CN110440714B - Phase unwrapping method based on multi-frequency and binary stripes - Google Patents
Phase unwrapping method based on multi-frequency and binary stripes Download PDFInfo
- Publication number
- CN110440714B CN110440714B CN201910836246.5A CN201910836246A CN110440714B CN 110440714 B CN110440714 B CN 110440714B CN 201910836246 A CN201910836246 A CN 201910836246A CN 110440714 B CN110440714 B CN 110440714B
- Authority
- CN
- China
- Prior art keywords
- period
- frequency
- binary
- phase
- stripes
- 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
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/24—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures
- G01B11/25—Measuring arrangements characterised by the use of optical techniques for measuring contours or curvatures by projecting a pattern, e.g. one or more lines, moiré fringes on the object
Abstract
The invention discloses a phase unwrapping method based on multi-frequency and binary stripes, which consists of three key parts, namely a phase shifting method basic principle, a multi-frequency method principle and a phase unwrapping principle. The invention has the advantages that: (1) a novel phase unwrapping method is provided, and the measuring effect on objects with complex surfaces is good. (2) And calculating the stripe level by using a binary coding and decoding algorithm, so that the judgment of the stripe level is not easy to make mistakes. (3) And high-frequency stripes are used, so that the measurement precision is high. The invention has the advantages that: the method has the advantages of simple calculation, flexible control, simple and convenient operation, higher robustness for the measurement of complex objects and isolated objects, and potential application prospect and practical value in precision measurement.
Description
Technical Field
The invention relates to an optical three-dimensional measurement method, belongs to the technical field of photoelectric detection, and particularly relates to a phase unwrapping method based on multi-frequency and binary stripes.
Technical Field
With the rapid development of modern industry and information technology, the requirements for the speed and precision of three-dimensional measurement of objects are higher and higher. Among a plurality of methods for acquiring three-dimensional information of an object, an optical three-dimensional measurement technology widely relates to various subjects such as optical imaging, computer technology, photoelectron information, image processing and the like, has the characteristic of integrating the advantages of other measurement methods, and gradually becomes a trend in the field of three-dimensional topography measurement. The optical three-dimensional measurement technology actually reconstructs a surface shape of a three-dimensional object by using a two-dimensional projection image, namely, information is acquired from the two-dimensional projection image, and then the geometric dimension of the object in a three-dimensional space is obtained by processing digital information. Among them, the three-dimensional measurement method based on the grating fringe projection is one of popular measurement methods in the optical three-dimensional measurement method, and has irreplaceable superiority for obtaining three-dimensional surface information, and in recent years, remarkable progress has been made in practical and commercial applications. The invention provides a novel phase unwrapping method, which has higher measurement precision and robustness and has potential application prospect and practical value in precision measurement.
An optical three-dimensional measurement system based on fringe projection is shown in fig. 1 and comprises a DLP projector 1, a CCD camera 2, a workstation 3, a measurement support 4, a reference plane 5 and an object to be measured 6. The DLP projector 1 and the CCD camera 2 are placed on a measuring bracket 4; the DLP projector 1 and the CCD2 are respectively connected with the workstation 3 through data lines; the object 6 to be measured is placed on the reference plane 5; the workstation 3 comprises an image acquisition card, projection software and measurement software. The DLP projector 1 focuses and projects the stripes with the characteristic information on the surface of the measured object 6, the CCD2 collects the stripe information, the characteristic information is extracted after the processing of the workstation 3, and the three-dimensional reconstruction is carried out according to a specific algorithm.
Disclosure of Invention
Based on the above problems, the present invention is directed to a phase unwrapping method based on multi-frequency and binary fringe.
The invention adopts the following technical scheme: generating four-step phase shift graphs with cycles changing according to exponential growth (the base number is 2, the index is n, and n is 1,2,3 and …) by using a computer, and respectively projecting the four-step phase shift graphs of each cycle to the surface of the measured object; then, the wrapping phase of each period is obtained by using a four-step phase shift algorithm. And carrying out binarization on the wrapping phase of each period according to a threshold value of 0 to generate binary stripes under each period. And calculating the fringe level K by using a binary encoding and decoding algorithm, then unfolding the wrapping phase under the highest period by using the K, and finally obtaining the continuous phase of the object.
Further, the frequency of the period must be chosen such that T-2n-1(n＝1,2,...,)。
The invention has the advantages that: (1) a novel phase unwrapping method is provided, and the measuring effect on objects with complex surfaces is good. (2) And calculating the stripe level by using a binary coding and decoding algorithm, so that the judgment of the stripe level is not easy to make mistakes. (3) And high-frequency stripes are used, so that the measurement precision is high. (4) The method has the advantages of simple calculation, flexible control, simple and convenient operation and higher robustness for the measurement of complex objects and isolated objects.
