CN106950716A - A kind of method and system that ophthalmic len number of degrees measurement is carried out by mobile phone photograph - Google Patents

Abstract

The present invention relates to a kind of method and system that ophthalmic len number of degrees measurement is carried out by mobile phone photograph.Using two identical Marker, in shooting process, a Marker is allowed to be deformed by eyeglass, and another is without eyeglass, and the size before Marker is deformed and after deformation is so obtained simultaneously, and then calculating obtains lens relevant parameter.Advantages of the present invention is embodied in by designing specific data acquisition, a handling process, just with Smartphone device and mirror, is simplified related procedure, is completed the glasses optometry flow that can only complete in laboratory conditions.

Description

A kind of method and system that ophthalmic len number of degrees measurement is carried out by mobile phone photograph

Technical field

The present invention relates to a kind of glasses optometry technology, and in particular to a kind of to carry out ophthalmic len number of degrees measurement by mobile phone photograph Method and system.

Background technology

The optometry technology of glasses, is realized and completes by the accurate measurement of specialty optics equipment and instrument all the time 's.But since informationization technology revolution, one side shopping at network is popularized all the more, and the demand of online purchase glasses is also ready to appear, It is that can not obtain the optical parametric of glasses and user (does not possess optical device instrument) under the conventional environments such as family, office； On the other hand, as smart mobile phone is popularized all the more, the sensor of mobile phone is senior all the more, and (resolution ratio more and more higher, gyroscope is more next It is more accurate etc.), complete positioning using smart mobile phone, the technology of mapping also emerges in an endless stream, for example very hot reality increasing instantly Strong technology (AR), positions surveying ＆ mapping (SLAM) etc. in real time, and its essence is all the related sensor (shooting by smart mobile phone Head, gyroscope), complete positioning and measure.Everything, the technology that interest concessions smart mobile phone completes glasses optometry becomes possibility.

The content of the invention

The purpose of the present invention is to pass through mobile phone photograph there is provided one kind for deficiency of the prior art to carry out the ophthalmic len number of degrees The method and system of measurement, by designing specific data acquisition, a handling process, just with Smartphone device and one Face mirror, simplifies related procedure, completes the glasses optometry flow that can only complete in laboratory conditions.

To achieve the above object, the invention discloses following technical scheme：

A kind of method that ophthalmic len number of degrees measurement is carried out by mobile phone photograph, comprises the following steps：

S1 shows two Marker of size identical on smart mobile phone screen, be respectively labeled as Marker1 and Marker2；

The fixed mirror of S2 selection one sides；

S3 ophthalmic lens tightly touch mirror surfaces；

S4 utilizes the front camera of smart mobile phone, mobile phone and minute surface keeping parallelism, shoots an image, it is desirable on screen Marker mono- deformed by eyeglass, one does not pass through eyeglass；

Two Marker on S5 identification images, detect two Marker same place, Features1 and Features2 Same place is constituted to set, the position coordinate before corresponding deformation and after deformation, can thus obtain Marker and deform it respectively Size after preceding and deformation；

S6 calculates two Features according to the mapping relations between in Features1 and Features2 every a pair points The scaling and spin matrix M of set；

S7 calculates mobile phone apart from mirror image apart from D according to Features1；

S8 show that object distance u and mobile phone, apart from d, meet u+d=D, and u to lens according to mirror imaging principle =d；

S9 is according to formula

Calculate the diopter of spherical mirror；

In formula, S is the diopter of lens, equal to the inverse of the focal length of lens；S passes through lens imaging for subject with it Scaling of the dummy object on mobile phone photograph afterwards；F is the focal length of lens；U is thing for the distance of subject to lens Away from d is distance of the mobile phone camera to lens；

In the case where eyeglass has astigmatism, eyeglass has a spherical lens and a cylindrical lens synthesis, therefore image contracts The ratio of putting is divided into the scaling Sx and Sy of two axial directions, and that obtained after eyeglass is imaged is an oval Marker, Oval major and minor axis just represents the scaling of image on both axes, and the oval angle theta with horizontal level represents axle Position；The point after 4 groups of points pair, including original point and deformation is obtained to carry out parameter calculating, it is assumed that：

In formula, x, y are original point coordinates, and x ', y ' are the point coordinates after deformation, and M is 2*2 deformation matrix：

