CN110068287B - Phase correction method, phase correction device, computer device and computer-readable storage medium - Google Patents
Phase correction method, phase correction device, computer device and computer-readable storage medium Download PDFInfo
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- CN110068287B CN110068287B CN201910336936.4A CN201910336936A CN110068287B CN 110068287 B CN110068287 B CN 110068287B CN 201910336936 A CN201910336936 A CN 201910336936A CN 110068287 B CN110068287 B CN 110068287B
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- 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
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Abstract
The present invention relates to a phase correction method, apparatus, computer device and computer readable storage medium, wherein the phase correction method comprises: acquiring a deformed fringe pattern shot by a camera, and extracting a measurement phase of the deformed fringe pattern; carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase; acquiring a characteristic parameter of the error phase, and acquiring an error amplitude corresponding to the error phase according to the characteristic parameter; and carrying out phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase. The phase correction method can be used for keeping the appearance details of the object after the phase correction is carried out on the measurement phase of the deformed fringe pattern.
Description
Technical Field
The present invention relates to the field of three-dimensional measurement technologies, and in particular, to a method and an apparatus for phase correction, a computer device, and a computer-readable storage medium.
Background
The optical three-dimensional sensing technology based on structured light illumination is widely applied to the fields of industrial detection, product quality control, machine vision, instant positioning and map construction (SLAM), film and television special effects, biomedicine and the like. The data density and the measurement precision obtained by the phase shift fringe projection three-dimensional measurement technology are high, and the phase shift fringe projection three-dimensional measurement technology is an important optical three-dimensional sensing technology. The phase measurement error is one of the key indexes of the measurement system and is directly related to the precision of three-dimensional measurement. The displacement (equivalent to phase shift) of projection defocusing is one of the methods for realizing high-speed measurement, but the compass grating contains rich harmonic waves and affects the phase measurement precision.
Conventionally, the measurement phase is corrected by low-pass filtering the measurement phase of the deformed fringe pattern, but this method blurs the details of the object topography while filtering out phase errors.
Disclosure of Invention
The application provides a phase correction method, a phase correction device, computer equipment and a computer readable storage medium, which can be used for keeping the appearance details of an object after the phase correction is carried out on the measurement phase of a deformed fringe pattern.
A method of phase correction, the method comprising:
acquiring a deformed fringe pattern shot by a camera, and extracting a measurement phase of the deformed fringe pattern;
carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase;
acquiring a characteristic parameter of the error phase, and acquiring an error amplitude corresponding to the error phase according to the characteristic parameter;
and carrying out phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase.
In an embodiment, the performing a high-pass filtering process on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase includes:
obtaining a plurality of stripes of the deformed stripe pattern, and obtaining a measurement phase corresponding to each stripe;
and carrying out high-pass filtering processing on the measurement phase of each stripe to obtain an error phase and an approximate phase corresponding to the measurement phase of each stripe.
In an embodiment, the high-pass filtering the phase of each stripe includes:
the phase of each stripe is high-pass filtered in the vertical direction of each stripe.
In an embodiment, the obtaining a characteristic parameter of the error phase and obtaining an error magnitude corresponding to the error phase according to the characteristic parameter includes:
acquiring an envelope curve of the error phase;
and obtaining the error amplitude corresponding to the error phase according to the envelope curve.
In an embodiment, the obtaining a characteristic parameter of the error phase and obtaining an error magnitude corresponding to the error phase according to the characteristic parameter includes:
acquiring a frequency spectrum of the error phase;
and acquiring the error amplitude corresponding to the error phase according to the frequency spectrum.
In an embodiment, the phase correcting the deformed fringe pattern according to the error amplitude and the approximate phase includes:
establishing a phase error expression of a deformed fringe pattern according to the characteristics of the projection grating;
substituting the error amplitude and the approximate phase into the phase error expression, and calculating to obtain the phase error of the deformed stripe;
and carrying out phase correction on the deformed fringe pattern according to the phase error.
