A method for measuring the three-dimensional profile of a spectacle frame

Abstract

The application discloses a kind of eyeglass frames three-dimensional profile measurement methods, it is related to eyeglass frames three-dimensional measurement technical field, the eyeglass frames three-dimensional profile measurement method, contains two parts of inside and outside contour measurement of frame, include the following steps: S1, setting reference and determining proportion conversion relationship;S2, eyeglass frames image acquisition and pretreatment;S3, eyeglass frames inside and outside edge contour size conversion;S4, eyeglass frames inside edge contour image restoration;S5, eyeglass frames inside groove measurement clamping;S6, eyeglass frames groove measurement data processing;S7, eyeglass frames three-dimensional profile reconstruction.The eyeglass frames three-dimensional profile measurement method, it is combined with the way that line laser sensor scans frame inner groove profile using based on area array CCD camera to carry out eyeglass frames inside contour size detection, can be converted to obtain eyeglass frames inside and outside edge contour length and width size information and eyeglass frames frame groove width size information by based on area array CCD camera to carry out eyeglass frames contour size detection, to restore eyeglass frames inside edge contour, part eyeglass frames inside groove measurement result is obtained by line structure light scanning along frame inside contour curve and is matched with coordinates, reconstructs eyeglass frames three-dimensional profile information.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of three-dimensional measurement of eyeglass frames, in particular to a measurement method for three-dimensional profiles of eyeglass frames. BACKGROUND

[0002] Eyeglass frames, also known as eyeglass frames, frames, and frames, are the skeleton of eyeglasses. Their main functions are to support lenses, position pupil distances, and provide comfort. Stylish eyeglass frames can also be aesthetically pleasing. They are suitable for vision correction, eye protection, clothing coordination, and social occasions. Generally, the shape of the frame profile edge is curved along the wearer's face from the side, so the eyeglass frame profile is a three-dimensional profile in space, requiring three-dimensional scanning measurement of the eyeglass frame profile. The frame profile scanning system is an important part and key technology of the eyeglass lens processing equipment. In recent years, the measurement of the frame three-dimensional profile has shifted to non-contact measurement based on photoelectric detection principles. Related research is still relatively rare, or only theoretical methods are proposed, and there is a lack of complete experiments and physical verification.

[0003] The mainstream products on the market use a contact scheme, which scans the frame inner groove profile or lens edge profile through a low-pressure contact probe to obtain lens processing parameters. This requires complex mechanical and numerical control systems, is relatively expensive, and is prone to workpiece scratches and probe wear. Domestic measurement of the frame profile is mainly two-dimensional, with a CCD camera collecting frame images to obtain eyeglass frame profile information. However, the acquisition of two-dimensional profile parameters is limited for accurate lens processing. Regardless of the current eyewear market or domestic enterprises and research universities, the research on frame scanners is basically focused on the measurement of the shape of the inner profile of the frame or the outer profile of the lens template, with few measurements of the frame groove. Therefore, we propose a measurement method for the three-dimensional profile of an eyeglass frame. SUMMARY

[0004] To overcome the deficiencies of the prior art, the present application provides a measurement method for the three-dimensional profile of an eyeglass frame, which solves the problem of high precision mechanical processing and erroneous measurement of three-dimensional profile curves due to the structure of the probe and the characteristics of contact measurement in the prior art.

[0005] To achieve the above purpose, the present application is implemented by the following technical scheme: a measurement method for the three-dimensional profile of an eyeglass frame, comprising two parts of frame inner and outer profile measurement, the measurement method for the three-dimensional profile of the eyeglass frame comprising the following steps:

[0006] S1, setting a reference object and determining the scaling relationship;

[0007] S2, glasses frame image acquisition and preprocessing;

[0008] S3, glasses frame inner and outer edge contour size conversion;

[0009] S4, glasses frame inner edge contour image restoration;

[0010] S5, glasses frame inner side groove measurement clamping;

[0011] S6, glasses frame groove measurement data processing;

[0012] S7, glasses frame three-dimensional contour reconstruction.

[0013] Further, the glasses frame three-dimensional contour measurement method comprises the following specific steps:

[0014] S1, setting a reference and determining a proportional conversion relationship

[0015] A standard part with known contour size information is taken as a reference, an image with the reference is collected as a reference image, pixel coordinates of the reference in the image coordinate system are obtained, and a proportional relationship between the actual size of the reference and the number of pixels is determined according to the physical size of the reference and the pixel coordinates of the reference in the reference image;

[0016] S2, glasses frame image acquisition and preprocessing

[0017] The glasses frame to be measured is fixed on the object table through a measured frame holding mechanism, an image of the measured glasses frame is collected through a face array CCD camera, edge point information of the glasses frame image is obtained after image preprocessing of the image through an image processing unit.

[0018] Further, the glasses frame three-dimensional contour measurement method further comprises the following specific steps:

[0019] S3, glasses frame inner and outer edge contour size conversion

[0020] (1), glasses frame inner edge contour horizontal and vertical size conversion: according to the glasses frame image edge information obtained in the above step two, setting parameter screening glasses frame inner edge contour, performing minimum rotating circumscribed rectangle operation on the contour, and using the proportional relationship between the actual size and the number of pixels obtained in step one to convert to obtain glasses frame inner edge contour length and width size information;

[0021] (2) The frame groove width size conversion of the glasses frame: according to the above steps, another parameter can be set to screen the outer edge contour of the glasses frame, based on the length and width size information of the inner and outer edge contour of the glasses frame obtained by the above steps, the corresponding upper and lower boundary points of the inner edge contour and the outer edge contour of the glasses frame are found respectively, and then the frame groove width size information of the glasses frame can be obtained by using the proportional relationship between the actual size and the number of pixels obtained in step 1.

[0022] Further, the glasses frame three-dimensional contour measurement method further comprises the following specific steps:

[0023] S4, glasses frame three-dimensional contour image restoration

[0024] The inner edge contour information of the glasses frame in the image to be measured is extracted, for the missing contour part such as the nose pad, the edge contour of the outer edge contour information of the glasses frame in the image to be measured is taken, based on the assumption that the frame groove width of each part of the frame is consistent, the missing inner contour edge pixel information is supplemented according to the obtained frame groove width, and the missing part contour is fitted with a high-order curve, and finally the inner edge contour of the glasses frame is restored.

[0025] S5, glasses frame inner groove measurement clamping

[0026] The line structure light sensor probe is fixed on a multi-degree-of-freedom customized steel plate connected to the end of the support rack, the glasses frame is clamped and fixed by the clamping mechanism, the direction of the support rack hydraulic rod is adjusted, the distance between the sensor and the measured frame is kept within the reference measurement range of the sensor, and the frame groove of the measured frame is as perpendicular as possible to the line structure light projected by the line structure light sensor.

[0027] Further, the glasses frame three-dimensional contour measurement method further comprises the following specific steps:

[0028] S6, glasses frame groove measurement data processing

[0029] (1) One-time measurement processing: the motion direction and motion speed of the one-dimensional electric displacement platform are set, the electric displacement platform is started, the measured frame moves in a single direction with the displacement platform, at this time the line structure light sensor completes the continuous scanning of the frame groove, and then the subsequent data processing part obtains the inner groove contour information of the glasses frame cross section through image processing and performs inclination correction processing;

[0030] (2) Secondary measurement processing: then the glasses frame is turned over 180° for secondary clamping measurement, and the above steps are repeated, and the subsequent data processing part obtains the inner groove contour information of the glasses frame cross section through image processing and performs inclination correction processing again, to complete the maximum range frame groove topography measurement;

[0031] S7, three-dimensional contour reconstruction of the spectacle frame

[0032] Since the inner groove of the spectacle frame has low measurement accuracy requirement, uniformity and elasticity, the inner groove measurement result is matched with the coordinate along the frame contour curve based on the frame inner edge contour image restoration in step four, the three-dimensional contour information of the spectacle frame is reconstructed, and the complete three-dimensional contour of the spectacle frame is obtained.

