Near-infrared light tooth imaging system, method and equipment based on liquid crystal spatial light modulation

Abstract

The invention discloses a near-infrared light tooth imaging system, method and equipment based on liquid crystal spatial light modulation, and relates to the technical field of medical instruments.The system comprises a near-infrared light source module, a liquid crystal spatial light modulation module, an upper computer and an image acquisition module, overexposure point detection is conducted on a tooth image through the upper computer, and if the requirement is not met, the tooth image is subjected to overexposure point detection; and if the requirement is met, modulating the amplitude of the near-infrared light by adopting a liquid crystal spatial light modulation module by utilizing a cyclic scanning method to obtain modulated near-infrared light, irradiating the tooth to be detected by utilizing the modulated near-infrared light, then carrying out overexposure point detection, and if the requirement is not met, carrying out cyclic iteration until the requirement is met to obtain a detection result of the tooth to be detected. The problems of partial overexposure and low contrast in near-infrared light tooth imaging are solved.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a near-infrared dental imaging system, method and device based on liquid crystal spatial light modulation. Background Art

[0002] With the advancement of science and technology and social development, people's living standards have also improved, and health issues have received more and more attention from people. Among them, dental problems have always been one of the focuses of people's attention. Dental problems, especially early tooth cracks, are not easy to show clinically. Therefore, early tooth crack detection is crucial to maintaining dental health. In order to meet the detection requirements of special groups, such as pregnant women and children who need radiation-free detection methods, and sensitive people who need non-contact and fast detection methods, it is particularly important to design a radiation-free, clear imaging optical detection method in dental imaging technology.

[0003] Near-infrared light is a non-destructive, non-invasive measurement technology that is non-destructive to the human body, and its wavelength is in the range of 780 to 2526 nm. The human body absorbs less near-infrared light in the 690-900 nm band, and it is often used for human tissue detection, and the health of the tissue is judged by the light intensity. Near-infrared light can easily penetrate dental tissue and does not cause radiation damage, so it can be used for daily non-destructive inspection of dental diseases. Affected by the degree of tooth calcification, thickness, and near-infrared imaging factors, the tooth images obtained by traditional transillumination imaging methods have problems such as partial clarity, partial overexposure, and low contrast, which leads to a significant decrease in image quality and limits the accurate identification of tooth diseased areas. Summary of the invention

[0004] The purpose of the present application is to provide a near-infrared dental imaging system, method and device based on liquid crystal spatial light modulation to solve the problems of partial overexposure and low contrast in near-infrared dental imaging.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a near-infrared dental imaging system based on liquid crystal spatial light modulation, the near-infrared dental imaging system based on liquid crystal spatial light modulation comprising: a near-infrared light source module, a liquid crystal spatial light modulation module, a host computer and an image acquisition module;

[0007] The near-infrared light source module is used to emit original near-infrared light, and use the original near-infrared light to illuminate the teeth to be inspected;

[0008] The image acquisition module is located on the emission light path of the original near-infrared light and is connected to the host computer. The image acquisition module is used to acquire the original tooth image of the tooth to be detected under the irradiation of the original near-infrared light and send the original tooth image to the host computer;

[0009] The host computer is connected to the liquid crystal spatial light modulation module, and the host computer is used to:

[0010] Perform overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image;

[0011] Determine whether the number of overexposed points in the overexposed point detection image corresponding to the original tooth image is less than a preset threshold, and obtain a first determination result;

[0012] If the first judgment result is yes, the original tooth image is used as the detection result of the tooth to be detected;

[0013] If the first judgment result is no, a corresponding modulation map is generated based on the overexposure point detection map corresponding to the original tooth image, and the modulation map corresponding to the original tooth image is sent to the liquid crystal spatial light modulation module; the modulation map is a grayscale map corresponding to the overexposure point detection map;

[0014] The liquid crystal spatial light modulation module is located in the outgoing light path of the original near-infrared light and between the near-infrared light source module and the tooth to be detected. The liquid crystal spatial light modulation module is used to modulate the amplitude of the original near-infrared light by a cyclic scanning method based on the overexposure point detection map and the modulation map corresponding to the original tooth image to obtain the near-infrared light after the initial modulation;

[0015] The liquid crystal spatial light modulation module, the image acquisition module, and the host computer jointly perform iterative detection on the teeth to be detected based on the near-infrared light after the initial modulation to obtain the detection results of the teeth to be detected; wherein the detection process under any current iteration number includes:

[0016] The liquid crystal spatial light modulation module modulates the amplitude of the near-infrared light at the previous iteration number based on the overexposure point detection map and modulation map corresponding to the tooth image at the previous iteration number by using a cyclic scanning method to obtain the modulated near-infrared light at the current iteration number, and uses the modulated near-infrared light at the current iteration number to irradiate the tooth to be detected to obtain the modulated tooth image at the current iteration number; wherein, when the current iteration number is the initial iteration number, the tooth image at the previous iteration number is the original tooth image, and the near-infrared light at the previous iteration number is the original near-infrared light;

[0017] The image acquisition module acquires the tooth image modulated at the current iteration number, and sends the tooth image modulated at the current iteration number to the host computer;

[0018] The host computer:

[0019] Perform overexposure point detection on the tooth image modulated at the current iteration number to obtain an overexposure point detection map corresponding to the tooth image modulated at the current iteration number;

[0020] Determine whether the number of overexposure points in the overexposure point detection image corresponding to the modulated tooth image at the current iteration number is less than the preset threshold, and obtain a second judgment result at the current iteration number;

[0021] Based on the second judgment result at the current iteration number, it is determined to use the tooth image modulated at the current iteration number, and the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected.

[0022] Optionally, based on the second judgment result at the current iteration number, determining to use the tooth image modulated at the current iteration number, and using the tooth image modulated at the current iteration number as the detection result of the tooth to be detected specifically includes:

[0023] If the second judgment result at the current iteration number is yes, the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected;

[0024] If the second judgment result at the current iteration number is no, based on the overexposure point detection map and the modulation map corresponding to the modulated tooth image at the current iteration number, the amplitude of the near-infrared light at the current iteration number is modulated by a cyclic scanning method to obtain the near-infrared light at the next iteration number, and the near-infrared light at the next iteration number is used to irradiate the teeth to be detected;

[0025] The image acquisition module acquires the tooth image modulated at the next iteration number, updates the tooth image modulated at the current iteration number to the tooth image modulated at the next iteration number, and sends the tooth image modulated at the current iteration number to the host computer until the second judgment result at the current iteration number is yes, and the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected.

[0026] Optionally, the near-infrared light source module includes a laser, a collimator, a beam expansion subsystem and a polarizer;

[0027] The laser and the tooth to be detected are located on a coaxial optical path at the same height, and the laser is used to emit near-infrared light;

[0028] The collimator and the laser are located on a coaxial optical path at the same height, and the collimator is used to collimate the near-infrared light to obtain collimated near-infrared light;

[0029] The polarizer and the collimator are located on a coaxial optical path at equal heights, and are used to convert the collimated near-infrared light into linearly polarized light;

[0030] The beam expansion subsystem and the polarizer are located on a coaxial optical path at the same height, and the beam expansion subsystem is used to expand the linearly polarized light to obtain original near-infrared light.

[0031] Optionally, the liquid crystal spatial light modulation module is a liquid crystal spatial light modulator.

[0032] In a second aspect, the present application provides a near-infrared light dental imaging method based on liquid crystal spatial light modulation, the near-infrared light dental imaging method based on liquid crystal spatial light modulation is applied to the near-infrared light dental imaging system based on liquid crystal spatial light modulation, the near-infrared light dental imaging method based on liquid crystal spatial light modulation includes:

[0033] Collecting original tooth images of the teeth to be inspected under original near-infrared light irradiation;

[0034] Perform overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image;

[0035] Determine whether the number of overexposed points in the overexposed point detection image corresponding to the original tooth image is less than a preset threshold, and obtain a first determination result;

[0036] If the first judgment result is yes, the original tooth image is used as the detection result of the tooth to be detected;

[0037] If the first judgment result is no, then generating a corresponding modulation map based on the overexposure point detection map corresponding to the original tooth image; the modulation map is a grayscale map corresponding to the overexposure point detection map;

[0038] Based on the over-exposure point detection map and modulation map corresponding to the original tooth image, the amplitude of the original near-infrared light is modulated using a cyclic scanning method to obtain the near-infrared light after the initial modulation;

[0039] Iterative detection is performed on the teeth to be detected based on the near-infrared light after the initial modulation to obtain the detection result of the teeth to be detected; wherein the detection process under any current iteration number includes:

[0040] Based on the overexposure point detection map and modulation map corresponding to the tooth image at the previous iteration number, the amplitude of the near-infrared light at the previous iteration number is modulated using a cyclic scanning method to obtain the modulated near-infrared light at the current iteration number, and the near-infrared light modulated at the current iteration number is used to irradiate the tooth to be detected to obtain the modulated tooth image at the current iteration number; wherein, when the current iteration number is the initial iteration number, the tooth image at the previous iteration number is the original tooth image, and the near-infrared light at the previous iteration number is the original near-infrared light;

[0041] Perform overexposure point detection on the tooth image modulated at the current iteration number to obtain an overexposure point detection map corresponding to the tooth image modulated at the current iteration number;

[0042] Determine whether the number of overexposure points in the overexposure point detection image corresponding to the modulated tooth image at the current iteration number is less than the preset threshold, and obtain a second judgment result at the current iteration number;

[0043] Based on the second judgment result at the current iteration number, it is determined to use the tooth image modulated at the current iteration number, and the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected.

[0044] Optionally, based on the second judgment result at the current iteration number, determining to use the tooth image modulated at the current iteration number, and using the tooth image modulated at the current iteration number as the detection result of the tooth to be detected specifically includes:

[0045] If the second judgment result at the current iteration number is yes, the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected;

[0046] If the second judgment result at the current iteration number is no, based on the overexposure point detection map and modulation map corresponding to the modulated tooth image at the current iteration number, the amplitude of the near-infrared light at the current iteration number is modulated by a cyclic scanning method to obtain the near-infrared light at the next iteration number;

[0047] irradiating the tooth to be inspected with near-infrared light at the next iteration number;

[0048] Collect the tooth image modulated at the next iteration number, update the tooth image modulated at the current iteration number to the tooth image modulated at the next iteration number, until the second judgment result at the current iteration number is yes, and use the tooth image modulated at the current iteration number as the detection result of the tooth to be detected.

[0049] Optionally, performing overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image specifically includes:

[0050] Obtain the grayscale value of each pixel in the original tooth image, and mark the pixel whose grayscale value is greater than the preset grayscale threshold as an overexposed point, and mark the pixel other than the overexposed point as a non-overexposed point;

[0051] The grayscale values ​​of overexposed points in the original tooth image are set to 255, and the grayscale values ​​of non-overexposed points are set to 0, so as to obtain an overexposed point detection image corresponding to the original tooth image.