In an embodiment, the substituting the error amplitude and the approximate phase into the phase error expression, and calculating the phase error of the deformed fringe includes:
acquiring a first error amplitude of each pixel point on each stripe according to the error amplitudes;
acquiring a first approximate phase corresponding to a first error amplitude of each pixel point according to the approximate phase;
and acquiring the phase error of each pixel point on each stripe according to the first error amplitude and the first approximate phase.
A phase correction apparatus, the apparatus comprising:
the first acquisition module is used for acquiring a deformed fringe pattern shot by the camera and extracting a measurement phase of the deformed fringe pattern;
the high-pass filtering module is used for carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern so as to obtain an error phase and an approximate phase;
the second obtaining module is used for obtaining the characteristic parameter of the error phase and obtaining the error amplitude corresponding to the error phase according to the characteristic parameter;
and the phase correction module is used for carrying out phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase.
The present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.
The present application also provides a computer-readable storage medium having stored thereon a computer program which, when being executed by a processor, carries out the steps of the above-mentioned method.
According to the phase correction method provided by the embodiment of the application, the deformation fringe pattern shot by the camera is obtained, and the measurement phase of the deformation fringe pattern is extracted; carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase; acquiring a characteristic parameter of the error phase, and acquiring an error amplitude corresponding to the error phase according to the characteristic parameter; and performing phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase, so that the morphology details of the object can be retained after the phase correction is performed on the measurement phase of the deformed fringe pattern.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a flow diagram of a method of phase correction provided in one embodiment;
FIG. 2 is a deformed fringe pattern of a simple curved surface provided in one embodiment;
FIG. 3 is a 300 line frequency spectrum of the error phase of the deformed fringe pattern of FIG. 2;
FIG. 4 is the error phase of the 300 th row stripe of the fringe pattern of FIG. 2;
FIG. 5 is an envelope of the error phase of the 300 th row stripe of the deformed stripe pattern of FIG. 4;
FIG. 6 is the phase of the deformed fringe pattern of FIG. 2 before correction;
FIG. 7 is the corrected phase of the deformed fringe pattern of FIG. 2;
FIG. 8 is a deformed stripe pattern of the flower pot;
FIG. 9 is the phase of the deformed fringe pattern of FIG. 8 before correction;
FIG. 10 is the corrected phase of the deformed fringe pattern of FIG. 8;
fig. 11 is a schematic structural diagram of a phase correction device provided in an embodiment;
fig. 12 is a schematic diagram of an internal structure of an electronic device in one embodiment.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to provide a thorough understanding of the present application, and in the accompanying drawings, preferred embodiments of the present application are set forth. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. In the description of the present application, "a number" means at least one, such as one, two, etc., unless specifically limited otherwise.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Fig. 1 is a flowchart of a phase correction method according to an embodiment, as shown in fig. 1, the phase correction method includes steps 110 to 140, wherein,
and step 110, acquiring a deformed fringe pattern shot by the camera, and extracting a measurement phase of the deformed fringe pattern.
The projector projects the stripe template with a set rule onto the surface of a measured object, the stripe template is deformed due to different depths of all points in the measured object to generate a deformed stripe pattern, and the camera is used for shooting the deformed stripe pattern modulated by the surface shape of the measured object.
In the full-period equal-interval N-step phase shift method, the deformed fringe pattern including higher harmonics captured by the camera can be expressed as follows:
wherein R (x, y) is the surface reflectance of the measurement object, M is the highest order of harmonics, a (x, y) is background illumination including ambient light, bj(x, y) is the harmonic amplitude of the projected fringes,
in order to distort the phase of the fringes,in, where N is the amount of phase shift and N is the total number of phase shift steps.
The measured phase of the deformed fringe pattern can be extracted from the deformed fringe pattern by:
since the measurement phase of the deformed fringe pattern is extracted in the same manner for each pixel in the deformed fringe pattern, the coordinates of the pixel are ignored in the following description for the sake of convenience. In the deformed fringe pattern, the phase error caused by the higher harmonics can be expressed as:
wherein m belongs to any integer. From the above formula, the measured phase of the deformed fringe pattern is only related to (m × N) ± 1 th harmonic.
