CN109212749B - Filter plate for realizing edge enhanced imaging and design method thereof - Google Patents
Filter plate for realizing edge enhanced imaging and design method thereof Download PDFInfo
- Publication number
- CN109212749B CN109212749B CN201810745546.8A CN201810745546A CN109212749B CN 109212749 B CN109212749 B CN 109212749B CN 201810745546 A CN201810745546 A CN 201810745546A CN 109212749 B CN109212749 B CN 109212749B
- Authority
- CN
- China
- Prior art keywords
- filter
- function
- point spread
- imaging
- spread function
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000003384 imaging method Methods 0.000 title claims abstract description 63
- 238000000034 method Methods 0.000 title claims abstract description 17
- 238000004364 calculation method Methods 0.000 claims abstract description 7
- 230000003595 spectral effect Effects 0.000 claims description 9
- 238000001228 spectrum Methods 0.000 claims description 4
- 230000000694 effects Effects 0.000 abstract description 7
- 238000009826 distribution Methods 0.000 description 21
- 238000010586 diagram Methods 0.000 description 7
- 230000007547 defect Effects 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000001914 filtration Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 208000025174 PANDAS Diseases 0.000 description 1
- 208000021155 Paediatric autoimmune neuropsychiatric disorders associated with streptococcal infection Diseases 0.000 description 1
- 240000000220 Panda oleosa Species 0.000 description 1
- 235000016496 Panda oleosa Nutrition 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000012984 biological imaging Methods 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/0012—Optical design, e.g. procedures, algorithms, optimisation routines
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Image Processing (AREA)
Abstract
The invention relates to the technical field of edge enhanced imaging, and discloses a filter for realizing edge enhanced imaging and a design method thereof, wherein the method comprises the following steps: superposing the four Gaussian functions to obtain a point spread function of a filter function; and performing inverse calculation on the point spread function by utilizing Fourier transform to obtain a filter function. The method combines the modulation effect of amplitude and phase on edge enhanced imaging, obtains a point spread function by superposing four Gaussian functions, meets the requirement that no redundant side lobe exists around a main lobe, and obtains a filter function of a filter by performing inverse calculation on the point spread function by utilizing Fourier transform.
Description
Technical Field
The invention relates to the technical field of edge enhancement imaging, in particular to a filter for realizing edge enhancement imaging and a design method thereof.
Background
Edge-enhanced imaging has found great application in the imaging field, in 1942, Zernike first achieved phase-contrast imaging, since then much work has been devoted to studying this technique, and Marr and Torre et al theoretically contributed much to edge-enhanced imaging.
In 2018, the Zhutengfeng realizes the edge enhanced imaging of the spatial differentiation in the experiment by utilizing the surface plasmon structure, but the digital imaging technology cannot well realize the phase pair under the condition that an object has no obvious characteristics. While differential interference contrast imaging is relatively simple to implement, spatial light modulators can be used to simplify the optical path and thus perform the imaging operation, the imaging results of this technique are anisotropic. The hilbert transform filtering imaging is to realize edge enhancement imaging by adding a filter on the spectrum surface of a 4f system by using the thought of the spatial filtering, and the most practical method is to use a spiral phase plate to realize hilbert transform.
In the field of optical microwaves, helical phase plates are used extensively to reconstruct amplitude and phase information at the edges of biological specimens. With the development of the technology, directionally selective edge enhanced imaging can be realized through a vector optical filter, a fractional order vortex filter and a phase shift vortex filter. Meanwhile, the vortex lens has great application value in edge enhanced imaging. However, we have found that since there are a large number of unwanted side lobes on both sides of the main lobe of the point spread function of the conventional vortex phase plate, this phenomenon causes diffraction noise to appear at the edges of the imaging result, making the result non-uniform, and the effect becomes severe as the topological sum increases. In order to solve the problem, thereby improving the imaging quality, the Laguerre Gaussian filter, the Bessel filter and the Airy spiral phase filter are designed to be used for inhibiting redundant side lobes, so that the uniform edge imaging result with high resolution ratio is obtained. The current edge enhancement imaging technology has great application prospect in the fields of infrared illumination, biological imaging, astronomical observation, fingerprint identification, remote sensing and the like.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide a filter plate for realizing edge enhanced imaging. The following technical scheme is adopted:
filter plate for realizing edge enhanced imaging and filter function thereof
Comprises the following steps:
(wherein,
represents the radial coordinates of the spectral plane, FT represents the fourier transform,
represents a circular hole of radius R, the circular hole being a defined field with an in-field value of 1, an out-of-field value of 0, and h (x, y) being a filter function
The point spread function of (a) is obtained by superposing four Gaussian functions, (x, y) represents the coordinates of an imaging plane, and omega0Is the Gaussian beam waist, d0Is an arbitrary constant).
