifted fringe image and a black-and-white Gray code image captured by the polarization camera 30, and extracting a phase-shifted image and a Gray code image from the polarization phase-shifted fringe image and the black-and-white Gray code image;

[0061] S20, segmenting the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restoring the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation;

[0062] S30, obtaining a linear polarization degree phase shift image, a linear polarization degree average light intensity image, and a grayscale average light intensity image based on the phase shift sub-image after the bilinear interpolation processing;

[0063] S40, performing threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask;

[0064] S50 , according to the depolarization region mask, complementary fuse the pixels marked as the depolarization region by the mask and the pixels marked as the normal polarization region by the mask to obtain a high dynamic range phase-shift image, and generate three-dimensional data in combination with the Gray code image.

[0065] The present disclosure provides a three-dimensional measurement method by fusing a linear polarization image with a grayscale image, which specifically includes the following steps:

[0066] S10 , acquiring a polarization phase-shifted fringe image and a black-and-white Gray code image captured by the polarization camera 30 , and extracting a phase-shifted image and a Gray code image from the polarization phase-shifted fringe image and the black-and-white Gray code image.

[0067] Figure 2 A schematic diagram of a three-dimensional measurement system that fuses linear polarization images and grayscale images in an embodiment of the present disclosure is shown. In this embodiment, image acquisition is performed using a polarization camera 30. First, an LCD projector 20 projects black and green polarization stripes and a black and white Gray code onto the object 10 being measured. Due to the color-combining prism within the LCD projector 20, the three primary colors projected by the LCD projector 20 have different polarization states. The LCD projector 20 controls the polarization state of light by utilizing the optical properties of the liquid crystal panel. The three light sources (red, green, and blue) maintain different polarization states, with green light having a horizontal polarization state and red and blue light having vertical polarization states. Green light displays a higher intensity on a grayscale camera, resulting in a higher signal-to-noise ratio. Therefore, the black and green stripes are selected as the phase-shifted stripes in this embodiment. The polarization camera 30 can capture polarization phase-shifted stripe images at different polarization angles. These images record phase change information reflected from the surface of the object 10 under different lighting conditions, which is used to calculate the three-dimensional topography of the object 10 surface. Finally, these two types of images are combined to obtain phase-shift images and Gray code images, thus providing the required basic data for subsequent three-dimensional measurement and reconstruction.

[0068] S20 , segmenting the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restoring the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation.

[0069] In this embodiment, the raw polarization image captured by a polarization monochrome CMOS camera (FLIR BFS-U3-51S5P-C) contains image information at four polarization angles, which needs to be extracted. The polarization sensor in polarization camera 30 utilizes a polarizer array overlying the photodiodes of a conventional CMOS image sensor. Four polarizers at different angles (0°, 90°, 45°, and 135°) are sequentially placed over individual pixels, with each four pixels forming an imaging unit. Because the individual units are not aligned, bilinear interpolation is used to align the polarization information images of each pixel to the 0° image to prevent minor displacements from affecting subsequent reconstruction.

[0070] Through bilinear interpolation, the phase-shifted sub-images at each angle are restored to their original resolution, which can be expressed as:

[0071] ,

[0072] ,

[0073] ,

[0074] Where, 、 and Represent the polarization images with polarization angles of 45°, 90°, and 135°, respectively. i is the vertical pixel coordinate, i -1 is i The pixel position of the pixel above, i +1 for i The next pixel position of the pixel, j is the horizontal axis, j -1 is j One pixel to the left, j +1 for j One pixel to the right.

[0075] S30 , obtaining a linear polarization degree phase shift image, a linear polarization degree average light intensity image, and a grayscale average light intensity image based on the phase shift sub-image after the bilinear interpolation processing.

[0076] In this embodiment, based on the phase-shifted sub-image after bilinear interpolation processing, a linear polarization phase-shifted image, a linear polarization average light intensity image and a grayscale average light intensity image are obtained, including: based on the interpolated phase-shifted sub-image, a linear polarization phase-shifted image is obtained by Stokes vector calculation; the average value of multiple frames of linear polarization phase-shifted images is calculated to obtain a linear polarization average light intensity image; the average value of the phase-shifted sub-images at each angle is calculated to obtain a grayscale average light intensity image.

