KR102299051B1 - Digital system providing 3D parameters for diagnosing the ophthalmic glasses - Google Patents

Abstract

The present invention relates to a three-dimensional parameter measuring apparatus and method using a QR code (Quick Response Code) for lens prescription, and more particularly, a ruler equipped with a QR code in the center is mounted on the forehead and left and right images are displayed. 3 using QR code to obtain three-dimensional parameters including the center of corneal curvature by photographing, automatically searching the QR code coordinates from the photographed image, searching for 8 upper and lower left and right marks of the eyeglass frame and two reflection points of the pupil It relates to an apparatus and method for measuring dimensional parameters.
The present invention is a ruler positioned on the subject's forehead, a camera that captures left and right facial images of the subject, and an operation processing unit that detects three-dimensional parameters for lens prescription using the ruler's image from the image captured by the camera In the three-dimensional parameter measurement device comprising It is characterized in that the three-dimensional parameter including the vertical length (B) of the spectacle frame is detected by using the set coordinate system as the common coordinate system.
The QR code has four points: an origin, a first point, a second point, and a third point, the origin is a point on the left side of the top of the QR code, and the first point is a point on the right side of the top of the QR code, A line connecting the origin and the first point indicates the X-axis, the second point is a point on the left side of the bottom of the QR code, and the line connecting the origin and the second point indicates the Y-axis, and the third point is the origin and the second point in the QR code. It is a single point located in places other than the 1st point, the 2nd point, and the 3rd point.

Description

Apparatus and method for measuring three-dimensional parameters for prescription of spectacle lenses {Digital system providing 3D parameters for diagnosing the ophthalmic glasses}

The present invention relates to a three-dimensional parameter measuring apparatus and method using position information of a specific mark, such as a QR code (Quick Response Code) for prescription for spectacle lenses, and more particularly, a ruler equipped with a mark such as a QR code in the center (ruler) is mounted on the forehead and left and right images are taken, the coordinates of the marks are automatically searched from the captured images, 8 upper and lower left and right marks of the eyeglass frame and 2 reflection points of the pupil are searched, 3 including the center of corneal curvature It relates to a three-dimensional parameter measuring apparatus and method for prescription spectacle lenses, obtaining a dimensional parameter.

People with an abnormal refractive power of the eye are prescribed spectacle lenses at an optician's office to correct the refractive power of their eyes. Due to the advent of special lenses such as lenses, the need for precisely prescribing spectacle frames and lenses according to a patient's vision habit or face shape is increasing.

Therefore, using a ruler, which is an auxiliary device necessary for length scaling, and a high-resolution CCD camera, various measurement parameters are obtained using images taken twice in succession of the front and side views of a patient wearing eyeglass frames. Although this has been proposed, there is a disadvantage in that the front and side views must be continuously taken. In addition, a technique for providing necessary data by simultaneously photographing a patient wearing glasses from different angles using two high-resolution CCD cameras has been proposed. However, there is a problem in that the distance from the camera to the subject must be fixed and two cameras must be used.

In the case of existing equipment, since the measurement method is simply a method of obtaining data by analyzing a two-dimensional image, not only the measurement values of length or angle are unclear, but also the left and right monocular PD is measured when a prism power prescription needs to be prescribed to a customer with oblique or strabismus. The downside was that it couldn't be done.

The parameters obtained by measuring the intrinsic length and angle representing the shape of the customer's face and the selected frame (ie, eyeglass frame) by analyzing two high-resolution images taken with a smart device are the horizontal length of the eyeglass frame (BOX A, A) and the length of the eyeglass frame. Length (BOX B, B), maximum length from pupil to frame (BOX ED), pupillary distance for both eyes (PD), distance from center of frame to left pupil (LPD), distance from center of frame to right pupil ( RPD), the length of the nose ring of the frame (DBL), the vertical distance from the bottom of the frame to the pupil (EP), the horizontal distance from the apex of the back of the lens to the apex of the pupil (VCD) when looking at a distance, and the distance from the center of the eyeglass frame to the pupil Horizontal (x-axis) distance (u), vertical (y-axis) distance from the center of the eyeglass frame to the pupil (v), the horizontal distance/vertical distance from the center of the eyeglass frame to the pupil (u/v), the vertical inclination angle of the eyeglass frame (PA) ), the horizontal angle between the frame and the face (FFA), the vertical tilt angle of the face (TA) when looking at a distant object, and the horizontal rotation angle (RA) of the face when looking at a distant object.

As a prior art, the present applicant has a domestic registered patent No. 10-1075972 'parameter measuring device for lens prescription'. In this invention, when a subject wearing spectacles frames equipped with a ruler that provides a length standard is positioned in front of the body, the eyes are guided to look at near and distant objects, It provides a parameter measuring device for lens prescription that analyzes the parameters necessary for lens prescription from a total of four digital images acquired with a camera by continuously shooting in the direction.

In the case of Korean Patent Registration No. 10-1075972, the parameter is detected using the length scaler in the ruler, and a transparent mirror with a dot mark is required. in need. In addition, since the predetermined ruler is mounted at a predetermined position of the eyeglass frame, the location varies depending on the eyeglass frame, which may cause measurement error, and thus the accuracy is relatively low, and the installation of the equipment (ie, the ruler) is difficult and inconvenient to use do.

Accordingly, the present invention proposes an apparatus and method for measuring a three-dimensional parameter that is simple in installation and use of a ruler and has higher accuracy.

The problem to be solved by the present invention is to mount a ruler equipped with a special mark such as a QR code in the center on the forehead, take left and right images, automatically search the coordinates of each mark from the photographed image, and improve the precision of location search In order to do this, it is to provide a three-dimensional parameter measuring apparatus and method for obtaining three-dimensional parameters including the center of corneal curvature by searching eight upper, lower, left and right marks attached to the demo lens of the spectacle frame and two reflection points of the pupil.

Another problem to be solved by the present invention is that the installation and use of the ruler is simple, the accuracy is higher, and when it is necessary to prescribe a prism power to a customer with a sagittal or strabismus, a lens prescription that can measure right and left monocular PD It is to provide a three-dimensional parameter measuring apparatus and method for

In order to solve the above problems, the present invention provides a three-dimensional (3D) lens prescription using a ruler positioned on the subject's forehead, a camera for photographing the left and right face images of the subject, and the ruler's image from the image taken from the camera. In the three-dimensional parameter measuring device comprising a calculation processing unit for detecting parameters, the central part of the ruler has a QR code unit with a QR code attached, and the calculation processing unit scans the QR code from the left and right face images received from the camera. It is characterized in that the three-dimensional parameters including the horizontal (A) length and the vertical length (B) of the spectacle frame are detected by using the coordinate system set by the QR code as the common coordinate system.

The QR code has four points: an origin, a first point, a second point, and a third point, the origin is a point on the left side of the top of the QR code, and the first point is a point on the right side of the top of the QR code, A line connecting the origin and the first point indicates the X-axis, the second point is a point on the left side of the bottom of the QR code, and the line connecting the origin and the second point indicates the Y-axis, and the third point is the origin and the second point in the QR code. It is a single point located in places other than the 1st point and the 2nd point.

The third point may be a point on the right side of the bottom of the QR code.

The ruler is a band positioned above the eyebrow from one eyebrow to the other eyebrow of the examinee, and a band above the eyebrow for mounting the QR code unit in the center; It is provided on both left and right sides under the band above the eyebrows, and consists of a front leg part positioned in front of the spectacle lens and a rear leg part positioned at the rear side of the spectacle lens, and configured to sandwich the spectacle lens between the front leg part and the rear leg part , a clip portion; may be included.

The ruler may be one equipped with a QR code in the center of the forehead band mounted on the frontal lobe. The surface of the QR code is the surface that can be adjusted vertically and is perpendicular to the subject's gaze.

A camera that takes a right face image of the subject is a first camera, a coordinate system parallel to the sensor surface of the first camera is a first coordinate system, and a camera that takes an image of the left face of the subject is a second camera, The second coordinate system parallel to the sensor surface of the camera is used as the second coordinate system, and the calculation processing unit calculates the vertical distance (L) from the QR code unit to the camera in the first coordinate system.