The second objective of the present invention is to provide a design method of a filter for realizing edge-enhanced imaging. The following technical scheme is adopted:
a design method of a filter plate for realizing edge enhanced imaging comprises the following steps:
superposing the four Gaussian functions to obtain a point spread function of a filter function;
and performing inverse calculation on the point spread function by utilizing Fourier transform to obtain a filter function.
As a further improvement of the present invention, the point spread function is:
(wherein, (x, y) represents coordinates of an imaging plane, ω0Is the Gaussian beam waist, d0Is an arbitrary constant);
the filter function is:
(wherein,
represents the radial coordinates of the spectral plane, FT represents the fourier transform,
representing a circular hole of radius R).
The invention has the beneficial effects that:
the invention discloses a filter and a design method thereof, wherein the modulation effect of amplitude and phase on edge enhanced imaging is combined, a point spread function is obtained by superposing four Gaussian functions, the condition that no redundant side lobe exists around a main lobe is met, the point spread function is reversely calculated by utilizing Fourier transform, and thus the filter function of the filter is obtained.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.
Drawings
FIG. 1 is a schematic diagram of a 4f system in an embodiment of the present invention;
FIGS. 2(a) and 2(b) are respectively filter functions in embodiments of the present invention
A two-dimensional planar distribution of the real part of the point spread function of (the vortex function) and a cross-sectional distribution profile of the radial values in the radial direction; FIGS. 2(c) and 2(d) are respectively filter functions in embodiments of the present invention
A two-dimensional planar distribution of the imaginary part of the point spread function (the swirl function) and a cross-sectional distribution profile of the radial values in the radial direction;
FIGS. 3(a) and 3(b) are respectively filter functions in embodiments of the present invention
A two-dimensional plane distribution of an imaginary part of the point spread function and a cross-sectional distribution of radial values in a radial direction of (Bessel function);
FIGS. 4(a) and 3(b) are respectively filter functions in embodiments of the present invention
The two-dimensional plane distribution of the real part of the point spread function and the section distribution diagram of the radial value in the radial direction; FIGS. 4(c) and 4(d) are respectively filter functions in embodiments of the present invention
A two-dimensional plane distribution of an imaginary part of the point spread function and a cross-sectional distribution diagram of radial values in a radial direction;
FIG. 5 is a comparison graph of theory and experiment of amplitude objects in an embodiment of the present invention;
fig. 6 is a comparison graph of theory and experiment of phase objects in an embodiment of the present invention.
Detailed Description
The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.
Fig. 1 is a schematic diagram of a 4f system in this embodiment, where the 4f system is a theoretical basis of a filter implementing edge enhanced imaging and a design method thereof according to the present invention. L1 and L2 are fourier thin lenses, both of which have a focal length of f. In FIG. 1, (x)0,y0) And (u, v) and (x, y) represent cartesian coordinates of an incident plane, a spectrum plane and an imaging plane, respectively. It is assumed here that the complex amplitude of the object on the plane of incidence is g (x)0,y0) The function of the filter on the spectral plane is H (u, v) and the complex amplitude of the emergent light field on the imaging plane is
According to the light path calculation of the 4f system, the emergent field can be calculatedDescribed in the following form:
where H (x, y) is the Fourier transform of the filter function H (u, v), the sign
Representing a convolution operator). According to the theory of convolution, it can be obtained that: if edge enhancement imaging is desired, the filter function requires two main properties, one to be able to darken the interior of the object and the other to brighten the edges of the object. In general, in order to satisfy the first property, the filter function needs to satisfy the following condition:
some constant terms are omitted from this equation, from which it can be derived that the middle of an object can be darkened as long as the center of the filter function is equal to zero. While the other property is difficult to satisfy, so we first analyze the influence of the phase and amplitude of the filter function on the imaging result separately, and for this reason we find a filter function with pure phase (vortex function) and a filter function with pure amplitude (Bessel function), whose expressions are:
wherein,represents the radial coordinate of the spectral plane,
represents a circle of radius RA circular hole having a definition field with an in-field value of 1 and an out-of-field value of 0, JlRepresenting the lth order Bessel function of the first kind, krIs the mode constant. Through fourier transform, the point spread functions of the two filter functions can be approximately expressed as follows:
wherein (r, θ) represents the radial coordinate of the imaging plane, λ represents the wavelength, J0Representing a first class Bessel function of order 0 th.