[0077] The linear polarization phase shift image is obtained by calculating the Stokes vector, which is expressed as:

[0078] ,

[0079] ,

[0080] Where, represents the total intensity of light, Represents the intensity difference between the horizontally polarized component and the vertically polarized component of light, It represents the intensity difference between the +45° polarization component and the -45° polarization component of light. is the sub-image captured by the polarization camera at 0° angle, This is the sub-image captured by the polarization camera at a 45° angle. is the sub-image captured by the polarization camera at a 90° angle, This is the sub-image captured by the polarization camera at an angle of 135°. represents the linear polarization phase shift image, n A natural number not less than 0 represents the number of steps of the phase shift image.

[0081] Furthermore, the average value of the multi-frame linear polarization phase shift image is calculated to obtain the linear polarization average light intensity image; the average value of the phase shift sub-images at each angle is calculated to obtain the grayscale average light intensity image, which is expressed as:

[0082] ,

[0083] ,

[0084] Where, is the linear polarization average intensity image, is the grayscale average light intensity image, is the phase shift image at 0° polarization angle, N is the number of phase shift steps.

[0085] S40 , performing threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask.

[0086] In this embodiment, the linear polarization average light intensity image and the grayscale average light intensity image are threshold segmented by the Otsu method to obtain a depolarization area mask, including: extracting a pixel area with a linear polarization degree greater than 0.8 from the linear polarization average light intensity image and using it as a high polarization area; setting the pixel values ​​of the linear polarization average light intensity image and the grayscale average light intensity image in the high polarization area to zero; and performing threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image after the pixel values ​​are set to zero by the Otsu method to obtain a depolarization area mask.

[0087] First, the linear polarization average intensity image Perform threshold extraction separately and extract the area where the linear polarization degree is greater than 0.8 separately to avoid the influence of this area on the subsequent mask. This area is the high polarization area M1. and grayscale average intensity image In the M1 region, the grayscale is set to zero, and we get 、 .

[0088] Then, using the Otsu method, 、 Substitute it into the adaptive threshold segmentation to accurately segment and extract the depolarized area, and obtain the depolarized binary mask image M2.

[0089] S50 , according to the depolarization region mask, complementary fuse the pixels marked as the depolarization region by the mask and the pixels marked as the normal polarization region by the mask to obtain a high dynamic range phase-shift image, and generate three-dimensional data in combination with the Gray code image.

[0090] In this embodiment, the pixels marked as depolarized areas on the mask are complementary fused with the pixels marked as normal polarized areas on the mask to obtain a high dynamic range phase-shifted image, which is expressed as:

[0091] ,

[0092] Where, represents the fused high dynamic range phase-shift image, k =0,45,90,135 represent four different polarization angles, is the depolarization area mask, represents the linear polarization phase shift image, n A natural number not less than 0.

[0093] Finally, according to the phase shift method calculation formula (here taking four-step phase shift as an example), the package phase of object 10 is obtained as:

[0094] ,

[0095] The absolute phase at this time is:

[0096] ,

[0097] Where, represents the wrapping phase, represents the absolute phase solved from the wrapped phase, The order of the sinusoidal fringes, that is, the number of periods of the sinusoidal fringes, can be solved by Gray code.

[0098] The disclosed embodiments utilize complementary fusion of linear polarization images and grayscale images, avoiding the depolarization issues encountered when using polarization information. This allows for high dynamic range imaging of complex scenes in a single exposure. Furthermore, the advantages of linear polarization images and grayscale images in their respective fields are leveraged to achieve fast, high-precision 3D measurement.