Then its characteristic value：

Wherein,

The characteristic value of Metzler matrix is to represent the deformation coefficient on two direction of principal axis, and the s in step S9 formula is equal to this herein In 1/ λ, when Δ calculated value be equal to 0 when, two characteristic values are equal, can calculate and obtain two related diopter numerical value, generation The table eyeglass only has myopia, without astigmatism；When Δ is less than 0, handled by Δ equal to 0；When Δ is more than 0, then it can obtain To two eigenvalue λs 1, λ 2, it can respectively be calculated according to formula in step S9 and obtain two diopters S1 and S2, then near-sighted SPH, Astigmatism CLY, axle position AXI computing formula is：

The further corrected parameters of S10：In view of we used mirror, thus actually Marker deformation be through After lens imaging twice, then correct myopia and astigmatism numerical value are the half of calculating gained numerical value in S9；The numerical value of axle position Keep constant.

The invention also discloses a kind of system that ophthalmic len number of degrees measurement is carried out by mobile phone photograph, including data acquisition mould Block, data processing module and data post-processing module：

Data acquisition module：

Data acquisition module obtains the Marker1 and Marker2 of smart mobile phone front camera collection image, and sends To data processing module；

Data processing module：

Data processing module identification image on two Marker, detect two Marker same place, Features1 and Features2 constitutes same place to set, and the position coordinate before corresponding deformation and after deformation, can thus be obtained respectively Size before Marker deformations and after deformation；

According to the mapping relations between in Features1 and Features2 every a pair points, two set of characteristic points are calculated Scaling and spin matrix M；

According to Features1, mobile phone is calculated apart from mirror image apart from D；

According to mirror imaging principle, show that object distance u and mobile phone, apart from d, meet u+d=D, and u=to lens d；

According to the two of deformation matrix characteristic values, and obtained object distance u and mobile phone are calculated to lens distance d, calculate To two diopters S1, S2；

According to S1 and S2 absolute values size, it is determined that locating after myopia SPH, astigmatism CLY and axle position AXI, and transmission to data Manage module；

Data Post module：

Due to having used mirror to be imaged, lens actually here are two ophthalmic len synthesis, therefore correctly Myopia and the half of astigmatism that myopia and astigmatism numerical value obtain for data processing module；Axle position keeps constant；Data Post mould The near-sighted value and astigmatism value that block is obtained to data processing module are handled, and value is myopia value and the 1/2 of astigmatism value.

A kind of method and system that ophthalmic len number of degrees measurement is carried out by mobile phone photograph disclosed by the invention, have with following Beneficial effect：

(1) present invention selection in shooting process, allows a Marker to be sent out by eyeglass using two identical Marker Change shape, and another is without eyeglass, and the size before Marker is deformed and after deformation is so obtained simultaneously, without Two pictures are shot (to take away glasses and shoot one, transmitted through glasses clap one again, during this, and the position and attitude of mobile phone is not It is evitable to change, the accuracy of measurement can be influenceed)；

(2) present invention is by by mirror, utilizing mirror image principle, on the one hand, utilize the mirror image of mobile phone screen Directly as Marker, Marker (mirror is relatively common), and hand are obtained by other modes such as printings without user Machine gauge size is relatively good to be obtained；On the other hand, object distance u and mobile phone can be obtained simultaneously away from distance from the lens d, it is to avoid multistep Operation.

Brief description of the drawings

Fig. 1 is lens imaging schematic diagram,

Fig. 2 is lens imaging and camera imaging schematic diagram,

Fig. 3 is that spherical mirror and cylindrical mirror scale schematic diagram,

Fig. 4 is mobile phone optometry flow chart,

Fig. 5 is relevant device schematic diagram,

Fig. 6 is mobile phone attitude verification side schematic view,

Fig. 7 is mobile phone attitude verification front schematic view,

Fig. 8 is to capture image side schematic view,

Fig. 9 is to capture image front schematic view,

Figure 10 is data processing module flow chart,

Figure 11 is to specify Marker area schematics.

Embodiment

The technical scheme in the embodiment of the present invention will be clearly and completely described below, it is clear that described implementation Example only a part of embodiment of the invention, rather than whole embodiments.Based on the embodiment in the present invention, this area is common The every other embodiment that technical staff is obtained under the premise of creative work is not made, belongs to the model that the present invention is protected Enclose.

Refer to Fig. 1.Glasses can be regarded as a thin lens, according to lens imaging principle, and the O points of lens represent lens Optical centre, A points are certain point in space, and A ' are its imaging after lens, and the distance of A points to lens is u (things Away from), the distance of A ' to lens is v (image distance), and the distance of F points to lens is f (focal length).According to two groups of similar triangles：

First：

Δ OAB~Δ OA ' B '

Obtain：

Have again simultaneously：

Δ FEO~Δ FA ' B '

Similarly obtain：

Formula (1) and formula (2) simultaneous are available：

Formula (4) is the general expression of lens imaging, from formula as can be seen that if it is known that object and lens it Between distance (object distance u), (image distance v) just can calculate the focal length (f) of lens with the distance between lens for imaging.

Therefore, primary and foremost purpose of the invention is that the survey of correlation distance (object distance, image distance) is completed by Smartphone device Amount, and its related image-forming principle, as shown in Figure 2.

Point C is photo centre (position of mobile phone camera), apart from the focal length that fx is camera, is arrived apart from d for photo centre The distance of lens, point A1 is imaging of the A points on mobile phone, and point A2 is A ' imagings on mobile phone, then similarly according to similar Triangle Principle：

First,

ΔO′CA2、ΔB′CA′

Obtain：

And because,

30′CA1、ΔBCA

Obtain：

Formula (5) and formula (6) simultaneous are obtained：

Order

Then have：

Had again according to formula (4)：

Formula (7) is substituted into, can be obtained：

Formula (8) is the general expression that glasses relevant parameter is obtained using smart mobile phone, wherein, s is subject Body and its dummy object after lens imaging, the scaling on mobile phone photograph, u is distance of the subject to lens (object distance), d is distance of the mobile phone camera to lens.

As can be seen that the key for carrying out glasses optometry with smart mobile phone be obtain image scaling ratio s, object distance u and Mobile phone is away from distance from the lens.

Therefore image scaling ratio be divided into two axial directions scaling Sx and Sy it is as shown in Figure 3.

Circle in figure represents Marker original shape, and what (sphere+cylinder) was obtained after eyeglass is imaged is One oval Marker, wherein：

Oval major and minor axis just represents the scaling of image on both axes, and the oval angle theta with horizontal level Represent axle position, it is however generally that, it would be desirable at least 4 groups points carry out the meter of relevant parameter to (original point, the point after deformation) Calculate, it is assumed that：

X is original point, and X ' represents the point after deformation, and M is 2*2 deformation matrix:

Then its characteristic value：

Wherein：

The characteristic value of Metzler matrix is to represent the deformation coefficient on two direction of principal axis, and the s in step S9 formula is equal to this herein In 1/ λ, when Δ calculated value be equal to 0 when, two characteristic values are equal, can calculate and obtain two related diopter numerical value, generation The table eyeglass only has myopia, without astigmatism；When Δ is less than 0, handled by Δ equal to 0；When Δ is more than 0, then it can obtain To two eigenvalue λs 1, λ 2, it can respectively be calculated according to formula in step S9 and obtain two diopters S1 and S2, then near-sighted SPH, Astigmatism CLY, axle position AXI computing formula is：

In view of we used mirror, thus actually Marker deformation be by lens imaging twice, So correct myopia and astigmatism numerical value are the half of calculating gained numerical value in S9；The numerical value of axle position keeps constant.

In order to complete the acquisition of above-mentioned parameter, the present invention devises a kind of by mobile phone photograph progress ophthalmic len number of degrees measurement System, including data acquisition module, data processing module and data post-processing module：

Data acquisition module：

Data acquisition module obtains the Marker1 and Marker2 of smart mobile phone front camera collection image, and sends To data processing module；

Data processing module：

Data processing module identification image on two Marker, detect two Marker same place, Features1 and Features2 constitutes same place to set, and the position coordinate before corresponding deformation and after deformation, can thus be obtained respectively Size before Marker deformations and after deformation；

According to the mapping relations between in Features1 and Features2 every a pair points, two set of characteristic points are calculated Scaling and spin matrix M；

According to Features1, mobile phone is calculated apart from mirror image apart from D；

According to mirror imaging principle, show that object distance u and mobile phone, apart from d, meet u+d=D, and u=to lens d；

According to the two of deformation matrix characteristic values, and obtained object distance u and mobile phone are calculated to lens distance d, calculate To two diopters S1, S2；

According to S1 and S2 absolute values size, it is determined that locating after myopia SPH, astigmatism CLY and axle position AXI, and transmission to data Manage module；

Data Post module：

Due to having used mirror to be imaged, lens actually here are two ophthalmic len synthesis, therefore correctly Myopia and the half of astigmatism that myopia and astigmatism numerical value obtain for data processing module；Axle position keeps constant；Data Post mould The near-sighted value and astigmatism value that block is obtained to data processing module are handled, and value is myopia value and the 1/2 of astigmatism value.

Actual mechanical process of the present invention is as shown in Figure 4：

1. input, be the equipment for needing in actual mechanical process to use, including smart mobile phone, need optometry glasses, with And mirror, as shown in Figure 5；

2. mobile phone is tightly touched into mirror plane, remains stationary state presses mobile phone volume key, records the appearance of current phone State information, as shown in Figure 6, Figure 7；

3. glasses have two eyeglasses, it is contemplated that the size of mobile phone screen, and the present invention is divided into two repeat step measurement left and right Eyeglass, after being fully completed, into step 9.；

4. the eyeglass of glasses is tightly touched into mirror plane, as shown in Figure 8, Figure 9；

5. the distance of the general temple of mobile phone displacement minute surface, then constantly adjusts the attitude of mobile phone；

6. when the attitude of mobile phone attitude and step 2. middle record is consistent, and image meets the front schematic view in Fig. 9, enters 5. 7. step, otherwise, continue step；

7. current image is captured；

8. resolved data, is shown in Figure 10 data processing module flows, into step 3. in detail；

9. output result

Data processing module flow is as shown in Figure 10：

1. input data is, the image that mobile phone is captured；

2. mirror-reflection is considered, in the case where environment is complicated, None- identified Marker situation occurs, on image Two Marker region is specified, as shown in figure 11；

3. respectively according to Marker regions, Marker1 and Marker2 is recognized；

4. by Marker1 and Marker2 corresponding relation, deformation matrix is calculated using formula (9)；

5. by Marker2, correlation distance is calculated using formula (6)；

6. correlation formula (8) (10) is utilized, (11) (12), (13) calculate relevant parameter；

7. output result.

Compared to the content introduced in background technology, present invention selection uses two identical Marker, in shooting process, A Marker is allowed to be deformed by eyeglass, and another is without eyeglass, so while before obtaining Marker deformations With the size after deformation, without shoot two pictures (take away glasses shoot one, transmitted through glasses clap one again, this During, the position and attitude of mobile phone inevitably changes, and can influence the accuracy of measurement)；

The present invention is by by mirror, utilizing mirror image principle, on the one hand, direct using the mirror image of mobile phone screen As Marker, Marker (mirror is relatively common), and Mobile phone type are obtained by other modes such as printings without user Number size is relatively good to be obtained；On the other hand, object distance u and mobile phone can be obtained simultaneously away from distance from the lens d, it is to avoid multistep behaviour Make.

The above is only the preferred embodiment of the present invention, rather than its limitations；Although it should be pointed out that with reference to above-mentioned each The present invention is described in detail embodiment, it will be understood by those within the art that, it still can be to above-mentioned each Technical scheme described in embodiment is modified, or carries out equivalent to which part or all technical characteristic；And this A little modifications and replacement, do not make the essence of corresponding technical scheme depart from the scope of various embodiments of the present invention technical scheme.

Claims (2)

1. a kind of method that ophthalmic len number of degrees measurement is carried out by mobile phone photograph, it is characterised in that comprise the following steps：

S1 shows two Marker of size identical on smart mobile phone screen, is respectively labeled as Marker1 and Marker2；

The fixed mirror of S2 selection one sides；

S3 ophthalmic lens tightly touch mirror surfaces；

S4 utilizes the front camera of smart mobile phone, mobile phone and minute surface keeping parallelism, shoots an image, it is desirable on screen Marker mono- is deformed by eyeglass, and one does not pass through eyeglass；

Two Marker on S5 identification images, detect two Marker same place, and Features1 and Features2 are constituted Same place is to set, the position coordinate before corresponding deformation and after deformation respectively, can thus obtain before Marker deformations and Size after deformation；

S6 calculates two Features set according to the mapping relations between in Features1 and Features2 every a pair points Scaling and spin matrix M；

S7 calculates mobile phone apart from mirror image apart from D according to Features1；

S8 show that object distance u and mobile phone, apart from d, meet u+d=D, and u=d to lens according to mirror imaging principle；

S9 is according to formula

$\frac{1}{f}=\left(1-s\right)*\frac{d+u}{d*u}$

Calculate the diopter of spherical mirror；

In formula, S is the diopter of lens, equal to the inverse of the focal length of lens；S is subject and its void after lens imaging Intend scaling of the object on mobile phone photograph；F is the focal length of lens；U is object distance, d for the distance of subject to lens For the distance of mobile phone camera to lens；

In the case where eyeglass has astigmatism, eyeglass has a spherical lens and a cylindrical lens synthesis, therefore image scaling ratio Example is divided into the scaling Sx and Sy of two axial directions, and that obtained after eyeglass is imaged is an oval Marker, oval Major and minor axis just represent the scaling of image on both axes, and the oval angle theta with horizontal level represents axle position；Obtain The point after 4 groups of points pair, including original point and deformation is taken to carry out parameter calculating, it is assumed that：

$\left[\begin{array}{c}{x}^{\′}\\ y^{\′}\end{array}\right]=M*\left[\begin{array}{c}x\\ y\end{array}\right]$

In formula, x, y are original point coordinates, and x ', y ' are the point coordinates after deformation, and M is 2*2 deformation matrix：

$M=\left[\begin{array}{cc}M00& M01\\ M10& M11\end{array}\right]$

Then its characteristic value：

$\mathrm{\λ}=\frac{tr\left(M\right)\±\sqrt{\mathrm{\Δ}}}{2}$

Wherein,

$\left\{\begin{array}{c}tr\left(M\right)=M00+M11\\ \det \left(M\right)=M00*M11-M01*M10\\ \mathrm{\Δ}=tr\left(M\right)*tr\left(M\right)-4*\det \left(M\right)\end{array}\right.$

The characteristic value of Metzler matrix is to represent the deformation coefficient on two direction of principal axis, and the s in step S9 formula is equal to here herein 1/ λ, when the calculated value of Δ is equal to 0, two characteristic values are equal, can calculate and obtain two related diopter numerical value, and representing should Eyeglass only has myopia, without astigmatism；When Δ is less than 0, handled by Δ equal to 0；When Δ is more than 0, then two can be obtained Individual eigenvalue λ 1, λ 2, can respectively calculate according to formula in step S9 and obtain two diopters S1 and S2, then near-sighted SPH, astigmatism CLY, axle position AXI computing formula is：

$SPH=\left\{\begin{array}{cc}S1& \left|S1\right|<\left|S2\right|\\ S2& \left|S2\right|<\left|S1\right|\end{array}\right.$

$CLY=\left\{\begin{array}{cc}S2-S1& \left|S1\right|<\left|S2\right|\\ S1-S2& \left|S2\right|<\left|S1\right|\end{array}\right.$

$AXI=\left\{\begin{array}{cc}a\tan \left(\frac{\mathrm{\&lambda;}1-M00}{M01}\right)& \left|S1\right|<\left|S2\right|\\ a\tan \left(\frac{\mathrm{\&lambda;}2-M00}{M01}\right)& \left|S2\right|<\left|S1\right|\end{array}\right.$

The further corrected parameters of S10：In view of we used mirror, therefore actually, Marker deformation is by two Secondary lens imaging, then correct myopia and astigmatism numerical value are the half of calculating gained numerical value in S9；The numerical value of axle position is kept It is constant.

2. a kind of system that ophthalmic len number of degrees measurement is carried out by mobile phone photograph, it is characterised in that including data acquisition module, number According to processing module and data post-processing module：

Data acquisition module：

Data acquisition module obtains the Marker1 and Marker2 of smart mobile phone front camera collection image, and sends to number According to processing module；

Data processing module：

Data processing module identification image on two Marker, detect two Marker same place, Features1 and Features2 constitutes same place to set, and the position coordinate before corresponding deformation and after deformation, can thus be obtained respectively Size before Marker deformations and after deformation；

According to the mapping relations between in Features1 and Features2 every a pair points, the contracting of two set of characteristic points is calculated Put and spin matrix M；

According to Features1, mobile phone is calculated apart from mirror image apart from D；

According to mirror imaging principle, show that object distance u and mobile phone, apart from d, meet u+d=D, and u=d to lens；

According to the two of deformation matrix characteristic values, and obtained object distance u and mobile phone are calculated to lens distance d, calculating obtains two Individual diopter S1, S2；

According to the size of S1 and S2 absolute values, it is determined that myopia SPH, astigmatism CLY and axle position AXI, and transmission is to Data Post mould Block；

Data Post module：

Due to having used mirror to be imaged, lens actually here are that two ophthalmic lens are synthesized, therefore correct myopia The myopia and the half of astigmatism obtained with astigmatism numerical value for data processing module；Axle position keeps constant；Data Post module pair The near-sighted value and astigmatism value that data processing module is obtained are handled, and value is myopia value and the 1/2 of astigmatism value.