CN106937048A - High speed wide area Techniques of Automatic Focusing based on numerical value front propagation - Google Patents
High speed wide area Techniques of Automatic Focusing based on numerical value front propagation Download PDFInfo
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- CN106937048A CN106937048A CN201710136527.0A CN201710136527A CN106937048A CN 106937048 A CN106937048 A CN 106937048A CN 201710136527 A CN201710136527 A CN 201710136527A CN 106937048 A CN106937048 A CN 106937048A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/67—Focus control based on electronic image sensor signals
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Abstract
The present invention relates to a kind of high speed wide area Techniques of Automatic Focusing based on numerical value front propagation, a sample image is shot first near focal plane, because it is not in focal plane, therefore the sample image for shooting is obscured.Overfocus is symmetrically gathered in the plane both sides and owe Jiao image.Gathered image is brought into the intensity transmission equation (GS TIE) based on Gerchberg Saxton algorithms so as to solve the phase distribution of middle position.With reference to the strength information that middle position is gathered, sample would know that in the wavefront distribution of middle position.This wavefront information is propagated along z-axis, the wavefront distribution at each position is obtained.The wavefront information at each position is evaluated using Tamura coefficients, so that it is determined that the position of the true focal plane of sample.Institute's test sample product are moved into focal plane position and verifies whether the position is focal plane position using motorized precision translation stage is automatic.
Description
Technical field
Focused on automatically the present invention relates to Techniques of Automatic Focusing, more particularly to a kind of high speed wide area based on numerical value front propagation
Technology.
Background technology
With biomedical development, sample observing result requirement more and more higher generally requires to reach micron even nanometer
Rank, used as the main tool of microexamination, microscope is widely used.In sample observation focusing, due to
Manual focus error is larger, and Techniques of Automatic Focusing arises at the historic moment.Relative to traditional manual focusing, Techniques of Automatic Focusing is focused on because of it
Accurately, without adjusting repeatedly, there is substantial amounts of application the advantages of in micro-imaging field.
Traditional Techniques of Automatic Focusing relies on laser reflection so as to realize the purpose of automatic focusing, can not calculate largely
In the case of quick positioning focal plane, however, its precision is highly dependent on reference surface.Due to cross-sections surfaces change, with reference to flat
The position in face changes therewith, therefore its error is higher.With the maturation of computer technology, in order to improve automatic focusedimage matter
Amount, the Techniques of Automatic Focusing based on Digital Image Processing arises at the historic moment, its core concept be along axle mobile example (or speck mirror),
So as to repeatedly record its intensity, extract various standards to determine focus according to the contrast of image, resolution ratio, frequency component and entropy
Position.Relative to manual focus, although the Techniques of Automatic Focusing can improve the speed and precision for focusing on, but it is dependent on many figures
As scanning and analysis, the automatic speed for focusing on still is restricted.Additionally, the image procossing of the movement of scanning translation stage and complexity
Reduce further automatic focusing speed.What is more important, the effective automatic focusing range of the technology is usually several microns,
The method is invalid when defocus is in larger distance.Additionally, for existing Techniques of Automatic Focusing for zonule automatic focusing more
Accurately, then for large sample, because its sample size is larger, had differences between different zones, if being applied to phase
, still there is certain difference in same algorithm, be unfavorable for the observation of sample between final focussing plane and true focal plane.
Therefore, high speed wide area Techniques of Automatic Focusing is particularly important, thus improve microscopic system automatically focus on speed and
Precision, obtains relatively sharp observed image.
The content of the invention
For the deficiency of existing Techniques of Automatic Focusing, the present invention provides a kind of high speed wide area Techniques of Automatic Focusing, Neng Gouyou
Effect solves the problems such as existing Techniques of Automatic Focusing focusing speed is slow, and algorithm is complicated, the scope of application is small.
The technical solution adopted for the present invention to solve the technical problems is：High speed wide area based on numerical value front propagation is automatic
Focusing technology.A sample image is shot first near focal plane, because it is not in focal plane, therefore the sample image for shooting
It is fuzzy.Overfocus is symmetrically gathered in the plane both sides and owe Jiao image.Gathered image is brought into based on Gerchberg-Saxton
So as to solve the phase distribution of middle position in the intensity transmission equation (GS-TIE) of algorithm.Gathered with reference to middle position
Strength information, sample would know that in the wavefront distribution of middle position.This wavefront information is propagated along z-axis, each position is obtained
Put the wavefront distribution at place.The wavefront information at each position is evaluated using Tamura coefficients, so that it is determined that sample is true
The position of focal plane.Institute's test sample product are moved into focal plane position using motorized precision translation stage is automatic.
Brief description of the drawings
Fig. 1 is the automatic focalizer schematic diagram based on numerical value front propagation；
Specific embodiment
Time-consuming more long present invention aim to address current microscope Techniques of Automatic Focusing, the complex problem of algorithm is carried
Go out a kind of high speed wide area Techniques of Automatic Focusing based on numerical value front propagation, improve speed and essence that microscope is focused on automatically
Degree, solves the automatic focus issues of microscope well.
In view of the shortcomings of the prior art, it is an object of the invention to provide a kind of high speed wide area based on numerical value front propagation certainly
Dynamic focusing technology, so as to realize that microscopic system high speed wide area is focused on automatically.
The present invention will be further described in detail below in conjunction with the accompanying drawings：
1st, focal plane vicinity IMAQ.In the presence of certain error during due to coarse adjustment, appoint first near focal plane
Meaning gathers a defocus picture at position, and the picture is fuzzy image.
2nd, symmetrical IMAQ.Two pictures are symmetrically gathered in above-mentioned picture lower regions, is distinguished relative to the picture
It is overfocus image I1With deficient burnt image I2。
3rd, phase solution is carried out using GS-TIE equations.
3.1st, using two-dimentional TIE equations expression formula：
OrderLight field complex amplitude is represented, I is light intensity,Amplitude is represented, P is phase
Position, z is optical axis direction, and ▽ represents the differential operator to (x, the y) direction perpendicular to z directions.Fresnel diffraction field is described
The relation that the axial gradient of middle light intensity I is distributed with the vertical direction of principal axis of phase P.
Bring (1) formula into two-dimentional Poisson's equation：
Using such as lower aprons：
I1、I2It is respectively two light distribution in face, Δ z is two axial distances in face.
TIE phase distributions P can be obtained.Its phase is expressed as with operational form：
In formula, FT represents two-dimentional Fourier transform, FT-1Two-dimentional fourier inverse transformation is represented,Representation space angle
Frequency vector kx、kyMould it is long, " " represents and acts on all items in the right, and " " represents that number multiplies,
The 3.2nd, TIE equation solutions are solved result P and substitutes into GS module iteration as initial value, reuse light intensity I1、I2Ginseng
With the light intensity alternative Process in GS modules；Selected limits of error parameter, iteration, iteration result are stopped when iteration error is less than the value
It is exactly phase that GS-TIE is recovered.
4th, numerical value front propagation.The strength information of the phase combination middle position collection that will be recovered obtains sample and exists
The wavefront distribution of middle position, this wavefront information is propagated along z-axis, to obtain the strength information at each position.
5th, numerical value is determined in focal plane.The strength information at each position is evaluated using Tamura coefficients, is looked for
To its maximum value position, it is believed that the position is in focal plane position.
5.1st, Tamura coefficient expressions are：
In formula, σ (I) by collection picture gray value standard deviation, ＜ I ＞ by collection picture gray value average value.
6th, verify whether to be in focal plane.Sample move to numerical computations in focal plane position, checking herein whether
It is in focal plane, if then automatic focus movement stops；If it is not, then repeat step 1~6, until finding in burnt position.
6.1st, verification method is：In numerical computations determination in focal plane position repeat step 1~5, if this time
It is that the position is in focal plane position at 0 that Tamura coefficients maximum is located at and passes distance；Otherwise the position is not in focal plane
Position is, it is necessary to carry out next loop processed.
Compared with the technology of the tradition based on Digital Image Processing of a large amount of focal intensities collection demands is needed, the present invention is carried
The automatic focusing strategy for going out needs only have the 2-3 treatment loop less than 10 multifocal intensity.Additionally, auto focusing method
Commercial microscopes are desirably integrated into, there is no extra complex device.In view of its high efficiency, big effective range and simple
System and operation, it is believed that method proposed by the invention can be with future for the fast automatic focusing in microscope.
Claims (9)
1. the high speed wide area Techniques of Automatic Focusing of numerical value front propagation is based on, it is characterised in that comprised the following steps：
One pictures of any collection near focal plane position；
One pictures of each collection at position symmetrical above and below；
Calculate the distribution of middle position wavefront；
Wavefront or so is propagated；
Tamura factor evaluations；
Numerical value is determined in focal plane position；
Sample stage moves to numerical value and determines in focal plane；
Whether what checking numerical value determined is in burnt position in burnt position.