[0099] Example 2

[0100] As another aspect of the embodiment of the present disclosure, a three-dimensional measurement system 100 for fusing linear polarization image and grayscale image is also provided. Figure 3 Shown, including:

[0101] Phase-shift image and Gray code image acquisition module 1 acquires the polarization phase-shift fringe image and the black-and-white Gray code image captured by the polarization camera 30, and extracts the phase-shift image and the Gray code image from the polarization phase-shift fringe image and the black-and-white Gray code image;

[0102] A bilinear interpolation processing module 2 segments the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restores the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation processing;

[0103] Polarization feature calculation module 3, based on the phase-shifted sub-image processed by bilinear interpolation, obtains a linear polarization degree phase-shifted image, a linear polarization degree average light intensity image, and a grayscale average light intensity image;

[0104] a depolarization region mask extraction module 4, which performs threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask;

[0105] The three-dimensional data generation module 5 complementarily fuses the pixels marked as depolarized areas with the pixels marked as normal polarized areas according to the depolarized area mask to obtain a high dynamic range phase-shifted image, and generates three-dimensional data in combination with the Gray code image.

[0106] In the absence of any contradiction, the above modules in the system of the embodiment of the present disclosure can implement any implementation of the above method.

[0107] Based on the description of the above embodiments, it can be seen that the embodiments of the present disclosure can achieve the following technical effects:

[0108] 1) The present disclosure combines polarization phase-shifted fringe images with a polarization camera 30, thereby avoiding the mechanical errors caused by traditional polarization methods for adjusting the optical path, and achieving high dynamic range scene reconstruction with only a single exposure.

[0109] 2) This disclosure uses an adaptive threshold segmentation algorithm based on the Otsu method to accurately extract the depolarized area, thereby providing a solid foundation for the complementary fusion of linear polarization images and grayscale images.

[0110] 3) By complementary fusing the linear polarization image and the grayscale image, the present disclosure obtains a high dynamic range image that has the dual advantages of grayscale phase shift and linear polarization phase shift. It can suppress highlights and enhance dark areas of the image while avoiding the influence of depolarization, so that the depolarized area can achieve the high quality effect of grayscale phase shift.

[0111] The present disclosure also provides an electronic device comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to implement the aforementioned three-dimensional measurement method by fusing linear polarization images with grayscale images. The electronic device can be provided as a terminal, server, or other device.

[0112] The present disclosure also provides a computer-readable storage medium having computer program instructions stored thereon. When executed by a processor, the computer program instructions implement the aforementioned three-dimensional measurement method by fusing a linear polarization image with a grayscale image. The computer-readable storage medium may be a non-volatile computer-readable storage medium.

[0113] Those skilled in the art will understand that in the three-dimensional measurement method and system for fusing linear polarization images and grayscale images in the specific implementation manner, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0114] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and the part of the module, program segment or instruction contains one or more executable instructions for realizing the prescribed logical function. In some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the prescribed function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0115] While various embodiments of the present disclosure have been described above, the above descriptions are illustrative, non-exhaustive, and not intended to be limiting of the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technical improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A three-dimensional measurement method using a fusion of linear polarization image and grayscale image, characterized in that: The steps include: S10, acquiring a polarization phase-shifted fringe image and a black-and-white Gray code image captured by a polarization camera, and extracting a phase-shifted image and a Gray code image from the polarization phase-shifted fringe image and the black-and-white Gray code image; S20, segmenting the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restoring the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation; S30, based on the phase-shifted sub-image after bilinear interpolation processing, obtaining a linear polarization degree phase-shifted image, a linear polarization degree average light intensity image, and a grayscale average light intensity image, including: Based on the interpolated phase-shift sub-image, the linear polarization phase-shift image is obtained by Stokes vector calculation; Calculate the average value of multiple frames of linear polarization phase shift images to obtain a linear polarization average light intensity image; Calculate the average value of the phase-shifted sub-images at each angle to obtain the grayscale average light intensity image; S40, performing threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask; S50, according to the depolarization region mask, complementary fusion is performed on the pixels marked as the depolarization region by the mask and the pixels marked as the normal polarization region by the mask to obtain a high dynamic range phase-shifted image, and combined with the Gray code image to generate three-dimensional data; The high dynamic range phase shift image is expressed as: ， Where, represents the fused high dynamic range phase-shift image, k =0,45,90,135 represent four different polarization angles, is the depolarization area mask, represents the linear polarization phase shift image, n A natural number not less than 0.

2. The method according to claim 1, characterized in that Through bilinear interpolation, the phase-shifted sub-images at each angle are restored to their original resolution, which can be expressed as: ， ， ， Where, 、 and Represent the polarization images with polarization angles of 45°, 90°, and 135°, respectively. i is the vertical pixel coordinate, i -1 is i The pixel position of the pixel above, i +1 for i The next pixel position of the pixel, j is the horizontal axis, j -1 is j One pixel to the left, j +1 for j One pixel to the right.

3. The method according to claim 1, characterized in that The linear polarization phase shift image is obtained by calculating the Stokes vector, which is expressed as: ， ， Where, represents the total intensity of light, Represents the intensity difference between the horizontally polarized component and the vertically polarized component of light, It represents the intensity difference between the +45° polarization component and the -45° polarization component of light. is the sub-image captured by the polarization camera at 0° angle, This is the sub-image captured by the polarization camera at a 45° angle. is the sub-image captured by the polarization camera at a 90° angle, This is the sub-image captured by the polarization camera at an angle of 135°. represents the linear polarization phase shift image, n A natural number not less than 0 represents the number of steps of the phase shift image.

4. The method according to claim 1, wherein Calculate the average value of multiple frames of linear polarization phase shift images to obtain the linear polarization average light intensity image; calculate the average value of each angle phase shift sub-image to obtain the grayscale average light intensity image, which is expressed as: ， ， Where, is the linear polarization average intensity image, is the grayscale average light intensity image, is the phase shift image at 0° polarization angle, N is the number of phase shift steps.

5. The method according to claim 1, wherein Threshold segmentation is performed on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask, including: Extracting pixel areas with a linear polarization degree greater than 0.8 from the linear polarization degree average light intensity image and treating them as high polarization areas; The pixel values ​​of the linear polarization average light intensity image and the grayscale average light intensity image in the high polarization area are set to zero; The linear polarization average light intensity image and the grayscale average light intensity image are threshold segmented after the pixel values ​​are set to zero using the Otsu method to obtain the depolarization area mask.

6. A three-dimensional measurement system that fuses linear polarization images and grayscale images, characterized in that: include: A phase-shift image and Gray code image acquisition module acquires the polarization phase-shift fringe image and the black-and-white Gray code image captured by the polarization camera, and extracts the phase-shift image and the Gray code image from the polarization phase-shift fringe image and the black-and-white Gray code image; A bilinear interpolation processing module segments the phase-shifted image to obtain four phase-shifted sub-images at different angles, and restores the phase-shifted sub-images at each angle to their original resolution through bilinear interpolation processing; The polarization feature calculation module obtains a linear polarization degree phase shift image, a linear polarization degree average light intensity image, and a grayscale average light intensity image based on the phase shift sub-image processed by bilinear interpolation, including: Based on the interpolated phase-shift sub-image, the linear polarization phase-shift image is obtained by Stokes vector calculation; Calculate the average value of multiple frames of linear polarization phase shift images to obtain a linear polarization average light intensity image; Calculate the average value of the phase-shifted sub-images at each angle to obtain the grayscale average light intensity image; a depolarization region mask extraction module, which performs threshold segmentation on the linear polarization average light intensity image and the grayscale average light intensity image by using the Otsu method to obtain a depolarization region mask; a three-dimensional data generation module, which, based on the depolarization region mask, complementarily fuses pixels marked as depolarization regions by the mask with pixels marked as normal polarization regions by the mask to obtain a high dynamic range phase-shifted image, and combines the image with the Gray code image to generate three-dimensional data; The high dynamic range phase shift image is expressed as: ， Where, represents the fused high dynamic range phase shift image, k =0,45,90,135 represent four different polarization angles, is the depolarization area mask, represents the linear polarization phase shift image, n A natural number not less than 0.

7. An electronic 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 three-dimensional measurement method of fusing the linear polarization image and the grayscale image according to any one of claims 1 to 5 is implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the three-dimensional measurement method of fusing a linear polarization image and a grayscale image according to any one of claims 1 to 5 is implemented.

Images