(However, the coordinates of the first point in the first coordinate system are (x' ₁ , y' ₁ , 0), and the coordinates of the second point in the first coordinate system are (x' ₂ , y' ₂ , 0) , the coordinates of the third point in the first coordinate system are (x' ₃ , y' ₃ , 0) , and the center (center) coordinates of the camera in the first coordinate system are (x' _s , y' _s , -sL) Lim)

is saved by

where s is

is obtained using

Let the coordinates (x ₃ , y ₃ , z ₃ ) of the third point be (αd, αd, 0) as the common coordinate system, and the coordinates (x ₁ , y ₁ , z ₁ ) of the first point to the common coordinate system (d , 0, 0), and when the coordinates of the second point (x ₂ , y ₂ , z ₂ ) are (0,d,0) in the common coordinate system, the Euler transformation angle (ψ,φ,θ) is

am.

The Euler transformation angle of the coordinates (x ₃ , y ₃ , z _{3 ) of the third point is}

, and the Euler transformation angle of the coordinates (x ₁ , y ₁ , z _{1 ) of the first point is}

, and the Euler transformation angle of the coordinates (x ₂ , y ₂ , z _{2 ) of the second point is}

am.

The coordinates of the points b, c, d, and e, which are the coordinates of the b, c, d, and e points along the lens frame of one side of the eyeglass frame (X _b , Y _b , Z _b ), the coordinates of the point c (X _c , Yc, Zc), the coordinates of the point d (X _d , Y _d , Z _d ), the coordinates of the point e (X _e , Y _e , Z _e ), and the other side of the eyeglass frame along the lens frame of the other side When we have the coordinates of the point f, the coordinates of the point f (X _f , Y _f , Z _f ), the vertical length (B) of the frame is

is saved by

The bridge length (DBL) is

is saved by

The width of the frame (A) and the face angle of the frame (FFA) are

is saved by

The pantascopic angle (PA, the vertical tilt angle of the frame) is

is obtained using

The point (x' ₁ , y' ₁ , 0) of the extension line passing through the center (center) point of the camera lens on the left and the bright point (a' _{1 ) reflected by the preset left camera flash is a point (} X ₁₀ , Y ₁₀ , Z ₁₀ ), and the center (center) coordinates (x' _1s , y' _1s , -L ₁ ) of the left camera are converted to common coordinates (X _1s , Y _1s , Z _1s ) The point on the left camera lens reflected by the camera flash (x' _1s + D, y' _1s , -L ₁ ) is converted into common coordinates (X _1l , Y _1l , Z _1l ), and the point (X ₁₀ , Y ₁₀ , Z ₁₀ ) and the point (X _1s , Y _1s , Z _1s ) When the coordinates of a point on the straight line are (X ₁ , Y ₁ , Z ₁ ), the point (X ₁ , Y _{1 )} , Z ₁ ) and the point (X1s , Y _1s , Z _1s ), the unit vector (a1) of the straight line is

Is to obtain a result, point _{(X 1, Y 1, Z} 1) and the point (X _{1l, 1l} Y, Z _1l) unit vector (b1) of a straight line connecting the

It is to obtain a result, point _{(X 1, Y 1, Z} 1) and the points _{(X1s, Y 1s, Z 1s} ) unit vector (a1) of the straight line connecting, the point _{(X 1, Y 1, Z} 1) The unit vector (c1) that divides the unit vector (b1) of the straight line connecting the point (X _1l , Y _1l , Z _{1l ) by the same angle is}

is saved by

Point _{(X 1, Y 1, Z} 1) went by the vector c ₁ parallel to a straight line l ₁ is the

(r ₁ is a variable representing a straight line and is a real number)

am.

The point (x' ₂ , y' ₂ , 0) of the extension line passing through the center (center) point of the right camera lens and the bright point (a' ₂ ) reflected by the preset right camera flash is a common coordinate point ( X ₂₀ , Y ₂₀ , Z ₂₀ ), and the center (center) point coordinates (x' _2s , y' _2s , -L ₂ ) of the right camera are common coordinates (X _2s , Y _2s , Z _2s ) , and the point on the right camera lens reflected by the camera flash (x' _2s + D, y' _2s , -L ₂ ) is converted into common coordinates (X _2l , Y _2l , Z _2l ), and the point ( When the coordinates of one of the straight lines connecting _{X 20} , Y ₂₀ , Z ₂₀ ) and the points (X _2s , Y _2s , Z _{2s ) are (X 2} , Y ₂ , Z ₂ ), the point (X ₂ , Y ₂ , Z ₂ ) and a straight line vector (a2) connecting the points (X _2s , Y _2s , Z _{2s ) is}

Is to obtain a result, point _{(X 2, Y 2, Z} 2) and the point (X _{2l, 2l} Y, Z _2l) linear vector (b2) for connecting the

Is to obtain a result, point _{(X 2, Y 2, Z} 2) and that the linear vector (a2) connecting the _{(X 2s, Y 2s, Z} 2s), point _{(X 2, Y 2, Z} 2) and The unit vector (c2) that divides the straight line vector (b2) connecting the points (X _2l , Y _2l , Z _{2l ) into equal angles is}

is saved by

_{The straight line l 2 passing through the bright point (a' 2} ) reflected by the right camera flash and parallel to the vector c2 is

(However, r ₂ is a variable representing a straight line and is a real number).

Straight lines l ₁ and the straight line distance center point corneal curvature is that the minimum between l _2, r ₁ and going to change the r ₂ to obtain the r ₁ and r ₂ that minimizes the distance between the two straight lines, a straight line l ₁ and the line Find _{the intersection of l 2} to find the center of corneal curvature and corneal curvature.

The _{same value of r 1} and r ₂ has a value (r), and _{the values of Z 1} and Z ₂ are positive in the interval,

Find the coordinates of (X ₁ , Y ₁ , Z ₁ ) and (X ₂ , Y ₂ , Z ₂ ) points that satisfy , and obtain the center of corneal curvature.

The length from the center of rotation of both eyes to the center of corneal curvature is the same, the ruler origin is located at the exact center between the pupils, the distance gaze coincides with the Z-axis, and the vertical and horizontal prisms move the eye up and down and left and right around the center of rotation. Assuming rotation and compensating for UpDown prism and InOut prism, the coordinates of the center of corneal curvature in the left eye distance scan are

(However, in the left eye distance scan, the coordinates of the center of corneal curvature are (x ₁ ', y ₁ ', z ₁ '), and the coordinates of the center of rotation are (x ₁ , y ₁ , z ₁ ), and the center point of corneal curvature (x ₁ ') , y ₁ ', z ₁ ') to the center of rotation (x ₁ , y ₁ , z ₁ ) is l ₁ , UpDown prism-related rotation angle is θud, InOut prism-related rotation angle is θio)

is saved by

Compensating for the UpDown prism and InOut prism, the coordinates of the center of rotation of the corneal curvature in the right eye distance scan are

(However, in the distance scan of the right eye, the center point of corneal curvature coordinates is (x ₂ ', y ₂ ', z ₂ '), the rotation center point coordinates are (x ₂ , y ₂ , z ₂ ), and the center point of corneal curvature (x ₂ ') , y ₂ ', z ₂ ') to the rotation center point (x ₂ , y ₂ , z ₂ ) is l ₂ , UpDown prism-related rotation angle is θ'ud, InOut prism-related rotation angle is θ'io Lim)

is saved by

As the dominant eye, the pupil rotation angle (θa) is

를(only,

cast

로 치환한 것임)

replaced by )

is saved by

The horizontal distance (VCD) from the vertex of the back of the lens to the apex of the pupil is the vertex of the left and right corneas in each of the left and right facial images, respectively, at point v ₁ Let the point v ₂ be the first sphere formed by b, c, d, e, which are four points on the upper, lower, left and right sides of the left eyeglass frame, and the second sphere formed by f, g, h, i, which are four points, upper, lower, left, and right of the right eyeglass frame. The vertical distance in the z-axis direction from the point v ₁ to the first sphere is obtained as the VCD value of the left eye, and the vertical distance in the z-axis direction _{from the point v 2} to the second sphere is obtained as the VCD value of the right eye.

