CN109035201A - A kind of object deflection acquisition methods based on digital picture diffraction - Google Patents
A kind of object deflection acquisition methods based on digital picture diffraction Download PDFInfo
- Publication number
- CN109035201A CN109035201A CN201810645210.4A CN201810645210A CN109035201A CN 109035201 A CN109035201 A CN 109035201A CN 201810645210 A CN201810645210 A CN 201810645210A CN 109035201 A CN109035201 A CN 109035201A
- Authority
- CN
- China
- Prior art keywords
- function
- deformation
- image
- result
- displacement
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000006073 displacement reaction Methods 0.000 claims abstract description 62
- 230000009466 transformation Effects 0.000 claims abstract description 23
- 238000004458 analytical method Methods 0.000 claims description 39
- 238000006243 chemical reaction Methods 0.000 claims description 15
- 230000014509 gene expression Effects 0.000 claims description 11
- 238000012545 processing Methods 0.000 claims description 11
- 239000011159 matrix material Substances 0.000 claims description 6
- 230000003595 spectral effect Effects 0.000 claims description 3
- 238000001228 spectrum Methods 0.000 description 8
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004925 denaturation Methods 0.000 description 1
- 230000036425 denaturation Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/0002—Inspection of images, e.g. flaw detection
- G06T7/0004—Industrial image inspection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
- G01B21/32—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant for measuring the deformation in a solid
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T2207/00—Indexing scheme for image analysis or image enhancement
- G06T2207/20—Special algorithmic details
- G06T2207/20048—Transform domain processing
- G06T2207/20056—Discrete and fast Fourier transform, [DFT, FFT]
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Quality & Reliability (AREA)
- Computer Vision & Pattern Recognition (AREA)
- Theoretical Computer Science (AREA)
- Image Analysis (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention belongs to engineering survey correlative technology fields, it discloses a kind of object deflection acquisition methods based on digital picture diffraction, method includes the following steps: (1) randomly selects the region of the same section of object as analyzed area respectively in two images before and after object deformation；(2) Fast Fourier Transform (FFT) is carried out to the gray value of the pixel of two analyzed areas respectively to respectively obtain the first transformation results before indicating object deformation and indicate deformed second transformation results of object, and then displacement and the scaling results function of angle variables caused by the gray value of pixel, deformation in the corresponding analyzed area of image before deforming are obtained, and then obtain the 5th function and the 6th function；(3) Fourier transformation is carried out to obtain the impulse function of the displacement generated comprising deformation to the 6th function, and then obtains the deflection that object deformation generates.The flexibility of object deflection acquisition methods provided by the invention is higher and with strong applicability.
Description
Technical Field
The invention belongs to the technical field related to engineering measurement, and particularly relates to an object deformation acquisition method based on digital image diffraction.
Background
Deformation measurement or monitoring of large engineering structures, such as bridges, transmission towers, tunnels and the like, is a major technical subject faced at present. The large-scale engineering structures are large in size, and people carry measuring instruments to measure the large-scale engineering structures, so that the large-scale engineering structures are difficult and dangerous.
At present, a feasible approach is provided for solving the problem at the beginning of the image vision system, the deformation method for measuring the large-scale structure by adopting the digital image has the characteristics of long distance, no damage, full field, high automation degree, fast data transmission and the like, but the measurement accuracy depends on the physical resolution of the digital image, has larger limitation and is not beneficial to popularization and application. Accordingly, there is a need in the art to develop a method for obtaining a deformation amount of an object with high flexibility.
Disclosure of Invention
Aiming at the defects or improvement requirements of the prior art, the invention provides an object deformation amount acquisition method based on digital image diffraction. The method for acquiring the object deformation amount is based on the fact that the object deformation causes surface displacement, a plurality of tiny characteristic points are arranged on the surface of the object and move along with the surface displacement, images of the object at the same position before and after denaturation are shot, Fourier transform processing is carried out on the images before and after deformation, namely, the images before and after deformation are equivalent to that digital speckle fringe patterns with equal intervals are generated by double-hole diffraction in physics, zero filling is carried out on the digital speckle fringe patterns, then Fourier transform is carried out again, sub-pixel precision displacement is obtained, the precision does not depend on the physical resolution of digital images, and the flexibility is high.
