CN107255903A - A kind of method that lens focus is measured based on Newton's ring - Google Patents
A kind of method that lens focus is measured based on Newton's ring Download PDFInfo
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- CN107255903A CN107255903A CN201710598937.7A CN201710598937A CN107255903A CN 107255903 A CN107255903 A CN 107255903A CN 201710598937 A CN201710598937 A CN 201710598937A CN 107255903 A CN107255903 A CN 107255903A
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- newton
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B43/00—Testing correct operation of photographic apparatus or parts thereof
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Abstract
The invention discloses a kind of method that lens focus is measured based on Newton's ring, light path including building automatic focusing, dispose focusing light source, Newton's ring film figure, focusing lens, camera lens, camera lens mounting seat successively from top to bottom on the same axis, prepare Newton's ring film figure, designed image Processing Algorithm.Newton's ring is searched by imaging is automatic by Newton's ring film G- Design algorithm, the definition evaluating of respective model is obtained for image processing algorithm, it is most articulation point that image processing algorithm, which calculates highest definition values,；Pass through Newton's ring film G- Design definition focusing algorithm, not only speed is fast, accuracy rate is high, and can be effective to the definition of various model camera lenses by the method carry out analysis judgement, improve production efficiency, product quality can more accurately be quantified by being applied on automatic focusing apparatus, have very high application value to improving factory products automation.
Description
Technical field
The present invention relates to lens focus focus technique field, more particularly to a kind of side that lens focus is measured based on Newton's ring
Method.
Background technology
Definition of the in the market at present to monitoring camera debugs main method or artificial using instrument progress manual focusing,
Differentiate definition using ad hoc approach, it is judged to be influenceed by workman's subjective factor, focusing position is not necessarily located in optimal clear
Point position, and whether the camera lens that is not easily distinguishable is qualified, traditionally the method to lens analysis is by modulation transfer function, MTF
As the characteristic curve that reaction shot is overall, it can weigh out for some images, MTF is reference value rather than complete
Portion, there is certain error in it, it is impossible to meet the upper high pass rate of production for the high-precision clear position for going to recognize camera lens
It is required that.
The content of the invention
It is an object of the invention to solve at least the above, and provide the advantage that at least will be described later.
It is luxuriant and rich with fragrance by Newton's ring it is a further object to provide a kind of method that lens focus is measured based on Newton's ring
Woods G- Design definition focusing algorithm, not only speed is fast, accuracy rate is high, and by the method to the clear of various model camera lenses
Degree can effectively carry out analysis judgement, improve production efficiency, being applied on automatic focusing apparatus more accurately to measure
Change product quality, have very high application value to improving factory products automation, with asking for solving to propose in above-mentioned background technology
Topic.
To achieve the above object, the present invention provides following technical scheme：A kind of side that lens focus is measured based on Newton's ring
Method,
Step 1, the light path for building automatic focusing：Dispose focusing light source, the Newton's ring film successively from top to bottom on the same axis
Figure, focusing lens, camera lens, camera lens mounting seat；
Step 2, prepare Newton's ring film figure：Using Newton's ring interference design film, Newton's ring film figure white line and
Visual field size and the resolution ratio of camera lens that the width of black line is imaged according to camera lens under teleconverter is designed, and circular is such as
Under：
Pixel resolution=visual field size（mm）/ number of pixels（pix）
Black line white line width and=broadside pixel resolution * 2；
Step 3, designed image Processing Algorithm：
General pattern is when reaching most articulation point, and boundary has obvious edge, and segmentation figure picture, Ran Houli are removed using this feature
Evaluating is provided with algorithm.
It is adapted to a variety of definition algorithms more commonly use, representative for the Newton's ring film figure of design, such as
It is can be applied to by following operator in Newton's ring film figure detection resolution.
（1）Gradient function
The Grad to image zooming-out both horizontally and vertically, defines image definition and is defined as follows respectively：
Form it is as follows：
Wherein：T is given edge detection threshold, and is the both horizontally and vertically volume of edge detection operator at pixel respectively
Product.
（2）Energy gradient function
Energy gradient function is defined as follows：
（3）Gray variance function
When being fully focused, image is most clear, and the high fdrequency component in image is also most, therefore can be evaluated grey scale change as focusing
Foundation, the formula of gray variance method is as follows：
Step 4, the Newton's ring film G- Design algorithm obtained by step 2 search Newton's ring by imaging is automatic, are obtained for step 3
To image processing algorithm obtain the definition evaluating of respective model, image processing algorithm calculates highest definition values
It is most articulation point；
Step 5, focusing environment under can calculate the definition values of center Newton's ring in real time manually or with mechanical rotation camera lens
And the definition values at four angles in edge, and record the relation of the most clear position of test center and marginal definition.
