Intelligent material scanning device and method based on multi-angle polarized light

Abstract

The invention discloses an intelligent material scanning device and method based on multi-angle polarized illumination, and the device comprises a box body, and a camera assembly, a polarization filter, an illumination assembly and a rotating table which are sequentially distributed in the box body from top to bottom, and the polarization filter is rotatably connected to the front end of an objective lens of the camera assembly. The lighting assembly is provided with a plurality of light sources distributed on the hemispherical surface in a longitude and latitude mode. The camera assembly obtains image data on the rotating table through the polarization filter. The objective of the invention is to design an intelligent material scanning device which is low in cost, high in precision and ecologically open, and based on the combination of a physical polarization means and a photometric stereo method, the generated material is real and uniform under different environment illumination.

Description

Technical Field

[0001] This invention relates to the technical field of material scanning, and in particular to an intelligent material scanning device and method based on multi-angle polarized light illumination. Background Technology

[0002] In the current field of 3D modeling, the acquisition and digitization of physically based rendering materials has become a key technical requirement for constructing high-quality 3D content. The hardware architecture of traditional scanning equipment is extremely complex, relying on precise robotic arms or multi-axis motion systems to change the lighting or observation angle. It requires regular accuracy calibration and is costly. Moreover, conventional scanners have limited physical data decoupling capabilities and cannot distinguish between the natural color and highlights of an object's surface. For materials with reflective characteristics such as brushed metal and silk, the capture of sample features is insufficient, and the 3D images generated by scanning under different lighting conditions appear fake. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, the present invention aims to provide a low-cost, high-precision, and ecologically open intelligent material scanning device. Based on physical polarization and photometric stereo method, the generated material appears realistic and uniform under different ambient lighting conditions, thus solving the problems of high cost, difficulty in physical data decoupling, and insufficient sample feature capture of existing scanning equipment.

[0004] The technical solution adopted in this invention is: an intelligent material scanning device based on multi-angle polarized light illumination, including a housing, and a camera assembly, a polarizing filter, an illumination assembly and a rotating stage arranged sequentially from top to bottom within the housing. The polarizing filter is rotatably connected to the front end of the objective lens of the camera assembly, and the illumination assembly is provided with several light sources distributed latitude and longitude on the hemispherical surface. The camera assembly acquires image data on the rotating stage through the polarizing filter.

[0005] As a further preferred technical solution of the present invention, the lighting component includes a hemispherical bracket and LED beads distributed in a latitude and longitude pattern on the surface of the hemispherical bracket. The rotating platform is coaxially distributed inside the hemispherical bracket, and the hemispherical bracket has a central hole. The camera component takes pictures in the direction of the rotating platform through the central hole.

[0006] As a further preferred technical solution of the present invention, the hemispherical fixing frame is provided with a plurality of countersunk holes distributed in a latitude and longitude pattern, and the LED lamp beads are connected to the hemispherical fixing frame through the countersunk holes, with the light-emitting surface of the LED lamp beads facing the direction of the rotating table.

[0007] As a further preferred technical solution of the present invention, the camera assembly includes an industrial camera, a mounting bracket, a turntable, and a motor. The industrial motor is mounted above the lighting assembly via the mounting bracket, and the turntable is rotatably connected to the mounting bracket. Multiple sets of polarizing filters are distributed circumferentially on the turntable, and a motor for controlling the rotation of the turntable at a fixed angle is provided on one side of the mounting bracket.

[0008] As a further preferred technical solution of the present invention, the transmission axis directions of adjacent polarizing filters on the turntable are different.

[0009] As a further preferred embodiment of the present invention, the camera assembly also includes a fan, which is fixedly connected to the top of the industrial camera.

[0010] This invention also provides a smart material scanning method based on multi-angle polarized light illumination, comprising the following steps: S1. Parallel polarization data acquisition: Place the sample on the rotating stage, control the illumination components to be fully lit, and control the rotating stage to rotate the polarization filter to an angle parallel to the shooting direction to acquire parallel image data containing specular reflection and diffuse reflection images; S2. Cross-polarization data acquisition: Place the sample to be scanned on a rotating stage, control the polarization filter to rotate to an angle orthogonal to the shooting direction, and acquire cross-polarization data containing only diffuse reflection images; S3. Obtain the sample's original color image: Subtract the parallel plot data from the cross plot data to obtain the original color image data containing only specular reflections; S4. Photometric Stereo Method Algorithm: Maintain the cross-polarization state, control the light source to light up one point at a time in sequence, and the camera component simultaneously takes multiple photos. By analyzing the brightness and darkness changes of the same pixel under different lighting angles, the surface normal vector data of the corresponding point is calculated. S5. Create sample surface texture: Using the original normal vector data calculated by photometric stereo method as input, and by repairing the normal calculation errors caused by shadow occlusion, the true surface texture of the sample is reconstructed.

[0011] As a further preferred technical solution of the present invention, in S3 above, the difference between parallel polarization and orthogonal polarization is used to calculate the roughness and metallicity of the sample surface.

[0012] As a further preferred technical solution of the present invention, in S5 above, the processed base color data, normal vector data, roughness data and metallicity data are integrated according to the standard PBR material process and exported as MaterialX format or glTF format.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The color and gloss of the sample are completely separated by physical polarization. Specifically, through cross-polarization imaging, specular reflection is directly filtered out to obtain pure diffuse reflection information. By calculating the difference between parallel and cross-polarized images, the highlight and reflection information are effectively separated, and the core physical parameters such as the roughness and metallicity of the material are calculated accordingly. This effectively solves the problem of the interference of diffuse reflection and highlight information on the material's true color in traditional photogrammetry, and achieves high-fidelity scanning of the sample. 2. A fixed semi-circular dome lighting array is used in conjunction with a fast sequential single-point lighting method to acquire photometric stereo data. The original normal map calculated by photometric stereo is used as input, and a neural network is used to correct normal calculation errors caused by shadow occlusion. This solution does not require a complex mechanical structure and can simulate multi-angle lighting of the entire hemisphere through electronic control, thereby accurately calculating the normal map of the micro-geometry of the object surface. It can capture fine surface texture details such as hair and fabric fibers, and significantly reduce costs.

[0014] 3. From raw RAW data acquisition to output in common formats such as MaterialX and glTF, enabling data to flow between different 3D software and platforms.

[0015] The embodiments of the present invention will be further described below with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a front view of the scanning device of the present invention; Figure 2 This is a cross-sectional view of the scanning device of the present invention; Figure 3 This is a perspective view of the hemispherical fixing frame of the present invention; Figure 4 This is a front view of the camera assembly of the present invention; Figure 5 For the present invention Figure 4 A sectional view of the view along direction A; Figure 6 This is a schematic flowchart of the scanning method of the present invention; Figure 7 This is a schematic diagram illustrating the photometric stereoscopic scanning of samples used in this invention. The components are: 1-box, 2-camera assembly, 3-polarizing filter, 4-lighting assembly, 5-rotary stage, 6-hemispherical bracket, 7-LED lamp bead, 8-center hole, 9-countersunk hole, 11-industrial camera, 12-fixed bracket, 13-turntable, 14-motor, 15-fan, 16-orthogonal linear polarizer, 17-parallel linear polarizer. Detailed Implementation

[0017] Embodiments of the present invention will now be described with reference to the accompanying drawings. In this process, to ensure clarity and convenience, we may exaggerate the width of lines or the size of constituent elements in the drawings.

[0018] Furthermore, the terms used below are defined based on the functions of this invention and may vary depending on the intentions or conventions of the user or operator. Therefore, these terms are defined based on the entire contents of this specification.

[0019] like Figure 1 , 2 As shown, the present invention discloses an intelligent material scanning device based on multi-angle polarized light illumination, including a housing 1, and a camera assembly 2, a polarizing filter 3, an illumination assembly 4, and a rotating stage 5 arranged sequentially from top to bottom within the housing 1. The polarizing filter 3 is rotatably connected to the front end of the objective lens of the camera assembly 2, and the illumination assembly 4 is provided with several light sources distributed latitude and longitude on the hemispherical surface. The camera assembly 2 acquires image data on the rotating stage 5 through the polarizing filter 3.

[0020] Combination Figure 3 As shown, in this embodiment, the lighting component 4 includes a hemispherical mounting bracket 6 and LED beads 7 distributed in a latitude and longitude pattern on the surface of the hemispherical mounting bracket 6. The rotating platform 5 is coaxially distributed inside the hemispherical mounting bracket 6. The hemispherical mounting bracket 6 has a central hole 8. The camera component 2 takes pictures in the direction of the rotating platform 5 through the central hole 8. The hemispherical mounting bracket 6 has a plurality of countersunk holes 9 distributed in a latitude and longitude pattern. The hemispherical mounting bracket 6 has 7 layers of LED beads 7 groups, and 21, 27, 29, 36, 36, 38, and 41 LED beads 7 are distributed from top to bottom. The LED beads 7 are connected to the hemispherical mounting bracket 6 through the countersunk holes 9, and the light-emitting surface of the LED beads 7 faces the direction of the rotating platform 5.

[0021] Combination Figure 4 , 5 As shown, in this embodiment, the camera assembly 2 includes an industrial camera 11, a mounting bracket 12, a turntable 13, a motor 14, and a fan 15. The industrial motor 14 is mounted above the lighting assembly 4 via the mounting bracket 12, and the mounting bracket 12 is rotatably connected to the turntable 13. Multiple polarizing filters 3 are circumferentially distributed on the turntable 13. A motor 14 for controlling the rotation of the turntable 13 at a fixed angle is provided on one side of the mounting bracket 12. The motor 14 and the turntable 13 are provided with meshing gears. The motor 14 controls the rotation of the turntable 13 at a fixed angle through the gears. The transmission axis directions of adjacent polarizing filters 3 on the turntable 13 are different, including an orthogonal linear polarizer 16 perpendicular to the light source direction and a parallel linear polarizer 17 parallel to the light source direction. The orthogonal linear polarizer 16 and the parallel linear polarizer 17 are alternately distributed on the turntable 13. The fan 15 is fixedly connected above the industrial camera 11.

[0022] Combination Figure 6 As shown, the present invention also provides a smart material scanning method based on multi-angle polarized light illumination, comprising the following steps: S1. Parallel polarization data acquisition: Place the sample on the rotating stage 5, control all LED beads 7 to be fully lit, and control the rotating stage 5 to rotate the parallel linear polarizer 17 to a parallel angle with the shooting direction to acquire parallel image data including specular reflection and diffuse reflection images. S2. Cross-polarization data acquisition: Place the sample to be scanned on the rotary stage 5, control the orthogonal linear polarizer 16 to rotate to an angle orthogonal to the shooting direction, and acquire cross-polarization data containing only diffuse reflection images; S3. Obtain the original color image of the sample: The image processing unit in the software automatically performs image subtraction operation, subtracts the parallel image data from the cross image data, removes specular interference, and obtains the original color image data with only specular reflection. The difference between parallel polarization and orthogonal polarization is used to calculate the roughness and metallicity of the sample surface. S4. Photometric Stereo Method Solution Algorithm Line: Combining Figure 7 As shown, the cross-polarization state is maintained, and the LED beads 7 are controlled to light up quickly and in sequence. When each LED bead 7 is lit, the industrial camera 11 simultaneously takes a sample photo, and finally obtains a set of sample images under the same viewpoint and different single direction of illumination. The camera component 2 simultaneously takes multiple photos, and by analyzing the brightness and darkness changes of the same pixel under different illumination angles, the surface normal vector data of the corresponding point is calculated. S5. Create Sample Surface Texture: Using the original normal vector data calculated by the photometric stereo method as input, and by repairing the normal calculation errors caused by shadow occlusion, the true surface texture of the sample is reconstructed. The processed base color data, normal vector data, roughness data and metallicity data are integrated according to the standard PBR material process and exported as MaterialX or glTF format.

[0023] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A smart material scanning device based on multi-angle polarized light illumination, characterized in that, The device includes a housing (1), and a camera assembly (2), a polarizing filter (3), an illumination assembly (4), and a rotating stage (5) arranged sequentially from top to bottom within the housing (1). The polarizing filter (3) is rotatably connected to the front end of the objective lens of the camera assembly (2). The illumination assembly (4) is provided with several light sources distributed in the latitude and longitude of the hemisphere. The camera assembly (2) obtains image data on the rotating stage (5) through the polarizing filter (3).

2. The intelligent material scanning device based on multi-angle polarized light illumination according to claim 1, characterized in that: The lighting assembly (4) includes a hemispherical bracket (6) and LED beads (7) distributed in a latitude and longitude pattern on the surface of the hemispherical bracket (6). The rotating platform (5) is coaxially distributed inside the hemispherical bracket (6). The hemispherical bracket (6) is provided with a central hole (8). The camera assembly (2) takes pictures in the direction of the rotating platform (5) through the central hole (8).

3. The intelligent material scanning device based on multi-angle polarized light illumination according to claim 2, characterized in that: The hemispherical bracket (6) is provided with several countersunk holes (9) distributed in a latitude and longitude pattern. The LED beads (7) are connected to the hemispherical bracket (6) through the countersunk holes (9), and the light-emitting surface of the LED beads (7) faces the rotating table (5).

4. The intelligent material scanning device based on multi-angle polarized light illumination according to claim 1, characterized in that: The camera assembly (2) includes an industrial camera (11), a mounting bracket (12), a turntable (13), and a motor (14). The industrial motor (14) is mounted above the lighting assembly (4) via the mounting bracket (12), and the mounting bracket (12) is rotatably connected to the turntable (13). Multiple sets of polarizing filters (3) are distributed circumferentially on the turntable (13). A motor (14) for controlling the rotation of the turntable (13) at a fixed angle is provided on one side of the mounting bracket (12).

5. The intelligent material scanning device based on multi-angle polarized light illumination according to claim 4, characterized in that: The transmission axis directions of adjacent polarizing filters (3) on the turntable (13) are different.

6. The intelligent material scanning device based on multi-angle polarized light illumination according to claim 5, characterized in that: The camera assembly (2) also includes a fan (15), which is fixedly connected above the industrial camera (11).

7. A smart material scanning method based on multi-angle polarized light illumination, employing the smart material scanning device based on multi-angle polarized light illumination as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Parallel polarization data acquisition: Place the sample on the rotating stage (5), control the illumination component (4) to be fully lit, and control the polarization filter (3) to rotate to an angle parallel to the shooting direction on the rotating stage (5) to obtain parallel image data containing specular reflection and diffuse reflection images; S2. Cross-polarization data acquisition: Place the sample to be scanned on the rotating stage (5), control the polarization filter (3) to rotate to an angle orthogonal to the shooting direction, and acquire cross-polarization data containing only diffuse reflection images; S3. Obtain the sample's original color image: Subtract the parallel plot data from the cross plot data to obtain the original color image data containing only specular reflections; S4. Photometric stereo method algorithm: Maintain the cross polarization state, control the light source to light up one point at a time in sequence, and the camera component (2) takes multiple photos at the same time. By analyzing the brightness and darkness changes of the same pixel under different lighting angles, the surface normal vector data of the corresponding point is calculated. S5. Create sample surface texture: Using the original normal vector data calculated by photometric stereo method as input, and by repairing the normal calculation errors caused by shadow occlusion, the true surface texture of the sample is reconstructed.

8. The intelligent material scanning method based on multi-angle polarized light illumination according to claim 7, characterized in that: In S3 above, the difference between parallel polarization and orthogonal polarization is used to calculate the roughness and metallicity of the sample surface.

9. The intelligent material scanning method based on multi-angle polarized light illumination according to claim 8, characterized in that: In S5 above, the processed base color data, normal vector data, roughness data and metallicity data are integrated according to the standard PBR material process and exported as MaterialX or glTF format.

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