KR101659443B1 - High resolution particle image velocimetry technique using combined cross corrleation and optical flow method - Google Patents
High resolution particle image velocimetry technique using combined cross corrleation and optical flow method Download PDFInfo
- Publication number
- KR101659443B1 KR101659443B1 KR1020150090302A KR20150090302A KR101659443B1 KR 101659443 B1 KR101659443 B1 KR 101659443B1 KR 1020150090302 A KR1020150090302 A KR 1020150090302A KR 20150090302 A KR20150090302 A KR 20150090302A KR 101659443 B1 KR101659443 B1 KR 101659443B1
- Authority
- KR
- South Korea
- Prior art keywords
- tracking
- image
- particle
- particles
- displacement
- Prior art date
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/18—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the time taken to traverse a fixed distance
- G01P5/22—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the time taken to traverse a fixed distance using auto-correlation or cross-correlation detection means
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Image Analysis (AREA)
Abstract
Description
The present invention relates to a method and an apparatus for measuring a high-precision particle image flow rate using a correlation coefficient and an optical flow integration method, and more particularly, Estimating the approximate velocity distribution of the particles through an existing correlation coefficient analysis method, transforming the captured second image based on the estimated velocity distribution, and calculating the sensitivity for the image based on the transformed second image and the first image To a method for measuring velocity distribution of particles in a flow field by reapplication of a high optical flow technique.
Image PIV (PIV) is an optical measurement technique that can simultaneously measure the velocity components of two- and three-dimensional all-propane fields. It is a technique to analyze the flow field using images obtained by inserting tracking particles into the flow field and applying appropriate illumination.
Conventional image particle velocimetry (PIV) uses a method to calculate the correlation coefficient between two image frames and to analyze the velocity of a predetermined interrogation area.
This method is highly reliable in analyzing the velocity distribution of particles in general, but requires an analysis area of more than a certain size, so there is a limit to the resolution of the space and it is necessary to observe the movement of particles over a certain distance between two image frames Do.
Therefore, in order to analyze the cross correlation coefficient, it is necessary to set the analysis area above a certain size. Therefore, there is a problem that the spatial resolution is limited in analyzing the particle velocity distribution. In order to measure the velocity distribution of the particle accurately, And it is necessary to set the size of the analysis area. If the above condition is not satisfied, there is a problem that the accuracy of the analysis of the velocity distribution of the particles is poor.
In this regard, Korean Patent Laid-Open Publication No. 10-2009-0114125 relates to a multi-plane particle image flow velocity measuring apparatus for observing a flow area of a large area and acquiring a flow field, A plurality of cameras each for acquiring an image, a horizontal guide for mounting the camera to adjust the horizontal position of the camera, and a vertical guide for adjusting the vertical position of the horizontal guide by mounting the horizontal guide. However, the techniques disclosed in the above patent documents do not solve the above-described problems.
Therefore, a technique for solving the above-described problems is required.
On the other hand, the background art described above is technical information acquired by the inventor for the derivation of the present invention or obtained in the derivation process of the present invention, and can not necessarily be a known technology disclosed to the general public before the application of the present invention .
An embodiment of the present invention has an object to prevent degradation of spatial resolution by setting an analysis area of a predetermined size or larger in order to calculate a displacement and a velocity corresponding to a position of a region by analyzing cross correlation coefficients.
In addition, one embodiment of the present invention is a method of converting a photographed frame using displacement and velocity distribution of a low-resolution particle calculated using a cross-correlation coefficient, thereby realizing high spatial resolution and accurate velocity distribution And the like.
According to a first aspect of the present invention, there is provided a method for measuring a displacement of a particle by photographing a flow field including at least one tracking particle that can be identified through a plurality of photographed images at a predetermined time interval, The method comprising the steps of: determining a pixel area of each image with respect to the plurality of images in a unit of an analysis area, which is a pixel area of a predetermined size, which includes at least one of the at least one tracking particle, Calculating a correlation coefficient on an analysis domain basis for each of the plurality of images based on the tracking particles included in each of the analysis regions of mutually corresponding positions between the plurality of images, , An average velocity fraction of the tracking particles contained in each interpretation region between the plurality of images A may include the step of calculating.
According to a second aspect of the present invention, there is provided a particle tracking apparatus for analyzing a displacement of a particle by photographing a flow field including at least one tracking particle capable of being identified through a plurality of photographed images at regular time intervals, A particle photographing unit that sequentially photographs a flow field including particles at a predetermined time interval and a particle photographing unit that includes at least one of the at least one tracking particle, Calculating a correlation coefficient for each of the plurality of images on the basis of the tracing particles included in each of the analysis regions of mutually corresponding positions between the plurality of images, for each of the plurality of images And based on the calculated correlation coefficients, Calculating an average of the velocity distribution of the particles contained trace cross-correlation calculations may include a.
According to one embodiment of the present invention, the analysis area is analyzed by analyzing the cross-correlation coefficients to set an analysis area having a predetermined size or larger to calculate a displacement and a velocity corresponding to the position of the area, It is possible to prevent degradation of resolution.
In addition, according to any one of the tasks of the present invention, the optical flow technique transforms photographed frames using displacement and velocity distributions of low-resolution particles calculated using cross-correlation coefficients, thereby achieving high spatial resolution and accuracy It is possible to obtain the velocity distribution of the particles having the particle size distribution.
The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.
1 is a block diagram of a particle tracking apparatus according to an embodiment of the present invention.
2 is a flowchart illustrating a particle tracking method according to an embodiment of the present invention.
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.
Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
Before describing this, we first define the meaning of the terms used below.
In the present invention, the 'tracking particle' is a particle capable of scattering light of a light source and being photographed through a camera, and is mixed with a fluid to move the particle so that the particle flow can be grasped in the fluid field.
In order to calculate the displacement of the tracking particle between consecutive two frames with a short interval of 'short interval', 'cross correlation method' And finding the displacement of the analysis region having the maximum correlation coefficient.
The network N may be a local area network (LAN), a wide area network (WAN), a value added network (VAN), a personal area network (PAN) mobile radio communication network, Wibro (Wireless Broadband Internet), Mobile WiMAX, HSDPA (High Speed Downlink Packet Access) or satellite communication network.
The
FIG. 1 is a block diagram for explaining a
First, the
That is, the
The
In other words, the local velocity of the flow field can be obtained by knowing the straight line distance and direction in which the tracking particles passing through a certain point move during the minute time interval.
For this purpose, the
For example, the
Then, based on the pixel values of the analyzed regions of the first image, the
For example, the
At this time, the
The cross
Thus, by performing a cross-correlation method on the entire captured image of the interpretation region set in the image, the displacement and velocity of all the tracking particles included in the captured image can be calculated.
The
For example, the
By doing so, it is possible to generate a transformed transformed frame such that the second image is similar to the first image, and the displacement of the tracing particle between the first image and the transformed frame becomes very small.
And the velocity
For example, the velocity
Then, the velocity
In this way, it is possible to obtain a spatial high-resolution velocity distribution that can be applied to all fields utilizing fluid, and precise measurement can be performed by applying this technique to the minute motion that was difficult to measure previously.
In addition to the fluid field, it can also be used as a measurement technique for multi-dimensionally measuring the shape and shape of solid structures and distortions, and precise measurement of very minute changes is possible
Also, it can be used as a measurement method for measuring the spatial density distribution of air, temperature distribution, and the like.
The particle tracking method according to the embodiment shown in FIG. 2 includes the steps of the
First, the
Then, the
To this end, the
And the
Based on the displacement of the tracking particles calculated as described above, the
Then, the
That is, the
For example, the
Then, the
For example, the
In this way, fine displacements can be calculated for each of at least one tracking particle between the first image and the transform frame.
Thereafter, the
The particle tracking method according to the embodiment described with reference to FIG. 2 may also be implemented in the form of a recording medium including instructions executable by a computer such as a program module executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium can include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.
The particle tracking method according to an embodiment of the present invention may also be implemented as a computer program (or a computer program product) including instructions executable by a computer. A computer program includes programmable machine instructions that are processed by a processor and can be implemented in a high-level programming language, an object-oriented programming language, an assembly language, or a machine language . The computer program may also be recorded on a computer readable recording medium of a type (e.g., memory, hard disk, magnetic / optical medium or solid-state drive).
Thus, the particle tracking method according to an embodiment of the present invention can be implemented by a computer program as described above being executed by a computing device. The computing device may include a processor, a memory, a storage device, a high-speed interface connected to the memory and a high-speed expansion port, and a low-speed interface connected to the low-speed bus and the storage device. Each of these components is connected to each other using a variety of buses and can be mounted on a common motherboard or mounted in any other suitable manner.
Where the processor may process instructions within the computing device, such as to display graphical information to provide a graphical user interface (GUI) on an external input, output device, such as a display connected to a high speed interface And commands stored in memory or storage devices. As another example, multiple processors and / or multiple busses may be used with multiple memory and memory types as appropriate. The processor may also be implemented as a chipset comprised of chips comprising multiple independent analog and / or digital processors.
The memory also stores information within the computing device. In one example, the memory may comprise volatile memory units or a collection thereof. In another example, the memory may be comprised of non-volatile memory units or a collection thereof. The memory may also be another type of computer readable medium such as, for example, a magnetic or optical disk.
And the storage device can provide a large amount of storage space to the computing device. The storage device may be a computer readable medium or a configuration including such a medium and may include, for example, devices in a SAN (Storage Area Network) or other configurations, and may be a floppy disk device, a hard disk device, Or a tape device, flash memory, or other similar semiconductor memory device or device array.
It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.
The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.
10: particle tracking device
110: particle photographing unit
120: cross-correlation calculation unit
130; The frame-
140: velocity distribution calculation unit
Claims (13)
Dividing a pixel region of each image with respect to the plurality of images into at least one of the one or more tracking particles and in units of analysis regions which are pixel regions of a predetermined size that perform tracking of the tracking particles included;
Calculating correlation coefficients for each of the plurality of images on an analysis region basis on the basis of the tracking particles included in each of the analysis regions corresponding to positions mutually corresponding to the plurality of images; And
And calculating an average velocity distribution of the tracking particles included in each of the analysis regions between the plurality of images based on the calculated correlation coefficients.
Wherein the calculating the correlation coefficient comprises:
Calculating a correlation coefficient between each interpretation area in the first image and each interpretation area in the second image taken consecutively with the first image,
Wherein the step of calculating the velocity distribution comprises:
Determining a position in a second image having a correlation coefficient calculated for each analysis region as the largest value as an average displacement of the tracking particles contained in each analysis region in the first image, .
The particle tracking method includes:
Using the average displacement of the tracking particles contained in each of the analysis regions to generate a transformed image in which the position of each tracking particle is corrected for the one or more tracking particles in the second image, Way.
Wherein the step of generating the transformed image comprises:
Reversing the position of the one or more tracking particles in the second image by a displacement of each tracking particle calculated for each analysis area in the second image.
The particle tracking method includes:
Further comprising calculating displacement of each of the one or more tracking particles based on the position of the one or more tracking particles in each of the first image and the transformed image.
Wherein calculating the displacement of each of the one or more tracking particles comprises:
Searching for the same tracking particle within the constant pixel distance from the same position as the position in the first image in the transformed image for each of the one or more tracking particles.
A particle photographing unit sequentially photographing a flow field including the at least one tracking particle at regular time intervals; And
Dividing a pixel region of each image with respect to the plurality of images in a unit of an analysis region that is a pixel region of a predetermined size that includes at least one of the one or more tracking particles and performs tracking of the included tracking particles; Calculating a correlation coefficient for each of the plurality of images on the basis of the analysis area on the basis of the tracking particles included in each of the analysis areas corresponding to the mutually corresponding positions of the plurality of images, And a cross-correlation calculation unit for calculating an average velocity distribution of the tracking particles included in the region.
The cross-
Calculating a correlation coefficient between each interpretation region in the first image and each interpretation region in the second image captured successively from the first image, And determines a position in the image as an average displacement of the tracking particles included in each of the analysis regions in the first image.
The particle tracking device comprises:
Further comprising a frame transformer for generating a transformed image by correcting the position of each of the tracking particles with respect to the at least one tracking particle in the second image by using an average displacement of the tracking particles included in each of the analysis areas, Tracking device.
The frame converter may include:
And moves the position of the one or more tracking particles in the second image back by a displacement of each tracking particle calculated for each analysis region in the second image.
The particle tracking device comprises:
Further comprising a velocity distribution calculation unit that calculates a displacement of each of the one or more tracking particles based on the position of the one or more tracking particles in each of the first image and the conversion image.
The velocity distribution calculation unit may calculate,
Wherein in the transformed image for each of the one or more tracking particles, the same tracking particle is searched within a certain pixel distance from the same position as the position in the first image.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR20150074585 | 2015-05-28 | ||
KR1020150074585 | 2015-05-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
KR101659443B1 true KR101659443B1 (en) | 2016-09-23 |
Family
ID=57047449
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
KR1020150090302A KR101659443B1 (en) | 2015-05-28 | 2015-06-25 | High resolution particle image velocimetry technique using combined cross corrleation and optical flow method |
Country Status (1)
Country | Link |
---|---|
KR (1) | KR101659443B1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109035324A (en) * | 2018-07-20 | 2018-12-18 | 润电能源科学技术有限公司 | A kind of coal dust flow-speed measurement method and device based on image recognition |
CN110440766A (en) * | 2019-08-13 | 2019-11-12 | 陕西煤业化工技术研究院有限责任公司 | A kind of water-bearing layer hydrogeological parameter measuring device and method |
KR102218310B1 (en) * | 2019-11-07 | 2021-02-23 | 강원대학교산학협력단 | Flow measurement device using image sensor |
CN113960043A (en) * | 2021-10-20 | 2022-01-21 | 中国人民解放军国防科技大学 | Method and device for determining time evolution characteristics of supersonic/hypersonic turbulence |
KR20220065436A (en) * | 2020-11-13 | 2022-05-20 | 단국대학교 산학협력단 | Determination method of the searching window based on optical flow alogorithm |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09152443A (en) * | 1995-11-29 | 1997-06-10 | Aisin A W Kogyo Kk | Flow velocity measuring method and apparatus by particle image |
JP2003084006A (en) * | 2001-09-13 | 2003-03-19 | Mitsubishi Electric Corp | Flow velocity measuring apparatus and method for measuring flow velocity using the same |
KR101305305B1 (en) * | 2012-06-12 | 2013-09-06 | 동의대학교 산학협력단 | System and method for measuring surface image velocity using correlation analysis of spatio-temporal images |
-
2015
- 2015-06-25 KR KR1020150090302A patent/KR101659443B1/en active IP Right Grant
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09152443A (en) * | 1995-11-29 | 1997-06-10 | Aisin A W Kogyo Kk | Flow velocity measuring method and apparatus by particle image |
JP2003084006A (en) * | 2001-09-13 | 2003-03-19 | Mitsubishi Electric Corp | Flow velocity measuring apparatus and method for measuring flow velocity using the same |
KR101305305B1 (en) * | 2012-06-12 | 2013-09-06 | 동의대학교 산학협력단 | System and method for measuring surface image velocity using correlation analysis of spatio-temporal images |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN109035324A (en) * | 2018-07-20 | 2018-12-18 | 润电能源科学技术有限公司 | A kind of coal dust flow-speed measurement method and device based on image recognition |
CN110440766A (en) * | 2019-08-13 | 2019-11-12 | 陕西煤业化工技术研究院有限责任公司 | A kind of water-bearing layer hydrogeological parameter measuring device and method |
KR102218310B1 (en) * | 2019-11-07 | 2021-02-23 | 강원대학교산학협력단 | Flow measurement device using image sensor |
KR20220065436A (en) * | 2020-11-13 | 2022-05-20 | 단국대학교 산학협력단 | Determination method of the searching window based on optical flow alogorithm |
KR102462351B1 (en) | 2020-11-13 | 2022-11-02 | 단국대학교 산학협력단 | Determination method of the searching window based on optical flow alogorithm |
CN113960043A (en) * | 2021-10-20 | 2022-01-21 | 中国人民解放军国防科技大学 | Method and device for determining time evolution characteristics of supersonic/hypersonic turbulence |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR101659443B1 (en) | High resolution particle image velocimetry technique using combined cross corrleation and optical flow method | |
EP3101387B1 (en) | Image processing apparatus and image processing method | |
US11100706B2 (en) | Three-dimensional reconstruction method, three-dimensional reconstruction apparatus, and generation method for generating three-dimensional model | |
EP3216216B1 (en) | Methods and systems for multi-view high-speed motion capture | |
US20180324359A1 (en) | Image processing for turbulence compensation | |
US8723926B2 (en) | Parallax detecting apparatus, distance measuring apparatus, and parallax detecting method | |
US8897539B2 (en) | Using images to create measurements of structures through the videogrammetric process | |
US9230335B2 (en) | Video-assisted target location | |
US8391542B2 (en) | Method for estimating the pose of a PTZ camera | |
WO2018142496A1 (en) | Three-dimensional measuring device | |
US20170171525A1 (en) | Electronic system including image processing unit for reconstructing 3d surfaces and iterative triangulation method | |
Falquez et al. | Inertial aided dense & semi-dense methods for robust direct visual odometry | |
KR20150107605A (en) | Image blurring method and apparatus, and electronic device | |
KR20080077987A (en) | Single-image vignetting correction | |
US20230083320A1 (en) | Systems and Methods for Remote Sensing of River Velocity Using Video and an Optical Flow Algorithm | |
US20110096169A1 (en) | Camera tracking system and method, and live video compositing system | |
US9826162B2 (en) | Method and apparatus for restoring motion blurred image | |
US20160034607A1 (en) | Video-assisted landing guidance system and method | |
Lawson et al. | Bias in particle tracking acceleration measurement | |
Lefloch et al. | Real-time motion artifacts compensation of tof sensors data on gpu | |
KR101555876B1 (en) | System and method for object tracking for video synthesis | |
KR20150119770A (en) | Method for measuring 3-dimensional cordinates with a camera and apparatus thereof | |
Rajakaruna et al. | Image deblurring for navigation systems of vision impaired people using sensor fusion data | |
Alphonse et al. | Depth estimation from a single RGB image using target foreground and background scene variations | |
Vasilyuk | Calculation of motion blur trajectories in a digital image as a special problem of inertial navigation |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
E701 | Decision to grant or registration of patent right | ||
GRNT | Written decision to grant | ||
FPAY | Annual fee payment |
Payment date: 20190902 Year of fee payment: 4 |