In order to more intuitively see the influence of the filter function on the imaging result, a point spread function distribution diagram of the filter function is drawn through numerical simulation.
As shown in FIG. 2, FIGS. 2(a) and 2(b) are filter functions, respectively
A two-dimensional planar distribution of the real part of the point spread function of (the vortex function) and a cross-sectional distribution profile of the radial values in the radial direction; FIGS. 2(c) and 2(d) are filter functions, respectively
A two-dimensional planar distribution of the imaginary part of the point spread function (the swirl function) and a cross-sectional distribution profile of the radial values in the radial direction; where R is 700mm, f is 400mm, and PSF represents the point spread function.
As shown in FIG. 3, FIGS. 3(a) and 3(b) are filter functions, respectivelyA two-dimensional plane distribution of an imaginary part of the point spread function and a cross-sectional distribution of radial values in a radial direction of (Bessel function); wherein l is 1, kr＝1.1mm-1。
By combining the imaging theory of convolution with fig. 2 and 3, iIt was found that
A main maximum lobe and a main minimum lobe exist in a real part and an imaginary part of a point spread function of a vortex function, and a plurality of redundant side lobes can appear around the main maximum lobe and the main minimum lobe, so that the filtering function can be predicted and utilized
Edge enhancement imaging (with a vortex function) can be achieved in all directions, but some smearing occurs at the imaged edges, making edge imaging non-uniform. For the filter function
(Bessel function) has point spread function with imaginary part, two great main lobes and one small main lobe, obvious difference between the two great main lobes and the small main lobe, small side lobes beside the great main lobe and the small main lobe and well suppressed diffraction noise, so that the filtering function has high filtering effect
(Bessel function) and the edge imaging can be realized in all directions, the imaging result is good in quality and isotropic, but two edge images appear at the edge.
Through the previous analysis, we find that the pure phase filter function and the pure amplitude filter function can realize the edge enhanced imaging, but there are some defects in the edge enhanced imaging, which shows that the amplitude and the phase of the filter function have certain influence on the edge enhanced imaging.
Therefore, in order to obtain better imaging quality, eliminate the imaging defects of a pure-phase filter function and a pure-amplitude filter function, combine the modulation effects of phase and amplitude on edge enhanced imaging, and calculate the point spread function of the filter function to ensure that the real part and the imaginary part of the point spread function meet the condition that only one main maximum lobe and one main minimum lobe exist, and redundant side lobes around the main maximum lobe and the main minimum lobe can be completely inhibited, so that the filter function corresponding to the point spread function can realize high-resolution and isotropic edge enhanced imaging, and realize simultaneous modulation on the amplitude and the phase. The design method of the filter segment proposed in this embodiment includes the following steps:
(wherein, (x, y) represents coordinates of an imaging plane, ω0Is the Gaussian beam waist, d0Is an arbitrary constant);
the Gaussian function is the simplest filter function, one Gaussian function has only one extreme value, and the superposition of two Gaussian beams can generate a maximum value and a minimum value, so that the superposition of two Gaussian functions with pure real numbers and two Gaussian functions with pure imaginary parts can ensure that the real part and the imaginary part of the point spread function only have a main maximum lobe and a main minimum lobe.