[0052] Optionally, generating a corresponding modulation map according to the overexposure point detection map specifically includes:

[0053] A grayscale image of the same size as the overexposure point detection image is defined, and the grayscale values ​​of the pixels corresponding to the overexposure points in the grayscale image are adjusted down to a preset range, and the grayscale values ​​of the remaining pixels are made the same as the grayscale values ​​of the non-overexposure points, to obtain the modulation image.

[0054] Optionally, based on the overexposure point detection map and the modulation map corresponding to the original tooth image, the amplitude of the original near-infrared light is modulated by a cyclic scanning method to obtain the near-infrared light after the initial modulation, specifically including:

[0055] Using a cyclic scanning method, the pixels of the liquid crystal spatial light modulation module are divided into N modulation areas;

[0056] Determine the modulation area where each overexposed point in the overexposed point detection image corresponding to the original tooth image is located;

[0057] For the modulation area where any overexposure point is located, the cyclic scanning method is used to modulate the amplitude of the original near-infrared light passing through the liquid crystal spatial light modulation module according to the grayscale values ​​of different pixel points in the modulation image corresponding to the original tooth image, so as to obtain the near-infrared light after the initial modulation.

[0058] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the near-infrared dental imaging method based on liquid crystal spatial light modulation.

[0059] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0060] The present application provides a near-infrared dental imaging system, method and equipment based on liquid crystal spatial light modulation, wherein a host computer and a liquid crystal spatial light modulation module are provided, and the host computer is used to perform overexposure point detection on the dental image. If the requirements are not met, the liquid crystal spatial light modulation module is used to modulate the amplitude of the near-infrared light using a cyclic scanning method to obtain modulated near-infrared light, and the modulated near-infrared light is used to irradiate the teeth to be detected, and then overexposure point detection is performed. If the requirements are not met, the system is iterated cyclically until the requirements are met, and the detection results of the teeth to be detected are obtained. The cyclic scanning method is used to more accurately modulate the area where the overexposure point is located without affecting the visual effect of the non-overexposed area, thereby solving the problems of partial overexposure and low contrast in near-infrared dental imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0062] Figure 1 This is a functional module diagram of a near-infrared dental imaging system based on liquid crystal spatial light modulation in one embodiment of the present application;

[0063] Figure 2 A schematic diagram of pixel division of a liquid crystal spatial light modulator provided in an embodiment of the present application;

[0064] Figure 3 A schematic diagram of the beam expansion principle of a beam expansion subsystem provided in one embodiment of the present application;

[0065] Figure 4 A schematic flow chart of a near-infrared tooth imaging method based on liquid crystal spatial light modulation provided in another embodiment of the present application;

[0066] Figure 5 A grayscale histogram of an overexposed image provided by an embodiment of the present application;

[0067] Figure 6 A schematic diagram of a cyclic scanning method provided in an embodiment of the present application;

[0068] Figure 7 A schematic diagram of small blocks divided into modulation areas according to an embodiment of the present application;

[0069] Figure 8 A schematic diagram of modulation area division of a liquid crystal spatial light modulator provided in an embodiment of the present application;

[0070] Fig. 9 A schematic diagram of a parameter setting process of a liquid crystal spatial light modulator provided in an embodiment of the present application;

[0071] Fig.10 A schematic diagram of the structure of a computer device provided by an embodiment of the present application.

[0072] Reference numerals:

[0073] Near-infrared light source module 1, laser 11, collimator 12, polarizer 13, beam expansion subsystem 14, liquid crystal spatial light modulation module 2, image acquisition module 3, tooth to be detected 4, and converging lens 5. DETAILED DESCRIPTION

[0074] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0075] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0076] In an exemplary embodiment, Figure 1 As shown, a near-infrared dental imaging system based on liquid crystal spatial light modulation is provided, comprising: a near-infrared light source module 11, a liquid crystal spatial light modulation module 2, a host computer and an image acquisition module 3.

[0077] The near-infrared light source module 1 is used to emit original near-infrared light, and utilize the original near-infrared light to illuminate the tooth 4 to be inspected.

[0078] The image acquisition module 3 is located on the emission optical path of the original near-infrared light and is connected to the host computer. The image acquisition module 3 is used to acquire the original tooth image of the tooth to be detected 4 under the irradiation of the original near-infrared light and send the original tooth image to the host computer.

[0079] The host computer is connected to the liquid crystal spatial light modulation module 2, and the host computer is used to:

[0080] The over-exposure points of the original tooth image are detected to obtain an over-exposure point detection map corresponding to the original tooth image.

[0081] It is determined whether the number of overexposed points in the overexposed point detection image corresponding to the original tooth image is less than a preset threshold value to obtain a first determination result.

[0082] If the first judgment result is yes, the original tooth image is used as the detection result of the tooth 4 to be detected.

[0083] If the first judgment result is no, a corresponding modulation map is generated based on the overexposure point detection map corresponding to the original tooth image, and the modulation map corresponding to the original tooth image is sent to the liquid crystal spatial light modulation module 2. The modulation map is a grayscale map corresponding to the overexposure point detection map.

[0084] The liquid crystal spatial light modulation module 2 is located in the outgoing optical path of the original near-infrared light and between the near-infrared light source module 1 and the tooth 4 to be detected. The liquid crystal spatial light modulation module 2 is used to modulate the amplitude of the original near-infrared light based on the overexposure point detection map and modulation map corresponding to the original tooth image using a cyclic scanning method to obtain the near-infrared light after the initial modulation. Among them, the host computer converts the modulation map to be loaded into a voltage signal and loads it onto the liquid crystal spatial light modulator. The voltage signal is determined according to the grayscale value of each pixel in the modulation map. The higher the grayscale value, the larger the corresponding voltage signal. When the voltage signal acts on the liquid crystal layer of the liquid crystal spatial light modulator, the electro-optical effect of the liquid crystal will cause the optical properties of the liquid crystal layer to change. Specifically, different voltages will lead to different arrangements of liquid crystal molecules, thereby changing the transmittance of the liquid crystal layer to light. Since the grayscale values ​​of each pixel in the modulation map are different, the voltage loaded to the liquid crystal spatial light modulator is also different, thereby achieving different degrees of modulation of the light amplitude. Among them, the pixel simulation schematic diagram of the liquid crystal spatial light modulator is as shown in Figure 2 shown.

[0085] The liquid crystal spatial light modulation module 2, the image acquisition module 3, and the host computer jointly perform iterative detection on the teeth to be detected 4 based on the near-infrared light after the initial modulation to obtain the detection result of the teeth to be detected 4; wherein the detection process under any current iteration number includes:

[0086] The liquid crystal spatial light modulation module 2 modulates the amplitude of the near-infrared light at the previous iteration number based on the overexposure point detection map and modulation map corresponding to the tooth image at the previous iteration number, using a cyclic scanning method to obtain the modulated near-infrared light at the current iteration number, and uses the modulated near-infrared light at the current iteration number to irradiate the tooth 4 to be detected, to obtain the modulated tooth image at the current iteration number; wherein, when the current iteration number is the initial iteration number, the tooth image at the previous iteration number is the original tooth image, and the near-infrared light at the previous iteration number is the original near-infrared light.

[0087] The image acquisition module 3 acquires the tooth image modulated at the current iteration number, and sends the tooth image modulated at the current iteration number to the host computer.

[0088] The host computer:

[0089] Perform overexposure point detection on the tooth image modulated at the current iteration number to obtain an overexposure point detection map corresponding to the tooth image modulated at the current iteration number;

[0090] Determine whether the number of overexposure points in the overexposure point detection image corresponding to the modulated tooth image at the current iteration number is less than the preset threshold, and obtain a second judgment result at the current iteration number;

[0091] Based on the second judgment result at the current iteration number, it is determined to use the tooth image modulated at the current iteration number, and the tooth image modulated at the current iteration number is used as the detection result of the tooth 4 to be detected.

[0092] As an optional implementation, based on the second judgment result at the current iteration number, determining to use the tooth image modulated at the current iteration number, and using the tooth image modulated at the current iteration number as the detection result of the tooth 4 to be detected, specifically includes:

[0093] If the second judgment result at the current iteration number is yes, the tooth image modulated at the current iteration number is used as the detection result of the tooth 4 to be detected;

[0094] If the second judgment result at the current iteration number is no, based on the overexposure point detection map and the modulation map corresponding to the modulated tooth image at the current iteration number, the amplitude of the near-infrared light at the current iteration number is modulated by a cyclic scanning method to obtain the near-infrared light at the next iteration number, and the near-infrared light at the next iteration number is used to irradiate the tooth to be detected 4;

[0095] The image acquisition module 3 acquires the tooth image modulated at the next iteration number, updates the tooth image modulated at the current iteration number to the tooth image modulated at the next iteration number, and sends the tooth image modulated at the current iteration number to the host computer until the second judgment result at the current iteration number is yes, and the tooth image modulated at the current iteration number is used as the detection result of the tooth 4 to be detected.

[0096] As an optional implementation, Figure 1 As shown, the near-infrared light source module 1 includes a laser 11 , a collimator 12 , a polarizer 13 and a beam expansion subsystem 14 .

[0097] The laser 11 and the tooth to be detected 4 are located on a coaxial optical path at the same height, and the laser 11 is used to emit near-infrared light. The laser 11 is a near-infrared laser with a beam diameter of about 0.7 mm.

[0098] The collimator 12 and the laser 11 are located on a coaxial optical path at the same height, and the collimator 12 is used to collimate the near-infrared light to obtain collimated near-infrared light.

[0099] The polarizer 13 and the collimator 12 are located on an equi-height coaxial optical path, and are used to convert the collimated near-infrared light into linearly polarized light. The polarizer 13 converts the collimated near-infrared light into linearly polarized light, and causes amplitude modulation by changing the polarization state of the light field. In addition, a polarizer 15 is provided between the liquid crystal spatial light modulation module 2 and the tooth to be detected 4, and is used in conjunction with the polarizer 13.

[0100] The beam expansion subsystem 14 and the polarizer 13 are located on the same coaxial optical path, and the beam expansion subsystem 14 is used to expand the linear polarized light to obtain the original near-infrared light. The beam expansion subsystem 14 expands the near-infrared light with a diameter of about 0.7 mm by 70 times, matching the liquid crystal spatial light modulator with a diagonal diameter of about 47 mm. Figure 3 As shown, Figure 3 Schematic diagram of the beam expansion subsystem 14, wherein the expansion factor n is calculated as: F2 / F1=n, wherein F1 and F2 represent the focal lengths of the two lens groups, respectively.

[0101] As an optional implementation, a converging lens 5 is further provided between the image acquisition module 3 and the tooth to be detected 4 .

[0102] As an optional implementation, the liquid crystal spatial light modulation module 2 is a liquid crystal spatial light modulator. The liquid crystal spatial light modulator adopts an amplitude and phase type transmissive liquid crystal spatial light modulator, and is connected to a host computer via HDMI and Mini-USB, and the modulation diagram generated by the host computer is loaded into the liquid crystal spatial light modulator.

[0103] As an optional implementation, the image acquisition module 3 is a near-infrared camera. The near-infrared camera uses an industrial camera produced by FLIR, which uses a USB3.0 interface, has a resolution of 1380×1036, a maximum frame rate of 45FPS, and supports 14-bit image acquisition and exposure time modulation. SpinView software is deployed in the host computer to control the near-infrared camera to acquire the tooth image of the tooth 4 to be detected.

[0104] Based on the same inventive concept, the embodiment of the present application also provides a near-infrared dental imaging method based on liquid crystal spatial light modulation based on the above-mentioned near-infrared dental imaging system applied to liquid crystal spatial light modulation. The implementation scheme for solving the problem provided by the method is similar to the implementation scheme recorded in the above-mentioned system, so the specific limitations in one or more embodiments of the near-infrared dental imaging method based on liquid crystal spatial light modulation provided below can refer to the above-mentioned limitations on the near-infrared dental imaging system based on liquid crystal spatial light modulation, and will not be repeated here.

[0105] In an exemplary embodiment, Figure 4As shown, a near-infrared tooth imaging method based on liquid crystal spatial light modulation is provided, comprising the following steps S1 to S11. Among them:

[0106] Step S1, collecting an original tooth image of the tooth 4 to be inspected under original near-infrared light irradiation.

[0107] Step S2, performing overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image.

[0108] Step S3, determining whether the number of overexposed points in the overexposed point detection image corresponding to the original tooth image is less than a preset threshold, and obtaining a first determination result.

[0109] Step S4: if the first judgment result is yes, the original tooth image is used as the detection result of the tooth 4 to be detected.

[0110] Step S5: if the first judgment result is no, a corresponding modulation map is generated based on the overexposure point detection map corresponding to the original tooth image. The modulation map is a grayscale map corresponding to the overexposure point detection map.

[0111] Step S6, based on the overexposure point detection map and the modulation map corresponding to the original tooth image, the amplitude of the original near-infrared light is modulated by using a cyclic scanning method to obtain the near-infrared light after the initial modulation.

[0112] Step S7, iteratively detecting the tooth 4 to be detected based on the near-infrared light after the initial modulation, to obtain the detection result of the tooth 4 to be detected; wherein the detection process at any current iteration number includes the following steps:

[0113] Step S8, based on the overexposure point detection map and modulation map corresponding to the tooth image at the previous iteration number, the amplitude of the near-infrared light at the previous iteration number is modulated by a cyclic scanning method to obtain the modulated near-infrared light at the current iteration number, and the near-infrared light modulated at the current iteration number is used to irradiate the tooth 4 to be detected to obtain the modulated tooth image at the current iteration number; wherein, when the current iteration number is the initial iteration number, the tooth image at the previous iteration number is the original tooth image, and the near-infrared light at the previous iteration number is the original near-infrared light.

[0114] Step S9, performing overexposure point detection on the tooth image modulated at the current iteration number to obtain an overexposure point detection map corresponding to the tooth image modulated at the current iteration number.

[0115] Step S10, determining whether the number of overexposure points in the overexposure point detection image corresponding to the modulated tooth image at the current iteration number is less than the preset threshold, and obtaining a second determination result at the current iteration number.

[0116] Step S11, based on the second judgment result at the current iteration number, determine the tooth image modulated at the current iteration number, and use the tooth image modulated at the current iteration number as the detection result of the tooth 4 to be detected.

[0117] As an optional implementation, step S2 specifically includes:

[0118] Step S21, obtain the gray value of each pixel in the original tooth image, and mark the pixel whose gray value is greater than the preset gray value threshold as overexposed point, and mark the pixel other than the overexposed point as non-overexposed point. Specifically, (1) overexposed point marking is: when the original tooth image has an overexposed area, its histogram usually has at least two peaks, such as Figure 5 As shown, at this time, the valley value between the right peak and the middle peak is set to L, that is, the preset grayscale threshold is L, and the pixel point with a grayscale value greater than L is defined as an overexposed point. (2) Overexposed point detection is to detect the overexposed points in the original tooth image, laying the foundation for the subsequent cyclic scanning method, specifically: determine whether the grayscale value of each pixel point in the original tooth image is greater than L. If it is greater than L, it is marked as an overexposed point.

[0119] Step S22, the grayscale values ​​of the overexposed points in the original tooth image are set to 255, and the grayscale values ​​of the non-overexposed points are set to 0, to obtain an overexposed point detection image corresponding to the original tooth image. Specifically, the grayscale values ​​of the pixels whose grayscale values ​​are greater than L are set to 255, and the grayscale values ​​of the pixels whose grayscale values ​​are less than or equal to L are set to 0, to obtain a binary image, i.e., the overexposed point detection image corresponding to the original tooth image.

[0120] As an optional implementation, in step S5, generating a corresponding modulation map according to the overexposure point detection map specifically includes:

[0121] A grayscale image of the same size as the overexposure point detection image is defined, and the grayscale values ​​of the pixels corresponding to the overexposure points in the grayscale image are adjusted down to a preset range, and the grayscale values ​​of the remaining pixels are made the same as the grayscale values ​​of the non-overexposure points, to obtain the modulation image.

[0122] As an optional implementation, step S6 specifically includes:

[0123] Step S61 : using a cyclic scanning method, the pixels of the liquid crystal spatial light modulation module 2 are divided into N modulation areas.

[0124] Step S62, determining the modulation area where each overexposed point in the overexposed point detection image corresponding to the original tooth image is located.

[0125] In step S63, for any modulation area where an overexposure point is located, a cyclic scanning method is used to modulate the amplitude of the original near-infrared light passing through the liquid crystal spatial light modulation module 2 according to the grayscale values ​​of different pixel points in the modulation image corresponding to the original tooth image to obtain the near-infrared light after the initial modulation.

[0126] Specifically, in step S61, the pixels of the liquid crystal spatial light modulator are divided into N modulation areas according to the basic principle of the cyclic scanning method, and then the grayscale control is performed on each modulation area. Among them, 1) the basic principle of the cyclic scanning method is: Figure 6 As shown, the pixels of the liquid crystal spatial light modulator are divided into blocks, and the grayscale of each modulation area is controlled separately, and then scanned from left to right and from top to bottom. If the overexposure points in the tooth image collected by the near-infrared camera decrease after a modulation area is modulated, then this modulation area is retained. If the overexposure points do not decrease, continue to scan the next modulation area. Since the number of pixels of the liquid crystal spatial light modulator is 1024×768, debugging pixel by pixel will greatly increase the workload, and the debugging time will also increase with the increase in the number of detection points. Therefore, choosing block modulation can speed up efficiency. Each modulation area is composed of multiple small blocks, such as Figure 7 As shown, each small block is composed of multiple pixels. Since this method scans and modulates each modulation area, it is applicable to all tooth images containing overexposed points. By loading different modulation patterns into the liquid crystal spatial light modulator, part of the light in the modulation area can be blocked. By detecting whether the light intensity is reduced and mapping it to the near-infrared camera, it is determined whether the number of overexposed points is reduced, thereby determining whether to retain the modulation area.

[0127] 2) Parameter setting of the cyclic scanning method. In the process of using the cyclic scanning method, the size of the block affects its modulation effect. When the block is small, the modulation process time will be increased and the modulation effect is not ideal; when the block is large, the overexposed area cannot be accurately modulated. Therefore, it is necessary to first define the modulation area of ​​the liquid crystal spatial light modulator, such as Figure 8As shown, typical area divisions include 2 areas, 4 areas, 9 areas, 16 areas, etc. Since the 2- and 4-area divisions lack modulation of the central area, and 16 areas are too many, which affects the modulation speed and the initial modulation accuracy, the present application uses 9-area division, that is, the pixels of the liquid crystal spatial light modulation module 2 are divided into 9 modulation areas to control the modulation effect. Among them, during the modulation process, the setting of the light intensity of each modulation area also affects the modulation effect of the light intensity in the imaging. The lower the gray value is set (the darker the color), the more obvious the effect of reducing the light intensity. However, if the gray value is set too low, the original detail effect of the image will also be lost, and the effect displayed in the imaging will be black, and the previous imaging information cannot be recognized. Since the overexposed area in the tooth image will be larger when the modulation map is not loaded, it is impossible to get the result from the modulated tooth imaging when adjusting one of the modulation areas. Therefore, in the modulation process, the original tooth image without the modulation map is first collected to determine the number of overexposed points in the overexposed area. Then, each divided modulation area is set to a fixed value to reduce the light intensity after passing through the liquid crystal spatial light modulator. Then, the cyclic scanning method is used to continue dimming it and record the most appropriate parameters. Fig. 9 The figure shows the parameter setting process of the liquid crystal spatial light modulator. By setting its parameters, the overexposed area can be modulated more accurately without affecting the visual effect of the non-overexposed area. That is, the block adjustment algorithm is used to amplitude modulate different blocks of the liquid crystal spatial light modulator, thereby solving some overexposure problems.

[0128] As an optional implementation, step S11 specifically includes:

[0129] Step S111: if the second judgment result at the current iteration number is yes, the tooth image modulated at the current iteration number is used as the detection result of the tooth 4 to be detected.

[0130] Step S112, if the second judgment result at the current iteration number is no, based on the overexposure point detection diagram and modulation diagram corresponding to the modulated tooth image at the current iteration number, the amplitude of the near-infrared light at the current iteration number is modulated using a cyclic scanning method to obtain the near-infrared light at the next iteration number.

[0131] Step S113, irradiating the tooth 4 to be inspected with near-infrared light of the next iteration number.

[0132] Step S114, collect the tooth image modulated at the next iteration number, update the tooth image modulated at the current iteration number to the tooth image modulated at the next iteration number, until the second judgment result at the current iteration number is yes, and use the tooth image modulated at the current iteration number as the detection result of the tooth 4 to be detected.

[0133] Furthermore, after the system is built, the system needs to be debugged on the device. First, the liquid crystal spatial light modulator needs to be connected and controlled to achieve precise control of the liquid crystal spatial light modulator on the modulated imaging. Secondly, the host computer needs to be connected to the camera to enable the camera to be turned on, the image to be captured, and the image to be saved for subsequent image analysis.

[0134] For the connection between the liquid crystal spatial light modulator and the host computer, the underlying driver is used to realize the host computer's control of the liquid crystal spatial light modulator. For the connection between the camera and the host computer, SpinView software is used to realize the camera's image acquisition and storage.

[0135] After the successful equipment construction and debugging, this application conducts imaging tests on high dynamic scenes. To verify the dimming effect of this system, this application designs two experimental schemes to test the system performance. The first scheme uses near-infrared laser as the light source to test the imaging effect of this system in high-brightness scenes. The second scheme puts this system into near-infrared tooth detection to observe whether the addition of this system makes the imaging effect of the tooth detection system clearer.

[0136] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.10 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a near-infrared light dental imaging method based on liquid crystal spatial light modulation is implemented.

[0137] Those skilled in the art will understand that Fig.10The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the above-mentioned method embodiments when executing the computer program.

[0138] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0139] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0140] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0141] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0142] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A near-infrared dental imaging system based on liquid crystal spatial light modulation, characterized in that: The near-infrared dental imaging system based on liquid crystal spatial light modulation comprises: a near-infrared light source module, a liquid crystal spatial light modulation module, a host computer and an image acquisition module; The near-infrared light source module is used to emit original near-infrared light, and use the original near-infrared light to illuminate the teeth to be inspected; The image acquisition module is located on the emission light path of the original near-infrared light and is connected to the host computer. The image acquisition module is used to acquire the original tooth image of the tooth to be detected under the irradiation of the original near-infrared light and send the original tooth image to the host computer; The host computer is connected to the liquid crystal spatial light modulation module, and the host computer is used to: Perform overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image; Determine whether the number of overexposed points in the overexposed point detection image corresponding to the original tooth image is less than a preset threshold, and obtain a first determination result; If the first judgment result is yes, the original tooth image is used as the detection result of the tooth to be detected; If the first judgment result is no, a corresponding modulation map is generated based on the overexposure point detection map corresponding to the original tooth image, and the modulation map corresponding to the original tooth image is sent to the liquid crystal spatial light modulation module; the modulation map is a grayscale map corresponding to the overexposure point detection map; The liquid crystal spatial light modulation module is located in the outgoing light path of the original near-infrared light and between the near-infrared light source module and the tooth to be detected. The liquid crystal spatial light modulation module is used to modulate the amplitude of the original near-infrared light by a cyclic scanning method based on the overexposure point detection map and the modulation map corresponding to the original tooth image to obtain the near-infrared light after the initial modulation; The liquid crystal spatial light modulation module, the image acquisition module, and the host computer jointly perform iterative detection on the teeth to be detected based on the near-infrared light after the initial modulation to obtain the detection results of the teeth to be detected; wherein the detection process under any current iteration number includes: The liquid crystal spatial light modulation module modulates the amplitude of the near-infrared light at the previous iteration number based on the overexposure point detection map and modulation map corresponding to the tooth image at the previous iteration number by using a cyclic scanning method to obtain the modulated near-infrared light at the current iteration number, and uses the modulated near-infrared light at the current iteration number to irradiate the tooth to be detected to obtain the modulated tooth image at the current iteration number; wherein, when the current iteration number is the initial iteration number, the tooth image at the previous iteration number is the original tooth image, and the near-infrared light at the previous iteration number is the original near-infrared light; The image acquisition module acquires the tooth image modulated at the current iteration number, and sends the tooth image modulated at the current iteration number to the host computer; The host computer: Perform overexposure point detection on the tooth image modulated at the current iteration number to obtain an overexposure point detection map corresponding to the tooth image modulated at the current iteration number; Determine whether the number of overexposure points in the overexposure point detection image corresponding to the modulated tooth image at the current iteration number is less than the preset threshold, and obtain a second judgment result at the current iteration number; Based on the second judgment result at the current iteration number, it is determined to use the tooth image modulated at the current iteration number, and the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected.

2. The near-infrared dental imaging system based on liquid crystal spatial light modulation according to claim 1, characterized in that: Based on the second judgment result at the current iteration number, determining to use the tooth image modulated at the current iteration number, and using the tooth image modulated at the current iteration number as the detection result of the tooth to be detected, specifically includes: If the second judgment result at the current iteration number is yes, the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected; If the second judgment result at the current iteration number is no, based on the overexposure point detection map and the modulation map corresponding to the modulated tooth image at the current iteration number, the amplitude of the near-infrared light at the current iteration number is modulated by a cyclic scanning method to obtain the near-infrared light at the next iteration number, and the near-infrared light at the next iteration number is used to irradiate the teeth to be detected; The image acquisition module acquires the tooth image modulated at the next iteration number, updates the tooth image modulated at the current iteration number to the tooth image modulated at the next iteration number, and sends the tooth image modulated at the current iteration number to the host computer until the second judgment result at the current iteration number is yes, and the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected.

3. The near-infrared dental imaging system based on liquid crystal spatial light modulation according to claim 1, characterized in that: The near-infrared light source module includes a laser, a collimator, a beam expansion subsystem and a polarizer; The laser and the tooth to be detected are located on a coaxial optical path at the same height, and the laser is used to emit near-infrared light; The collimator and the laser are located on a coaxial optical path at the same height, and the collimator is used to collimate the near-infrared light to obtain collimated near-infrared light; The polarizer and the collimator are located on a coaxial optical path at equal heights, and are used to convert the collimated near-infrared light into linearly polarized light; The beam expansion subsystem and the polarizer are located on a coaxial optical path at the same height, and the beam expansion subsystem is used to expand the linearly polarized light to obtain original near-infrared light.