And 120, performing high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase.
In one embodiment, a plurality of stripes of a deformed stripe pattern are obtained, and a measurement phase corresponding to each stripe is obtained; and carrying out high-pass filtering processing on the measurement phase of each stripe to obtain an error phase and an approximate phase corresponding to the measurement phase of each stripe.
Each deformation stripe image comprises a plurality of rows or a plurality of columns of stripes, firstly, the plurality of rows or the plurality of columns of stripes are obtained, and the high-pass filtering processing is carried out on the phase of each stripe along the vertical direction of each stripe. As shown in fig. 2, the fringes of the deformed fringe pattern are approximately vertical, and then the high-pass filtering is performed on the measured phase pattern line by line, so that the error phase and the approximate phase of each pixel point on each line are obtained. And carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern in the vertical direction of the projection fringe, and filtering out the error phase of the deformed fringe pattern. And simultaneously subtracting the error phase from the measured phase to obtain an approximate phase close to the ideal phase (the phase can filter the error and simultaneously blur the details of the object morphology). It can be understood that if the deformed fringe pattern is a vertical fringe, the phase of each row of fringes is subjected to a high-pass filtering process; if the deformed fringe pattern is a horizontal fringe, the phase of each column of fringes is subjected to a high-pass filtering process. For setting measuring phase
For indicating, error phase
For indicating, approximating, phase
Representing, high-pass filter pulsesThe response function is denoted by h, and this process can be expressed by the following equation:
and step 130, acquiring a characteristic parameter of the error phase, and acquiring an error amplitude corresponding to the error phase according to the characteristic parameter.
The characteristic parameter of the error phase may be an envelope of the error phase; and obtaining the error amplitude corresponding to the error phase according to the envelope curve.
The characteristic parameter of the error phase may also be the frequency spectrum of the error phase; and obtaining the error amplitude corresponding to the error phase according to the frequency spectrum.
In the present embodiment, the characteristic parameter of the error phase is taken as the envelope of the error phase. To obtain
And obtaining the error amplitude of each pixel point on the envelope line by the envelope line of each row/column error phase, thereby calculating the error amplitude.
And step 140, performing phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase.
In one embodiment, a phase error expression of a deformed fringe pattern is established according to the characteristics of a projection grating; substituting the error amplitude and the approximate phase into a phase error expression, and calculating to obtain the phase error of the deformed stripe; and carrying out phase correction on the deformed fringe pattern according to the phase error.
According to equation (3), the phase error caused by the higher harmonics can be approximately expressed as:
it can be seen that the phase error of the measured phase of the deformed fringe pattern is a signal combination of m × N multiple frequency periods of the deformed fringe pattern.
Further, by approximating the phase
Instead of in formula (5)
The phase error due to the higher harmonics can be expressed as:
by finding the approximate phase
And the margin of error CmThat is, the phase error of the deformed fringe pattern can be obtained
In an embodiment, a first error amplitude of each pixel point on each stripe is obtained according to the error amplitude; each deformation fringe pattern comprises a plurality of rows or a plurality of columns of fringes, each row or each column of fringes comprises a plurality of pixel points, first error amplitudes of the pixel points in each row or each column of fringes can be obtained firstly, and similarly, the first error amplitudes of the pixel points in the deformation fringe pattern can be obtained. According to the approximate phase, acquiring a first approximate phase corresponding to the first error amplitude of each pixel point; and acquiring the phase error of each pixel point on each stripe according to the first error amplitude and the first approximate phase.