And 2, performing inverse calculation on the point spread function by utilizing Fourier transform to obtain a filter function.
The filter function is:
(wherein,
represents the radial coordinates of the spectral plane, FT represents the fourier transform,
representing a circular aperture of radius R on the spectral plane, the circular aperture being a defined field, having an in-domain value of 1 and an out-of-domain value of 0).
Due to the round hole on the frequency spectrum surface
Influence of, filter function
The actual point spread function can be expressed in radial coordinates as:
in this embodiment, the filter implementing edge enhanced imaging is designed by the above design method, and its filter function is:
as shown in FIG. 4, FIGS. 4(a) and 4(b) are filter functions, respectively
The two-dimensional plane distribution of the real part of the point spread function and the section distribution diagram of the radial value in the radial direction; FIGS. 4(c) and 4(d) are filter functions, respectively
A two-dimensional plane distribution of an imaginary part of the point spread function and a cross-sectional distribution diagram of radial values in a radial direction; wherein, ω is0＝d0＝26mm。
From fig. 4, a filter function can be foundUnwanted side lobes (diffraction noise) in the real and imaginary parts of the point spread function have been completely suppressed, so for the filter function
It can realize edge enhancement imaging in all directions in 4f imaging system, and it isIsotropic, uniform distribution of the image, with image quality comparable to the filter function
(vortex function) and Filter functionThe Bessel function is much better, the defects in imaging are eliminated, and an edge image with better effect and higher resolution can be obtained.
Fig. 5 shows a comparison graph of theory and experiment of amplitude objects in an embodiment of the present invention. Wherein the amplitude object is a simple circular hole (radius 7mm), the first row is the theoretical result, the second row is the experimental result, (a) and (e) are photographs of the object, (b) and (f) are through a filter (filter function is 7mm)
) The latter images, (c) and (g) being passed through a filter (filter function of
) The latter images, (d) and (h) being passed through a filter (filter function of
) The latter image.
Fig. 6 shows a comparison graph of theory and experiment of phase objects in the embodiment of the present invention. Wherein the phase object is a panda (phase change of 0-pi), the first line is the theoretical result, the second line is the experimental result, (a) and (e) are photographs of the object, (b) and (f) are filtered (filter function is of) The latter images, (c) and (g) being passed through a filter (filter function of
) The latter images, (d) and (h) being passed through a filter (filter function of
) The latter image.
From FIGS. 5 and 6, it can be seen that the filter function is
The filter can modulate the amplitude and the phase of an object simultaneously, so that high-resolution isotropic edge enhancement imaging is realized, the imaging quality is greatly improved compared with the traditional filter, and the imaging defect is eliminated.
The invention has the beneficial effects that:
the invention discloses a filter and a design method thereof, wherein the modulation effect of amplitude and phase on edge enhanced imaging is combined, a point spread function is obtained by superposing four Gaussian functions, the condition that no redundant side lobe exists around a main lobe is met, the point spread function is reversely calculated by utilizing Fourier transform, and thus the filter function of the filter is obtained.
The above embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.
Claims (2)
1. A filter segment for performing edge enhanced imaging, comprising:
superposing the four Gaussian functions to obtain a point spread function of a filter function;
and utilizing Fourier transform to perform inverse calculation on the point spread function to obtain a filter function of the filter plate:
wherein,
represents the radial coordinates of the spectral plane, FT represents the fourier transform,representing a circular aperture of radius R on the spectral plane, the circular aperture being a defined field with a value of 1 inside the defined field, a value of 0 outside the defined field, and h (x, y) being a filter function
The point spread function of (a) is obtained by superposing four Gaussian functions, (x, y) represents the coordinates of an imaging plane, and omega0Is the Gaussian beam waist, d0Is an arbitrary constant.