4. The near-infrared dental imaging system based on liquid crystal spatial light modulation according to claim 1, characterized in that: The liquid crystal spatial light modulation module is a liquid crystal spatial light modulator.

5. A near-infrared tooth imaging method based on liquid crystal spatial light modulation, characterized in that: The near-infrared light tooth imaging method based on liquid crystal spatial light modulation is applied to the near-infrared light tooth imaging system based on liquid crystal spatial light modulation according to any one of claims 1 to 4, and the near-infrared light tooth imaging method based on liquid crystal spatial light modulation comprises: Collecting original tooth images of the teeth to be inspected under original near-infrared light irradiation; Perform overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image; Determine whether the number of overexposed points in the overexposed point detection image corresponding to the original tooth image is less than a preset threshold, and obtain a first determination result; If the first judgment result is yes, the original tooth image is used as the detection result of the tooth to be detected; If the first judgment result is no, a corresponding modulation map is generated based on the overexposure point detection map corresponding to the original tooth image, and the modulation map corresponding to the original tooth image is sent to the liquid crystal spatial light modulation module; the modulation map is a grayscale map corresponding to the overexposure point detection map; Based on the over-exposure point detection map and modulation map corresponding to the original tooth image, the amplitude of the original near-infrared light is modulated using a cyclic scanning method to obtain the near-infrared light after the initial modulation; Iterative detection is performed on the teeth to be detected based on the near-infrared light after the initial modulation to obtain the detection result of the teeth to be detected; wherein the detection process under any current iteration number includes: Based on the overexposure point detection map and modulation map corresponding to the tooth image at the previous iteration number, the amplitude of the near-infrared light at the previous iteration number is modulated using a cyclic scanning method to obtain the modulated near-infrared light at the current iteration number, and the near-infrared light modulated at the current iteration number is used to irradiate the tooth to be detected to obtain the modulated tooth image at the current iteration number; wherein, when the current iteration number is the initial iteration number, the tooth image at the previous iteration number is the original tooth image, and the near-infrared light at the previous iteration number is the original near-infrared light; Perform overexposure point detection on the tooth image modulated at the current iteration number to obtain an overexposure point detection map corresponding to the tooth image modulated at the current iteration number; Determine whether the number of overexposure points in the overexposure point detection image corresponding to the modulated tooth image at the current iteration number is less than the preset threshold, and obtain a second judgment result at the current iteration number; Based on the second judgment result at the current iteration number, it is determined to use the tooth image modulated at the current iteration number, and the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected.

6. The near-infrared tooth imaging method based on liquid crystal spatial light modulation according to claim 5, characterized in that: Based on the second judgment result at the current iteration number, determining to use the tooth image modulated at the current iteration number, and using the tooth image modulated at the current iteration number as the detection result of the tooth to be detected, specifically includes: If the second judgment result at the current iteration number is yes, the tooth image modulated at the current iteration number is used as the detection result of the tooth to be detected; If the second judgment result at the current iteration number is no, based on the overexposure point detection map and modulation map corresponding to the modulated tooth image at the current iteration number, the amplitude of the near-infrared light at the current iteration number is modulated by a cyclic scanning method to obtain the near-infrared light at the next iteration number; irradiating the tooth to be inspected with near-infrared light at the next iteration number; Collect the tooth image modulated at the next iteration number, update the tooth image modulated at the current iteration number to the tooth image modulated at the next iteration number, until the second judgment result at the current iteration number is yes, and use the tooth image modulated at the current iteration number as the detection result of the tooth to be detected.

7. The near-infrared tooth imaging method based on liquid crystal spatial light modulation according to claim 5, characterized in that: Perform overexposure point detection on the original tooth image to obtain an overexposure point detection map corresponding to the original tooth image, specifically including: Obtain the grayscale value of each pixel in the original tooth image, and mark the pixel whose grayscale value is greater than the preset grayscale threshold as an overexposed point, and mark the pixel other than the overexposed point as a non-overexposed point; The grayscale values ​​of overexposed points in the original tooth image are set to 255, and the grayscale values ​​of non-overexposed points are set to 0, so as to obtain an overexposed point detection image corresponding to the original tooth image.

8. The near-infrared tooth imaging method based on liquid crystal spatial light modulation according to claim 5, characterized in that: Generate a corresponding modulation diagram based on the overexposure point detection diagram, specifically including: A grayscale image of the same size as the overexposure point detection image is defined, and the grayscale values ​​of the pixels corresponding to the overexposure points in the grayscale image are adjusted down to a preset range, and the grayscale values ​​of the remaining pixels are made the same as the grayscale values ​​of the non-overexposure points, to obtain the modulation image.

9. The near-infrared tooth imaging method based on liquid crystal spatial light modulation according to claim 5, characterized in that: Based on the overexposure point detection map and modulation map corresponding to the original tooth image, the amplitude of the original near-infrared light is modulated using the cyclic scanning method to obtain the near-infrared light after the initial modulation, specifically including: Using a cyclic scanning method, the pixels of the liquid crystal spatial light modulation module are divided into N modulation areas; Determine the modulation area where each overexposed point in the overexposed point detection image corresponding to the original tooth image is located; For the modulation area where any overexposure point is located, the cyclic scanning method is used to modulate the amplitude of the original near-infrared light passing through the liquid crystal spatial light modulation module according to the grayscale values ​​of different pixel points in the modulation image corresponding to the original tooth image, so as to obtain the near-infrared light after the initial modulation.

10. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the near-infrared dental imaging method based on liquid crystal spatial light modulation as described in any one of claims 5-9.

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