EH _L using d(X _d , Y _d , Z _d ) and point g1 (x _g1 , y _g1 , z _{g1 )} (eye height) value is

is saved by

The u-value (u _L ) and v-value (v _L ) of the left frame are

is saved by

Near left PD (LPD_N) and near right PD (RPD_N) are

is saved by

In addition, the present invention is located on the subject's forehead, the central portion of the QR code is attached to the ruler; A calculation processing unit that detects a QR code from the left and right face images of the subject and detects three-dimensional parameters including the horizontal (A) and vertical length (B) of the spectacle frame using the coordinate system set by the QR code as the common coordinate system; includes; In the driving method of a three-dimensional parameter measuring device, the calculation processing unit receives the left and right images of the photographed face, recognizes a QR code among the received images, and obtains the QR code coordinates, a QR code coordinate search step; After the QR code coordinate search step, 8 upper, lower, left and right marks (b,c,d,e points and f,g,h,i points) of the frame set by the user (inspector) and 2 reflection points of the pupil (point a) ' ₁ , point a' ₂ ) receiving the calculation processing unit, the upper and lower left and right marks of the frame and the reflection point setting value receiving step of the pupil; After receiving the set value of the upper and lower left and right marks of the frame and the reflection point of the pupil, the calculation processing unit is the shooting distance of the left and right images from the mark position of the QR code, that is, from the QR code unit to each camera in each of the first and second coordinate systems. calculating the vertical distance of the left and right images from the QR code; After the step of calculating the shooting distance of the left and right images from the QR code, the calculation processing unit Euler transformation angle between the coordinate system parallel to the camera sensor plane and the coordinate plane parallel to the ruler QR code plane in each of the first coordinate system and the second coordinate system Obtaining , Euler rotation angle calculation step; characterized in that it is made including.

The driving method of the three-dimensional parameter measuring device includes, after the Euler rotation angle calculation step, the arithmetic processing unit including the coordinates of the first point and the coordinates of the second point included in the QR code, the Euler transformation angle of the coordinates of the third point, A matrix element calculation step for converting to a common coordinate system, calculating a matrix element to be converted into a common coordinate system of the QR code surface; After the matrix element calculation step for transformation into the common coordinate system, the operation processing unit obtains the actual three-dimensional coordinates in the common coordinate system of the eight upper, lower, left, and right marks of the frame, the actual three-dimensional coordinate calculation step of the upper, lower, left, and right marks of the frame; further including is done

The driving method of the three-dimensional parameter measuring device is that the calculation processing unit uses the coordinate system obtained in the actual three-dimensional coordinate calculation step of the upper, lower, left, and right marks of the frame to obtain A, B, DBL, PA, FFA, and A, B, DBL and Calculating PA and FFA; further comprising.

After the step of calculating A and B, DBL, PA and FFA, the driving method of the three-dimensional parameter measuring device uses a line connecting the reflection point of the pupil of the left and right eyes and the sensor center point of the camera of each coordinate system to the calculation processing unit obtaining the center of corneal curvature, obtaining the center of corneal curvature; further including

In the driving method of the three-dimensional parameter measuring device, after the step of obtaining the center of corneal curvature, the operation processing unit determines whether a prism prescription value has been received, and if the prism prescription value is received, resets the coordinates of the center of corneal curvature ( S200). resetting the coordinates of the center of corneal curvature; further including

In the driving method of the three-dimensional parameter measuring device, the calculation processing unit calculates LPD, RPD, PD, u, v, VCD, EH using the corneal curvature coordinates, LPD, RPD, PD, u, v, VCD and EH step; further including

According to the apparatus and method for measuring a three-dimensional parameter using a QR code for prescription for spectacle lenses of the present invention, a band-type ruler equipped with a QR code in the center is mounted on the forehead, the left and right images are taken, and the QR code is obtained from the photographed image. The code coordinates are automatically searched, and the three-dimensional parameters including the center of corneal curvature are obtained by searching for 8 upper, lower, left and right marks of the eyeglass frame and two reflection points of the pupil.

According to the present invention, the installation and use of the ruler is simple, the accuracy is higher, and when it is necessary to prescribe a prism power to a customer with a son-in-law or strabismus, the right and left monocular PD can be measured, and the price can be made relatively inexpensively. have. In addition, the present invention can be used as a single camera in some cases.

The present invention is applied to a customized glasses prescription system, and by measuring and providing customer variables necessary for prescribing customized glasses at an optician's office, progressive lenses for presbyopia correction, special glasses lenses for high astigmatism and strabismus correction, and wearable mobile It dramatically improves the accuracy of prescription for custom spectacle lenses, such as Google Glass, which is a device, and provides various contents to help select lens options such as lens coating conditions.

1 is a ruler using a QR code according to an embodiment of the present invention.
FIG. 2 is a side view of the ruler of FIG. 1 ;
3 is an explanatory diagram schematically illustrating the configuration of a three-dimensional parameter measuring apparatus using a QR code of the present invention.
FIG. 4 is an explanatory diagram for explaining the coordinate system of FIG. 3 .
5 is an image taken while wearing the ruler of FIG. 1 .
6 is a ruler using a QR code according to another embodiment of the present invention.
FIG. 7 is an example of the ruler of FIG. 6 .
8 is an image taken with the ruler of FIG. 6 mounted.
9 is an explanatory diagram for explaining the recognition of the QR code unit 130 in the present invention.
10 is an explanatory diagram for explaining a method of detecting the vertical distance (L) from the QR code unit 130 to the camera in the first coordinate system.
11 is an explanatory diagram for explaining points of a frame of a spectacle frame for calculation of A and B values.
12 is a diagram illustrating a bright point reflected by a camera flash.
13 is an explanatory diagram for explaining a method for obtaining a center of corneal curvature from a distance gaze.
_{14 is a point P(X 1} , Y ₁ , Z by changing the t value in the equation of a straight line connecting the points (X ₁₀ , Y ₁₀ , Z ₁₀ ) and the points (X _1s , Y _1s , Z _{1s ) 1} ) is a diagram showing.
15 is a view showing the gaze state of the left eye far-sighted.
16 is a diagram illustrating a gaze state of a right eye far-sighted.
17 shows the left and right eyes in a state in which the face is turned to the left and the pupil is rotated to the opposite side as the dominant eye.
18 is an explanatory diagram for explaining a sphere passing through four points in a three-dimensional space.
Fig. 19 is an explanatory diagram for explaining the binocular interpupillary distance (PD) on the left and right of the near field.
20 is a flowchart schematically illustrating a three-dimensional parameter measurement method using a QR code of the present invention in an operation processing unit.
21 is a schematic diagram for explaining the eight marks mounted on the upper and lower left and right of the spectacle frame.

Hereinafter, the configuration and operation of a three-dimensional parameter measuring apparatus and method using a QR code according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a ruler using a QR code according to an embodiment of the present invention, FIG. 2 is a side view of the ruler of FIG. 1, and the ruler 100 is an eyebrow band 110, a QR code unit 130, and a clip unit. (190) is included.

The band on the eyebrows 110 is a band positioned from one eyebrow to the other eyebrow, and is a means for mounting the QR code unit 130 in the center. It can be used as a length scale by having marks 113 at both ends, and in some cases, the marks 113 can be omitted.

The QR code unit 130 has three points, and provides an origin, an X-axis, and a Y-axis.

The clip part 190 includes a front leg part 193 positioned in front of the spectacle lens and a rear leg part 195 positioned at the rear of the spectacle lens, so that the spectacle frame, that is, the spectacle lens, is connected to the front leg part 193 and the eyeglass lens. It is made to be sandwiched between the rear leg parts 195 . Clip parts 190 are positioned on the left and right sides of the band 110 above the eyebrows.

3 is an explanatory diagram for schematically explaining the configuration of a three-dimensional parameter measuring apparatus using a QR code of the present invention, and FIG. 4 is an explanatory diagram for explaining the coordinate system of FIG. 3 .

As shown in FIG. 3 , two cameras, that is, a first camera 10 and a second camera 20 are provided to photograph the left and right sides. 3 shows that two cameras are used for convenience, this may be used by sequentially photographing the left and right sides with one camera.