Drawings
FIG. 1 is a schematic diagram of a three-dimensional measurement system of the present invention.
Fig. 2 is a schematic diagram of a three-dimensional measurement process according to the present invention.
Fig. 3 is a graph of four pairs of four-step phase-shifted fringes produced in an example of the present invention.
FIG. 4 is a graph of fringe order and wrapped phase in an example of the present invention.
FIG. 5 is a graph of continuous phase and wrapped phase in an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the following description of the drawings, which are not intended to limit the present invention, and all similar structures and similar variations using the present invention shall fall within the scope of the present invention.
With reference to the flowchart of fig. 2, the phase unwrapping method based on multi-frequency and binary fringe according to the present invention includes the following steps:
(1) generation of sinusoidal phase-shifted fringe patterns
Four pairs of sinusoidal fringe patterns with phase shifts of 0, pi/2, pi, 3 pi/2 are generated by a computer, and the intensities are as follows:
I0＝A(x,y)+B(x,y)cos(φ) (2)
I1＝A(x,y)+B(x,y)cos(φ-π/2) (3)
I2＝A(x,y)+B(x,y)cos(φ-π) (4)
I3＝A(x,y)+B(x,y)cos(φ-3π/2) (5)
where a (x, y) and B (x, y) denote the amplitude modulation degrees of the background light component and the stripe, respectively.
(2) Wrapped phase and continuous phase solution
Solving the wrapping phase of an object by using the formula (6)
The continuous phase phi (x, y) of the object is solved using equation (7).
(3) Binary solving of fringe order
Firstly, selecting a proper threshold (the threshold is selected to be 0 by the method), binarizing the wrapping phase of each period to obtain a corresponding binary image, wherein black represents 0, white represents 1, and the basic principle is as follows by taking three periods as an example:
converting the binary number (such as 111, 110, 101, 100, …) corresponding to each digit into decimal number to obtain the fringe order k, and obtaining the continuous phase of the object by using the formula (7).
Claims (4)
1. A phase unwrapping method based on multi-frequency and binary stripes is characterized in that: generating four-step phase shift graphs with periods changing according to exponential growth by using a computer, and respectively projecting the four-step phase shift graphs of each period to the surface of an object to be measured; then, a four-step phase shift algorithm is used for obtaining wrapping phases of all periods, binarization is carried out on the wrapping phases of all periods, binary stripes under all periods are generated, a stripe level K is calculated by a binary encoding and decoding algorithm, then the wrapping phases under the highest period are unfolded by the K, and finally the continuous phase of the object is obtained.
2. The method of claim 1, wherein the method further comprises: the four-step phase shift diagram is a fringe diagram generated by a computer, and the period is increased exponentially, the base number of the period increase is 2, the exponent is n, and n is 1,2,3 and ….
3. A method as claimed in claim 1The phase unwrapping method based on the multi-frequency and binary stripes is characterized in that: the period selection must satisfy T-2n-1(n＝1,2,...,)。
4. The method of claim 1, wherein the method further comprises: and carrying out binarization on the wrapping phase of each period according to a threshold value of 0 to generate binary stripes under each period, and solving the stripe level K.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910836246.5A CN110440714B (en) | 2019-09-05 | 2019-09-05 | Phase unwrapping method based on multi-frequency and binary stripes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910836246.5A CN110440714B (en) | 2019-09-05 | 2019-09-05 | Phase unwrapping method based on multi-frequency and binary stripes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110440714A CN110440714A (en) | 2019-11-12 |
| CN110440714B true CN110440714B (en) | 2021-01-08 |
Family
ID=68439280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910836246.5A Active CN110440714B (en) | 2019-09-05 | 2019-09-05 | Phase unwrapping method based on multi-frequency and binary stripes |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110440714B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111174730B (en) * | 2020-01-07 | 2021-07-16 | 南昌航空大学 | Rapid phase unwrapping method based on phase encoding |
| CN111524173B (en) * | 2020-04-01 | 2022-09-06 | 中国科学技术大学 | Rapid large-range phase unwrapping method based on double reference planes |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101182995A (en) * | 2007-12-21 | 2008-05-21 | 东南大学 | Quick phase demodulation method based on fringes perturbation |
| CN104315996A (en) * | 2014-10-20 | 2015-01-28 | 四川大学 | Method for realizing fourier transform profilometry by using binary encoding strategy |
| CN104457614A (en) * | 2014-11-11 | 2015-03-25 | 南昌航空大学 | Stripe reflection three-dimensional measurement method based on binary stripe defocusing |