For measuring phase
The following formula is adopted for processing:
that is, the measured phase and the obtained phase error are subjected to subtraction processing, so that the corrected phase can be obtained
It should be understood that, although the steps in the flowchart of fig. 1 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 1 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
In the embodiment of the present application, experiments were performed by using the compass grating projection and the 3-step phase shift method. Firstly, high-pass filtering is carried out on a measured phase, and data containing errors and low-frequency information close to an ideal phase are obtained at the same time; analyzing the obtained error data, and obtaining error amplitude according to the frequency spectrum or envelope curve of the error data; and then, correcting the measured phase by using low-frequency information according to the characteristics of the Luoman grating harmonic wave and the corresponding error characteristics. The method reduces the periodic error and simultaneously retains the appearance details of the object.
The compass grating is a binary grating with the same black and white proportion, and the projection image is subjected to Fourier expansion to obtain:
wherein f is0The fundamental frequency of qi grating is only odd harmonic. The higher the harmonic order, the lower the amplitude. The actually photographed deformed fringe pattern only contains odd harmonics, namely j in the formula (1) is only an odd number. When 3-step phase shift with full period equal interval is adopted, only the 5,7,9,11,13 and … subharmonics have the influence on the measuring phase of the deformed fringe pattern. By(5) As can be seen, the error in the measured phase only contains the integer multiple of the fringe 6, i.e. the periodic error of 6,12,18, …, and the magnitude of the error decreases with the increase of the multiple.
The compass grating defocusing projection is equivalent to low-pass filtering of a projected fringe pattern, and higher defocusing amount is larger, higher harmonics are filtered more, and fringe contrast is reduced more. The magnitude of the error in the deformed fringe pattern is related to the magnitude of the higher harmonics. In practice, harmonics not less than 11 th order of the out-of-focus fringes are filtered out, and only harmonics not more than 7 th order of the fringes cause phase measurement errors (the corresponding phase measurement error frequency is 6 times the frequency of the fringes). This embodiment only considers the phase measurement error of the frequency multiplication of the fringes 6. When the defocusing amount is constant, the higher harmonic filtering amount of the compass grating with different frequencies is different.
First 1 simple curve (curved a4 paper) was measured for experimental validation. Fig. 2 is a deformed fringe pattern of a simple curved surface. Fig. 3 is a spectrum diagram of line 300 of the error phase of the deformed fringe pattern of fig. 2, and it can be seen that the harmonics are primarily 3, 5, 7. Wherein, 3 harmonics have no influence on phase measurement, and 5 and 7 harmonics generate 6 frequency multiplication phase errors. Fig. 4 is an error phase of the 300 th stripe of the deformed stripe pattern of fig. 2, and fig. 5 is an envelope of the error phase of the 300 th stripe of the deformed stripe pattern of fig. 4. It can be seen that different positions have different defocus degrees and different error amplitudes, and cannot be corrected by using uniform correction parameters. Fig. 6 is a phase before the deformed fringe pattern of fig. 2 is corrected (here, the phases are shown as phases after subtracting the reference plane), and fig. 7 is a phase after the deformed fringe pattern of fig. 2 is corrected. As can be seen from fig. 6 and 7, the periodic error is greatly attenuated. The corrected phase standard deviation was reduced from 0.102 radians to 0.0328 radians, which was originally about 1/3 radians.
In an embodiment, the effectiveness of the phase correction method provided by the present embodiment is verified by measuring the deformed fringe patterns of 1 flowerpot. Fig. 8 is a deformed fringe pattern of the flowerpot, fig. 9 is a phase before the deformed fringe pattern of fig. 8 is corrected, and fig. 10 is a phase after the deformed fringe pattern of fig. 8 is corrected. As can be seen from fig. 9 and 10, the periodic error of the deformed stripe pattern of the flowerpot is greatly attenuated. It can be seen that the phase correction method provided by the present application is effective.
According to the phase correction method provided by the embodiment of the application, the deformation fringe pattern shot by the camera is obtained, and the measurement phase of the deformation fringe pattern is extracted; carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase; acquiring characteristic parameters of the error phase, and acquiring error amplitude corresponding to the error phase according to the characteristic parameters; and performing phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase, so that the morphology details of the object can be retained after the phase correction is performed on the measured phase of the deformed fringe pattern. In addition, the compass grating projection system has different fringe widths, different defocusing degrees and different harmonic proportions. Conventionally, on the premise that the fringe period is different but the harmonic ratio is not changed, the phase correction is performed by table lookup by building an error correction table in advance. However, the fringe period used to create the table is much larger than the fringe period used for measurement, and thus this method is not suitable for phase correction in a compass grating projection system. The method provided by the embodiment of the application can be used for carrying out phase correction on the deformed fringe pattern in the compass grating projection system, and the method can improve the correction speed without increasing the displacement times.
Fig. 11 is a schematic structural diagram of a phase correction apparatus provided in an embodiment, and as shown in fig. 11, the phase correction apparatus includes: a first acquisition module 1110, a high-pass filtering module 1120, a second acquisition module 1130, and a phase correction module 1140, wherein,
a first obtaining module 1110, configured to obtain a deformed fringe pattern captured by a camera, and extract a measurement phase of the deformed fringe pattern;
the high-pass filtering module 1120 is used for performing high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase;
in one embodiment, a plurality of stripes of a deformed stripe pattern are obtained, and a phase corresponding to each stripe is obtained;
and carrying out high-pass filtering processing on the phase of each stripe to obtain an error phase and an approximate phase corresponding to the phase of each stripe.
In one embodiment, the phase of each stripe is high-pass filtered along its vertical direction.
A second obtaining module 1130, configured to obtain a characteristic parameter of the error phase, and obtain an error amplitude corresponding to the error phase according to the characteristic parameter;
in one embodiment, the second obtaining module 1130 obtains an envelope of the error phase; and obtaining the error amplitude corresponding to the error phase according to the envelope curve.
In one embodiment, the second obtaining module 1130 obtains a spectrum of the error phase;
and obtaining the error amplitude corresponding to the error phase according to the frequency spectrum.
And a phase correction module 1140, configured to perform phase correction on the deformed fringe pattern according to the error magnitude and the approximate phase.
In one embodiment, the phase correction module 1140 establishes a phase error expression of the deformed fringe pattern according to the characteristics of the projection grating;
substituting the error amplitude and the approximate phase into a phase error expression, and calculating to obtain the phase error of the deformed stripe;
and carrying out phase correction on the deformed fringe pattern according to the phase error.
In one embodiment, the phase calibration module 1140 obtains a first error magnitude of each pixel point on each stripe according to the error magnitudes;
according to the approximate phase, acquiring a first approximate phase corresponding to the first error amplitude of each pixel point;
and acquiring the phase error of each pixel point on each stripe according to the first error amplitude and the first approximate phase.
The division of the modules in the phase correction apparatus is only for illustration, and in other embodiments, the phase correction apparatus may be divided into different modules as needed to complete all or part of the functions of the phase correction apparatus.
For the specific definition of the phase correction device, reference may be made to the above definition of the phase correction method, which is not described herein again. The respective modules in the phase correction apparatus described above may be implemented in whole or in part by software, hardware, and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
The implementation of each module in the phase correction apparatus provided in the embodiment of the present application may be in the form of a computer program. The computer program may be run on a terminal or a server. The program modules constituted by the computer program may be stored on the memory of the terminal or the server. Which when executed by a processor, performs the steps of the method described in the embodiments of the present application.
FIG. 12 is a diagram showing an internal configuration of a computer device according to an embodiment. As shown in fig. 12, the computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein, the processor is used for providing calculation and control capability and supporting the operation of the whole computer equipment. The memory is used for storing data, programs and the like, and the memory stores at least one computer program which can be executed by the processor to realize the wireless network communication method suitable for the computer device provided by the embodiment of the application. The memory may include a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The computer program is executable by a processor for implementing a method of phase correction as provided in the following embodiments. The internal memory provides a cached execution environment for the operating system computer programs in the non-volatile storage medium. The network interface may be an ethernet card or a wireless network card, etc. for communicating with an external computer device. The computer device may be a mobile terminal, a tablet computer or a personal digital assistant or a wearable device, etc.
The phase correction method mentioned above may specifically be:
acquiring a deformed fringe pattern shot by a camera, and extracting a measurement phase of the deformed fringe pattern;
carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase;
acquiring characteristic parameters of the error phase, and acquiring error amplitude corresponding to the error phase according to the characteristic parameters;
and performing phase correction on the deformed fringe pattern according to the error amplitude and the approximate phase.
The embodiment of the application also provides a computer readable storage medium. One or more non-transitory computer-readable storage media containing computer-executable instructions that, when executed by one or more processors, cause the processors to perform the steps of the phase correction method.
A computer program product comprising instructions which, when run on a computer, cause the computer to perform the steps of the phase correction method.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (9)
1. A method of phase correction, the method comprising:
acquiring a deformed fringe pattern shot by a camera, and extracting a measurement phase of the deformed fringe pattern;
carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern to obtain an error phase and an approximate phase;
acquiring a characteristic parameter of the error phase, and acquiring an error amplitude corresponding to the error phase according to the characteristic parameter;
establishing a phase error expression of a deformed fringe pattern according to the characteristics of the projection grating; substituting the error amplitude and the approximate phase into the phase error expression, and calculating to obtain the phase error of the deformed stripe; and carrying out phase correction on the deformed fringe pattern according to the phase error.
2. The method of claim 1, wherein the high-pass filtering the measured phase of the deformed fringe pattern to obtain an error phase and an approximate phase comprises:
obtaining a plurality of stripes of the deformed stripe pattern, and obtaining a measurement phase corresponding to each stripe;
and carrying out high-pass filtering processing on the measurement phase of each stripe to obtain an error phase and an approximate phase corresponding to the measurement phase of each stripe.
3. The method of claim 2, wherein the high-pass filtering the phase of each stripe comprises:
the phase of each stripe is high-pass filtered in the vertical direction of each stripe.
4. The method according to claim 1, wherein the obtaining a characteristic parameter of the error phase and obtaining an error magnitude corresponding to the error phase according to the characteristic parameter comprises:
acquiring an envelope curve of the error phase;
and obtaining the error amplitude corresponding to the error phase according to the envelope curve.
5. The method according to claim 1, wherein the obtaining a characteristic parameter of the error phase and obtaining an error magnitude corresponding to the error phase according to the characteristic parameter comprises:
acquiring a frequency spectrum of the error phase;
and acquiring the error amplitude corresponding to the error phase according to the frequency spectrum.
6. The method of claim 1, wherein the substituting the error magnitude and the approximate phase into the phase error expression, and the calculating the phase error of the deformed stripe comprises:
acquiring a first error amplitude of each pixel point on each stripe according to the error amplitudes;
acquiring a first approximate phase corresponding to a first error amplitude of each pixel point according to the approximate phase;
and acquiring the phase error of each pixel point on each stripe according to the first error amplitude and the first approximate phase.
7. A phase correction apparatus, characterized in that the apparatus comprises:
the first acquisition module is used for acquiring a deformed fringe pattern shot by the camera and extracting a measurement phase of the deformed fringe pattern;
the high-pass filtering module is used for carrying out high-pass filtering processing on the measurement phase of the deformed fringe pattern so as to obtain an error phase and an approximate phase;
the second obtaining module is used for obtaining the characteristic parameter of the error phase and obtaining the error amplitude corresponding to the error phase according to the characteristic parameter;
the phase correction module is used for establishing a phase error expression of the deformed fringe pattern according to the characteristics of the projection grating; substituting the error amplitude and the approximate phase into the phase error expression, and calculating to obtain the phase error of the deformed stripe; and carrying out phase correction on the deformed fringe pattern according to the phase error.
8. A computer device comprising a memory and a processor, the memory storing a computer program, wherein the processor implements the steps of the method of any one of claims 1 to 6 when executing the computer program.
9. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 6.
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