Preferably, the infrastructure device that the light path of automatic focusing is built in step 1 is automatic focusing apparatus, including workbench
Frame, control panel, focusing test zone, focusing test zone is realized by motor pacifies to focusing light source, focusing lens, camera lens
Fill seat is accurately positioned control, and is provided with the focus adjusting mechanism for adjusting focusing handwheel.
Preferably, the focusing lens used in step 1 is teleconverter, for the distance that can just see clearly under will be relatively remote
Shortened under teleconverter in short distance.
Preferably, the Newton's ring film figure in step 1 is close to focusing light source lower surface, and camera lens is positioned over camera lens installation
The upper surface center of seat.
Preferably, the Newton's ring film figure in step 2 is replaceable, and design customization is calculated according to actual.
Preferably, in the test process of step 5, optimal state is center and peripheral while reaching most clearly
Location point, actually because the reason such as manufacture craft edge and center are difficult while it is all most clearly location point, one to rest on
As the artificial main method in test process be that central sharp position reaches that edge reaches the definition model of permission to highest simultaneously
In enclosing.
The present invention at least includes following beneficial effect：
1st, the automatic debugging algorithm of definition is designed, quantifies the clear location criteria of focal length, can quickly be adjusted to definition position, and can
Effectively to distinguish qualified camera lens and unqualified camera lens；
2nd, using the diameter and Newton's ring black and white of the Newton's ring film figure of autonomous Design, including film center Newton's ring
The size of spacing, by Newton's ring film G- Design definition focusing algorithm, not only speed is fast, accuracy rate is high, and passes through this
Method can be effective to the definition of various model camera lenses carry out analysis judgement；
3rd, throughput dissolves corresponding resolution standard value, the problem of effectively avoiding lens articulation malposition, greatly
Production efficiency is improved greatly, product quality can more accurately be quantified by being applied on automatic focusing apparatus, to improving factory products
Automation has very high application value；
4th, the corresponding resolution standard value of different model camera lens can be provided, newton ring design is simple, and different model camera lens can be entered
Row analysis, adapts to model scope extensively, analysis result has higher matching degree with eye recognition definition.
Further advantage, target and the feature of the present invention embodies part by following explanation, and part will also be by this
The research and practice of invention and be understood by the person skilled in the art.
Brief description of the drawings
Fig. 1 is camera lens test Newton's ring film figure used；
Fig. 2 is automatic focusing application environment schematic diagram.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation is described, it is clear that described embodiment is only a part of embodiment of the invention, rather than whole embodiments.It is based on
Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not made
Embodiment, belongs to the scope of protection of the invention.
It should be appreciated that such as " having ", "comprising" and " comprising " term used herein are not precluded from one or many
The presence or addition of individual other elements or its combination.
Fig. 1-2 is referred to, the present invention provides a kind of technical scheme：A kind of method that lens focus is measured based on Newton's ring,
Step 1, the light path for building automatic focusing：Dispose focusing light source, the Newton's ring film successively from top to bottom on the same axis
Figure, focusing lens, camera lens, camera lens mounting seat, the infrastructure device for building the light path of automatic focusing are automatic focusing apparatus, including work
Make platform frame, control panel, focusing test zone, focusing test zone is realized to focusing light source, focusing lens, mirror by motor
Head mounting seat is accurately positioned control, and is provided with the focus adjusting mechanism for adjusting focusing handwheel, and focusing lens is teleconverter, use
The distance that can just see clearly under will be relatively remote is shortened in short distance under teleconverter, and Newton's ring film figure is close to focusing light
Source lower surface, camera lens is positioned over the upper surface center of camera lens mounting seat；
Step 2, prepare Newton's ring film figure：Film is designed using the interference of Newton's ring, Newton's ring film figure is replaceable,
The visual field that the width of the actual calculating design customization of foundation, Newton's ring film figure white line and black line is imaged according to camera lens under teleconverter
Size and the resolution ratio of camera lens are designed, and circular is as follows：
Pixel resolution=visual field size（mm）/ number of pixels（pix）
Black line white line width and=broadside pixel resolution * 2；
Step 3, designed image Processing Algorithm：
General pattern is when reaching most articulation point, and boundary has obvious edge, and segmentation figure picture, Ran Houli are removed using this feature
Evaluating is provided with algorithm.