2. as described in the appended claim 1, it is characterised in that one pictures of any collection near focal plane position, due to the position
It is not true in burnt position to put, and the picture for being gathered is fuzzy.
3. as described in the appended claim 1, it is characterised in that respectively gathered at the position symmetrical above and below of the position in claim 2
One pictures, the picture for being collected equally is fuzzy.
4. as described in the appended claim 1, it is characterised in that the distribution of middle position wavefront is calculated, first with GS-TIE equations
Phase solution is carried out, the distribution of its wavefront is obtained then in conjunction with middle position intensity signal.
5. as described in the appended claim 1, it is characterised in that axially left and right is propagated for the numerical value wavefront distribution that will be calculated
Wavefront information at each position, it is hereby achieved that the strength information at each position.
6. as described in the appended claim 1, it is characterised in that propagated at each position for obtaining using Tamura coefficients logarithm value
Strength information is evaluated.
7. as described in the appended claim 1, it is characterised in that according to Tamura factor evaluation curves, it is believed that its maximum position
Put as truly in focal plane position.
8. as described in the appended claim 1, it is characterised in that sample stage move to numerical computations determination in focal plane position, test
Whether card is herein in burnt position.
9. as described in the appended claim 1, it is characterised in that verification method is：In numerical computations determination in focal plane position
Above step is repeated, if this time Tamura coefficient curves maximum is that at 0, the position is in focal plane position positioned at distance is passed
Put；Otherwise the position is not in focal plane position, it is necessary to carry out next loop processed.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107655405A (en) * | 2017-08-29 | 2018-02-02 | 南京理工大学 | The method that axial range error between object and CCD is eliminated using self-focusing iterative algorithm |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080179521A1 (en) * | 2003-11-10 | 2008-07-31 | Technology Innovations, Llc | Digital imaging assembly & methods thereof |
| CN101769717A (en) * | 2008-12-29 | 2010-07-07 | 株式会社三丰 | Extended range focus detection apparatus |
| CN103718008A (en) * | 2011-08-04 | 2014-04-09 | 透明医疗体系公司 | A large diopter range real time sequential wavefront sensor |
| US20140347672A1 (en) * | 2011-07-29 | 2014-11-27 | Ecole Polytechnique Federale De Lausanne (Epfl) | Apparatus and method for quantitive phase tomography through linear scanning with coherent and non-coherent detection |
| US20160154377A1 (en) * | 2006-11-17 | 2016-06-02 | Celloptic, Inc. | System, apparatus and method for extracting three-dimensional information of an object from received electromagnetic radiation |
-
2017
- 2017-03-09 CN CN201710136527.0A patent/CN106937048A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080179521A1 (en) * | 2003-11-10 | 2008-07-31 | Technology Innovations, Llc | Digital imaging assembly & methods thereof |
| US20160154377A1 (en) * | 2006-11-17 | 2016-06-02 | Celloptic, Inc. | System, apparatus and method for extracting three-dimensional information of an object from received electromagnetic radiation |
| CN101769717A (en) * | 2008-12-29 | 2010-07-07 | 株式会社三丰 | Extended range focus detection apparatus |
| US20140347672A1 (en) * | 2011-07-29 | 2014-11-27 | Ecole Polytechnique Federale De Lausanne (Epfl) | Apparatus and method for quantitive phase tomography through linear scanning with coherent and non-coherent detection |
| CN103718008A (en) * | 2011-08-04 | 2014-04-09 | 透明医疗体系公司 | A large diopter range real time sequential wavefront sensor |
Non-Patent Citations (2)
| Title |
|---|
| MEMMOLO P ET AL.: "Automatic focusing in digital holography and its application to stretched holograms", 《OPTICS LETTERS》 * |
| 杨晗: "基于光强分布的相位恢复记载激光湍流传输中的应用", 《中国优秀硕士学位论文全文数据库信息科技辑》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107655405A (en) * | 2017-08-29 | 2018-02-02 | 南京理工大学 | The method that axial range error between object and CCD is eliminated using self-focusing iterative algorithm |
| CN107655405B (en) * | 2017-08-29 | 2020-01-24 | 南京理工大学 | Method for eliminating axial distance error between object and CCD by using self-focusing iterative algorithm |
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Application publication date: 20170707 |