In order to achieve the above object, the present invention provides an object deformation amount obtaining method based on digital image diffraction, which mainly comprises the following steps:
(1) respectively and randomly selecting areas of the same part of the object from the two images before and after the object is deformed as analysis areas;
(2) performing fast Fourier transform on the gray values of the pixel points of the two analysis areas respectively to obtain a first transform result representing the deformation of the object and a second transform result representing the deformation of the object respectively, and further obtain a conversion result function of the gray values of the pixel points in the analysis areas corresponding to the image before deformation, displacement caused by deformation and angle variables;
(3) respectively calculating a first function, a second function, a third function and a fourth function when the angle variable is used for obtaining a first preset value, a second preset value, a third preset value and a fourth preset value, and carrying out mathematical processing on the first function, the second function, the third function and the fourth function so as to offset coefficients caused by conjugate multiplication to obtain a fifth function;
(4) with the fringe image corresponding to the fifth function as a center, expanding the fringe image by k times in a zero adding mode around the fringe image to obtain a sixth function;
(5) and performing Fourier transform on the sixth function to obtain a pulse function containing displacement generated by deformation, and calculating to obtain the coordinate of the highest pulse point of the pulse function so as to obtain the deformation generated by the deformation of the object.
Further, the step (1) includes a step of taking images of the object before and after deformation at the same position by using a camera, wherein the two images respectively include at least one same part of the object.
Further, in the step (2), the second transformation result is multiplied by an angle variable to obtain a third transformation result, the first transformation result and the third transformation result are added to obtain a conversion result, the conversion result is a matrix, and the matrix is subjected to conjugate multiplication processing to obtain a gray value of a pixel point in an analysis area corresponding to the image before deformation, a displacement caused by deformation and a conversion result function of the angle variable.
Further, the third transformation result is expressed by the following formula:
in the formula, F0(u, v) is the first transform result; f1(u, v) is the second transform result; (x, y) is the coordinate in the space-time region composed of the image plane displacement and the gray value of the pixel point; (u, v) are the fourier transformed coordinates; j is an imaginary unit;displacement variables that need to be added; e is the natural logarithm.
Further, the result of the first transformation is an exponential function F0(u, v), the second transformation result is an exponential function F1(u, v), the two exponential functions are respectively expressed by the following formulas:
in the formula, (x, y) is a coordinate in a space-time region composed of image plane displacement and gray values of pixel points; dx and dy are displacements of the pixel points in the x direction and the y direction respectively caused by deformation, and (u, v) are coordinates after Fourier transform; j is an imaginary unit; e is a natural logarithm; pi is a mathematical middle angle equal to 180 °; f. of0(x, y) a function representing the relationship between the grey values of the image before deformation and the coordinates, f0(x-dx, y-dy) represents a relation function between the gray value and the coordinates of the deformed image; the number of pixels in the x-direction and the y-direction of the analysis area is M.
Further, the expression of the scaling result function is:
in the formula, F0(u, v) is that the result of said first transformation is an exponential function；F1(u, v) is that the second transformation result is an exponential function; (x, y) is the coordinate in the space-time region composed of the image plane displacement and the gray value of the pixel point; (u, v) are the fourier transformed coordinates; j is an imaginary unit; e is a natural logarithm;displacement variables that need to be added; the number of pixels in the x-direction and the y-direction of the analysis area is M.
Further, the expression of the fifth function is:
wherein, I1、I2、I3And I4The first function, the second function, the third function and the fourth function are respectively; (u, v) are the coordinates after Fourier transform, respectively; the number of pixels in the x direction and the y direction of the analysis area is M; dx and dy are displacement amounts in the x direction and the y direction caused by the deformation, respectively; pi equals 180 deg.
Further, the expression of the sixth function is:
in the formula, region D0In the range of D0The analysis method comprises the following steps of (1), (u, v) | u belongs to (S, S + M-1), and v belongs to (S, S + M-1) }, namely, the selected analysis area is obtained; region D1For the expanded region, the range isThe point (S, S) is a region D0In the region D1When M is an even number,when the number of M is an odd number,k is the magnification of the image corresponding to the fifth function, and k is an even number greater than 1.
Further, the first function, the second function, the third function and the fourth function are respectively corresponding to I1、I2、I3And I4The expressions are respectively:
in the formula,F0(u, v) is the first transform result; denotes it as a transpose of the function shown.
Further, the expression of the pulse function is:
wherein, (x, y) is the coordinate in the space-time region composed of the image plane displacement and the gray value of the pixel point; (dx ', dy') is the coordinate corresponding to the peak in the fourier transformed spectral domain; δ (x) is a dirac function.
Generally, compared with the prior art, the method for acquiring the deformation of the object based on digital image diffraction provided by the invention mainly has the following beneficial effects:
1. the object deformation amount acquisition method is used for carrying out Fourier transform processing on the images before and after deformation, namely, the images before and after deformation are subjected to double-hole diffraction in physics, digital speckle fringe patterns with equal intervals can be generated, zero filling is carried out on the digital speckle fringe patterns, then Fourier transform is carried out again, sub-pixel precision displacement is obtained, precision does not depend on the physical resolution of digital images, and flexibility is high.
2. The method for acquiring the object deformation does not depend on the physical resolution of the digital image, so that a shooting device with high precision is not needed, the use cost is reduced, and the applicability is improved.
3. The method for acquiring the deformation of the object is simple, easy to implement and beneficial to popularization and application.
4. The method for acquiring the object deformation can acquire the expected sub-pixel precision in a zero filling mode, improves the precision and provides powerful data support for the research of the object deformation.
Drawings
Fig. 1 is a schematic flow chart of an object deformation amount acquisition method based on digital image diffraction according to a first embodiment of the present invention.
Fig. 2A and fig. 2B are speckle patterns of the same position before and after deformation obtained by using MATLAB software in the method for obtaining an object deformation amount based on digital image diffraction according to the second embodiment of the present invention.
Fig. 3 is a fringe pattern of a fifth function obtained by using the method for obtaining an object deformation amount based on digital image diffraction according to the second embodiment of the present invention.
Fig. 4 is a frequency spectrum diagram of a pulse function obtained by using the method for obtaining the deformation of the object based on digital image diffraction according to the second embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Referring to fig. 1, a method for obtaining an object deformation amount based on digital image diffraction according to a first embodiment of the present invention mainly includes the following steps:
respectively and randomly selecting areas of the same part of the object from two images before and after the object is deformed as analysis areas, wherein the shapes and the contained pixel numbers of the two analysis areas are the same, and the initial coordinates and the end coordinates of the pixels of the two analysis areas in the corresponding images are also the same respectively.
In particular, a photographing device (e.g., a camera) is used to photograph two images of the same object before and after deformation at the same location, both images including at least one identical portion of the object. Then, a square analysis area is randomly selected from areas of the same part of the object in the two images, the shapes and the contained pixel numbers of the two analysis areas are the same, and simultaneously, the initial coordinates and the end coordinates of the pixels of the two analysis areas in the corresponding images are also respectively the same.
And secondly, performing fast Fourier transform on the gray values of the pixel points of the two analysis areas respectively to obtain a first transform result before representing the deformation of the object and a second transform result after representing the deformation of the object, and further obtain a conversion result function of the gray values of the pixel points in the analysis areas corresponding to the image before deformation, displacement caused by deformation and angle variables.
Specifically, fast fourier transform is performed on gray values of pixel points in two analysis regions respectively to obtain a first transform result representing the deformation of an object and a second transform result representing the deformation of the object, the second transform result is a function of the first transform result due to the deformation of the image after the deformation of the object relative to the image before the deformation, an angle variable is multiplied by the second transform result to obtain a third transform result, the first transform result and the third transform result are added to obtain a conversion result, the conversion result is a matrix, and the matrix is subjected to conjugate multiplication processing to obtain a function of the gray values of the pixel points in the analysis region corresponding to the image before the deformation, the displacement caused by the deformation and the conversion result of the angle variable.
And step three, respectively calculating a first function, a second function, a third function and a fourth function when the angle variable obtains a first preset value, a second preset value, a third preset value and a fourth preset value, and performing mathematical processing on the first function, the second function, the third function and the fourth function to offset coefficients caused by conjugate multiplication to obtain a fifth function.
Specifically, the first predetermined value, the second predetermined value, the third predetermined value and the fourth predetermined value are 0, pi/2, pi and 3 pi/2, respectively; and performing mathematical processing on the first function, the second function, the third function and the fourth function to offset a coefficient caused by conjugate multiplication of gray values of the image before object deformation in a frequency domain, so as to obtain a fifth function.
The fifth function I obtained5The following formula is adopted:
wherein, I1、I2、I3And I4The first function, the second function, the third function and the fourth function are respectively; (u, v) are the coordinates after Fourier transform, respectively; the number of pixels in the x direction and the y direction of the square analysis area is M; dx and dy are displacement amounts in the x direction and the y direction caused by the deformation, respectively; pi is the mathematically mean angle and equals 180.
And fourthly, with the fringe image corresponding to the fifth function as a center, expanding the fringe image by k times in a zero adding mode around the fringe image to obtain a sixth function, wherein k is an even number greater than 1.
The expression of the sixth function is as follows:
in the formula, region D0In the range of D0The analysis method comprises the following steps of (1), (u, v) | u belongs to (S, S + M-1), and v belongs to (S, S + M-1) }, namely, the selected analysis area is obtained; region D1For the expanded region, the range isThe point (S, S) is a region D0In the region D1When M is an even number,when the number of M is an odd number,k is the expansion multiple of the image corresponding to the fifth function, k is an even number, M is the number of pixels of the selected analysis area in the x direction, and the number of pixels of the analysis area in the y direction is also M.
And fifthly, performing Fourier transform on the sixth function to obtain a pulse function containing displacement generated by deformation, and calculating to obtain the coordinate of the highest pulse point of the pulse function so as to obtain the deformation generated by deformation of the object.
Specifically, the pulse function is expressed by the following formula:
in the formula, (x, y) is a coordinate in a space-time region composed of image plane displacement and gray values of pixel points; dx and dy are the amount of surface displacement in the x-direction and y-direction, respectively, caused by the deformation; (dx ', dy') is the coordinate corresponding to the peak in the spectrum domain after fourier transform, and (u, v) are the coordinates after fourier transform, respectively; j is an imaginary unit; δ (x) is a dirac function; e is the natural logarithm.
In this embodiment, when M is an even number,when the number of M is an odd number,the frequency spectrum domain of the digital stripe image is expanded to k times of the original frequency spectrum domain, and each pixel in the frequency spectrum domain represents the original displacement valueThe sub-pixel precision displacement of the object in the X direction and the Y direction is respectivelyAnd
referring to fig. 2A, fig. 2B, fig. 3 and fig. 4, a method for obtaining an object deformation amount based on digital image diffraction according to a second embodiment of the present invention mainly includes the following steps:
s1, using a program written by MATLAB software to obtain simulated speckle images of the object before and after deformation, as shown in fig. 2A and 2B, fig. 2A is an image of a speckle part before deformation, and fig. 2B is an image of a speckle part after deformation, and the two images include the same part of the object, i.e., the speckle part.
And S2, randomly selecting analysis areas in the areas near the speckles in the two images, wherein the two analysis areas are the same in shape and are both square, and the number of pixels contained in the two analysis areas is the same. In this embodiment, the start coordinates of the selected pixels in the pre-deformed and post-deformed images are all (180, 150), the end coordinates of the pixels are all (280, 250), and the analysis area size is all 101 × 101.