2. A design method of a filter for realizing edge enhanced imaging is characterized by comprising the following steps:
superposing the four Gaussian functions to obtain a point spread function of a filter function;
performing inverse calculation on the point spread function by utilizing Fourier transform to obtain a filter function;
the point spread function is:
wherein (x, y) represents coordinates of an imaging plane, ω0Is the Gaussian beam waist, d0Is an arbitrary constant;
the filter function is:
wherein,
represents the radial coordinates of the spectral plane, FT represents the fourier transform,
represents a circular hole with radius R on the spectrum plane, the circular hole is a defined domain, the value in the defined domain is 1, and the value outside the defined domain is 0.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810745546.8A CN109212749B (en) | 2018-07-09 | 2018-07-09 | Filter plate for realizing edge enhanced imaging and design method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810745546.8A CN109212749B (en) | 2018-07-09 | 2018-07-09 | Filter plate for realizing edge enhanced imaging and design method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109212749A CN109212749A (en) | 2019-01-15 |
| CN109212749B true CN109212749B (en) | 2020-01-10 |
Family
ID=64990349
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810745546.8A Active CN109212749B (en) | 2018-07-09 | 2018-07-09 | Filter plate for realizing edge enhanced imaging and design method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109212749B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110811615A (en) * | 2019-11-20 | 2020-02-21 | 中国科学院电子学研究所 | Terahertz imaging method and device based on spiral phase contrast imaging |
| CN114429549A (en) * | 2020-10-28 | 2022-05-03 | 北京小米移动软件有限公司 | Image edge extraction method, image edge extraction device, and storage medium |
| CN114217454B (en) * | 2022-02-22 | 2022-06-10 | 华中科技大学 | Design and implementation method of spatial frequency spectrum modulation device based on diffraction optical element |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5499137A (en) * | 1991-09-06 | 1996-03-12 | Nikon Corporation | Exposure method and apparatus therefor |
| CN101794024A (en) * | 2010-04-02 | 2010-08-04 | 上海理工大学 | Device and method for generating column vector beams |
| CN203232201U (en) * | 2013-01-18 | 2013-10-09 | 苏州大学 | Generating device for partially coherent Airy beam |
| CN105182547A (en) * | 2015-10-19 | 2015-12-23 | 山东师范大学 | Method and device using birefraction polarization beam splitter to generate vector beam |
| CN105225243A (en) * | 2015-10-15 | 2016-01-06 | 徐德明 | One can antimierophonic method for detecting image edge |
| CN105607267A (en) * | 2016-03-07 | 2016-05-25 | 东南大学 | Device for generating diffraction-free needle-shaped light field |
| GB2536276A (en) * | 2015-03-12 | 2016-09-14 | Powerphotonic Ltd | Field mapper |
| CN106441084A (en) * | 2016-11-21 | 2017-02-22 | 深圳大学 | Wave-front sensor, wave-front detection method and wave-front detection system based on microholographic array |
| CN106444048A (en) * | 2016-09-06 | 2017-02-22 | 苏州大学 | Shaping method and shaping system of Gaussian Sherrer mode light beam |
| CN106644105A (en) * | 2016-10-26 | 2017-05-10 | 深圳大学 | Wavefront sensor based on double helix point spread function, detection method, and system |
| CN107621701A (en) * | 2017-09-07 | 2018-01-23 | 苏州大学 | Produce the method and system of double index Bessel-Gaussian beams |
| CN108254917A (en) * | 2018-01-29 | 2018-07-06 | 哈尔滨工业大学 | A kind of edge enhancing imaging device and method based on fractional order photon trajectory angular momentum |
-
2018
- 2018-07-09 CN CN201810745546.8A patent/CN109212749B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5499137A (en) * | 1991-09-06 | 1996-03-12 | Nikon Corporation | Exposure method and apparatus therefor |
| CN101794024A (en) * | 2010-04-02 | 2010-08-04 | 上海理工大学 | Device and method for generating column vector beams |
| CN203232201U (en) * | 2013-01-18 | 2013-10-09 | 苏州大学 | Generating device for partially coherent Airy beam |
| GB2536276A (en) * | 2015-03-12 | 2016-09-14 | Powerphotonic Ltd | Field mapper |
| CN105225243A (en) * | 2015-10-15 | 2016-01-06 | 徐德明 | One can antimierophonic method for detecting image edge |
