3D scanner, system and 3D reconstruction method

Abstract

The present disclosure relates to a three-dimensional scanner, a system, and a three-dimensional reconstruction method. The three-dimensional scanner includes an emitter for emitting a predetermined light beam including at least two monochromatic light beams, a collimator for homogenizing the predetermined light beam, a pattern shaping device for projecting the homogenized predetermined light beam as a structured light pattern, a light path adjuster for changing the transmission path of the structured light pattern to project the structured light pattern onto a target object, and a structured light pattern modulated by the target object to an image collecting device, which disperses the structured light pattern modulated by the target object, and collects the dispersed structured light patterns by different cameras for three-dimensional reconstruction. The present disclosure realizes a reduction in hardware costs required for the three-dimensional reconstruction method, and enables three-dimensional reconstruction to be performed using only two-dimensional images acquired at a single time, greatly improving the efficiency of image reconstruction.

Description

[Technical field]

[0001] TECHNICAL FIELD The embodiments of the present disclosure relate to the technical field of 3D scanning, and in particular to a 3D scanner, a system and a 3D reconstruction method.

[0002] This disclosure claims priority to a Chinese patent application filed with the China Patent Office on April 13, 2021, bearing application number 2021103931908 and entitled "3D scanner, system and 3D reconstruction method," the entire contents of which are incorporated herein by reference. [Background technology]

[0003] Currently, the method of acquiring dental model data in the field of dental diagnosis and treatment internationally is gradually shifting from 3D impression scanning to intraoral 3D scanning. Intraoral scanning technology mainly uses a 3D scanner (also called an oral digital impression machine), which is an instrument that uses an invasive optical scan head to directly scan the inside of the patient's oral cavity to acquire 3D morphology and color texture information of the soft and hard tissue surfaces in the oral cavity, such as teeth, gums, and mucosa.

[0004] Intraoral scanning technology uses the principle of active structured light triangulation imaging, projects active light patterns using a digital projection system, and then uses algorithm processing to perform 3D reconstruction and stitching after the pattern is acquired by a camera acquisition system to obtain the patient's tooth images. However, in the prior art, a 3D reconstruction method based on time coding and decoding is used, that is, tooth images need to be collected at multiple times and encoded / decoded and reconstructed in different time series, which makes it difficult to realize small handheld scanning and cannot be applied to the field of intraoral 3D scanning. In addition, the 3D reconstruction method based on time coding further requires high frame rate cameras and high speed algorithm support, which further increases the manufacturing cost of 3D scanning equipment and is disadvantageous to popular use. Summary of the Invention [Problem to be solved by the invention]

[0005] In order to solve the above technical problems or at least partially solve the above technical problems, the embodiments of the present disclosure provide a 3D scanner, system, and 3D reconstruction method, which realizes a reduction in the hardware costs required for the 3D reconstruction method, and enables 3D reconstruction to be performed with only 2D images acquired at a single time, greatly improving the efficiency of image reconstruction. [Means for solving the problem]

[0006] The present disclosure provides a three-dimensional scanner, the three-dimensional scanner including a projection device, an image acquisition device, and an optical path adjustment device; the projection system includes an illumination system, a collimation system, and a patterning system; The emitting device is adapted to emit a predetermined light beam including at least two monochromatic light beams, The collimating device is used to homogenize the predetermined light beam, the pattern forming device is used for projecting a uniformed predetermined light beam as a structured light pattern; the light path adjusting device is used for changing a transmission path of the structured light pattern to project the structured light pattern onto a target object, and projecting the structured light pattern modulated by the target object onto an image collecting device; The image capture device disperses the structured light pattern modulated by the target object, and collects a number of dispersed structured light patterns with different cameras for 3D reconstruction.

[0007] The present disclosure provides a 3D scanning system, the 3D scanning system including a 3D scanner and an image processing device in communication with the 3D scanner; the three-dimensional scanner includes a projection device, an image acquisition device, and an optical path adjustment device, the projection device includes an emission device, a collimation device, and a pattern shaping device; the three-dimensional scanner emits a predetermined light beam by an emission device, homogenizes the predetermined light beam by collimating it, projects the homogenized predetermined light beam as a structured light pattern by the pattern forming device, changes a transmission path of the structured light pattern by the light path adjustment device to project the structured light pattern onto a target object, projects the structured light pattern modulated by the target object onto an image collection device, disperses the structured light pattern modulated by the target object by the image collection device, and collects the dispersed structured light patterns by different cameras for use in three-dimensional reconstruction; the predetermined light beam includes at least two types of monochromatic light beams; An image processing device receives the dispersed structured light patterns scanned by the 3D scanner and performs 3D reconstruction based on the dispersed structured light patterns.

[0008] An embodiment of the present disclosure further provides a 3D reconstruction method, which is applied to the image processing apparatus described above, comprising: Obtaining a plurality of dispersed structured light patterns scanned by a three-dimensional scanner; and performing a 3D reconstruction based on a predetermined encoding rule, a predetermined encoding table of a structured light stripe map, and the dispersed structured light patterns. Effect of the Invention

[0009] The above technical solutions according to the embodiments of the present disclosure have the following advantages over the prior art:

[0010] In the embodiments of the present disclosure, the collected multiple dispersed structured light patterns are based on a spatial coding format, so that 3D reconstruction of the target object can be achieved with only 2D images acquired at a single time, eliminating the need for dynamic projection, which greatly reduces the frame rate of the camera in the 3D scanner and the algorithm calculation cost, improves the speed of dynamic scanning inside the oral cavity, and reduces the size of the camera required for the 3D scanner, which can be applied to scanning the oral cavity to obtain tooth images; and, since 3D reconstruction of the target object can be achieved with only 2D images acquired at a single time, the acquisition time difference between the reconstruction map and the texture map of the 3D scanner is reduced, and the time required for projection and photography during 3D reconstruction of the target object is reduced; and, since the 3D scanner uses color as spatial coding information, the spatial coding information in color form is more easily recognized, thereby improving the recognition accuracy. In addition, since the color features of the monochromatic light rays (e.g., blue stripes) in the generated multiple dispersed structured light patterns and the monochromatic light rays dispersed from white light (e.g., blue texture maps) are prominent, 3D reconstruction can be performed based on the blue-green stripes and the color stripes, and 3D reconstruction can be performed based on the blue texture map and the red-green texture map, thereby improving the image quality of the reconstructed image. If there is enamel on the surface of the tooth, the 3D scanner can also separate the reflected light of the enamel to prevent the reflected light and scattered light of the enamel from affecting the quality of the reconstructed image.