S3, performing fast Fourier transform on the gray values of the pixel points in the two analysis regions respectively to obtain a first transform result before representing the deformation of the object and a second transform result after representing the deformation of the object, wherein the first transform result is an exponential function F0(u, v), the second transformation result is an exponential function F1(u, v), two exponential functions are respectively as follows:
in the formula, (x, y) is a coordinate in a space-time region composed of image plane displacement and gray values of pixel points; dx and dy are displacements of the pixel points in the x direction and the y direction respectively caused by deformation, and (u, v) are coordinates after Fourier transform; j is an imaginary unit; e is a natural logarithm; pi is a mathematical middle angle equal to 180 °; f. of0(x, y) a function representing the relationship between the grey values of the image before deformation and the coordinates, f0(x-dx, y-dy) represents the deformed imageThe relationship function between the gray value and the coordinate. Since the displacement before and after deformation can be considered as a translation relation, the gray values of the image pixels before and after deformation have displacement values in the X-direction and the Y-direction, namely dx and dy, respectively, that is, the surface displacement amount generated before and after deformation of the object.
Fast Fourier transform result of the image gray value function after deformation, namely the second transform result F1(u, v) multiplied by an angle variableObtaining a third transformation result F3(u, v) as shown in the following formula:
in the formula, (x, y) is a coordinate in a space-time region composed of image plane displacement and gray values of pixel points; dx and dy are displacements in the x-direction and y-direction, respectively; (u, v) are the fourier transformed coordinates; j is an imaginary unit;to require an increased displacement variable.
The amount of displacement due to deformation is a result of a relative movement, which depends on the gray value of the image before deformation, and is therefore increasedIt is to utilize the increased displacement amount in the post-processing to make the displacement amount caused by the deformation independent of the gray value of the image before the deformation, thereby providing the possibility of solving the displacement amount caused by the deformation.
F3(u, v) is a group with F0(u, v), surface displacement dx and dy, and angle variablesA function of interest, thenThe function is compared with the result F of fast Fourier transform of the image before deformation0(u, v) are added to obtain a function Ai(u, v), the function is the conversion result, and the specific process is shown as the following formula:
will represent the function A of the conversion resulti(u, v) conjugate multiplication to obtain a function I of gray values of pixel points in an analysis region of the image before deformation, displacement caused by deformation and angle variablesi(u, v) to obtain a product of formula (I) and (II)0(u, v), surface displacement amounts dx and dy, and among the variablesThe function of interest is shown as:
wherein,denotes it as a transpose of the function shown.
And S4, respectively calculating a first function when the angle variable is taken as a first preset value, a second function when the angle variable is taken as a second preset value, a third function when the angle variable is taken as a third preset value and a fourth function when the angle variable is taken as a fourth preset value. In this embodiment, the first predetermined value, the second predetermined value, the third predetermined value, and the fourth predetermined value are respectivelyPi/2, pi and 3 pi/2, wherein the obtained first function, the second function, the third function and the fourth function are respectively corresponding to I1、I2、I3AndI4the method comprises the following steps:
in the formula,
s5, performing mathematical processing on the first function, the second function, the third function, and the fourth function to cancel out the gray values of the pixels in the four functions, so as to obtain a fifth function related to the surface displacement dx and dy, where the fifth function is a trigonometric function as follows:
then, the trigonometric function I is matched by software MATLAB5(u, v) are plotted to obtain a fringe pattern with respect to the surface displacement amount dx and dy, as shown in FIG. 3.
S6, using the stripe image corresponding to the fifth function as the center, enlarging the stripe image by k times by adding zero around the stripe image, thereby obtaining a sixth function. In this embodiment, the sixth function I is obtained by taking k as 106The following were used:
in the formula, region D0In the range of D0{ (u, v) | u ∈ (S, S + M-1), v ∈ (S, S + M-1) }, region D1In the range of D1{ (u, v) | u ∈ (-5M,5M-1), v ∈ (-5M,5M-1) }; the point (S, S) is a region D0In the region D1The start position coordinates of (1); when M is an even number, the number of bits is,when the number of M is an odd number,
s7, for the sixth function I6(u, v) performing fourier transform, expanding a frequency spectrum domain after the transform by 10 times, namely, improving the resolution by 10 times, thereby obtaining a pulse function containing the displacement generated by the deformation, calculating and obtaining a position coordinate of a highest point in the pulse function, and obtaining the displacement generated by the deformation of the object according to the position coordinate, wherein the following steps are specifically performed:
and calculating the position of the coordinate point corresponding to the peak value by using MATLAB software or other software writing programs, so as to obtain the specific numerical value of the solved surface displacement. In the present embodiment, since the spectrum domain is expanded to 10 times, the displacement value represented by each pixel in the spectrum domain is 0.1 times of the original displacement value; the coordinates of the positions corresponding to the peak points in the obtained spectral domain are (-42, -33) and (42, 33), and the calculated displacement amounts dx and dy with sub-pixel accuracy are 4.2 pixels and 3.3 pixels, respectively. The pulse function was plotted using software, as shown in fig. 4.
The invention provides an object deformation amount obtaining method based on digital image diffraction, which is characterized in that surface displacement is caused based on object deformation, a plurality of tiny characteristic points are arranged on the surface of an object, the tiny characteristic points move along with the surface displacement, images before and after the same position of the object is denatured are shot, Fourier transform processing is carried out on the images before and after the deformation, namely, double-hole diffraction in physics can generate digital speckle fringe patterns with equal intervals, zero filling is carried out on the digital speckle fringe patterns, Fourier transform is carried out again, sub-pixel precision displacement is obtained, the precision does not depend on the physical resolution of a digital image, and the flexibility is higher.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (10)
1. An object deformation amount acquisition method based on digital image diffraction is characterized by comprising the following steps:
(1) respectively and randomly selecting areas of the same part of the object from the two images before and after the object is deformed as analysis areas;
(2) performing fast Fourier transform on the gray values of the pixel points of the two analysis areas respectively to obtain a first transform result representing the deformation of the object and a second transform result representing the deformation of the object respectively, and further obtain a conversion result function of the gray values of the pixel points in the analysis areas corresponding to the image before deformation, displacement caused by deformation and angle variables;
(3) respectively calculating a first function, a second function, a third function and a fourth function when the angle variable is used for obtaining a first preset value, a second preset value, a third preset value and a fourth preset value, and carrying out mathematical processing on the first function, the second function, the third function and the fourth function so as to offset coefficients caused by conjugate multiplication to obtain a fifth function;
(4) with the fringe image corresponding to the fifth function as a center, expanding the fringe image by k times in a zero adding mode around the fringe image to obtain a sixth function;
(5) and performing Fourier transform on the sixth function to obtain a pulse function containing displacement generated by deformation, and calculating to obtain the coordinate of the highest pulse point of the pulse function so as to obtain the deformation generated by the deformation of the object.
2. The method for acquiring the amount of deformation of the object based on the diffraction of the digital image as set forth in claim 1, wherein: the step (1) further comprises the step of shooting images of the object before and after deformation by using a camera at the same position, wherein the two images respectively comprise at least one same part of the object.
3. The method for acquiring the amount of deformation of the object based on the diffraction of the digital image as set forth in claim 1, wherein: in the step (2), the second transformation result is multiplied by an angle variable to obtain a third transformation result, the first transformation result and the third transformation result are added to obtain a conversion result, the conversion result is a matrix, and the matrix is subjected to conjugate multiplication processing to obtain a gray value of a pixel point in an analysis area corresponding to the image before deformation, a displacement caused by deformation and a conversion result function of the angle variable.
4. The method for acquiring the amount of deformation of the object based on the diffraction of the digital image as set forth in claim 3, wherein: the third transformation result is expressed by the following formula:
in the formula, F0(u, v) is the first transform result; f1(u, v) is the second transform result; (x, y) is the coordinate in the space-time region composed of the image plane displacement and the gray value of the pixel point; (u, v) are the fourier transformed coordinates; j is an imaginary unit;displacement variables that need to be added; e is the natural logarithm.
5. The method for obtaining an object deformation amount based on digital image diffraction according to any one of claims 1 to 4, wherein: the result of the first transformation is an exponential function F0(u, v), the second transformation result is an exponential function F1(u, v), the two exponential functions are respectively expressed by the following formulas:
in the formula, (x, y) is a coordinate in a space-time region composed of image plane displacement and gray values of pixel points; dx and dy are displacements of the pixel points in the x direction and the y direction respectively caused by deformation, and (u, v) are coordinates after Fourier transform; j is an imaginary unit; e is a natural logarithm; pi is a mathematical middle angle equal to 180 °; f. of0(x, y) a function representing the relationship between the grey values of the image before deformation and the coordinates, f0(x-dx, y-dy) represents a relation function between the gray value and the coordinates of the deformed image; the number of pixels in the x-direction and the y-direction of the analysis area is M.
6. The method for obtaining an object deformation amount based on digital image diffraction according to any one of claims 1 to 4, wherein: the expression of the conversion result function is as follows:
in the formula, F0(u, v) is that the first transformation result is an exponential function; f1(u, v) is that the second transformation result is an exponential function; (x, y) is the coordinate in the space-time region composed of the image plane displacement and the gray value of the pixel point; (u, v) are the fourier transformed coordinates; j is an imaginary unit; e is a natural logarithm;displacement variables that need to be added; the number of pixels in the x-direction and the y-direction of the analysis area is M.
7. The method for obtaining an object deformation amount based on digital image diffraction according to any one of claims 1 to 4, wherein: the expression of the fifth function is:
wherein, I1、I2、I3And I4The first function, the second function, the third function and the fourth function are respectively; (u, v) are the coordinates after Fourier transform, respectively; the number of pixels in the x direction and the y direction of the analysis area is M; dx and dy are displacement amounts in the x direction and the y direction caused by the deformation, respectively; pi equals 180 deg.
8. The method for acquiring the amount of deformation of the object based on the diffraction of the digital image as set forth in claim 7, wherein: the expression of the sixth function is:
in the formula, region D0In the range of D0The analysis method comprises the following steps of (1), (u, v) | u belongs to (S, S + M-1), and v belongs to (S, S + M-1) }, namely, the selected analysis area is obtained; region D1For the expanded region, the range isThe point (S, S) is a region D0In the region D1When M is an even number,when the number of M is an odd number,k is the magnification of the image corresponding to the fifth function, and k is an even number greater than 1.
9. The method for acquiring the amount of deformation of the object based on the diffraction of the digital image as set forth in claim 7, wherein: the first function, the second function, the third function and the fourth function are respectively corresponding to I1、I2、I3And I4The expressions are respectively:
in the formula, B0(u,v)＝2F0(u,v)F0 *(u,v)；F0(u, v) is the first transform result; denotes it as a transpose of the function shown.
10. The method for obtaining an object deformation amount based on digital image diffraction according to any one of claims 1 to 4, wherein: the expression of the pulse function is:
wherein, (x, y) is the coordinate in the space-time region composed of the image plane displacement and the gray value of the pixel point; (dx ', dy') is the coordinate corresponding to the peak in the fourier transformed spectral domain; δ (x) is a dirac function.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810645210.4A CN109035201B (en) | 2018-06-21 | 2018-06-21 | Object deformation obtaining method based on digital image diffraction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810645210.4A CN109035201B (en) | 2018-06-21 | 2018-06-21 | Object deformation obtaining method based on digital image diffraction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109035201A true CN109035201A (en) | 2018-12-18 |
| CN109035201B CN109035201B (en) | 2021-01-01 |
Family
ID=64610697
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810645210.4A Active CN109035201B (en) | 2018-06-21 | 2018-06-21 | Object deformation obtaining method based on digital image diffraction |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109035201B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112797923A (en) * | 2021-01-05 | 2021-05-14 | 上海交通大学 | Method, system and medium for correcting center and Euler angle of particle diffraction image pattern |
| CN114740008A (en) * | 2022-03-31 | 2022-07-12 | 杭州今誉信息科技有限公司 | Super-resolution wafer defect detection system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110243393A1 (en) * | 2010-03-30 | 2011-10-06 | Alexander Berkovich | Repeating Band Print Artifact Evaluation |
| CN103093461A (en) * | 2013-01-14 | 2013-05-08 | 大连理工大学 | Shape matching method based on measurement information |
| CN104200474A (en) * | 2014-09-04 | 2014-12-10 | 华中科技大学 | Digital image analysis method for obtaining object deformation quantity |
-
2018
- 2018-06-21 CN CN201810645210.4A patent/CN109035201B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110243393A1 (en) * | 2010-03-30 | 2011-10-06 | Alexander Berkovich | Repeating Band Print Artifact Evaluation |
| CN103093461A (en) * | 2013-01-14 | 2013-05-08 | 大连理工大学 | Shape matching method based on measurement information |
| CN104200474A (en) * | 2014-09-04 | 2014-12-10 | 华中科技大学 | Digital image analysis method for obtaining object deformation quantity |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112797923A (en) * | 2021-01-05 | 2021-05-14 | 上海交通大学 | Method, system and medium for correcting center and Euler angle of particle diffraction image pattern |
| CN112797923B (en) * | 2021-01-05 | 2022-12-30 | 上海交通大学 | Method, system, and medium for correcting center and euler angle of particle diffraction image pattern |
| CN114740008A (en) * | 2022-03-31 | 2022-07-12 | 杭州今誉信息科技有限公司 | Super-resolution wafer defect detection system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109035201B (en) | 2021-01-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109087279B (en) | Method for rapidly acquiring object deformation based on digital image diffraction | |
| KR101475382B1 (en) | Method for extracting self adaptive window fourie phase of optical three dimensionl measurement | |
| CN100520285C (en) | Vision measuring method for projecting multiple frequency grating object surface tri-dimensional profile | |
| CN109242905B (en) | Method for determining object displacement and direction based on digital image diffraction | |
| CN110136114B (en) | Wave surface height measuring method, terminal equipment and storage medium | |
| CN104103058B (en) | Image matching system and method | |
| CN104376553B (en) | A kind of vision measuring method at the single-shaft-rotation angle based on mobile camera and dual-target | |
| JP4941565B2 (en) | Corresponding point search apparatus and corresponding point searching method | |
| CN109035201B (en) | Object deformation obtaining method based on digital image diffraction | |
| CN104376550A (en) | Super-resolution image reconstruction method based on integral-contained balancing model | |
| CN108008389A (en) | A kind of fast frequency-domain rear orientation projection three-D imaging method based on GPU | |
| KR101627950B1 (en) | Image processing device, distortion correction map creation device, and semiconductor measurement device | |
| CN104697463A (en) | Blanking feature constraining calibrating method and device for binocular vision sensor | |
| CN105469398A (en) | Deformation speckle generation method based on reverse mapping method | |
| WO2018056206A1 (en) | Displacement measurement device, displacement measurement system, displacement measurement method, and program | |
| JP5795095B2 (en) | Phase analysis method of lattice image using weighting | |
| CN112767536B (en) | Three-dimensional reconstruction method, device and equipment for object and storage medium | |
| CN101917624B (en) | Method for reconstructing high resolution video image | |
| CN103440618A (en) | Block-based texture synthesis method and device | |
| Zhang et al. | On-orbit space camera self-calibration based on the orthogonal vanishing points obtained from solar panels | |
| CN109859313B (en) | 3D point cloud data acquisition method and device, and 3D data generation method and system | |
| CN103323844B (en) | Multi-channel interferometric synthetic aperture radar elevation rebuilding method and device | |
| CN110033435B (en) | High-sensitivity digital image displacement frequency domain analysis method | |
| CN107588741A (en) | A kind of measuring method and system of the camera depth change based on Moire fringe | |
| JP2022117666A5 (en) | Chart generation method, resolution measurement method, resolution measurement system, and program |
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 |