| CN106091981A (en) * | 2016-05-27 | 2016-11-09 | 西安交通大学 | Region projection method for measuring optical three-dimensional contour for HDR object |
| CN107036556A (en) * | 2017-04-28 | 2017-08-11 | 南昌航空大学 | Structural light three-dimensional measurement method based on segment quantization phase code |
| CN108534714A (en) * | 2018-03-09 | 2018-09-14 | 南昌航空大学 | Based on sinusoidal and binary system fringe projection quick three-dimensional measurement method |
| WO2019088982A1 (en) * | 2017-10-30 | 2019-05-09 | Hewlett-Packard Development Company, L.P. | Determining surface structures of objects |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109141291A (en) * | 2018-09-25 | 2019-01-04 | 南昌航空大学 | A kind of fast phase unwrapping algorithm |
-
2019
- 2019-09-05 CN CN201910836246.5A patent/CN110440714B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101182995A (en) * | 2007-12-21 | 2008-05-21 | 东南大学 | Quick phase demodulation method based on fringes perturbation |
| CN100487364C (en) * | 2007-12-21 | 2009-05-13 | 东南大学 | Quick phase demodulation method based on fringes perturbation |
| CN104315996A (en) * | 2014-10-20 | 2015-01-28 | 四川大学 | Method for realizing fourier transform profilometry by using binary encoding strategy |
| CN104457614A (en) * | 2014-11-11 | 2015-03-25 | 南昌航空大学 | Stripe reflection three-dimensional measurement method based on binary stripe defocusing |
| CN106091981A (en) * | 2016-05-27 | 2016-11-09 | 西安交通大学 | Region projection method for measuring optical three-dimensional contour for HDR object |
| CN107036556A (en) * | 2017-04-28 | 2017-08-11 | 南昌航空大学 | Structural light three-dimensional measurement method based on segment quantization phase code |
| WO2019088982A1 (en) * | 2017-10-30 | 2019-05-09 | Hewlett-Packard Development Company, L.P. | Determining surface structures of objects |
| CN108534714A (en) * | 2018-03-09 | 2018-09-14 | 南昌航空大学 | Based on sinusoidal and binary system fringe projection quick three-dimensional measurement method |
Non-Patent Citations (1)
| Title |
|---|
| A multi-frequency binary phase;张鹏飞;《Sixth Symposium on Novel Optoelectronic Detection Technology and Applications》;20200908;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110440714A (en) | 2019-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhang | Absolute phase retrieval methods for digital fringe projection profilometry: A review | |
| Zuo et al. | High-speed three-dimensional shape measurement for dynamic scenes using bi-frequency tripolar pulse-width-modulation fringe projection | |
| CN111174730B (en) | Rapid phase unwrapping method based on phase encoding | |
| CN107036556B (en) | Structured light three-dimensional measurement method based on segmented quantization phase coding | |
| Song et al. | A new phase unwrapping algorithm based on three wavelength phase shift profilometry method | |
| Porras-Aguilar et al. | Absolute phase recovery in structured light illumination systems: sinusoidal vs. intensity discrete patterns | |
| CN110440714B (en) | Phase unwrapping method based on multi-frequency and binary stripes | |
| CN112146596B (en) | Optimal quantization phase coding three-dimensional measurement method | |
| CN110174079B (en) | Three-dimensional reconstruction method based on four-step phase-shift coding type surface structured light | |
| CN111156927A (en) | Mirror surface object three-dimensional measurement method based on sine pulse width modulation stripes | |
| CN102261896A (en) | Method and system for measuring three-dimensional shape of object based on phase measurement | |
| CN108596008B (en) | Face shake compensation method for three-dimensional face measurement | |
| CN103791856A (en) | Phase solving and unwrapping method based on four-width optical grating stripe image | |
| CN111207694B (en) | Three-dimensional measurement method combining double-step phase shift method with phase coding | |
| CN110849290B (en) | Three-dimensional measurement method for segmented quantization coding intensity based on morphological operation | |
| CN105300317A (en) | Three-dimensional measurement method on the basis of projection of sinusoidal stripes and triangular wave stripes | |
| JP2017116420A (en) | Data processing device and method of data processing | |
| CN110608687A (en) | Color coding grating crosstalk compensation method based on projection plane | |
| CN114777677A (en) | Single-frame dual-frequency multiplexing fringe projection three-dimensional surface type measuring method based on deep learning | |
| CN115790451A (en) | Superposition coding phase unwrapping method based on phase quantization | |
| CN113959364B (en) | Three-frequency phase unwrapping method and measuring device | |
| CN110428459A (en) | A method of the Phase- un- wrapping based on numerical order coding | |
| CN108534715A (en) | A kind of expansion phase solution phase method applied to different wave length three-dimensional measurement | |
| CN114252026B (en) | Three-dimensional measurement method and system for modulating three-dimensional code on periodic edge | |
| CN114152203B (en) | Bearing inner and outer diameter dimension measuring method based on phase coding structured light |
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 |