It is adapted to a variety of definition algorithms more commonly use, representative for the Newton's ring film figure of design, such as
It is can be applied to by following operator in Newton's ring film figure detection resolution.
（1）Gradient function
The Grad to image zooming-out both horizontally and vertically, defines image definition and is defined as follows respectively：
Form it is as follows：
Wherein：T is given edge detection threshold, and is the both horizontally and vertically volume of edge detection operator at pixel respectively
Product.
（2）Energy gradient function
Energy gradient function is defined as follows：
（3）Gray variance function
When being fully focused, image is most clear, and the high fdrequency component in image is also most, therefore can be evaluated grey scale change as focusing
Foundation, the formula of gray variance method is as follows：
Step 4, the Newton's ring film G- Design algorithm obtained by step 2 search Newton's ring by imaging is automatic, are obtained for step 3
To image processing algorithm obtain the definition evaluating of respective model, image processing algorithm calculates highest definition values
It is most articulation point；
Step 5, focusing environment under can calculate the definition values of center Newton's ring in real time manually or with mechanical rotation camera lens
And the definition values at four angles in edge, in test process, optimal state is center and peripheral while reaching most clearly
Location point, actually because the reason such as manufacture craft edge and center are difficult while it is all most clearly location point, one to rest on
As the artificial main method in test process be that central sharp position reaches that edge reaches the definition model of permission to highest simultaneously
In enclosing, the relation of the record most clear position of test center and marginal definition.
The Primary regulation process of teleconverter is as follows：Gained 6mm resolution of lens is calculated according to resolution ratio under actual teleconverter
It is 0.18mm to test Newton's ring black line line width by 2560*1440, and white line line width is 0.22mm.Generally for the width of black line white line
Degree difference causes the probability very little of focusing position failure within 10%, same Newton's ring can be used to be tested.
The automatic debugging algorithm of definition is designed, quantifies the clear location criteria of focal length, can quickly be adjusted to definition position, and
Qualified camera lens and unqualified camera lens can be effectively distinguished, using the Newton's ring film figure of autonomous Design, including in film
The diameter of heart Newton's ring and the size of Newton's ring black and white spacing, are focused by Newton's ring film G- Design definition and calculated
Method, and specific measuring method is provided, analyzed in terms of gray scale, acutance, not only speed is fast, accuracy rate is high, Er Qietong
The carry out analysis judgement that the method can be effective to the definition of various model camera lenses is crossed, throughput dissolves corresponding definition
Standard value, the problem of effectively avoiding lens articulation malposition, substantially increases production efficiency, is applied to automatic tune
Product quality can more accurately be quantified in burnt equipment, have very high application value to improving factory products automation, can provide
The corresponding resolution standard value of different model camera lens, newton ring design is simple, different model camera lens can be analyzed, ecad
Number scope is wide, and analysis result has higher matching degree with eye recognition definition.
Although embodiment of the present invention is disclosed as above, it is not restricted in specification and embodiment listed
With it can be applied to various suitable the field of the invention completely, for those skilled in the art, for ability
For the those of ordinary skill in domain, these embodiments can be carried out without departing from the principles and spirit of the present invention many
Change, modification, replacement and modification are planted, therefore under the universal limited without departing substantially from claim and equivalency range, this hair
It is bright to be not limited to specific details and shown here as the legend with description.
Claims (6)
1. a kind of method that lens focus is measured based on Newton's ring, it is characterised in that comprise the following steps：
Step 1, the light path for building focusing：Dispose focusing light source, Newton's ring film figure successively from top to bottom on the same axis, adjust
Focus lens, by focusing lens, camera lens mounting seat；
Step 2, prepare Newton's ring film figure：Film is designed using the interference of Newton's ring, makes Newton's ring on camera lens
Imaging, has reached the limiting resolution of camera lens；The width of Newton's ring film figure white line and black line according to camera lens under teleconverter into
The visual field size of picture and the resolution ratio of camera lens are designed, and circular is as follows：
Pixel resolution=visual field size（mm）/ number of pixels（pix）
Black line white line width and=broadside pixel resolution * 2；
Step 3, designed image Processing Algorithm：
General pattern is when reaching most articulation point, and boundary has obvious edge, and segmentation figure picture, Ran Houli are removed using this feature
Evaluating is provided with algorithm；
It is adapted to a variety of definition algorithms more commonly use, representative for the Newton's ring film figure of design, such as passes through
Following operator can be applied in Newton's ring film figure detection resolution；
（1）Gradient function
The Grad to image zooming-out both horizontally and vertically, defines image definition and is defined as follows respectively：
Form it is as follows：
Wherein：T is given edge detection threshold, and is the both horizontally and vertically volume of edge detection operator at pixel respectively
Product；
（2）Energy gradient function
Energy gradient function is defined as follows：
（3）Gray variance function
When being fully focused, image is most clear, and the high fdrequency component in image is also most, therefore can be evaluated grey scale change as focusing
Foundation, the formula of gray variance method is as follows：
Step 4, the Newton's ring film G- Design algorithm obtained by step 2 search Newton's ring by imaging is automatic, are obtained for step 3
To image processing algorithm obtain the definition evaluating of respective model, image processing algorithm calculates highest definition values
It is most articulation point；
Step 5, focusing environment under can calculate the definition values of center Newton's ring in real time manually or with mechanical rotation camera lens
And the definition values at four angles in edge, and record the relation of the most clear position of test center and marginal definition.
2. a kind of method that lens focus is measured based on Newton's ring according to claim 1, it is characterised in that：In step 1
Build automatic focusing light path infrastructure device be automatic focusing apparatus, including worktable frame, control panel, focusing test section
Domain, focusing test zone is realized by motor and focusing light source, focusing lens, camera lens mounting seat is accurately positioned control, and set
It is equipped with the focus adjusting mechanism for adjusting focusing handwheel.
3. a kind of method that lens focus is measured based on Newton's ring according to claim 1, it is characterised in that：In step 1
The focusing lens used is teleconverter, and the distance for can just see clearly under will be relatively remote shortens to short distance under teleconverter
It is interior.
4. a kind of method that lens focus is measured based on Newton's ring according to claim 1, it is characterised in that：In step 1
Newton's ring film figure be close to focusing light source lower surface, camera lens is positioned over the upper surface center of camera lens mounting seat.
5. a kind of method that lens focus is measured based on Newton's ring according to claim 1, it is characterised in that：In step 2
Newton's ring film figure it is replaceable, calculate design customization according to actual.
6. a kind of method that lens focus is measured based on Newton's ring according to claim 1, it is characterised in that：In step 5
Test process in, optimal state is center and peripheral while most clearly location point is reached, actually due to making work
The reason such as skill edge and center be difficult while it is all most clearly location point to rest on, it is general artificial main in test process
Method is that central sharp position reaches that highest is reached in the range of the definition of permission at edge simultaneously.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108833770A (en) * | 2018-05-23 | 2018-11-16 | 释码融和（上海）信息科技有限公司 | Image definition calculation method, calculating equipment and focusing system for focusing |
| CN110009636A (en) * | 2019-05-13 | 2019-07-12 | 招商局重庆交通科研设计院有限公司 | A kind of varifocal vision detection system of the vcehicular tunnel of integrated form |
| CN110864880A (en) * | 2019-10-22 | 2020-03-06 | 歌尔股份有限公司 | DLP projector definition evaluation method and detection system thereof |
| CN111800579A (en) * | 2020-08-27 | 2020-10-20 | 杭州涂鸦信息技术有限公司 | Lens focusing method and system and related equipment |
| CN113810616A (en) * | 2021-09-27 | 2021-12-17 | 季华实验室 | Aperture focal length adjusting method, system, electronic device and storage medium |
| CN116256373A (en) * | 2023-05-15 | 2023-06-13 | 南京华视智能科技有限公司 | Perovskite battery film surface defect detection method |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108833770A (en) * | 2018-05-23 | 2018-11-16 | 释码融和（上海）信息科技有限公司 | Image definition calculation method, calculating equipment and focusing system for focusing |
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| CN110009636A (en) * | 2019-05-13 | 2019-07-12 | 招商局重庆交通科研设计院有限公司 | A kind of varifocal vision detection system of the vcehicular tunnel of integrated form |
| CN110864880A (en) * | 2019-10-22 | 2020-03-06 | 歌尔股份有限公司 | DLP projector definition evaluation method and detection system thereof |
| CN111800579A (en) * | 2020-08-27 | 2020-10-20 | 杭州涂鸦信息技术有限公司 | Lens focusing method and system and related equipment |
| CN113810616A (en) * | 2021-09-27 | 2021-12-17 | 季华实验室 | Aperture focal length adjusting method, system, electronic device and storage medium |
| CN116256373A (en) * | 2023-05-15 | 2023-06-13 | 南京华视智能科技有限公司 | Perovskite battery film surface defect detection method |
| CN116256373B (en) * | 2023-05-15 | 2023-09-12 | 南京华视智能科技有限公司 | Perovskite battery film surface defect detection method |
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