[0033] Further, in the process of step one of setting a reference object and determining a proportional conversion relationship, the proportional relationship between the actual size of the reference object and the number of pixels is: k=d pixel / d. In the formula, k is the pixel ratio of a given measurement unit, with the unit of pxiel / mm, which reflects the conversion relationship between the pixel size of the measurement system and the actual physical size, and d is the actual size of the reference object, d pixel is the size of the standard part in pixels under the measurement system.

[0034] Further, in the process of step two of image acquisition and preprocessing of the spectacle frame, the image preprocessing step includes: converting the acquired image of the spectacle frame to be measured into a gray-scale image; smoothing the gray-scale image based on a Gaussian filter; extracting all contour edges of the image of the spectacle frame to be measured based on a Canny edge detection operator; and removing interfering fine textures in the edge information of the image of the spectacle frame to be measured based on a morphological algorithm.

[0035] Further, in the process of step three of size conversion of the inner edge contour of the spectacle frame, the length and width size information of the inner edge contour of the spectacle frame is obtained by conversion based on the length pixel number and width pixel number of the smallest rotating circumscribed rectangle containing the inner edge contour of the spectacle frame and the pixel ratio k of a quantitative measurement unit.

[0036] Further, in the process of step three of size conversion of the inner edge contour of the spectacle frame, when the frame groove width size of the spectacle frame is converted, the frame groove width size information of the spectacle frame is obtained by conversion based on the arithmetic average of the upper and lower extreme point pixel coordinates of the inner edge contour of the spectacle frame and the pixel ratio k of a quantitative measurement unit.

[0037] Further, in the process of step five of clamping of the inner groove of the spectacle frame, in order to avoid the shielding effect of the frame groove part opposite to the measured inner groove part of the frame on the contour scanning effect when the line structure light is projected, the line structure light sensor probe can only project and scan the required measurement inner groove part of the frame from the outside of the frame.

[0038] The present application provides a measurement method for the three-dimensional contour of a spectacle frame, which has the following beneficial effects:

[0039] The measurement method of the three-dimensional profile of the spectacle frame adopts a combination of the spectacle frame inner profile size detection based on the area array CCD camera and the line laser sensor scanning of the frame inner groove profile, can obtain the inner and outer edge profile length and width size information of the spectacle frame and the frame groove width size information through the spectacle frame profile size detection based on the area array CCD camera, so as to restore the inner edge profile of the spectacle frame, and can obtain the complete three-dimensional profile of the spectacle frame through the coordinate matching of the partial frame inner groove measurement result along the frame profile curve based on the restoration of the inner edge profile image of the spectacle frame, and the three-dimensional profile information reconstruction of the spectacle frame, so that the combination of the line laser sensor scanning of the frame inner groove and the spectacle frame inner profile size detection based on the area array CCD camera can complete the inner and outer profile measurement of the frame, and is beneficial to realize the three-dimensional profile measurement of the spectacle frame. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a flowchart of the measurement method of the three-dimensional profile of the spectacle frame of the application.

[0041] Figure 2 It is a flowchart of the measurement of the inner edge profile size and frame groove width of the spectacle frame.

[0042] Figure 3 It is a restoration result diagram of the inner edge profile of the spectacle frame.

[0043] Figure 4 It is a measurement result diagram of the inner groove profile of the spectacle frame.

[0044] Figure 5 It is a three-dimensional profile structure diagram of the spectacle frame. DETAILED DESCRIPTION

[0045] Please refer to Figure 1 The application provides a technical scheme: a measurement method of the three-dimensional profile of a spectacle frame, which comprises two parts of inner and outer profile measurement of the frame, wherein the inner profile measurement of the frame please refer to Figure 2 The measurement method of the three-dimensional profile of the spectacle frame comprises the following steps:

[0046] S1, setting a reference object and determining a proportional conversion relationship;

[0047] S2, image acquisition and pretreatment of the spectacle frame;

[0048] S3, conversion of the inner and outer edge profile size of the spectacle frame;

[0049] S4, eyeglass frame inner edge contour image restoration;

[0050] S5, eyeglass frame inner side groove measurement clamping;

[0051] S6, eyeglass frame groove measurement data processing;

[0052] S7, eyeglass frame three-dimensional contour reconstruction.

[0053] The measurement method of the three-dimensional contour of the eyeglass frame comprises the following specific steps:

[0054] S1, setting a reference object and determining a proportional conversion relationship

[0055] A standard part with known contour size information is taken as a reference object, an image with the reference object is collected as a reference image, pixel coordinates of the reference object in the image coordinate system are obtained, and a proportional relationship between the actual size of the reference object and the number of pixels is determined according to the physical size of the reference object and the pixel coordinates of the reference object in the reference image;

[0056] In the process of step one of setting a reference object and determining a proportional conversion relationship, the proportional relationship between the actual size of the reference object and the number of pixels is: k = d pixel / d. In the formula, k is the pixel proportion of a given measurement unit, with the unit of pxiel / mm, which reflects the conversion relationship between the pixel size of the measurement system and the actual physical size, d is the actual size of the reference object, and d pixel is the size of the standard part in pixels under the measurement system;

[0057] S2, eyeglass frame image acquisition and preprocessing

[0058] The eyeglass frame to be measured is fixed on the object table through the eyeglass frame holding mechanism, and the image of the eyeglass frame to be measured is collected through the area array CCD camera. After image preprocessing by the image processing unit, the edge point information of the eyeglass frame image is obtained;

[0059] In the process of step two of eyeglass frame image acquisition and preprocessing, the image preprocessing step includes: performing gray image conversion on the collected eyeglass frame image to be measured to generate a gray image; smoothing the gray image based on a Gaussian filter; extracting all contour edges of the eyeglass frame image to be measured based on a Canny edge detection operator; and removing interfering fine textures in the edge information of the eyeglass frame image to be measured based on a morphological algorithm;

[0060] S3, eyeglass frame inner and outer edge contour size conversion

[0061] (1), the inner edge profile of the glasses frame horizontal size and vertical size conversion: according to the above step two obtained glasses frame image edge information, set parameter screening glasses frame inner edge profile, the minimum rotating rectangle operation is carried out on the profile, the length and width size information of the inner edge profile of the glasses frame is obtained by using the proportional relationship between the actual size and the number of pixels obtained in step one;

[0062] (2), the width size conversion of the frame groove of the glasses frame: according to the above step, another parameter can be set to screen the outer edge profile of the glasses frame, and the length and width size information of the inner and outer edge profile of the glasses frame is obtained based on the above step, and the corresponding upper and lower boundary points of the inner and outer edge profile of the glasses frame are found, respectively, then the width size information of the frame groove of the glasses frame is obtained by using the proportional relationship between the actual size and the number of pixels obtained in step one;

[0063] In the process of step three, the length and width size information of the inner edge profile of the glasses frame is obtained based on the length pixel number and width pixel number of the minimum rotating rectangle containing the inner edge profile of the glasses frame and the pixel ratio k of the quantitative unit; When the width size of the frame groove of the glasses frame is converted, the width size information of the frame groove of the glasses frame is obtained based on the arithmetic average of the upper and lower extreme point pixel coordinates of the inner edge profile of the glasses frame and the outer edge profile of the glasses frame and the pixel ratio k of the quantitative unit;

[0064] S4, glasses frame three-dimensional profile image restoration

[0065] Please refer to Figure 3 , the inner edge profile information of the glasses frame in the image to be measured is extracted, the edge profile of the outer edge profile information of the glasses frame in the image to be measured is taken for the missing profile part such as the nose pad, based on the assumption that the frame groove width of each part of the frame is consistent, the missing inner profile edge pixel information is supplemented according to the obtained frame groove width, and the missing part profile is fitted with high order curve, and finally the inner edge profile of the glasses frame is restored;

[0066] S5, glasses frame inner side groove measurement clamping

[0067] The line structure light sensor probe is fixed on the multi-degree-of-freedom customized steel plate connected with the end of the support rack, the glasses frame is clamped and fixed by the clamping mechanism, the direction of the support rack hydraulic rod is adjusted, the distance between the sensor and the measured frame is kept within the reference measurement range of the sensor, and the frame groove of the measured frame is as perpendicular as possible to the line structure light projected by the line structure light sensor;

[0068] In the process of measuring and clamping the inner side groove of the spectacle frame in step five, in order to avoid the blocking effect of the frame groove part opposite to the measured inner side groove part of the frame on the profile scanning when the line structured light is projected, the line structured light sensor probe can only project and scan vertically from the outside of the frame to the required measurement inner side groove part of the frame;

[0069] S6, spectacle frame groove measurement data processing

[0070] (1) One-time measurement processing: set the motion direction and speed of the one-dimensional electric displacement platform, start the electric displacement platform, and move the measured frame in a single direction with the displacement platform. At this time, the line structured light sensor completes continuous scanning of the frame groove. Then, the subsequent data processing part obtains the inner groove profile information of the cross section of the spectacle frame through image processing and performs inclination correction processing. After correction, the inner side groove profile of the frame is shown in Figure 4 ;

[0071] (2) Secondary measurement processing: then, the spectacle frame is flipped 180° for secondary clamping measurement, and the above steps are repeated. The subsequent data processing part obtains the inner groove profile information of the cross section of the spectacle frame through image processing and performs inclination correction processing again, and the maximum range of the frame groove topography measurement is completed;

[0072] S7, three-dimensional profile reconstruction of the spectacle frame

[0073] Please refer to Figure 5 Since the inner side groove of the spectacle frame has the characteristics of low measurement accuracy requirement, uniformity, and elasticity, finally, based on the image restoration of the inner edge profile of the spectacle frame in step four, the inner side groove measurement results of part of the frame are matched along the frame profile curve to reconstruct the three-dimensional profile information of the spectacle frame, and the complete three-dimensional profile of the spectacle frame is obtained.

[0074] In summary, the measurement method of the three-dimensional profile of the spectacle frame includes the following specific steps:

[0075] A standard part with known outer profile size information is taken as a reference object, an image with the reference object is collected as a reference image, pixel coordinates of the reference object in the image coordinate system are obtained, and a proportional relationship between the actual size of the reference object and the number of pixels is determined according to the physical size of the reference object and the pixel coordinates of the reference object in the reference image. The proportional relationship between the actual size of the reference object and the number of pixels is: k = d pixel / d. In the formula, k is the pixel proportion of a given unit of measurement, with the unit of pxiel / mm, which represents the conversion relationship between the pixel size of the measurement system and the actual physical size, d is the actual size of the reference object, and d pixel is the size of the standard part in pixels under the measurement system;

[0076] The to-be-tested spectacle frame is fixed on the object table by the to-be-tested frame holding mechanism, and the image of the to-be-tested spectacle frame is collected by a planar array CCD camera, and the edge point information of the spectacle frame image is obtained after image preprocessing of the image by an image processing unit; wherein the image preprocessing step comprises: converting the collected to-be-tested spectacle frame image into a gray scale image; smoothing the gray scale image based on a Gaussian filter; extracting all contour edges of the to-be-tested spectacle frame image based on a Canny edge detection operator; removing the interfering fine texture in the edge information of the to-be-tested spectacle frame image based on a morphological algorithm;

[0077] Based on the edge information of the spectacle frame image obtained in the above step two, parameters are set to screen the inner edge contour of the spectacle frame, a minimum rotating rectangle operation is performed on the contour, and the horizontal and vertical size information of the inner edge contour of the spectacle frame is obtained by using the proportional relationship between the actual size and the number of pixels obtained in step one; the horizontal and vertical size information of the inner edge contour of the spectacle frame is obtained by converting the length and width pixel numbers of the minimum rotating rectangle containing the inner edge contour of the spectacle frame and the pixel ratio k of the quantitative unit; another parameter is set to screen the outer edge contour of the spectacle frame according to the above step, and the corresponding upper and lower boundary points of the inner edge contour of the spectacle frame and the outer edge contour of the spectacle frame are found based on the length and width size information of the inner and outer edge contours of the spectacle frame, and then the frame groove width size information of the spectacle frame is obtained by using the proportional relationship between the actual size and the number of pixels obtained in step one; the frame groove width size information of the spectacle frame is obtained by converting the arithmetic mean of the upper and lower extreme point pixel coordinates of the inner edge contour of the spectacle frame and the pixel ratio k of the quantitative unit;

[0078] The inner edge contour information of the spectacle frame in the to-be-tested spectacle frame image is extracted, the edge contour of the outer edge contour information of the spectacle frame in the to-be-tested spectacle frame image is taken for the missing contour part such as the nose pad, based on the assumption that the frame groove width of each part of the frame is consistent, the missing inner contour edge pixel information is supplemented according to the obtained frame groove width, and the missing part contour is fitted by a high-order curve, and finally the inner edge contour of the spectacle frame is restored.

[0079] The linear structure light sensor probe is fixed on a multi-degree-of-freedom customized steel plate connected to the end of the support stand, the spectacle frame is clamped and fixed by a clamping mechanism, the direction of the hydraulic rod of the support stand is adjusted, the distance between the sensor and the to-be-tested frame is kept within the reference measurement range of the sensor, and the frame groove of the to-be-tested frame is as perpendicular as possible to the linear structure light projected by the linear structure light sensor; in order to avoid the blocking effect of the frame groove part opposite to the inner groove part of the measured frame on the contour scanning effect when the linear structure light is projected, the linear structure light sensor probe can only vertically project and scan the inner groove part of the required measurement frame from the outside of the frame.

[0080] The motion direction, motion speed and the like of the one-dimensional electric displacement platform are set, the electric displacement platform is started, the measured spectacle frame moves in a single direction with the displacement platform, at this time the line structured light sensor completes continuous scanning of the frame groove of the spectacle frame, then the subsequent data processing part obtains the groove profile information in the cross section of the spectacle frame through image processing and performs tilt correction processing; then the spectacle frame is turned over 180° for secondary clamping measurement, and the above steps are repeated, the subsequent data processing part again obtains the groove profile information in the cross section of the spectacle frame through image processing and performs tilt correction processing, and the spectacle frame groove appearance measurement in the maximum range is completed;

[0081] Since the inner groove of the spectacle frame has the characteristics of low measurement accuracy requirement, uniformity and elasticity, finally, based on the restoration of the spectacle frame inner edge profile image in step four, the measurement results of part of the inner groove of the spectacle frame are matched along the spectacle frame profile curve to reconstruct the three-dimensional profile information of the spectacle frame, and the complete three-dimensional profile of the spectacle frame is obtained.

Claims

1. A method for measuring the three-dimensional contour of an eyeglass frame, characterized in that, The method for measuring the three-dimensional contour of the eyeglass frame includes two parts: measuring the inner and outer contours of the frame, and includes the following steps: S1. Set up a reference object and determine the proportional conversion relationship; S2. Image acquisition and preprocessing of eyeglass frames; S3, conversion of the inner and outer edge contour dimensions of the eyeglass frame, (1) Based on the edge information of the eyeglass frame image obtained in step two above, set parameters to filter the inner edge contour of the eyeglass frame, perform minimum rotation circumscribed rectangle operation on the contour, and use the ratio of the actual size to the number of pixels obtained in step one to convert the length and width dimensions of the inner edge contour of the eyeglass frame. (2) According to the above steps, another parameter can be set to filter the outer edge contour of the eyeglass frame. Based on the length and width dimensions of the inner and outer edge contours of the eyeglass frame obtained in the above steps, the corresponding upper and lower boundary points of the inner edge contour and the outer edge contour of the eyeglass frame can be found respectively. Then, the width dimension of the eyeglass frame groove can be calculated by using the proportional relationship. S4. Image restoration of inner edge contour of eyeglass frame: Extract the inner edge contour information of eyeglass frame from the image of eyeglass frame to be tested. For the missing contour part, extract the reliable edge contour of the outer edge contour information of eyeglass frame from the image of eyeglass frame to be tested. Based on the assumption that the frame groove width of each part of the frame is consistent, supplement the missing inner contour edge pixel information according to the obtained frame groove width, and perform high-order curve fitting on the missing contour part to finally restore the inner edge contour of eyeglass frame. S5. Measurement clamping of the inner groove of the eyeglass frame: The eyeglass frame is clamped and fixed by the clamping mechanism. The distance between the line structured light sensor and the frame to be measured is adjusted to be kept within the reference measurement range of the sensor, so that the groove of the frame to be measured is as perpendicular as possible to the line structured light projected by the line structured light sensor. S6. Data processing of eyeglass frame groove measurement: (1) First measurement processing: Start the electric displacement platform, and the eyeglass frame to be measured moves in one direction with the displacement platform. The line structure light sensor completes the continuous scanning of the eyeglass frame groove. Then, the subsequent data processing part obtains the contour information of the inner groove of the eyeglass frame cross section through image processing and performs tilt correction processing. (2) Secondary measurement and processing: Then, the eyeglass frame is rotated 180° for secondary clamping and measurement, and the above steps are repeated. The subsequent data processing part is used again to obtain the inner groove contour information of the eyeglass frame cross section through image processing and perform tilt correction processing to complete the maximum range of eyeglass frame groove morphology measurement. S7. Reconstruction of the three-dimensional contour of the eyeglass frame: Based on the restoration of the inner edge contour image of the eyeglass frame in step four, take part of the measurement results of the inner groove of the frame and perform coordinate matching along the contour curve of the frame to reconstruct the three-dimensional contour information of the eyeglass frame and obtain the complete three-dimensional contour of the eyeglass frame.

2. The method for measuring the three-dimensional contour of an eyeglass frame according to claim 1, characterized in that, The method for measuring the three-dimensional contour of the eyeglass frame includes the following specific steps: S1. Set up a reference point and determine the proportional conversion relationship. A standard part with known outline and size information is used as a reference object. An image with the reference object is collected as a reference image. The pixel coordinates of the reference object in the image coordinate system are obtained. The ratio between the actual size of the reference object and the number of pixels is determined based on the physical size of the reference object and the pixel coordinates of the reference object in the reference image. S2. Image acquisition and preprocessing of eyeglass frames The eyeglass frame to be tested is fixed on the stage by the eyeglass frame holding mechanism, and the image of the eyeglass frame to be tested is acquired by the area array CCD camera. After the image is preprocessed by the image processing unit, the edge point information of the eyeglass frame image is obtained.

3. The method for measuring the three-dimensional contour of an eyeglass frame according to claim 2, characterized in that, In step one, when setting the reference object and determining the proportional conversion relationship, the proportional relationship between the actual size of the reference object and the number of pixels is as follows: in the formula The pixel ratio given a unit of measurement, in units of This demonstrates the conversion relationship between the pixel size of the measurement system and the actual physical size. The actual size of the reference object. The dimension of the standard part in pixels under the measurement system.

4. The method for measuring the three-dimensional contour of an eyeglass frame according to claim 2, characterized in that, In the process of image acquisition and preprocessing of the eyeglass frame in step two, the image preprocessing steps include: converting the acquired eyeglass frame image to grayscale to generate a grayscale image; smoothing the grayscale image based on a Gaussian filter; extracting all contour edges of the eyeglass frame image based on the Canny edge detection operator; and removing interfering fine textures from the edge information of the eyeglass frame image based on a morphological algorithm.

5. The method for measuring the three-dimensional contour of an eyeglass frame according to claim 1, characterized in that, In step three, during the conversion of the inner edge contour dimensions of the eyeglass frame, the length and width dimensions of the inner edge contour are based on the ratio of the length and width pixels of the smallest rotated bounding rectangle containing the inner edge contour to the pixel units of measurement. Obtained through conversion.

6. The method for measuring the three-dimensional contour of an eyeglass frame according to claim 1, characterized in that, In step three, during the conversion of the inner edge contour size of the eyeglass frame, the conversion of the frame groove width size is based on the ratio of the arithmetic mean of the upper and lower extreme pixel coordinates of the inner edge contour of the eyeglass frame to the pixel ratio of the quantitative unit. Obtained through conversion.

Images