That is, one of the left and right sides is photographed with the first camera 10 , the other side of the left and right sides is photographed with the second camera 20 , and the photographed image is transmitted to the calculation processing unit 30 and three-dimensional parameters for lens prescription save

4A is a first coordinate system, which is a coordinate system parallel to the sensor surface of the first camera 10 . That is, it is the coordinate system of the image photographed by the first camera 10 .

4B is a second coordinate system, which is a coordinate system parallel to the sensor surface of the second camera 20 . That is, it is the coordinate system of the image photographed by the second camera 20 . In (c) of FIG. 4, O represents a central point.

Figure 4 (c) is a common coordinate system, that is, a (X, Y, Z) coordinate system, a coordinate system based on the mark of the QR code. That is, it is the coordinate system of the image seen with the eyes of the actual customer.

The (X, Y, Z) coordinate system is positioned so that the first coordinate system, the second coordinate system, and the origin coincide, and the (X, Y, Z) coordinate system is based on the QR code mark. All coordinates are calculated in the (X,Y,Z) coordinate system. Here, the direction perpendicular to the QR code plane is the Z-axis.

5 is an image taken while wearing the ruler of FIG. 1 .

FIG. 5A is a face image of one of the left and right sides of the subject (customer) photographed by the first camera 10, and is referred to herein as the first image for convenience.

In FIG. 5B , the face image of the other one of the left and right sides of the subject photographed by the second camera 20 is referred to as a second image for convenience.

As shown in Figure 5, since the origin of the present invention is determined in the QR code, the origin of the image itself has a predetermined distance from the X-axis and the Y-axis. That is, in FIG. 5 , the center of the first image is (x' _1s , y' _1s , 0), and the center of the second image is (x' _2s , y' _2s , 0).

When using the QR code as a reference ruler, the reference coordinate system is a fixed coordinate system that connects the center of the outer rectangle of the QR code. and the direction entering the image direction is the Z-axis direction.

Fig. 6 is a ruler using a QR code according to another embodiment of the present invention, Fig. 7 is an example of the ruler of Fig. 6, and Fig. 8 is an image taken with the ruler of Fig. 6 mounted.

The ruler 100 of FIG. 6 includes a forehead band 120 and a QR code unit 130 .

The forehead band 120 is a band mounted on the frontal lobe, and is a means for mounting the QR code unit 130 in the center. It can be used as a length scale by providing a plurality of marks 123 of the through hole type, and in some cases the marks 123 can be omitted.

Since the QR code unit 130 is the same as that of FIG. 1 , a description thereof will be omitted.

Fig. 7(a) is an example of the ruler of Fig. 6, Fig. 7(b) is a rear view of the ruler of Fig. 7, and Fig. 7(c) is a side view of the ruler of Fig. 7 .

As in FIG. 7 , the QR code unit 130 has a QR code 137 attached to the upper surface of the QR code supporting unit 134 , and the column unit 139 is a forehead band on the bottom of the QR code supporting unit 134 . It is configured to be inserted into and fixed to the column insertion part 129 in the center of the 120 . By having the pillar portion 139, as a predetermined distance is spaced between the QR code unit 130 and the forehead band 120, the angle of the QR code surface can be adjusted up and down.

8A is a first image, that is, a face image of one of the left and right sides of the subject (customer) photographed by the first camera 10 .

8 (b) is a second image, that is, a face image of the other side of the left and right sides of the subject photographed by the second camera 20 .

Next, a method of detecting the vertical distance L from the QR code unit 130 to each camera in the first coordinate system and the second coordinate system in the operation processing unit will be described.

9 is an explanatory diagram for explaining the recognition of the QR code unit 130 in the present invention, and FIG. 10 is a method of detecting the vertical distance (L) from the QR code unit 130 to the camera in the first coordinate system. It is an explanatory diagram.

Fig. 9 (a) is a diagram showing a point used in a QR code.

9(b) is a diagram for explaining the X-axis and Y-axis indicated by points in the QR code.

In Figure 9 (a), the QR code has an origin, a first point (P1), a second point (P2), and a third point (P3).

The origin is the point on the left side of the top of the QR code, based on this point. It can be expressed as the coordinates of the origin (x ₀ , y ₀ , z _{0 ).}

The first point P1 is a point on the right side of the upper part of the QR code, that is, the x-axis square mark of the QR code. The coordinates (x ₁ , y ₁ , z ₁ ) of the first point P1 are coordinates of the center of the x-axis square mark of the QR code.

The second point P2 is a point on the left side of the bottom of the QR code, that is, the y-axis square mark of the QR code. The coordinates (x ₂ , y ₂ , z ₂ ) of the second point P2 are the y-axis square mark center coordinates of the QR code.

The third point (P3) is shown as a point on the right side of the bottom of the QR code in FIG. ), it can be anywhere on the QR code except for the origin, the first point (P1), and the second point (P2). It may be expressed as _{coordinates (x 3} , y ₃ , z ₃ ) of the third point P3 .

From the position where the first point P1 is captured on the two-dimensional image plane to the actual camera, that is, the three-dimensional coordinates (x ₁ , y ₁ , z ₁ ) of the first point P1 in the common coordinate system and the first It can be assumed that the coordinates (x' ₁ , y' ₁ , 0) in the coordinate system have the same image point. The coordinates of the origin of the first coordinate system may be (x' ₀ , y' ₀ , 0).

From the position where the second point P2 is captured on the two-dimensional image plane to the actual camera, that is, the three-dimensional coordinates (x ₂ , y ₂ , z ₂ ) of the second point P2 in the common coordinate system and the first It can be assumed that coordinates (x' ₂ , y' ₂ , 0) in the coordinate system have the same image point.

From the position where the third point P3 is captured on the two-dimensional image plane to the actual camera, that is, the coordinates (x ₃ , y ₃ , z ₃ ) of the third point P3 in the common coordinate system and the first coordinate system It can be assumed that the coordinates of (x' ₃ , y' ₃ , 0) have the same image point.

As in FIG. 10, the coordinates of the first point P1, that is _{, a line passing through (x 1} , y ₁ , z ₁ ) and (x' ₁ , y' ₁ , 0), and the second point P2 A line passing through the coordinates, ie (x ₂ , y ₂ , z ₂ ) and (x' ₂ , y' ₂ , 0), and the coordinates of the third point P3 , ie (x ₃ , y ₃ , z _{3 )} The point where the line passing through ) and (x' ₃ , y' ₃ , 0) meets is the center (center) coordinate of the camera in the first coordinate system, and the center (center) coordinate of the camera is (x' _s , y' _s) , -sL).

Each coordinate value is expressed in pixels of the camera, and s is a coefficient indicating how many millimeters one pixel of an image actually corresponds to. s is a value stored by photographing and measuring an image in advance according to the distance with a camera at the beginning of use of this three-dimensional parameter measuring device or at the beginning of inspection.

The equation of the straight line connecting the point (x' ₁ , y' ₁ , 0) and the point (x' _s , y' _s , -sL) is the same as Equation 1.

Here, t is a variable representing a straight line and is a real number.

_{The condition for the point (x 1} , y ₁ , z ₁ ) to exist on the straight line formed by the equation of the straight line is the same as in Equation 2.

'represents a _1, y ₁ to y' to x _1, x represents ₁ as equation (3).

The length from the origin to the point (x ₁ , y ₁ , z ₁ ) is the same as d, which is the distance between points of the actual QR code (mark), and is expressed as an equation, x ₁ and y obtained in Equation 3 _{Substituting 1} gives Equation 4.

_{Since there are innumerable pairs of (z 1} , L, s) satisfying Equation 4, a desired solution of L cannot be obtained only by the above conditions. To get the (z ₁ , L, s) pair solution, use the information about the other points on the ruler (x ₂ , y ₂ , z _{2 ) as follows:}

The equation of the straight line connecting the point (x' ₂ , y' ₂ , 0) and the point (x' _s , y' _s , -sL) is as shown in Equation 5.

_{The condition for the point (x 2} , y ₂ , z ₂ ) to exist on the straight line formed by the equation of this straight line is the same as in Equation (6).

'represents a _2, a y ₂ y' to x ₂ x ₂ it represents the same as equation (7).

In the same way, the straight line connecting _{(x' s} ,y' _s , -sL ) and the point (x' ₃ , y' ₃ ,0) must pass through _{(x 3} ,y ₃ ,z _{3 ),} It is expressed as Equation 8.

When x ₃ is represented by x ₁ and x _{2 , y 3} is represented by y ₁ and y ₂ , and z ₃ is represented by z ₁ and z ₂ , (x ₃ ,y ₃ ,z ₃ ) is the same as Equation 9.

α is a number indicating the position of the 3rd point (3rd point) of the QR code (mark), the length from the origin to the 1st QR code point (1st point) and the It is the ratio of the X-coordinate size values.

Here, if x ₁ , x ₂ , and x ₃ are replaced with the above expressions (refer to Equations 3, 7 and 8) expressed as x' ₁ , x' ₂ , x' _{3 , x 3} , y ₃ , z ₃ is It is obtained as in Equation 10.

Summarizing this, Equation 11 is obtained.

Substituting z ₃ (refer to Equation 10) in the above equations gives Equation 12.

Equation 12 is rearranged, and _{z 1} is obtained and applied from the formula (refer to Equation 3) representing _{x 1} as x' ₁ , and z1 is obtained and applied from the formula (refer to Equation 3) representing _{y 1} as y' ₁ So, rearranging it, Equation 13 is the same.

Arranged in this way, as a result, it can be expressed as Equation (14).

Equation 4 obtained above is as follows.

And by the same method as in Equation 4, _{the length from the origin to the point (x 2} , y ₂ , z ₂ ) is the same as the distance d between the points of the actual QR code, which is expressed by the equation, and in Equation 7 Substituting the obtained x ₂ and y ₂ , it becomes as in Equation 15.

Equation 16 is obtained by substituting _{x 2} and y ₂ obtained in Equation 7 into Equation 15 to obtain _{z 2} .

In Equation 16, a part was substituted with B, and B is as follows.

(x ₁ , y ₁ , z ₁ ) and (x ₂ , y ₂ , z ₂ ) are perpendicular to each other, as in Equation 17.

In Equation 17, a part was substituted with A. That is, the vectors (x ₁ , y ₁ z ₁ ) and (x ₂ y ₂ z ₂ ) are perpendicular, A=x ₁ x ₂ +y ₁ y ₂ am.

_{Equation 18 is obtained by substituting z 2} obtained in Equation 16 into Equation 17 to summarize.

Z ₁ ² using the equation (14) in the z ₂ / z ₁ sL and / sL and, equation (18) to obtain the z ₁ z ₂ is obtained.

Then, s is obtained using Equation 4 below.

Then, L is obtained using Equation 14 below.

And, using the s and L obtained above, the coordinates of three points excluding the origin of the QR code (x ₁ , y ₁ , z ₁ ), (x ₂ , y ₂ , z ₂ ) and (x ₃ , y ₃ , z ₃ ) is found.

The photographing distances L' and s' are obtained from the images photographed in the other direction in which the second coordinate system is set using the same method.

The following describes a method of converting the coordinates on the QR code of the first coordinate system and the second coordinate system into the coordinate system (X, Y, Z) set in the QR code, that is, the common coordinate system.

Obtain the Euler transformation angle between the coordinate system parallel to the camera sensor plane and the coordinate plane parallel to the QR code plane of the ruler.

The third point P3 is a small rectangular mark as shown in (a) of FIG. 9 , and the coordinates (x ₃ , y ₃ , z ₃ ) of the third point P3 are small rectangular mark coordinates. It is (αd, αd, 0) in the common coordinate system (ie the (X,Y,Z) coordinate system). That is, (x ₃ , y ₃ , z ₃ ) is (αd, αd, O) in the common coordinate system.

The first point P1 is an x-axis end mark as shown in (a) of FIG. 9 , and the coordinates (x ₁ , y ₁ , z ₁ ) of the first point P1 are the x-axis end mark coordinates. It is (d,0,0) in the common coordinate system (ie the (X,Y,Z) coordinate system). That is, (x ₁ , y ₁ , z ₁ ) is (d,0,0) in the common coordinate system.

The second point P2 is the y-axis end mark as shown in FIG. 9A , and the coordinates (x ₂ , y ₂ , z ₂ ) of the second point P2 are the x-axis end mark coordinates. It is (0,d,0) in the common coordinate system (ie the (X,Y,Z) coordinate system). That is, (x ₂ , y ₂ , z ₂ ) is (0,d,0) in the common coordinate system.

A coordinate transformation matrix T (y-axis: θ, x-axis: ψ, y-axis: φ) from a predetermined (x, y, z) coordinate system to a common coordinate system, ie, (X, Y, Z) coordinate system, is as follows.

That is, it represents the coordinate transformation matrix T (rotates about the y-axis, rotates about the x-axis, rotates about the y-axis) from the (x, y, z) coordinate system to the (X, Y, Z) coordinate system. . Here, the (x,y,z) coordinate system refers to the coordinate system formed by the cameras.

Using this, the Euler transformation angle of the coordinates (x ₃ , y ₃ , z ₃ ) of the third point P3 is obtained as shown in Equation 19.

Equation 20 is obtained when the Euler transformation angle of the coordinates (x ₁ , y ₁ , z _{1 ) of the first point P1 is obtained.}

Equation 21 is obtained when the Euler transformation angle of the coordinates (x ₂ , y ₂ , z _{2 ) of the second point P2 is obtained.}

Here, θ, ψ, and φ are the same as in Equation 22.

This is the Euler transformation angle between the coordinate system parallel to the camera sensor plane and the coordinate plane parallel to the ruler plane for the right camera. For the left camera, the same equation is developed to obtain the Euler transformation angle between the coordinate system parallel to the camera sensor plane and the coordinate plane parallel to the ruler plane.

The following describes how to detect A/B, DBL, FFA, and PA values in the operation processing unit.

11 is an explanatory diagram for explaining points of a frame of a spectacle frame for calculation of A and B values.

In order to measure the A/B value, 4 points b, c, d, e are taken along the lens frame on one side of the spectacle frame as in the image of FIG. 11 . Obtain the coordinate values of each point transformed into a common coordinate system (X, Y, Z) fixed on the QR code plane. If you take a straight line from the zoom center of the two cameras to each point and get the point of intersection, the coordinates of that point become 3D real coordinates. Marks can be affixed or printed on the demo lens of the frame to specify the exact position.

The coordinates of the b,c,d,e points obtained along the lens frame on one side of the frame, that is, the coordinates of the point b (X _b , Y _b , Z _b ), the coordinates of the point c (X _c , Yc, Zc), The coordinates of the point d (X _d , Y _d , Z _d ), the coordinates of the point e (X _e , Y _e , Z _e ), and the coordinates of the point f obtained along the lens frame of the other side of the eyeglass frame, that is, the point f Set the coordinates of (X _f , Y _f , Z _f ).

B is a numerical value indicating the width of the spectacle frame, A is a numerical value indicating the length of the spectacle frame. Reference) .

A value of B indicating the vertical length of the frame is expressed in Equation 23.

The bridge length DBL is expressed by Equation (24).

The horizontal length A of the frame and the facial angle FFA of the frame are the same as in Equation 25.

The pantascopic angle (PA) is expressed by Equation 26.

Next, a method for calculating the center of curvature of the distant gaze from the calculation processing unit will be described.

12 is a diagram illustrating a bright point reflected by a camera flash, FIG. 13 is an explanatory diagram illustrating a method for obtaining the center of curvature of the far gaze, and FIG. 14 is a point (X ₁₀ , Y ₁₀ , Z ₁₀ ) and a point (X _1s , Y _1s , Z _1s ) It is a diagram showing a point according to changing the t value in the equation of the straight line connecting.

Point a' represents the bright point reflected by the camera flash. _{That is, points a' 1} , a' ₂ in FIGS. 12 and 13 . represents the bright spot reflected by the camera flash.

The red line in FIG. 13 , that is, a straight line between the camera and the flash, is a straight line perpendicular to the corneal curvature considering the reflection at _{points a' 1} and a' _{2 .}

In addition, in FIG. 13 , the Z (ruler coordinate) axis direction represents a direction perpendicular to the QR code plane, O represents the rotation center point, O'(Xo, Yo, Zo) represents the corneal curvature center point, and V'(Xo) , Yo, Zo - r) represents the corneal apex, and r represents the center of corneal curvature.

_{A 10} '(x' ₁ , y' ₁ , 0), which is the point of the extension line passing through the center (center) point of the camera lens on the left and the point a' _{1 , is a 10} '(X) as a common coordinate using the Euler matrix obtained earlier. ₁₀ , Y ₁₀ , Z _{10 ), and a 20} '(x' ₂ , y' ₂ , 0), which is the point of the extension line passing through the center (center) point of the right camera lens and point a' _{2 , is a common coordinate.} a ₂₀ '(X ₂₀ , Y ₂₀ , Z ₂₀ ), and the center (center) coordinate S'(x' _1s , y' _1s , -L ₁ ) of the camera on the left is the common coordinate S'(X _{1s )} , Y _1s , Z _{1s ), and P'(x' 1s} + D, y' _1s , -L ₁ ), which is a point on the left camera lens reflected by the camera flash, is a common coordinate P'(X _1l , Y _1l , Z _1l ), and the center (center) coordinate S'(x' _2s , y' _2s , -L ₂ ) of the right camera lens is the common coordinate S'(X _2s , Y _2s , Z _2s ) _{P'(x' 2s} + D, y' _2s , -L ₂ ), which is a point on the right camera lens reflected by the camera flash, is converted _{to P'(X 2l} , Y _2l , Z _2l ) as a common coordinate. do.

13, H'(x' _1s + D/2, y' _1s , -L ₁ ) is P'(x' _1s + D, y' _1s , -L ₁ ) and S'(X _1s , Y _1s , Z _1s ), H'(x' _2s + D/2, y' _2s , -L ₂ ) is P'(x' _2s + D, y' _2s , -L ₂ ) and S'(x ' _2s , y' _2s , -L ₂ ).

The equation of the straight line connecting the points (X ₁₀ , Y ₁₀ , Z ₁₀ ) and the points (X _1s , Y _1s , Z _{1s ) is as shown in Equation 27.}

Here, it is possible to assume the coordinates of a point on a straight line while changing the t value.

If the coordinates of one of them are (X ₁ , Y ₁ , Z ₁ ), it can be expressed as shown in FIG. 14 .

A unit vector of a straight line connecting the points P(X ₁ , Y ₁ , Z ₁ ) and the points (X1s , Y _1s , Z _{1s ) is expressed by Equation 28.}

A unit vector of a straight line connecting the points (X ₁ , Y ₁ , Z ₁ ) and the points (X _1l , Y _1l , Z _{1l ) is expressed by Equation 29.}

A unit vector dividing two straight line vectors by the same angle is expressed by Equation (30).

A straight line l ₁ passing through the point P and _{parallel to the vector c 1} is expressed in Equation 31.

where r ₁ is the variable of the straight line and is a real number.

The same process is repeated for the image by the second camera.

A straight line vector connecting the points (X ₂ , Y ₂ , Z ₂ ) and the points (X _2s , Y _2s , Z _2s ) is expressed by Equation 32.

A straight line vector connecting the points (X ₂ , Y ₂ , Z ₂ ) and the points (X _2l , Y _2l , Z _2l ) is expressed in Equation 33.

A unit vector dividing two straight line vectors by the same angle is expressed in Equation 34.

_{A straight line l 2} passing through the point a ₂ and parallel to the vector c2 passes through the center of corneal curvature, as in Equation 35.

where r ₂ is the variable of the straight line and is a real number.

The point where the length between the straight line l ₁ and the straight line l ₂ is the minimum is the center of corneal curvature. Therefore, while changing r1 and r2, find r1 and r2 where the distance between the two straight lines is the minimum, and find the intersection point to find the center of corneal curvature and the corneal curvature. At this time, assuming that the cornea is 球, ideally r1 and r2 values should be the same, the value is the curvature of the cornea, and the vector in Equation 36 represents the center of corneal curvature.

Putting this together, we get Equation 37.

The coordinates of _{(X 1} , Y ₁ , Z ₁ ) and (X ₂ , Y ₂ , Z ₂ ) points satisfying Equation 37 are found.

In this case, the search interval must be a positive interval in which the values _{of Z 1} and Z _{2 are positive.}

The following describes the process of searching for the pupil rotation center point in the calculation processing unit.

For this, the following assumptions are required.

First, the length from the center of rotation of both eyes to the center of corneal curvature is the same.

Second, the ruler origin is located in the middle between the pupils.

Third, the distant gaze coincides with the Z-axis.

Fourth, the vertical and horizontal prisms rotate the eyeball vertically and horizontally around the center of rotation.

Under this assumption, the pupil rotation center point search process is as follows.

UpDown prism-related center of corneal curvature coordinate detection step. For UpDown prisms of the left and right eyes, compensated center coordinates of corneal curvature are obtained when prescribing it.

In the step of detecting the center coordinates of the corneal curvature related to the InOut prism, the center coordinates of the corneal curvature compensated when prescribing the InOut prisms of the left and right eyes are obtained.

In the step of detecting the center coordinates of the eye-related corneal curvature rotated to the dominant eye, finally, the center coordinates of the corneal curvature are obtained for the eye rotated to the dominant eye for the left and right eyes.

Through these three steps, the center of rotation is obtained with the compensated corneal curvature coordinates.

15 is a view showing the gaze state of the left eye at a distance, FIG. 16 is a view showing the gaze state of the right eye at a distance, and FIG. indicates.

15 and 16, θud is the UpDown prism-related rotation angle, that is, the angle of the pupil rotated by the strabismus corresponding to the BASE UP/DOWN prism, and θio is the InOut prism-related rotation angle, that is, the BASE IN/OUT prism. It is the angle of the pupil rotated by the strabismus corresponding to the prism. In addition, θa is the angle of the pupil in which the gaze direction is fixed and returned by the rotation of the face by the left and right eyes in addition to the rotation angle (θio) of the pupil due to the strabismus corresponding to the BASE IN/OUT prism.

In the distance gaze of the left eye of FIG. 15 _{, a line (l) from the center of corneal curvature (x 1} ', y ₁ ', z ₁ ') to the center of rotation (x ₁ , y ₁ , z ₁ ) and the center of rotation (x ₁₎ , y ₁ , z ₁ ), the angle of the pupil returned by the strabismus corresponding to the UpDown prism (θud) and the angle of the pupil returned by the strabismus corresponding to the InOut prism (θio) are located between the lines parallel to the x-axis. do. As a result, if the UpDown prism and the InOut prism are compensated, the coordinates of the center of corneal curvature as in Equation 38 are obtained.

In the same way, if the UpDown prism and the InOut prism are compensated for in the distance scan of the right eye of FIG. 16 , the coordinates of the center of corneal curvature as in Equation 39 are obtained.

As such, it is necessary to consider the case where the prism is compensated but the dominant eye, that is, (as the dominant eye, the face is turned to the left and the pupil is rotated to the opposite side.

in Figure 17. The plane PA is a reference plane perpendicular to the line segment passing through the vertical center point of the QR code plane and connecting the centers of corneal curvature of the two eyes. The distance from point A, which is the intersection of the line segment connecting the center of corneal curvature to the center of curvature, is not the same as the eyeball is rotated.

In FIG. 17 , r is the corneal curvature, R is the distance from the tip of the cornea to the center of rotation, and l is the distance from the center of the cornea to the center of rotation.

Here, R = (39.23-1.976*r)/2.0 and l=R-r.

Considering the rotation angle of the pupil as the dominant eye, that is, the angle θa of the pupil where the gaze direction is fixed and returned as the face is rotated by the dominant eye, Equations 38 and 39 are rearranged, as in Equation 40 And, assuming that the lengths from the center of rotation of both eyes to the center of corneal curvature are the same, the rotation angle θa of the pupil is calculated as the dominant eye.

However, in the above, B and C are substituted as follows.

Also, the maximum distance between the points of the QR code is 22.764999 mm.

Here, the sign of the prism is based on the left and right sides of the image, not the actual left and right of the subject.

In general, in BaseUp prism, θud and θud' have negative values, and in BaseDown prism, θud and θ ud' have positive values.

In general, in a BaseIn prism, θio' of the left eye has a positive value, and θio of the right eye has a negative value. Also, in the BaseOut prism, θ io' of the left eye has a negative value, and θio of the right eye has a positive value.

The following describes the process of calculating the vertex-cornea distance (VCD) in the operation processing unit. That is, the process of obtaining the horizontal distance (VCD) from the vertex of the rear surface of the lens to the vertex of the pupil will be described.

Points v ₁ and v ₂ represent the vertices of the left and right corneas in each image. In the QR code common coordinate system (X, Y, Z), the vertex coordinates of the cornea are as shown in Equation 41.

The vertical distance in the z-axis direction from the points v ₁ and v ₂ to the two spheres formed by the four points b, c, d, e and f, g, h, i in space becomes the VCD value in the left and right eyes, respectively. That is, the sphere (S1) formed by b, c, d, e, and the sphere (S2) formed by f, g, h, i become the spectacle lens surface, and two spheres from the corneal apex v1 and v2 obtained earlier The distance to the intersection point along the Z axis to (S1 and S2) is called the left and right eye VCD.

It is assumed that the points where the two straight lines intersect the sphere are _{called g 1} and g ₂ , respectively, and have the following coordinates.

For the two spheres formed by b,c,d,e and f,g,h,i, a sphere passing through 4 points in 3D space is obtained, and g ₁ , g ₂ coordinates are obtained from the obtained sphere to obtain the VCD value. can be obtained

Here, the sphere passing through 4 points in 3D space can be obtained by the method posted in PRECISION POINT. (Reference: http://www.jpe.nl/downloads/Fit-sphere-through-points.pdf #search='Fit+sphere+through+4+data')

A sphere passing through 4 points in 3D space will be briefly described.

18 is an explanatory diagram for explaining a sphere passing through four points in a three-dimensional space.

If the center (center) coordinates of the sphere are (x _c , y _c , z _c ) and the radius of the sphere is R, the equation of the z(x,y) plane is as follows.

Here, the data points can be said to be

By applying the center coordinates and radius of the sphere, it is as follows.

Here, if ^{the value of R 2} is close to 1, it indicates that it is closer to the sphere.

The following describes the calculation process of EH (eye height) and u/v in the calculation processing unit.

EH (eye height) is obtained by using the point d(X _d , Y _d , Z _d ) and the point g1 (xg1', yg1, zg1), as in Equation 42, the EH _L value of the left frame can be obtained.

The u and v values of the left frame are the same as in Equation 43, and u/v values can be obtained using them.

The following describes the short-distance left and right PD calculation process in the operation processing unit.

Fig. 19 is an explanatory diagram for explaining the binocular interpupillary distance (PD) on the left and right of the near field.

Using 35cm as the reading distance, obtain the coordinates of the gaze passing through the frame, which is rotated around the circle point obtained from the front end (i.e., the pupil rotation center point). is calculated as in Equation 44.

Here, LPD_F is the distance pupil distance of the left eye, VCD_L is the distance from the corneal apex of the left eye to the lens, and RC_L is the distance from the corneal apex to the center of rotation.

The following describes the overall process of obtaining the three-dimensional parameter measurement method using the QR code of the present invention in the operation processing unit.

20 is a flowchart schematically illustrating a three-dimensional parameter measurement method using a QR code of the present invention in an operation processing unit.

In the QR code coordinate search step, in the QR code coordinate search step, the operation processing unit 30 receives the left and right images of the photographed face (S110), recognizes the QR code among the received images, and obtains the QR code coordinates (S120) ). Here, QR code recognition can also use pattern recognition.

In the stage of receiving the set value of the upper, lower, left and right marks of the frame and the reflection point of the pupil, 8 upper, lower, left and right marks of the frame (ie, b,c,d,e and f,g,h,i points) and 2 reflection points of the pupil (ie, points a' ₁ , a' ₂ ) can be set by the user on the display screen (ie, GUI), and 8 upper, lower, left, and right marks of the set frame and two reflection points of the pupil are received from the calculation processing unit 30 ( S130).

In the step of calculating the shooting distance of the left and right images from the QR code, the shooting distance of the left and right images from the mark position of the QR code, that is, the vertical distance from the QR code unit 130 to each camera in the first coordinate system and the second coordinate system (L ) is calculated (S140). That is, L is obtained using Equation 14.

In the Euler rotation angle calculation step, the Euler rotation angle from each camera coordinate system to the common coordinate system is calculated (S150). That is, the Euler transformation angle is obtained between the coordinate plane parallel to the camera sensor plane and the coordinate plane parallel to the ruler QR code plane. That is, the Euler transform angle is obtained using Equation (22).

As a matrix element calculation step for transformation into a common coordinate system, a matrix element to be transformed into a common coordinate system of the QR code surface is calculated (S160). That is, the Euler transformation angle of the coordinates (x1, y1, z1) of the first point (P1), the coordinates (x2, y2, z2) of the second point (P2), and the third point (P3) are calculated using Equation 20, Math It is obtained using Equation 21, etc.

In the step of calculating the actual three-dimensional coordinates of the upper, lower, left, and right marks of the frame, the actual three-dimensional coordinates in the common coordinate system of the eight upper, lower, left, and right marks of the frame are obtained (S170). In other words, the coordinates of each point converted to the common coordinate system (X, Y, Z) fixed to the QR code plane are also eight upper, lower, left, and right marks (i.e., b,c,d,e and f,g,h,i points). get the value That is, if a straight line is taken from the zoom center of the two cameras to each point and the intersection is obtained, the coordinates of that point become 3D real coordinates.

In the step of calculating A, B, DBL, PA, FFA, the length and angle of A, B, DBL, PA, FFA are obtained using the coordinate system obtained in the actual three-dimensional coordinate calculation step of the upper, lower, left, and right marks of the frame (S180) ). That is, they are obtained using Equations 23 to 26.

In the step of obtaining the center of corneal curvature, the center of corneal curvature is obtained using a line connecting the bright point of the pupil of the left and right eyes and the center point of the sensor of each camera (S190). That is, the coordinates of _{(X 1} , Y ₁ , Z ₁ ) and (X ₂ , Y ₂ , Z ₂ ) points satisfying Equation 37 are found.

In the prism prescription value reception determination step, it is determined whether the prism prescription value has been received. If the prism prescription value is received, that is, if there is a prism prescription value for the left and right eyes of the subject (customer), the coordinates of the center of the corneal curvature are reset (S200). That is, in the step of detecting the center of corneal curvature related to the UpDown prism, the coordinates of the center of corneal curvature compensated when prescribing it for the UpDown prisms of the left and right eyes are obtained, and in the step of detecting the center of corneal curvature related to the InOut prism, the InOut prisms of the left and right eyes When prescribing this, the coordinates of the center of corneal curvature compensated are obtained, and in the step of detecting the center coordinates of the eye-related corneal curvature rotated to the dominant eye, finally, the center coordinates of the corneal curvature are obtained for the eye rotated to the dominant eye for the left and right eyes. This is calculated using Equation 38, Equation 39, and Equation 40.

In the LPD, RPD, PD, u, v, VCD, EH operation step, LPD, RPD, PD, u, v, VCD, and EH are obtained with the corneal curvature coordinates (S220). That is, it is obtained using Equation 42, Equation 43, and the like.

In the foregoing, the present invention has been shown and described with respect to certain preferred embodiments. However, the present invention is not limited to the above-described embodiments, and those of ordinary skill in the art to which the present invention pertains can make various changes without departing from the spirit of the present invention described in the claims below. will be able to carry out

10: first camera 20: second camera
30: arithmetic processing unit 93: front leg part
95: rear leg part 100: ruler
110: band on the eyebrows 113: mark
120: forehead band 123: hole-shaped mark
129: column insert 130: QR code part
134: QR code support part 137: QR code on the upper surface
139: pillar portion 190: clip portion

Claims (33)

A ruler positioned on the subject's forehead, a camera for photographing the subject's face image, and an arithmetic processing unit for detecting a three-dimensional parameter for lens prescription using the image of the ruler from the image photographed from the camera; A dimensional parameter measuring device comprising:
At the center of the ruler, a mark having four points of origin, first point, second point, and third point is provided,
The calculation processing unit detects the position of the mark in the left and right face images received from the camera,
It is made to detect a three-dimensional parameter including the vertical length (B) of the spectacle frame by using the coordinate system set by the mark as a common coordinate system,
The mark is a QR code, and the part of the ruler including the mark is called a QR code part, and the origin is a point on the left side of the upper part of the QR code, and the first point is a point on the right side of the upper part of the QR code. A line connected by 1 point represents the X axis of the common coordinate system, and the second point is a point on the left side of the bottom of the QR code. It is a single point located in places other than the origin, the first point, the second point, and the third point,
Let the camera that takes the image of the left face of the subject as the first camera, the camera as the first camera, and the coordinate system parallel to the sensor surface of the first camera as the first coordinate system,
A camera that takes a right face image of the subject is a second camera, and a coordinate system parallel to the sensor surface of the second camera is used as a second coordinate system,
Let the coordinates of the third point (x ₃ , y ₃ , z ₃ ) be (αd, αd, 0) in the common coordinate system,
The coordinates of the first point (x ₁ , y ₁ , z ₁ ) are (d, 0, 0) in the common coordinate system,
The coordinates of the second point (x ₂ , y ₂ , z ₂ ) are (0, d, 0) in the common coordinate system,
α is a number indicating the position of the third point, and is the ratio of the length from the origin to the first point and the value of the X-coordinate size of the third point,
When d is the distance between points within the mark
Euler transformation angles (ψ, φ, θ) are

A three-dimensional parameter measuring device, characterized in that. delete delete The method of claim 1, wherein the ruler
a band located above the eyebrow from one eyebrow to the other eyebrow of the examinee, the band above the eyebrow allowing the mark to be placed in the center;
It is provided on both left and right sides under the band above the eyebrows, and consists of a front leg part positioned in front of the spectacle lens and a rear leg part positioned at the rear side of the spectacle lens, and configured to sandwich the spectacle lens between the front leg part and the rear leg part , clip part;
A three-dimensional parameter measuring device, characterized in that it comprises a. delete According to claim 1,
The calculation processing unit calculates the vertical distance (L) from the mark to the camera in the first or second coordinate system.

(However, the coordinates of the first point in the first coordinate system are (x' ₁ , y' ₁ , 0), and the coordinates of the second point in the first coordinate system are (x' ₂ , y' ₂ , 0) , the coordinates of the third point in the first coordinate system are (x' ₃ , y' ₃ , 0) , and the center (center) coordinates of the camera in the first coordinate system are (x' _s , y' _s , -sL) , and s is a coefficient indicating how many millimeters one pixel of an image actually corresponds to, and it is a value obtained by taking an image according to the distance with a camera at the beginning of use or at the beginning of inspection, and measuring how many mm one image pixel actually corresponds to)
A three-dimensional parameter measuring device, characterized in that obtained by 7. The method of claim 6,
s is

(However, d is the distance between points within the mark)
A three-dimensional parameter measuring device, characterized in that it is obtained using delete 7. The method of claim 6,
The Euler transformation angle of the coordinates (x ₃ , y ₃ , z _{3 ) of the third point is}

ego,
The Euler transformation angle of the coordinates (x ₁ , y ₁ , z _{1 ) of the first point is}

ego,
The Euler transformation angle of the coordinates of the second point (x ₂ , y ₂ , z _{2 ) is}

A three-dimensional parameter measuring device, characterized in that. 10. The method of claim 9,
The coordinates of the points b, c, d, and e, which are the coordinates of the b, c, d, and e points along the lens frame of one side of the eyeglass frame (X _b , Y _b , Z _b ), the coordinates of the point c (X _c , Yc, Zc), the coordinates of the point d (X _d , Y _d , Z _d ), the coordinates of the point e (X _e , Y _e , Z _e ), and the other side of the eyeglass frame along the lens frame of the other side The coordinates of the f point, (X _f , Y _f , Z _f ) allow the subject to find the coordinate value of the same point in the left and right images taken by attaching an identification mark on the demo lens of the frame worn by the subject, Using the coordinate values of the same point on the image, the vertical length of the frame (B), the horizontal length of the frame (A), the bridge length (DBL), the facial angle (FFA), and the vertical inclination angle (PA) of the eyeglass frame are calculated. A three-dimensional parameter measuring device. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete a ruler positioned on the subject's forehead and attached with a QR code in the center; 3D parameter including; In the method of driving a measuring device,
The operation processing unit receives the left and right images of the photographed face, recognizes the QR code among the received images, and obtains the QR code coordinates, a QR code coordinate search step;
After the QR code coordinate search step, 8 upper, lower, left and right marks (b,c,d,e points and f,g,h,i points) of the frame set by the user (inspector) and 2 reflection points of the pupil (point a) ' ₁ , point a' ₂ ) receiving the calculation processing unit, the upper and lower left and right marks of the frame and the reflection point setting value receiving step of the pupil;
After receiving the set value of the upper and lower left and right marks of the frame and the reflection point of the pupil, the calculation processing unit is the shooting distance of the left and right images from the mark position of the QR code, that is, from the QR code unit to each camera in each of the first and second coordinate systems. calculating the vertical distance of the left and right images from the QR code;
After the step of calculating the shooting distance of the left and right images from the QR code, the calculation processing unit Euler transformation angle between the coordinate system parallel to the camera sensor plane and the coordinate plane parallel to the ruler QR code plane in each of the first coordinate system and the second coordinate system Calculating Euler rotation angle to obtain ;
A method of driving a three-dimensional parameter measuring device, characterized in that it comprises a. 28. The method of claim 27,
After the Euler rotation angle calculation step, the operation processing unit converts the coordinates of the first point included in the QR code, the coordinates of the second point, and the Euler transformation angle of the coordinates of the third point to the common coordinate system of the QR code surface. (matrix element), a matrix element calculation step for transformation into a common coordinate system;
After the matrix element calculation step for transformation into the common coordinate system, the operation processing unit calculates the actual three-dimensional coordinates of the upper, lower, left, and right marks of the frame, in which the operation processing unit obtains the actual three-dimensional coordinates in the common coordinate system of the eight upper, lower, left, and right marks of the frame;
A method of driving a three-dimensional parameter measuring device, characterized in that it further comprises a. 29. The method of claim 28,
The calculation processing unit uses the coordinate system obtained in the actual three-dimensional coordinate calculation step of the upper, lower, left, and right marks of the eyeglass frame, the horizontal length of the eyeglass frame (A), the vertical length of the eyeglass frame (B), the bridge length (DBL), and the PA), calculating the facial angle (FFA), calculating A and B and DBL and PA and FFA;
A method of driving a three-dimensional parameter measuring device, characterized in that it further comprises a. 30. The method of claim 29,
After the step of calculating A and B, DBL, PA and FFA, the calculation processing unit calculates the center of corneal curvature, using a line connecting the reflection point of the pupil of the left and right eyes and the center point of the sensor of the camera in each coordinate system. obtaining;
A method of driving a three-dimensional parameter measuring device, characterized in that it further comprises a. 31. The method of claim 30,
After the step of obtaining the center of corneal curvature, the operation processing unit determines whether a prism prescription value has been received, and if the prism prescription value is received, resetting the coordinates of the center of corneal curvature, resetting the coordinates of the center of corneal curvature;
A method of driving a three-dimensional parameter measuring device, characterized in that it further comprises a. 32. The method of claim 31,
The calculation processing unit uses the corneal curvature coordinates to determine the distance from the center of the eyeglass frame to the left pupil (LPD), the distance from the center of the eyeglass frame to the right pupil (RPD), the pupillary distance of both eyes (PD), and the horizontal distance from the center of the eyeglass frame to the pupil. (u), the vertical distance from the center of the frame to the pupil (v), the horizontal distance from the apex of the back of the lens to the apex of the pupil (VCD), EH (eye height), LPD, RPD, PD, u, v, VCD, and EH operation step;
A method of driving a three-dimensional parameter measuring device, characterized in that it further comprises a. According to any one of claims 1, 4, 6, 7, 9, 10,
In order to obtain coordinates of points located on the top, bottom, left, and right along the lens frame of the spectacle frame, a three-dimensional parameter characterized in that marks are attached or printed on the top, bottom, left, and right of the demo lens mounted on the spectacle frame. Variable Measuring Device.

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