[0011] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure.

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure.

[0013] In order to more clearly describe the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly describes the drawings that need to be used in the description of the embodiments or the prior art, and obviously, those skilled in the art can also obtain other drawings based on these drawings without requiring creative labor. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a structural schematic diagram of a 3D scanner in accordance with one or more embodiments of the present disclosure. [Diagram 2] FIG. 2 is a structural schematic diagram of another 3D scanner in accordance with one or more embodiments of the present disclosure. [Diagram 3] FIG. 3 is a structural schematic diagram of a 3D scanning system in accordance with one or more embodiments of the present disclosure. [Figure 4] FIG. 4 is a flow chart of a 3D reconstruction method in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In order to make the objectives, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure are described below clearly and completely, and obviously, the described embodiments are only a part of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without requiring creative labor shall all fall within the protection scope of the present disclosure.

[0016] In the related technology, when a 3D scanner is used to collect intraoral images, the 3D scanning technology is used to insert the invasive optical scan head of the 3D scanner into the oral cavity and directly scan the patient's oral cavity to obtain the 3D morphology and color texture information of the soft and hard tissue surfaces in the oral cavity, such as teeth, gums, and mucosa. Because the oral cavity is narrow and the size of the invasive optical scan head is limited, the size of the invasive scan head is generally controlled within 30 mm, and the invasive optical scan head can only acquire tooth images of up to two teeth at a time. However, in the dental industry, in the process of designing and manufacturing teeth, it is mostly necessary to acquire all the teeth and gum data in the oral cavity, and stitch the tooth images acquired at one time to form 3D spatial data that matches all the teeth in the oral cavity.

[0017] In order to improve the single scan speed and the stitching speed of the tooth image, on the one hand, it is necessary to improve the single scan efficiency, and on the other hand, it is necessary to improve the stitching success rate and stitching efficiency. The factors that determine the single scan time are often related to the execution time of the structured light encoding / decoding algorithm. When designing a structured light coding pattern, it is usually considered to decode the entire image, for example, by using methods such as time phase expansion and spatial phase expansion to obtain the folded phase and then perform phase expansion to obtain the true absolute phase, so as to solve the periodicity problem of the folded phase. In order to expand the phase globally, it is necessary to consider multiple image sequences or to be based on a complex spatial encoding process. However, the above encoding and decoding will greatly increase the single scan time, so if we want to shorten the single scan time, we need to reduce the data amount of the sequence image and shorten the time of the decoding algorithm, but this will result in a deterioration of the image quality. It can be seen that the above scanning method cannot well balance the advantages of short scanning time and ensuring high scanned image quality.

[0018] In addition, in the process of encoding and decoding the collected image using the above structured light encoding and decoding algorithm, the neighboring pixel information needs to be considered when obtaining the encoding value of a single pixel, and the more neighboring pixels considered, the higher the decoding accuracy, so sufficient encoding information is required in the neighboring pixels. However, there is a wealth of contour information on the tooth surface, including gingival sulcus, tooth gap, adjacent tooth interruption, and narrow space of the tooth, etc., and due to these contour information, there are a large amount of discontinuous surface information and structured light patterns in the acquired tooth image, which causes the neighboring pixel information to be lost and further fails to decode the pixel position, that is, the integrity of the area data is reduced.

[0019] In addition to the above defects, when scanning intraoral images using a 3D scanner, the inherent enamel on the surface of the teeth poses a great challenge to optical measurement methods. The enamel has high reflectivity, can transmit light, and can diffuse light. High reflectivity and light diffusion seriously reduce the overall signal-to-noise ratio of object imaging, reduce the intensity of light, change the incident point of light, and further affect the depth information of the 3D reconstruction. To solve the above problems, in actual operation, it has been attempted to spray solid powder or apply liquid coating on the teeth and gums, so that the powder or coating can be used to block the incident light and control the thickness of the powder or coating to restore the 3D information of the tooth surface under the powder layer. However, powder and coating have some disadvantages, such as patients having allergies or difficulty in accepting them, extending the overall scanning time, and the thickness value of the powder or coating also directly affects the accuracy of the 3D data, hiding the defects on the tooth surface, and failing to obtain the true tooth color. Obviously, when a 3D scanner scans teeth, the enamel with high reflectivity characteristics affects the quality of the tooth image.

[0020] In conclusion, in the process of using the above-mentioned 3D scanner to scan the oral cavity and obtain dental images, the scanning time and cost is high, it is difficult to realize a small handheld scanner, and a high frame rate camera and the support of high-speed algorithms are required, which requires high costs and is disadvantageous for widespread use. In addition, the method of obtaining images based on the confocal microscope 3D imaging principle requires a large number of lenses, high precision, and moving parts, which increases the hardware processing costs.

[0021] To solve the above problems, the embodiments of the present disclosure provide a 3D scanner, a system, and a 3D reconstruction method, which can reduce the hardware cost required for the 3D reconstruction method, and can perform 3D reconstruction with only 2D images acquired at a single time, greatly improving the image reconstruction efficiency and reducing the required cost.

[0022] <Example 1> FIG. 1 shows a schematic diagram of the structure of a three-dimensional scanner. As shown in FIG. 1, the three-dimensional scanner includes a projection device 10, an optical path adjustment device 20, and an image acquisition device 30. Projection system 10 includes an illumination system 100 , a collimating system 200 , and a patterning system 300 .

[0023] The emitting device 100 is adapted to emit a predetermined light beam including at least two monochromatic light beams, The collimator 200 is used to homogenize a certain light beam. The pattern forming device 300 is used to project a uniformed predetermined light beam into a structured light pattern; The light path adjusting device 20 is used for changing the transmission path of the structured light pattern to project the structured light pattern onto the target object, and projecting the structured light pattern modulated by the target object onto the image collecting device 30; The image acquisition device 30 disperses the structured light pattern modulated by the target object, and collects a number of dispersed structured light patterns by different cameras for use in 3D reconstruction.

[0024] In the embodiment of the present disclosure, when the emitting device 100 is used to emit a predetermined light beam, an emitting device of a corresponding color can be arranged according to the emission needs. For example, when emitting a blue light beam, an emitting device emitting a blue light beam is arranged, and when emitting a green light beam, an emitting device emitting a green light beam is arranged. The predetermined light beam in the embodiment of the present disclosure includes at least two kinds of monochromatic light beams, and the predetermined light beam includes at least a blue light beam and a green light beam as an example to specifically describe the solution of the embodiment of the present disclosure.

[0025] In an alternative embodiment, the radiation device 100 includes at least two sets of light source modules and at least one color synthesis device, each set of light source modules being adapted to emit one type of monochromatic light; The color combiner is used to combine the light beams emitted from at least two sets of light source modules into one optical path.

[0026] Specifically, each set of light source modules may be formed by combining a laser emitter and a cylindrical lens, may be formed by combining a digital light processing (abbreviated as DLP) and a cylindrical lens, or may be formed by combining a liquid crystal on silicon (abbreviated as LCOS) and a cylindrical lens. The color synthesis device may be a color synthesis mirror, or may be other devices having a color synthesis function.

[0027] A detailed description will be given with reference to another structural schematic diagram of the three-dimensional scanner shown in FIG. 2. Each set of light source modules of the emission device 100 includes a laser emitter and a cylindrical lens, and the color synthesis device is a color synthesis mirror. The first laser emitter 101 is disposed below the first cylindrical lens 102, and emits a first light beam by the first laser emitter 101, and the first cylindrical lens 102 collects the light beam; the second laser emitter 103 is disposed to the left of the second cylindrical lens 104, and emits a second light beam by the second laser emitter 103, and the second cylindrical lens 104 collects the second light beam; and then, the first and second light beams collected are combined into one optical path by the color synthesis mirror 105 to form a predetermined light beam. One of the first and second light beams is a blue light beam, and the other is a green light beam.

[0028] In addition, the laser light emitted from the laser emitter has the advantages of excellent directionality, very high brightness, very pure color, and excellent coherence, which helps to obtain high-quality dental images. The advantage of using a cylindrical lens to focus the light beam is that it avoids the dispersion of the light beam emitted from the laser emitter and improves the utilization rate of the laser light. In addition, the emission device composed of a laser emission device, a cylindrical lens, and a color synthesis device is less expensive than DLP and LCOS, thus reducing the hardware cost of the 3D scanner.

[0029] In another optional embodiment, the radiation device 100 may further include three or more sets of light source modules, and include at least one color synthesis device. Specifically, each set of light source modules is provided correspondingly, and the above description can be referred to for the application, and each color synthesis device synthesizes two or more kinds of light beams, and the synthesized light beam is a predetermined light beam.

[0030] Since the coherence of the laser light itself makes it easy for diffraction spots to occur in the projection pattern, it is necessary to use a decoherence uniform illumination system, and a small motor is arranged in the emission device 100 to drive the phase modulation element, the beam combining system, and the light rod. Specifically, the phase modulation element is driven by the small motor to rotate at a constant speed around the rotation axis, so that the laser phase is modulated in real time, and the modulated predetermined light beam is incident on the light rod by the beam combining system, and the incident beam is reflected and mixed multiple times on the inner surface of the light rod, and a light field with uniform intensity is output at the output end of the light rod, so that the predetermined light beam is projected uniformly.

[0031] In an embodiment of the present disclosure, the collimator 200 includes at least one compound lens, which homogenizes the predetermined light beam and projects the homogenized predetermined light beam onto the pattern shaping device.

[0032] Referring to the specific description of another structural schematic diagram of the three-dimensional scanner shown in Figure 2, the collimating device 200 includes a first compound lens 201 and a second compound lens 202. The first compound lens 201 and the second compound lens 202 are arranged in parallel between the emission device 100 and the pattern forming device 300. The collimating device 200 can homogenize the predetermined light beam and homogenize the predetermined light beam in terms of energy, thereby obtaining high light energy utilization rate and large area uniform illumination, which is helpful in projecting a uniform predetermined light beam and avoiding the occurrence of diffraction spots, and improving the utilization rate of the light beam.

[0033] In an embodiment of the present disclosure, the patterning device 300 is a color grating film; The color grating film is used to transmit the homogenized predetermined light beam and generate a structured light pattern projected in a stripe shape.

[0034] In the embodiment of the present disclosure, the projection apparatus 10 may further include a projection lens 400 that transmits the predetermined light beams projected in a stripe shape.

[0035] In the embodiment of the present disclosure, the light path adjustment device 20 may include a reflecting device that reflects a predetermined light beam projected in a stripe shape from the projection lens to a target object. The reflecting device may be a reflecting mirror, or may be other devices specifically having a reflecting function. The target object may include teeth, gums, etc.

[0036] Referring to another structural schematic diagram of a three-dimensional scanner shown in FIG. 2, along the optical path transmission path from the radiation device 100 to the collimation device 200, a color grating film 300, a projection lens 400 and a reflection mirror 210 are sequentially arranged on the right side of the collimation device 200.

[0037] Specifically, a MASK pattern is provided on the color grating film 300, and the types of colors contained in the MASK pattern of the color grating film 300 can correspond one-to-one to the types of wavelength ranges contained in the transmitted light, that is, the MASK pattern of the color grating film 300 may include at least blue and green, and generates a predetermined light beam projected in a stripe shape based on the transmitted predetermined light beam, and further transmits the predetermined light beam projected in a stripe shape by the projection lens 400 and condenses the predetermined light beam projected in a stripe shape, thereby projecting the transmitted predetermined light beam onto the reflection mirror 210, and the transmission path of the predetermined light beam is changed by the reflection mirror 210, and the predetermined light beam with the changed transmission path is projected onto the target object.

[0038] In an embodiment of the present disclosure, image capture device 30 includes a dichroic prism, a black and white camera, and a color camera.

[0039] The dichroic prism splits the structured light pattern, one split light beam is a monochromatic light beam and is collected by the black and white camera, and the other split light beam is collected by the color camera. Specifically, the monochromatic light beam collected by the black and white camera may be a blue stripe map, and the other light beam collected by the color camera may be a green stripe map. The dichroic prism may be a right-angle dual-channel dichroic prism, or may be a dichroic prism of other shapes with dichroic function.

[0040] Optionally, the image acquisition device 30 may further include an imaging lens.

[0041] Referring to the specific description of another structural schematic diagram of the three-dimensional scanner shown in Fig. 2, the image collecting device 30 is disposed obliquely below the light path adjusting device 20. The image collecting device 30 includes an imaging lens 304, a dichroic prism 303, a black-and-white camera 301, and a color camera 302. Specifically, the structured light pattern modulated by the target object is projected onto the imaging lens 304 of the image collecting device 30, and the transmitted structured light pattern is split into two light beams by the dichroic prism 303, one of which is a blue stripe map and is collected by the black-and-white camera 301, and the other is a green stripe map and is collected by the color camera 302.

[0042] In addition, the 3D scanner collects the monochromatic light beams split by the structured light pattern, and then performs 3D reconstruction based on the split monochromatic light beams. Specifically, the 3D reconstruction can be performed based on the split blue stripe map and green stripe map.

[0043] In the embodiment of the present disclosure, the 3D scanner may further include an illumination device, which is used for projecting white light onto the target object, and the light path adjustment device is further used for changing the transmission path of the white light to reflect the white light onto the target object.

[0044] Specifically, the illumination device may include a white light source and a condensing lens, the white light source is used for emitting white light, the condensing lens is used for condensing the white light, and projecting the condensed white light onto the optical path adjusting device.

[0045] In addition, the dichroic prism is further used to split the white light modulated by the target object, one split light is a monochromatic texture map and collected by the black and white camera, and the other split light is collected by the color camera, and the two texture maps split from the white light are used for texture reconstruction. Specifically, the two texture maps split from the white light may include a blue texture map and a red-green texture map.

[0046] Referring to the specific description of another structural schematic diagram of the three-dimensional scanner shown in FIG. 2, the illumination device 40 is disposed at the lower left of the light path adjustment device 20, and includes a white light source 401 and a condenser lens 402. The white light source 401 is used for emitting white light, and the condenser lens 402 is used for condensing the white light and projecting the condensed white light to the light path adjustment device 20, so that the transmission path of the white light is changed by the light path adjustment device 20 to reflect the white light to the target object. In addition, the exposure light modulated by the target object is projected to the imaging lens 304 of the image collection device 30, and the transmitted structured light pattern is split into two light beams by the dichroic prism 303, one light beam is a blue texture map and is collected by the black and white camera 301, and the other light beam is a red-green texture map and is collected by the color camera 302.

[0047] Furthermore, the 3D scanner collects monochromatic light beams obtained by splitting white light, and then performs texture reconstruction based on two split texture maps, specifically, a blue texture map and a red-green texture map.

[0048] In addition, the three-dimensional scanner may further include a timing control circuit for controlling the projection device to emit the predetermined light beam and the illumination device to emit the white light. The predetermined light beam and the white light may be emitted simultaneously or sequentially, and in this embodiment, it is preferable to emit the predetermined light beam and then emit the white light.

[0049] In the 3D scanner according to the embodiment of the present disclosure, the collected multiple dispersed structured light patterns are based on a spatial coding format, so that 3D reconstruction of the target object can be realized with only 2D images acquired at a single time, eliminating the need for dynamic projection. This greatly reduces the frame rate of the camera in the 3D scanner and the algorithm calculation cost, improves the speed of dynamic scanning inside the oral cavity, and reduces the size of the camera required for the 3D scanner, which can be applied to scanning the oral cavity to obtain tooth images. In addition, since 3D reconstruction of the target object can be realized with only 2D images acquired at a single time, the acquisition time difference between the reconstruction map and the texture map of the 3D scanner is shortened, and the time required for projection and photography during 3D reconstruction of the target object is shortened. Since the 3D scanner uses color as spatial coding information, the spatial coding information in color format is easily recognized, and the recognition accuracy is improved. In addition, since the color features of the monochromatic light rays (e.g., blue stripes) in the generated multiple dispersed structured light patterns and the monochromatic light rays dispersed from white light (e.g., blue texture maps) are prominent, 3D reconstruction can be performed based on the blue-green stripes and the color stripes, and 3D reconstruction can be performed based on the blue texture map and the red-green texture map, thereby improving the image quality of the reconstructed image. If there is enamel on the surface of the tooth, the 3D scanner can also separate the reflected light of the enamel to prevent the reflected light and scattered light of the enamel from affecting the quality of the reconstructed image.

[0050] <Example 2> A structural schematic diagram of a 3D scanning system is shown in Fig. 3. As shown in Fig. 3, the 3D scanning system includes a 3D scanner 1 and an image processing device 2 communicatively connected to the 3D scanner 1.

[0051] The 3D scanner 1 includes a projection device, an image acquisition device, and an optical path adjustment device, and the projection device includes an emission device, a collimation device, and a pattern shaping device.

[0052] The three-dimensional scanner 1 emits a predetermined light beam using an emission device, homogenizes the predetermined light beam by collimating it, projects the homogenized predetermined light beam as a structured light pattern using a pattern forming device, changes a transmission path of the structured light pattern using an optical path adjustment device to project the structured light pattern onto a target object, projects the structured light pattern modulated by the target object onto an image collection device, disperses the structured light pattern modulated by the target object using the image collection device, and collects the dispersed structured light patterns using different cameras for use in three-dimensional reconstruction, the predetermined light beam including at least two types of monochromatic light beams, The image processing device 2 receives the plurality of dispersed structured light patterns scanned by the three-dimensional scanner, and performs three-dimensional reconstruction based on the plurality of dispersed structured light patterns.

[0053] Optionally, the radiation device of the 3D scanner 1 includes at least two light source modules and at least one color synthesis device; Each light source module is used to emit one type of monochromatic light, The color combiner is used to combine the light beams emitted from at least two sets of light source modules into one optical path.

[0054] Optionally, the collimating device of the 3D scanner 1 comprises at least one compound lens; The compound lens homogenizes the predetermined light beam and projects the homogenized predetermined light beam onto the pattern forming device.

[0055] Optionally, the pattern forming device of the 3D scanner 1 is a color grating film; The color grating film is used to transmit a uniformized predetermined light beam to generate a structured light pattern projected in stripes.

[0056] Optionally, the image acquisition device of the 3D scanner 1 includes a dichroic prism, a color camera, and a black and white camera; A dichroic prism splits the structured light pattern into monochromatic beams that are collected by the black and white camera and into color beams that are collected by the color camera.

[0057] Optionally, the 3D scanner further comprises an illumination device; The illuminator projects white light onto the target object; The light path adjusting device is further used for changing a transmission path of the white light to reflect the white light to the target object; The image acquisition device is further used for splitting the white light modulated by the target object, and collecting two light beams split by the white light with a multi-camera; Accordingly, the image processing device 2 is further used to perform texture reconstruction based on the two beams into which the white light is split.

[0058] In addition, in order to obtain all the teeth and gums data in the oral cavity, the determined 3D reconstruction map of each frame and the texture reconstruction map of each frame need to be stitched together, whereby the image processing device 2 is further used to stitch the 3D reconstructed 3D reconstruction image to obtain a target reconstruction image of the target object, and map the texture reconstructed texture reconstruction image to obtain a target texture image of the target object.

[0059] Specifically, according to the image information of the 3D reconstruction map, the 3D reconstruction map is stitched to obtain a 3D reconstruction image of the target object, and according to the texture information of the texture reconstruction map, the texture reconstruction map is mapped to obtain a texture reconstruction map corresponding to the target. The image information includes, but is not limited to, the grayscale value and morphological features of the 3D reconstruction map or the texture reconstruction map.

[0060] In the technical solution of this embodiment, the 3D scanner uses color as spatially encoded information, so that the spatially encoded information in color format is easily recognized, and the recognition accuracy is improved, and the 3D reconstruction and texture reconstruction of the target object can be realized with only a 2D image at a single time, so that the reconstruction efficiency of the 3D reconstruction and texture reconstruction and the image quality of the reconstructed image can be improved. The generated 3D reconstruction map and texture reconstruction map have high image quality and are generated quickly, so that the efficiency and stitching accuracy of image stitching and texture stitching can be improved.

[0061] The above description will be illustratively explained with reference to the structural schematic diagram of a three-dimensional scanner shown in Fig. 2. As shown in Fig. 2, the three-dimensional scanner 1 includes a projection device, an illumination device, an image collection device, and an optical path adjustment device, and the projection device includes an emission device, a collimation device, a pattern forming device, and a projection lens.

[0062] The emission device includes two light source modules and one color synthesis device. One of the two light source modules is a blue light source module for projecting blue light, and the other is a green light source module for projecting green light, where the blue light source module includes a blue light source and a cylindrical lens, and the green light source module includes a green light source and a cylindrical lens. The color synthesis device is a color synthesis mirror, where the blue light source module is directed to one surface of the color synthesis mirror, and the green light source module is directed to the other surface of the color synthesis mirror, and the green light beam projected from the green light source module and the blue light beam projected from the blue light source module are transmitted to the color synthesis mirror and are synthesized into one optical path by the color synthesis mirror, that is, a blue-green light beam is synthesized. The collimation device includes a first compound lens and a second compound lens. The pattern forming device is a color grating film.

[0063] The illumination device includes a white light source and a collecting lens.

[0064] The image acquisition device includes an imaging lens, a dichroic prism, a color camera, and a monochrome camera. The dichroic prism is a right-angled dual channel dichroic prism with one channel being a blue light channel and the other channel being a red-green light channel. The color camera is aimed at a side of the right-angled dual channel dichroic prism corresponding to the red-green light channel, and the monochrome camera is aimed at a side of the right-angled dual channel dichroic prism corresponding to the blue light channel.

[0065] The light path adjusting device is a reflecting mirror. The projection device, the illumination device and the image collecting device are all directed toward the light path adjusting device.

[0066] The blue light source module and the green light source module work synchronously to project, and the two light beams, the blue light beam projected from the blue light source module and the green light beam projected from the green light source module, are combined into a blue-green light beam by the color combining mirror, and the blue-green light beam is sequentially transmitted to the first compound lens, the second compound lens, the color grating film, the projection lens and the reflection mirror, and projected to the outside in the form of a blue-green stripe structured light pattern, that is, the emitting device projects a blue-green stripe structured light pattern.

[0067] The emitting device projects a blue-green striped structured light pattern, which is reflected by a reflecting mirror to a target object and modulated and deformed by the target object, and a surface image of the target object is reflected by the reflecting mirror and transmitted to an image collecting device.

[0068] The surface image of the target object is sequentially transmitted to the imaging lens and the orthogonal dual-channel dichroic prism, which disperses the surface image of the target object, the blue light is transmitted through the blue light channel to the black-and-white camera, which obtains a deformed blue stripe structured light pattern, and the green light is transmitted through the red-green light channel to the color camera, which obtains a deformed green stripe structured light pattern.

[0069] The white light source is operative to project and reflect the white light onto the target object by the reflecting mirror, and the surface image of the target object is reflected by the reflecting mirror and transmitted to the image capture device.

[0070] The surface image of the target object is sequentially transmitted to the imaging lens and the right-angled dual-channel dichroic prism, which disperses the surface image of the target object, the blue light is transmitted through the blue light channel to the black-and-white camera, which obtains a blue texture map, and the red-green light is transmitted through the red-green light channel to the color camera, which obtains a red-green texture map.

[0071] The projection device and the illumination device operate alternately to project, the image capture device and the projection device operate synchronously, and the image capture device and the illumination device operate synchronously.

[0072] The 3D scanning system includes a 3D scanner and an image processing device communicatively connected to the 3D scanner, the image processing device acquiring the blue stripe structured light pattern and the green stripe structured light pattern collected by the 3D scanner to perform 3D reconstruction, and the image processing device acquiring the blue texture map and the red-green texture map collected by the 3D scanner to perform texture reconstruction.

[0073] The image processing device is preset with the calibration parameters of the three-dimensional scanner, the encoding rules, and the encoding table of the blue-green striped structured light pattern, including the internal and external parameters of the emitting device and the image collecting device, the light surface of each stripe in the blue-green striped structured light pattern, etc.

[0074] The image processing device performs the following method to produce a true color 3D reconstruction of the target object.

[0075] Obtaining a blue stripe structured light pattern and a green stripe structured light pattern collected by a three-dimensional scanner; Obtaining a predetermined encoding rule; determining a coding table for the blue stripe structured light pattern according to a predetermined coding rule; determining a coding table for the green stripe structured light pattern according to a predetermined coding rule; Combining the coding table of the blue stripe structured light pattern and the coding table of the green stripe structured light pattern based on pixels at the same location to determine a combined coding table; Obtaining a coding table for a predetermined blue-green striped structured light pattern; Matching the combined coding table with a coding table of a predetermined blue-green striped structured light pattern to determine a light plane corresponding to each stripe in the blue striped structured light pattern; Acquiring internal and external parameters of the radiation device and the image acquisition device; 3D reconstructing a point cloud of a target object according to the blue stripe structured light pattern, the light planes corresponding to each stripe in the blue stripe structured light pattern, and the internal and external parameters of the emission device and the image acquisition device; Obtaining a blue texture map and a red-green texture map collected by a 3D scanner; determining a true color texture map by combining the blue texture map and the red-green texture map based on pixels at the same location; Texture mapping is performed on the point cloud and the true color texture map based on the pixels at the same location of the blue stripe structured light pattern and the texture map to obtain a true color three-dimensional model of the target object.

[0076] <Example 3> Figure 4 shows a flow chart of the 3D reconstruction method. The 3D reconstruction method is applied to the image processing device described in the above embodiment. The image processing device may be a terminal device such as a desktop computer, a mobile phone, a notebook computer, etc. As shown in Figure 4, the 3D reconstruction method includes the following steps:

[0077] S310 obtains a plurality of dispersed structured light patterns scanned by a three-dimensional scanner.

[0078] As described in the above embodiments, the 3D scanner includes a projection device, an image collection device, and an optical path adjustment device, the projection device includes an emission device, a collimation device, and a pattern shaping device, the emission device is used for emitting a predetermined light beam including at least two kinds of monochromatic light beams, the collimation device is used for homogenizing the predetermined light beam, the pattern shaping device is used for projecting the homogenized predetermined light beam as a structured light pattern, the optical path adjustment device is used for changing the transmission path of the structured light pattern to project the structured light pattern onto a target object, and projecting the structured light pattern modulated by the target object onto an image collection device, and the image collection device disperses the structured light pattern modulated by the target object, and collects the dispersed structured light patterns by different cameras.

[0079] Furthermore, the 3D scanner transmits the dispersed structured light patterns collected by the camera to an image processing device, and the image processing device processes the dispersed structured light patterns to perform 3D reconstruction.

[0080] S320, performing a 3D reconstruction based on the predetermined encoding rule, the encoding table of the predetermined structured light stripe map, and the dispersed multiple structured light patterns.

[0081] In an embodiment of the present disclosure, a 3D reconstruction method includes a step of determining a code corresponding to each light ray dispersed from a structured light pattern based on the predetermined encoding rule to obtain an encoding table corresponding to each light ray, a step of combining codes at the same pixel coordinates in the encoding tables corresponding to each light ray to obtain a combined encoding table, a step of matching the combined encoding table with an encoding table of the predetermined structured light stripe map to determine a light surface corresponding to each light ray, and a step of performing 3D reconstruction based on the light surface corresponding to each light ray.

[0082] In an embodiment of the present disclosure, when the two dispersed light beams are a blue stripe map and a green stripe map respectively, the specific steps of the above 3D reconstruction process are: determining a code corresponding to each pixel at the stripe center line of the blue stripe map according to a predetermined encoding rule to obtain an encoding table of the blue stripe map; determining a code corresponding to each pixel at the stripe center line of the green stripe map according to a predetermined encoding rule to obtain an encoding table of the green stripe map; combining the codes at the same pixel coordinates in the encoding table of the blue stripe map and the encoding table of the green stripe map to obtain a combined encoding table; matching the combined encoding table with the encoding table of the predetermined structured light stripe map to determine a light surface corresponding to each stripe in the blue stripe map and a light surface corresponding to each stripe in the green stripe map; and performing 3D reconstruction according to each stripe in the blue stripe map and the corresponding light surface, and the light surface corresponding to each stripe in the green stripe map.

[0083] Exemplarily, the predetermined coding rule may be R=0, G=1, B=2, and for 27 stripes arranged in the order of red, red, red, green, red, blue, blue, red, green, green, red, green, blue, red, blue, green, red, blue, blue, green, green, blue, red, blue, blue, green, the coding sequence is {0,0,0,1,0,2,2,0,1,1,0,1,2,0,2,1,0,2,2,1,1,1,2,0,2,2,1}. In the coding sequence, any sequence consisting of three consecutive codes is unique. For example, the first three-digit sequence is {0,0,0}, the second three-digit sequence is {0,0,1}, ..., the last three-digit sequence is {2,2,1}, so that each three-digit sequence occurs only once in the entire coding sequence. Each code can correspond to one color stripe, and each three-digit sequence can correspond to one stripe in the basic sequence, i.e., it is the coding value of one stripe, which is used to recognize and position the stripe, and the sequence corresponds to 27 stripes.

[0084] In the embodiment of the present disclosure, the sequence of three digits in the sequence corresponds to one of the stripes and is the coded value of the stripe. {0,0,0} is the coded value of the first stripe in the stripe sequence, and {0,0,1} is the coded value of the second stripe in the stripe sequence, and thus the consecutive three digit coded values ​​are the stripe numbers corresponding to the first coded value. Currently, the consecutive three digit coded values ​​can also be the stripe numbers corresponding to the second or third coded values, i.e. {0,0,0} is the coded value of the second or third stripe in the stripe sequence.

[0085] It should be noted that the coding table of the blue stripe map and the coding table of the predetermined green stripe map each correspond to a standard light surface, and the standard light surface can be determined in advance, so that after matching the code corresponding to each pixel on the stripe center line of the obtained blue stripe with the coding table of the blue stripe map, the light surface corresponding to the blue stripe is determined according to the matching result and the standard light surface; similarly, after matching the code corresponding to each pixel on the stripe center line of the obtained green stripe with the coding table of the green stripe map, the light surface corresponding to the green stripe is determined according to the matching result and the standard light surface.

[0086] The above is a reconstruction method when the image collecting device of the three-dimensional scanner is a monocular device. When the image collecting device of the three-dimensional scanner is a binocular device, the left and right images are acquired by the three-dimensional scanner, the corresponding stripes are determined based on the numbers of each stripe in the left and right images, and three-dimensional reconstruction is performed for the blue stripes and the green stripes based on each stripe in the left and right images and the calibrated camera parameters. Specifically, the light plane corresponding to the blue stripe map is determined based on the optical centers of the left and right cameras, the code corresponding to each pixel at the stripe center line in the blue stripe map, and the calibrated camera parameters, and three-dimensional reconstruction is performed based on the light plane corresponding to the blue stripe. Similarly, the light plane corresponding to the green stripe map is determined based on the optical centers of the left and right cameras, the code corresponding to each pixel at the stripe center line in the green stripe map, and the calibrated camera parameters, and three-dimensional reconstruction is performed based on the light plane corresponding to the green stripe.

[0087] Furthermore, the method further includes a step of acquiring two beams of dispersed white light scanned by a three-dimensional scanner, and a step of performing texture reconstruction based on the two beams of dispersed white light and the dispersed structured light patterns.

[0088] In an embodiment of the present disclosure, the step of performing texture reconstruction based on the two light rays into which white light is dispersed and the plurality of dispersed structured light patterns may include a step of generating a first texture reconstructed image based on a correspondence between pixels in a texture map corresponding to the two light rays into which white light is dispersed, and a step of generating a second texture reconstructed image having texture information based on each light beam into which the structured light pattern is dispersed and the first texture reconstructed image.

[0089] In an embodiment of the present disclosure, when the two light rays split from white light are a blue texture map and a red-green texture map, the specific steps of the above texture reconstruction process are: synthesizing textures corresponding to each pixel of the white light texture map based on the pixel correspondence between the blue texture map and the red-green texture map; and synthesizing three-dimensional data having texture information based on the pixel correspondence between the blue stripes, the green stripes and the white light texture map.

[0090] In the technical solution of this embodiment, the 3D scanner uses color as spatial coding information, so that the spatial coding information in color format is easily recognized, and the recognition accuracy is improved, and the 3D reconstruction and texture reconstruction of the target object can be realized with only one frame of 2D image, and the reconstruction efficiency of the 3D reconstruction and texture reconstruction and the image quality of the reconstructed image can be improved. Then, the 3D reconstruction is performed according to a predetermined coding rule and a predetermined coding table of the structured light stripe map, and the texture reconstruction is performed according to the correspondence between the pixels in the texture map corresponding to the two light rays obtained by splitting the white light and each light ray obtained by splitting the structured light pattern, so that the high-quality 3D reconstruction map and the texture reconstruction map can be quickly generated, and the generated 3D reconstruction map and the texture reconstruction map have high image quality and are generated quickly, so that the efficiency and stitching accuracy of the image stitching and the texture stitching can be improved.

[0091] <Example 4> An embodiment provides a storage medium including computer-executable instructions, which, when executed by a computer processor, are used to perform a three-dimensional reconstruction method, the method comprising: Obtaining a plurality of dispersed structured light patterns scanned by a three-dimensional scanner; and performing a 3D reconstruction based on a predetermined encoding rule, a predetermined encoding table of a structured light stripe map, and the dispersed structured light patterns.

[0092] Of course, in a storage medium including computer-executable instructions according to an embodiment of the present disclosure, the computer-executable instructions are not limited to the above method operations, but may also perform related operations of the 3D reconstruction method according to any embodiment of the present disclosure.

[0093] From the description of the above embodiments, those skilled in the art can clearly understand that the present disclosure can be realized by software and necessary general-purpose hardware, and of course can also be realized by hardware, but in many cases the former is a more preferred embodiment. Based on this understanding, the technical solution of the present disclosure can be essentially embodied in the form of a software product, or a part that contributes to the prior art. The computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (FLASH), a hard disk, or an optical disk, and includes a plurality of instructions for causing a computer device (such as a personal computer, a server, or a network device) to execute the 3D reconstruction method according to each embodiment of the present disclosure.

[0094] It should be noted that the above is merely a preferred embodiment of the present disclosure and the technical principles used. Those skilled in the art can understand that the present disclosure is not limited to the specific embodiments described herein, and various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the scope of protection of the present disclosure. Therefore, although the present disclosure has been described in detail by the above embodiments, the present disclosure is not limited to the above embodiments, and can include many other equivalent embodiments without departing from the concept of the present disclosure, and the scope of the present disclosure is determined by the appended claims. [Industrial Applicability]

[0095] The 3D scanner disclosed herein reduces the hardware costs required for 3D reconstruction methods and can perform 3D reconstruction using only 2D images acquired at a single time, significantly improving the efficiency of image reconstruction and making it highly industrially practical.

Claims

1. 1. A three-dimensional scanner, comprising: The present invention includes a projection device, an image acquisition device, and an optical path adjustment device, the projection system includes an illumination system, a collimation system, and a patterning system; The emitting device is adapted to emit a predetermined light beam including at least two monochromatic light beams, The collimating device is used to homogenize the predetermined light beam, the pattern forming device is used for projecting a uniformed predetermined light beam as a structured light pattern; the light path adjusting device is used for changing a transmission path of the structured light pattern to project the structured light pattern onto a target object, and projecting the structured light pattern modulated by the target object onto an image collecting device; The image capture device disperses the structured light pattern modulated by the target object and collects a plurality of dispersed structured light patterns with different cameras; a coding table for each of the plurality of dispersed structured light patterns collected by the different cameras is determined based on a predetermined coding rule, a combined coding table is determined based on the coding tables corresponding to each of the structured light patterns, and a three-dimensional reconstruction is performed based on the combined coding table.

2. The radiation device includes at least two light source modules and at least one color synthesis device; Each set of the light source modules is used to emit one kind of monochromatic light beam; 2. The three-dimensional scanner according to claim 1, wherein the color synthesis device is used for synthesizing the light beams emitted from at least two sets of light source modules into one optical path.

3. the collimating device includes at least one binocular lens; 2. The three-dimensional scanner according to claim 1, wherein the compound lens homogenizes the predetermined light beam and projects the homogenized predetermined light beam onto the pattern forming device.

4. the pattern forming device is a color grating film; 2. The 3D scanner according to claim 1, wherein the color grating film is used to transmit the uniformized predetermined light beam to generate a structured light pattern projected in a stripe shape.

5. the image acquisition device includes a dichroic prism, a color camera, and a black and white camera; 2. The 3D scanner of claim 1, wherein the dichroic prism splits the structured light pattern into a monochromatic beam that is collected by the black-and-white camera and a second split beam that is collected by the color camera.

6. The three-dimensional scanner further includes an illumination device; the lighting device is used to project white light onto the target object; The three-dimensional scanner according to claim 5 , wherein the optical path adjusting device is further used for changing a transmission path of the white light to reflect the white light to the target object.

7. 7. The 3D scanner of claim 6, wherein the dichroic prism is further used to split the white light modulated by the target object, one of the split light rays being a monochrome texture map and collected by the monochrome camera, and the other split light rays being collected by the color camera, and the two texture maps split from the white light are used for texture reconstruction.

8. 1. A three-dimensional scanning system, comprising: a three-dimensional scanner; and an image processing device communicatively connected to the three-dimensional scanner; the three-dimensional scanner includes a projection device, an image acquisition device, and an optical path adjustment device, the projection device includes an irradiation device, a collimation device, and a pattern shaping device; the three-dimensional scanner emits a predetermined light beam using an emission device, homogenizes the predetermined light beam by collimating it, projects the homogenized predetermined light beam as a structured light pattern using the pattern forming device, changes a transmission path of the structured light pattern using the optical path adjustment device to project the structured light pattern onto a target object, projects the structured light pattern modulated by the target object onto an image collection device, disperses the structured light pattern modulated by the target object using the image collection device, and collects a plurality of dispersed structured light patterns using different cameras for three-dimensional reconstruction; the predetermined light beam includes at least two types of monochromatic light beams; The three-dimensional scanning system is characterized in that an image processing device receives a plurality of dispersed structured light patterns scanned by the three-dimensional scanner, determines a coding table for each of the dispersed structured light patterns based on a predetermined coding rule, determines a combined coding table based on the coding table corresponding to each of the structured light patterns, and performs three-dimensional reconstruction based on the combined coding table.

9. The three-dimensional scanner further includes an illumination device; the illumination device projects white light onto the target object; The light path adjustment device is further used for changing a transmission path of the white light to reflect the white light to the target object, The image acquisition device is further used for splitting the white light modulated by the target object, and collecting two light beams obtained by splitting the white light by a multi-camera; Accordingly, the image processing device is further used for performing texture reconstruction based on the two light beams into which white light is split.

10. The 3D scanning system of claim 9, characterized in that the image processing device is further used for stitching the 3D reconstructed 3D reconstruction image to obtain a target reconstructed image of the target object, and mapping the texture reconstructed texture reconstruction image to obtain a target texture image of the target object.

11. A three-dimensional reconstruction method is applied in an image processing device according to any one of claims 9 to 10, said method comprising the steps of: Obtaining a plurality of dispersed structured light patterns scanned by a three-dimensional scanner; and performing a three-dimensional reconstruction based on a predetermined encoding rule, an encoding table of a predetermined structured light stripe map, and the dispersed structured light patterns.

12. The step of performing a three-dimensional reconstruction based on a predetermined encoding rule, a predetermined encoding table of a structured light stripe map, and the dispersed structured light patterns includes: determining a code corresponding to each light beam obtained by splitting the structured light pattern based on the predetermined encoding rule to obtain an encoding table corresponding to each light beam; combining codes at the same pixel coordinates in the coding tables corresponding to each ray to obtain a combined coding table; matching the combined coding table with the coding table of the predetermined structured light stripe map to determine a light surface corresponding to each light ray; and performing a three-dimensional reconstruction based on a light plane corresponding to each of the rays.

13. Obtaining two beams of light obtained by splitting white light scanned by a three-dimensional scanner; 12. The method of claim 11, further comprising: performing texture reconstruction based on the two light beams into which white light is separated and the plurality of separated structured light patterns.

14. The step of performing texture reconstruction based on the two light beams obtained by splitting white light and the plurality of split structured light patterns includes: generating a first texture reconstructed image based on a correspondence between pixels in a texture map corresponding to two light beams obtained by splitting the white light; and generating a second texture reconstruction image having texture information based on each light beam into which the structured light pattern is dispersed and the first texture reconstruction image.

Images