| CN105182547A (en) * | 2015-10-19 | 2015-12-23 | 山东师范大学 | Method and device using birefraction polarization beam splitter to generate vector beam |
| CN105607267A (en) * | 2016-03-07 | 2016-05-25 | 东南大学 | Device for generating diffraction-free needle-shaped light field |
| CN106444048A (en) * | 2016-09-06 | 2017-02-22 | 苏州大学 | Shaping method and shaping system of Gaussian Sherrer mode light beam |
| CN106644105A (en) * | 2016-10-26 | 2017-05-10 | 深圳大学 | Wavefront sensor based on double helix point spread function, detection method, and system |
| CN106441084A (en) * | 2016-11-21 | 2017-02-22 | 深圳大学 | Wave-front sensor, wave-front detection method and wave-front detection system based on microholographic array |
| CN107621701A (en) * | 2017-09-07 | 2018-01-23 | 苏州大学 | Produce the method and system of double index Bessel-Gaussian beams |
| CN108254917A (en) * | 2018-01-29 | 2018-07-06 | 哈尔滨工业大学 | A kind of edge enhancing imaging device and method based on fractional order photon trajectory angular momentum |
Non-Patent Citations (2)
| Title |
|---|
| Laguerre-Gaussian radial Hilbert transform for edge-enhancement Fourier transform x-ray microscopy;Bokor, Nandor等;《OPTICS EXPRESS》;20090330;第17卷(第7期);第5533-5539页 * |
| 基于螺旋相位滤波的图像边缘增强研究;吴华钦等;《福建师范大学学报（自然科学版）》;20150531;第31卷(第3期);第118-124页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109212749A (en) | 2019-01-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108873323B (en) | Method and system for realizing edge enhanced imaging | |
| CN109212749B (en) | Filter plate for realizing edge enhanced imaging and design method thereof | |
| CN104102017B (en) | The super diffraction limit imaging system of random scatter optics and method shone based on structure light | |
| EP3602163B1 (en) | Structured illumination with optimized illumination geometry | |
| CN113487637B (en) | Multidirectional edge detection method based on superimposed spiral phase filter | |
| CN105759440A (en) | Random scattering optical super-diffraction limit imaging method based on structured illumination | |
| Sharma et al. | Directional edge enhancement using superposed vortex filter | |
| CN108537735A (en) | A kind of image split-joint method of focal plane terahertz imaging | |
| Li et al. | Far‐Field Synthetic Aperture Imaging via Fourier Ptychography with Quasi‐Plane Wave Illumination | |
| Li et al. | Scalar and vectorial vortex filtering based on geometric phase modulation with a q-plate | |
| Kim et al. | Phase Differences Averaging (PDA) Method for Reducing the Phase Error in Digital Holographic Microscopy (DHM) | |
| Grebenyuk et al. | An off-axis digital holographic microscope with quasimonochromatic partially spatially coherent illumination in transmission | |
| Venkanna et al. | Edge imaging characteristics of aberrated coherent optical systems by edge masking of circular apertures | |
| Han et al. | Optimization of structured illumination microscopy with designing and rotating a grid pattern using a spatial light modulator | |
| Xie et al. | An extended depth-of-field imaging system with a non-rotationally symmetric phase mask | |
| Tien | Development of multi-spectral three-dimensional micro particle tracking velocimetry1 | |
| Enyama et al. | Method of improving image sharpness for annular-illumination scanning electron microscopes | |
| Cao et al. | Combination of color coding and wavefront coding for extended depth of field | |
| Zhao et al. | Bilinear interpolation algorithm based on gradient-weighted optimization | |
| Mo et al. | Alleviating image artifacts in wavefront coding extended depth of field imaging system | |
| Cheng et al. | Partially coherent spiral phase contrast imaging with a 3D-like effect | |
| Reddy et al. | Three Zone Asymmetric Pupil Filter for Increasing Two-point Resolution of Optical Imaging Systems | |
| Meneses et al. | Extended depth of field using shapelet-based image analysis | |
| Bagheri et al. | A fast optimization method for extension of depth-of-field in three-dimensional task-specific imaging systems | |
| Li et al. | Three-dimensional coherent transfer function in reflection-mode confocal microscopy with two-zone phase filters |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |