CN104729427A - Optical three-dimensional profile measuring method of self-adaptation multi-frequency space-time color coding - Google Patents
Optical three-dimensional profile measuring method of self-adaptation multi-frequency space-time color coding Download PDFInfo
- Publication number
- CN104729427A CN104729427A CN201410787529.2A CN201410787529A CN104729427A CN 104729427 A CN104729427 A CN 104729427A CN 201410787529 A CN201410787529 A CN 201410787529A CN 104729427 A CN104729427 A CN 104729427A
- Authority
- CN
- China
- Prior art keywords
- coding
- passage
- image
- space
- color
- 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
Abstract
Provided is an optical three-dimensional profile measuring method of self-adaptation multi-frequency space-time color coding. The method comprises the steps that firstly, a white image is projected on a to-be-tested object, a coding pass suitable for a surface reflection characteristic of the object is obtained through self-adaptation; and then, by using multi-frequency multi-color stripes to form a cyclical combined stripe, local space coding on the stripe is completed; finally, time coding is carried out on the cycle of the space coding by using Grey binary coding. A coded pattern is projected to carry out measuring on a profile, and three-dimensional profile data of a measured target are obtained. On the premise of guaranteeing the measuring efficiency, the problems of the color coding measuring precision and the decoding reliability are solved.
Description
Technical field
The invention belongs to technical field of electro-optical measurement, relate to a kind of method for measuring optical three-dimensional contour, especially a kind of method for measuring optical three-dimensional contour of self-adaptation multifrequency space-time coloud coding.
Background technology
Optical three-dimensional contour measuring technique is the focus that three-dimensional sensing and metering field are studied always, is widely used in the aspects such as manufacturing industry, computer-aided medical science, virtual reality, cultural heritage protection.Because it has, noncontact, non-demolition, speed are fast, precision high, become ideal profile pattern measurement means.
Structural light three-dimensional contour measuring method, demodulates the three-dimensional information of measured object field according to the geometric relationship of the light field projected on object and optical projection system, acquisition system and measured object benchmark.Need to encode, mutually to distinguish to the every root striped projected out.Coding can be divided into space encoding and time encoding.Space encoding method generally adopts multicolour pattern, and only need once to project the depth image that just can obtain testee, be suitable for kinetic measurement, but resolving power can't meet the demands at present,, there is decoding error in the noise spot impact that coding pattern is subject to scenery character of surface difference and produces; In addition, the use of multicolour pattern can introduce RGB passage offset error and colour contamination, reduces measuring accuracy.Time encoding is commonly used binary coding and is got up to decode by repeatedly different projective patterns coding sequence combination, and decoding error rate is low, but its method requires that projecting space position remains unchanged, and repeatedly projects, and therefore measuring speed is affected.
In sum, need to choose a kind of suitable method, under equal projected fringe density, measuring accuracy and decoding reliability can be ensured, can coding rate be improved again.Therefore, a kind of measuring three-dimensional profile method that can coordinate or solve the problem of very necessary research.
Summary of the invention
The object of the invention is to the shortcoming overcoming above-mentioned prior art, a kind of method for measuring optical three-dimensional contour of self-adaptation multifrequency space-time coloud coding is provided, under it can ensure the prerequisite of measurement efficiency, solve coloud coding measuring accuracy and decoding integrity problem.
The object of the invention is to be achieved through the following technical solutions:
The method for measuring optical three-dimensional contour of this self-adaptation multifrequency space-time coloud coding, comprises the following steps:
1) first to testee projection white image, drawn the reflection characteristic of body surface by the analysis of the RGB passage to shooting image, and choose encoded color passage according to reflection characteristic self-adaptation;
2) multifrequency color space coding pattern is generated according to the above-mentioned encoded colors passage chosen: first choose the high and uniform passage of reflectivity in encoded color passage as most hf channel, only strip extraction is carried out to the candy strip of this passage; Using remaining passage as coding pass;
3) binary gray code is utilized to carry out time encoding to multicycle striped in units of each cycle of above-mentioned space encoding pattern; Or, replace binary-coded piece image with a passage in a width coloured image;
4) use digital projection device to be projected to testee surface above-mentioned space-time coloud coding striped, and with color camera, image is gathered;
5) Gray's coded image is decoded, obtain the coding code value in space encoding each cycle; Taken out by the gray level image of highest frequency passage in the space encoding image photographed, the difference according to each interchannel fringe frequency carries out colour contamination rectification, and the grayscale bar print image after correcting colour contamination carries out fringe center extraction; By the analysis of rest channels image, decoded in extraction fringe center position within the space encoding cycle, and finally obtain the encoded radio of every root highest frequency fringe center;
6) extraction fringe center and structural light three-dimensional contour measuring method is utilized to resolve the profile information of testee.
Further, the Color Channel using self-adaptation to choose generates multifrequency color circle candy strip and Gray code pattern, and the projection that both combined is measured, and have periodically in conjunction with color fringe and the different feature filtering cross-color interference of each channel frequence.
The present invention has following beneficial effect:
Owing to present invention uses the colored space-time code of multifrequency, ensure certain measure the prerequisite of efficiency under reduce coloud coding measuring error and the bit error rate, effectively solve low precision in color structured light coding measuring three-dimensional profile, problem that reliability is low.
Accompanying drawing explanation
Fig. 1 is measurement mechanism schematic diagram of the present invention;
Fig. 2 is the self-adaptation multifrequency colored space-time code realization flow figure in the present invention;
Fig. 3 is multifrequency color space coding schematic diagram;
Fig. 4 is Gray code coloud coding schematic diagram;
Fig. 5 is coding projection image (for center to be extracted striped 32); Wherein (a) is strip encoding image, and (b) is the cross section normalization light distribution of strip encoding;
Fig. 6 is the decoding schematic diagram projecting striped shown in Fig. 5.
Embodiment
The technical scheme that the method for measuring optical three-dimensional contour of self-adaptation multifrequency space-time coloud coding of the present invention adopts is: first by projecting white image to testee, and self-adaptation draws the coding pass of applicable body surface reflection characteristic; Then adopt the multicolored striped formation of multifrequency periodically to combine striped, replace traditional spatial colour encoding pattern, complete and the local space of striped is encoded; Finally utilize Gray's binary coding to carry out time encoding to the cycle of above-mentioned space encoding, for raising the efficiency further, the some passages gone back in available color pattern replace a wherein width black and white pattern.Project above-mentioned coding pattern to measure profile, obtain the three-D profile data of measurand.Its concrete steps are as follows:
1) first to testee projection white image, drawn the reflection characteristic of body surface by the analysis of the RGB passage grey scale change to shooting image, and choose coding pass according to reflection characteristic self-adaptation;
2) multifrequency period color space coding pattern is generated according to the above-mentioned encoded colors passage chosen: first choose the high and more uniform passage of reflectivity in coding pass as most hf channel, the candy strip image quality of this passage is better like this; Only strip extraction is carried out to the candy strip of this passage, can avoid like this misplacing the error brought due to RGB passage; Using remaining passage as coding pass, in these passages, the frequency of striped is different, but all lower than the fringe frequency of highest frequency passage, and the integral multiple that highest frequency is other strip encoding frequencies need be met, the decoding reliability of fringe center can be ensured so to greatest extent; In addition, feature that can be different according to the frequency in each passage is corrected interchannel colour contamination.
3) in order to improve the reliability of decoding further, the cycle of general above-mentioned space encoding candy strip is not easily long, and therefore the recycling cycle of binary gray code to above-mentioned space encoding pattern carries out time encoding; In addition, measuring efficiency for improving, also can replace a binary-coded width gray level image with a passage of a width coloured image.
4) digital projection device is utilized by above-mentioned space-time code pattern projection to testee surface.
5) each cycle of space encoding in Gray's coded image is identified and decoded.
6) gray level image space encoding being taken image highest frequency passage takes out, and first carries out colour contamination rectification according to frequency information, carries out fringe center extraction to the gray level image after correcting; By the analysis of all the other two channel image, to the decoding of extracting fringe center position and carrying out in the space encoding cycle, in conjunction with 5) in decoded result finally obtain the encoded radio of every root highest frequency fringe center.
7) highest frequency passage fringe center and structural light three-dimensional contour measuring method in space-time code pattern is utilized to resolve the profile information of testee.
Below in conjunction with accompanying drawing, the present invention is described in further detail.
1) adaptive process of encoded colors is realized
One width white image is projected to testee, analyzes the reflection characteristic of the RGB passage of shooting image, following three kinds of situations can be drawn: a) RGB passage is all applicable to encoding; B) two passages are applicable to encoding; C) passage is applicable to coding.Corresponding coding flow process signal as shown in Figure 2.
2) encode for above-mentioned three kinds of situations
A.RGB passage is all applicable to encoding.Whole coding divides room and time to encode two parts.
Space encoding: the image of three passages is all the striped of mechanical periodicity, choose the best passage of wherein reflection characteristic as highest frequency passage, its frequency is designated as f
1, the frequency of other two passages is f
1and f
3suppose f
1>f
2, and f
2and f
3meet f respectively
2=f
1/ k
1, f
3=f
1/ k
2.K
1and k
2the principle one chosen ensures that the peak value place of all intermediate frequencies and low frequency fringes overlaps with the peak value of corresponding position high frequency, and two is to make the cycle T of coding long as far as possible.The former is the reliability in order to improve decoding to greatest extent, and the latter is the efficiency improving coding to greatest extent; T is the repetition period (as Fig. 3) of the color sequence of adjacent n (2≤n≤4) root striped.Such as, the highest R passage of Fig. 3 medium frequency is as location striped passage, and G and channel B are coding pass, wherein k
1=3, k
2=4, so both ensure that three-channel frequency had enough intervals, the striped peak value of three kinds of frequencies can be made again to overlap.
Time encoding: space encoding is generally utilize the color sequences of adjacent n root striped to carry out coding and decoding, and therefore must ensure the uniqueness of order in coding result of the n root striped of arbitrary neighborhood, general n representative value gets 3.In order to ensure the reliability of coding and decoding, the minimum period length of the multifrequency coding completed above is unsuitable oversize, therefore only can not meet large view field measurement requirement by the space encoding of one-period under normal circumstances, in order to identify each cycle T, recycling time encoding is distinguished.Time encoding is intended adopting gray encoding, usual time encoding image adopts black white image, for raising the efficiency further, also each passage of available color image replaces a width black and white coding, according to from the high-order order to low level of coding, every three width black and white coded images are converted to a width coloured image and project.Encode schematic diagram as shown in Figure 4, for three Gray codes (for three gray encodings in example, as needs increase by coding, then needing a passage of increase by width coloured image) in figure.So far Three Channel Color space-time code completes.
B. two passages are applicable to coding.Only carry out room and time coding with two passages be applicable to.Rule and the triple channel of coding are similar.
C. a passage is applicable to coding.Now cannot use colouring information, directly adopt Gray code time encoding.
3) utilize digital projection device that above-mentioned space-time code pattern (as shown in Figure 5) is projected to testee.
4) each cycle of space encoding in Gray's time encoding image is identified and decoded, as shown in Figure 6
5) then, space encoding being taken the taking-up of image highest frequency channel image utilizes the difference of each channel frequence information to correct (method such as available filtering or empirical mode decomposition) colour contamination according to frequency information, and carries out fringe center extraction to the result after correcting; By the analysis of all the other two channel image, utilize dynamic programming algorithm to the decoding of extracting the pixel at place, fringe center position and carrying out in the space encoding cycle, and finally obtain the encoded radio of every root highest frequency fringe center, as shown in Figure 6.
6) in usage space coding pattern, the calibrating parameters of highest frequency passage calculates three-dimensional information and utilizes highest frequency passage striped centre data in space-time code pattern and structure based light measuring three-dimensional profile method, resolves the profile information of testee.
The method has only used a Color Channel as placed channel, thus the error that the dislocation that completely avoid Color Channel causes; Because coding pass has neither part nor lot in fringe location, then the positioning precision that color correction can not affect striped is carried out on coding pass; Moreover the fringe frequency to project due to each passage is different, utilizes frequency information to be convenient to the solution of colour contamination problem like this; Simultaneously in order to ensure the reliability of coding and decoding, take room and time encode the method combined, the error brought by decoding error suppression is within a time encoding cycle.
Claims (2)
1. a method for measuring optical three-dimensional contour for self-adaptation multifrequency space-time coloud coding, is characterized in that, comprise the following steps:
1) first to testee projection white image, drawn the reflection characteristic of body surface by the analysis of the RGB passage to shooting image, and choose encoded color passage according to reflection characteristic self-adaptation;
2) multifrequency color space coding pattern is generated according to the above-mentioned encoded colors passage chosen: first choose the high and uniform passage of reflectivity in encoded color passage as most hf channel, only strip extraction is carried out to the candy strip of this passage; Using remaining passage as coding pass;
3) binary gray code is utilized to carry out time encoding to multicycle striped in units of each cycle of above-mentioned space encoding pattern; Or, replace binary-coded piece image with a passage in a width coloured image;
4) use digital projection device to be projected to testee surface above-mentioned space-time coloud coding striped, and with color camera, image is gathered;
5) Gray's coded image is decoded, obtain the coding code value in space encoding each cycle; Taken out by the gray level image of highest frequency passage in the space encoding image photographed, the difference according to each interchannel fringe frequency carries out colour contamination rectification, and the grayscale bar print image after correcting colour contamination carries out fringe center extraction; By the analysis of rest channels image, decoded in extraction fringe center position within the space encoding cycle, and finally obtain the encoded radio of every root highest frequency fringe center;
6) extraction fringe center and structural light three-dimensional contour measuring method is utilized to resolve the profile information of testee.
2. the method for measuring optical three-dimensional contour of self-adaptation multifrequency space-time coloud coding according to claim 1, it is characterized in that, the Color Channel using self-adaptation to choose generates multifrequency color circle candy strip and Gray code pattern, and the projection that both combined is measured, and have periodically in conjunction with color fringe and the different feature filtering cross-color interference of each channel frequence.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410787529.2A CN104729427B (en) | 2014-12-17 | 2014-12-17 | A kind of method for measuring optical three-dimensional contour of self adaptation multifrequency space-time coloud coding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410787529.2A CN104729427B (en) | 2014-12-17 | 2014-12-17 | A kind of method for measuring optical three-dimensional contour of self adaptation multifrequency space-time coloud coding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104729427A true CN104729427A (en) | 2015-06-24 |
| CN104729427B CN104729427B (en) | 2017-06-06 |
Family
ID=53453553
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410787529.2A Active CN104729427B (en) | 2014-12-17 | 2014-12-17 | A kind of method for measuring optical three-dimensional contour of self adaptation multifrequency space-time coloud coding |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104729427B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105651203A (en) * | 2016-03-16 | 2016-06-08 | 广东工业大学 | High-dynamic-range three-dimensional shape measurement method for self-adaptation fringe brightness |
| CN106091986A (en) * | 2016-06-08 | 2016-11-09 | 韶关学院 | A kind of method for three-dimensional measurement being applicable to glossy surface |
| CN108332670A (en) * | 2018-02-06 | 2018-07-27 | 浙江大学 | A kind of structured-light system coding method for merging the positive and negative Gray code of RGB channel and striped blocks translation |
| CN110440712A (en) * | 2019-08-26 | 2019-11-12 | 英特维科技(苏州)有限公司 | Adaptive big depth of field 3-D scanning method and system |
| CN113696939A (en) * | 2021-08-25 | 2021-11-26 | 北京博研盛科科技有限公司 | Marker-based railcar positioning method, system and equipment |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102243103A (en) * | 2011-04-13 | 2011-11-16 | 西安交通大学 | Method for quickly measuring colors and three-dimensional profile of object |
| US20110286524A1 (en) * | 2008-12-18 | 2011-11-24 | Yu Wen Wu | Method and device for encoding a block of an image using a reference block of a further image, data carrier carrying an encoded block of an image and method for decoding a block of an image |
| CN102607465A (en) * | 2012-03-13 | 2012-07-25 | 西安交通大学 | Phase unwrapping method based on colored phase shift stripe secondary encoding |
-
2014
- 2014-12-17 CN CN201410787529.2A patent/CN104729427B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110286524A1 (en) * | 2008-12-18 | 2011-11-24 | Yu Wen Wu | Method and device for encoding a block of an image using a reference block of a further image, data carrier carrying an encoded block of an image and method for decoding a block of an image |
| CN102243103A (en) * | 2011-04-13 | 2011-11-16 | 西安交通大学 | Method for quickly measuring colors and three-dimensional profile of object |
| CN102607465A (en) * | 2012-03-13 | 2012-07-25 | 西安交通大学 | Phase unwrapping method based on colored phase shift stripe secondary encoding |
Non-Patent Citations (1)
| Title |
|---|
| 单鹂娜等: "《彩色梯度相移与格雷码相结合的三维测量方法》", 《光学精密工程》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105651203A (en) * | 2016-03-16 | 2016-06-08 | 广东工业大学 | High-dynamic-range three-dimensional shape measurement method for self-adaptation fringe brightness |
| CN105651203B (en) * | 2016-03-16 | 2018-09-04 | 广东工业大学 | A kind of high dynamic range 3 D measuring method of adaptive striped brightness |
| CN106091986A (en) * | 2016-06-08 | 2016-11-09 | 韶关学院 | A kind of method for three-dimensional measurement being applicable to glossy surface |
| CN106091986B (en) * | 2016-06-08 | 2018-12-11 | 韶关学院 | A kind of method for three-dimensional measurement suitable for glossy surface |
| CN108332670A (en) * | 2018-02-06 | 2018-07-27 | 浙江大学 | A kind of structured-light system coding method for merging the positive and negative Gray code of RGB channel and striped blocks translation |
| CN110440712A (en) * | 2019-08-26 | 2019-11-12 | 英特维科技(苏州)有限公司 | Adaptive big depth of field 3-D scanning method and system |
| CN113696939A (en) * | 2021-08-25 | 2021-11-26 | 北京博研盛科科技有限公司 | Marker-based railcar positioning method, system and equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104729427B (en) | 2017-06-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102519394B (en) | High-adaptability three-dimensional measuring method based on color structured light | |
| CN104729427A (en) | Optical three-dimensional profile measuring method of self-adaptation multi-frequency space-time color coding | |
| CN101608906B (en) | Method for measuring optical three-dimensional contour of space coding | |
| CN106840036B (en) | A kind of diadactic structure light optimization method suitable for fast three-dimensional appearance measuring | |
| CN102322823B (en) | Phase grade self-coding-based optical three-dimensional measurement method | |
| CN101504277B (en) | Method for acquiring object three-dimensional image by optical three-dimensional sensing | |
| CN101975558B (en) | Rapid three-dimensional measurement method based on color grating projection | |
| CN100573040C (en) | The scaling method of object surface three-dimensional contour structure light measurement system | |
| CN102878950B (en) | System and method for 3D profile measurement | |
| CN102607465B (en) | Phase unwrapping method based on colored phase shift stripe secondary encoding | |
| CN104677308A (en) | Three-dimensional scanning method for high-frequency two-value strip | |
| CN105844633B (en) | Single frames structure optical depth acquisition methods based on De sequence and phase code | |
| CN104567730B (en) | A kind of method that space-time binary coding produces sinusoidal light field | |
| CN108332670B (en) | Structured light system coding method integrating positive and negative gray codes of RGB (red, green and blue) channels and stripe block translation | |
| CN104390608A (en) | Projection grating phase method based structured light three-dimensional shape construction method | |
| CN103033171B (en) | Encoding mark based on colors and structural features | |
| CN107036556A (en) | Structural light three-dimensional measurement method based on segment quantization phase code | |
| CN108592823A (en) | A kind of coding/decoding method based on binocular vision color fringe coding | |
| CN110849290A (en) | Three-dimensional measurement method for segmented quantization coding intensity based on morphological operation | |
| CN102708566B (en) | Novel single-camera and single-projection light source synchronous calibrating method | |
| WO2023082816A1 (en) | Structured light coding method and system for three-dimensional information reconstruction | |
| CN107705356A (en) | Image processing method and device | |
| CN114170345A (en) | Fringe pattern design method for structured light projection nonlinear correction | |
| CN112923870B (en) | Color object structured light three-dimensional measurement method based on phase shift and multi-bit code | |
| CN103438833A (en) | Color coded stripe patterns used for three-dimensional shape measurement |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |