A stripe direction angle fast unwrapping method based on reliability ranking

Abstract

This invention discloses a fast unpacking method for fringe direction angles based on reliability ranking. The method includes: first, calculating the gradient using an interferogram; then, calculating the density map; calculating the reliability value from the density map; ranking the reliability values; and then unpacking the relative direction angles of adjacent pixels in order of reliability value magnitude to obtain the pointing map. This invention uses a non-continuous unpacking path, solving the problem of slow processing speed in traditional algorithms when handling large images due to the limitation of continuous paths.

Description

Technical Field

[0001] This invention belongs to the field of image processing technology, and in particular to a fast unpacking algorithm for stripe direction angle based on reliability sorting. Background Technology

[0002] The fringe orientation contains crucial information about the interference fringe pattern and is an important component of many existing denoising algorithms and single-frame demodulation techniques. The fringe orientation angle is generally obtained through the fringe intensity gradient. Because the fringe intensity gradient is used instead of the actual phase gradient to calculate the orientation angle, the orientation angle is confined to the range [-π / 2, π / 2]. Unpacking the fringe pattern is the process of restoring the true orientation pattern from the orientation angles confined to [-π / 2, π / 2].

[0003] To effectively perform orientation angle unpacking operations, scholars both domestically and internationally have proposed unpacking methods such as regularized phase tracking and quality map-guided unpacking. Both of these algorithms are based on the most reliable pixels from previous unpacking, falling under the category of continuous path algorithms. However, these algorithms are limited by the continuous path limitation when processing large images, resulting in long unpacking times and failing to meet the real-time requirements of single-frame interferogram processing. Therefore, it is necessary to provide a fast unpacking algorithm using non-continuous paths. Summary of the Invention

[0004] The purpose of this invention is to address the deficiencies and shortcomings of the existing technology by providing a fast unpacking method for directional patterns that is fast and has strong anti-interference capabilities.

[0005] The technical solution to achieve the objective of this invention is as follows: On the one hand, a fast unpacking method for stripe direction angle based on reliability ranking is provided, including the following steps:

[0006] Step 1: Calculate the gradient values ​​of the interferogram fringes;

[0007] Step 2: Calculate the fringe density map based on the fringe gradient values;

[0008] Step 3: Calculate the vertical reliability value and the horizontal reliability value using the fringe density map;

[0009] Step 4: Guide the relative unpacking of two adjacent pixels based on the reliability value position;

[0010] Step 5: Repeat step 4 until unpacking is complete, and obtain the pointer graph.

[0011] Further, the calculation of the interferogram fringe gradient value in step 1 specifically involves:

[0012] Calculate the horizontal gradient of the interferometric image Where f(i,j) and f(i-1,j) are the pixel values ​​of the interference image at positions (i,j) and (i-1,j), respectively;

[0013] Calculate the vertical gradient of the interferometric image

[0014] Further, step 2, which involves calculating the fringe density map based on the fringe gradient values, specifically involves:

[0015]

[0016] In the formula, D q (i,j) represents the fringe density value of the interferometric image at position (i,j), with the symbol... K represents the convolution operator. ρ This represents a Gaussian filter with kernel size ρ.

[0017] Further, step 3, which involves calculating the horizontal and vertical reliability values ​​based on the fringe density map, specifically involves:

[0018] Calculate the horizontal reliability value E h E h (i,j)=D q (i,j)+D q (i+1,j);

[0019] Calculate the vertical reliability value E v E v (i,j)=D q (i,j)+D q (i,j+1);

[0020] In the formula, E h (i,j) represents the horizontal reliability value of the interferogram at position (i,j), E v (i,j) represents the vertical reliability value of the image at position (i,j), D q (i+1,j) represents the fringe density value of the interference image at position (i+1,j).

[0021] Furthermore, step 4, which guides the relative unpacking of two adjacent pixels based on the reliability value location, specifically includes:

[0022] Before unpacking, group all pixels separately: find two pixels A and B with adjacent reliability values, assuming A belongs to G. A Group B belongs to G B Group, calculate the angular difference Δ between the two points. β Determine if groups A and B are the same. If they are the same, skip this reliability value; otherwise, determine cos(Δ). βIf α is greater than zero, then let α = 0; otherwise, let α = 1.

[0023] Determine G A Is the number of elements in the group greater than G? B The number of elements in a group; if so, then G B Add α×π to all direction angles within the group and add them to G. A Group, otherwise G A Add α×π to all direction angles within the group and add them to G. B Group.

[0024] Furthermore, step 5 involves repeating step 4 until the unpacking is complete, resulting in a pointing graph. Specifically, this involves sequentially unpacking all edge values ​​for all direction angles and enclosing the unpacking results within the range [-π, π], which forms the pointing graph.

[0025] Furthermore, before step 5 is executed, the following is also included:

[0026] Sort the reliability values ​​obtained in step 3 in descending order.

[0027] On the other hand, a fast unpacking system for stripe direction angles based on reliability sorting is provided, the system comprising sequentially executed:

[0028] The first module is used to calculate the gradient values ​​of the interferogram fringes;

[0029] The second module is used to calculate the fringe density map based on the fringe gradient value;

[0030] The third module is used to calculate the vertical reliability value and the horizontal reliability value using the stripe density map;

[0031] The fourth module is used to guide the relative unpacking of two adjacent pixels based on the location of the reliability value;

[0032] The fifth module is used to repeatedly run the fourth module until the unpacking is complete, and obtain the pointer graph.

[0033] Furthermore, the system also includes the following steps prior to the execution of the fourth module:

[0034] The sixth module is used to sort the reliability values ​​obtained from the third module in descending order.

[0035] Compared with the prior art, the significant advantages of this invention are:

[0036] 1) First, perform relative unfolding of high-quality pixels, and then perform relative unfolding of low-quality pixels to avoid propagation errors caused by the unfolding path passing through low-quality areas first.

[0037] 2) This algorithm is a non-continuous path algorithm, which reduces the operation of selecting the next expanded pixel relative to the already expanded pixel, thus reducing the computation time.

[0038] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0039] Figure 1 This is a flowchart of the fast unpacking algorithm for stripe direction angle based on reliability sorting in this invention.

[0040] Figure 2 This is a flowchart of the algorithm that guides unpacking by the location of reliability values.

[0041] Figure 3 This is an interference fringe pattern with background and noise components removed in one embodiment.

[0042] Figure 4 In one embodiment, a gradient algorithm is used to... Figure 3 Calculated fringe pattern.

[0043] Figure 5 For one embodiment Figure 3 The obtained fringe density map.

[0044] Figure 6 for Figure 5 Example diagram of local reliability value calculation.

[0045] Figure 7 This is a pointer diagram after final unpacking in one embodiment. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0047] It should be noted that the terms "comprising" and "specific" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover a non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product or device.

[0048] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0049] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0050] In one embodiment, combined Figure 1 This paper provides a fast unpacking method for stripe direction angle based on reliability ranking, including the following steps:

[0051] Step 1: Calculate the gradient values ​​of the interferogram fringes;

[0052] Step 2: Calculate the fringe density map based on the fringe gradient values;

[0053] Step 3: Calculate the vertical reliability value and the horizontal reliability value using the fringe density map;

[0054] Step 4: Sort the reliability values ​​obtained in Step 3 in descending order;

[0055] Step 5: Guide the relative unpacking of two adjacent pixels based on the reliability value position;

[0056] Step 6: Repeat step 5 until unpacking is complete, and obtain the pointer graph.

[0057] Furthermore, in one embodiment, the calculation of the interferogram fringe gradient value in step 1 specifically involves:

[0058] Calculate the horizontal gradient of the interferometric image Where f(i,j) and f(i-1,j) are the pixel values ​​of the interference image at positions (i,j) and (i-1,j), respectively;

[0059] Calculate the vertical gradient of the interferometric image

[0060] Furthermore, in one embodiment, step 2, calculating the fringe density map based on the fringe gradient value, specifically involves:

[0061]

[0062] In the formula, D q (i,j) represents D q (i,j) represents the fringe density value of the interferometric image at position (i,j), with the symbol... K represents the convolution operator. ρ This represents a Gaussian filter with kernel size ρ.

[0063] Furthermore, in one embodiment, step 3, calculating the horizontal reliability value and the vertical reliability value based on the fringe density map, specifically involves:

[0064] Calculate the horizontal reliability value E h E h (i,j)=D q (i,j)+D q (i+1,j);

[0065] Calculate the vertical reliability value E v E v (i,j)=D q (i,j)+D q (i,j+1);

[0066] In the formula, E h (i,j) represents the horizontal reliability value of the interferogram at position (i,j), E v (i,j) represents the vertical reliability value of the image at position (i,j), D q (i+1,j) represents the fringe density value of the interference image at position (i+1,j).

[0067] Furthermore, in one embodiment, step 5, which guides the relative unpacking of two adjacent pixels based on the reliability value location, specifically includes:

[0068] Before unpacking, group all pixels separately: find two pixels A and B with adjacent reliability values, assuming A belongs to G. A Group B belongs to G B Group, calculate the angular difference Δ between the two points. β Determine if groups A and B are the same. If they are the same, skip this reliability value; otherwise, determine cos(Δ). β If α is greater than zero, then let α = 0; otherwise, let α = 1.

[0069] Determine G A Is the number of elements in the group greater than G?B The number of elements in a group; if so, then G B Add α×π to all direction angles within the group and add them to G. A Group, otherwise G A Add α×π to all direction angles within the group and add them to G. B Group.

[0070] Furthermore, in one embodiment, step 6 involves repeating step 5 until the unpacking is complete, resulting in a pointing graph. Specifically, this involves sequentially unpacking all edge values ​​for all direction angles and wrapping the unpacking results within the range [-π, π], which is the pointing graph.

[0071] In one embodiment, a fast unpacking system for stripe orientation angles based on reliability ranking is provided, the system comprising sequentially executing:

[0072] The first module is used to calculate the gradient values ​​of the interferogram fringes;

[0073] The second module is used to calculate the fringe density map based on the fringe gradient value;

[0074] The third module is used to calculate the vertical reliability value and the horizontal reliability value using the stripe density map;

[0075] The fourth module is used to sort the reliability values ​​obtained from the third module in descending order.

[0076] The fifth module is used to guide the relative unpacking of two adjacent pixels based on the location of the reliability value;

[0077] The sixth module is used to repeatedly run the fourth module until the unpacking is complete, and obtain the pointer graph.

[0078] Specific limitations regarding the fast unpacking system for stripe orientation angles based on reliability ranking can be found in the limitations of the fast unpacking method for stripe orientation angles based on reliability ranking described above, and will not be repeated here. Each module in the aforementioned fast unpacking system for stripe orientation angles based on reliability ranking can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in hardware or independently of the processor in a computer device, or stored in software in the memory of a computer device, so that the processor can call and execute the corresponding operations of each module.

[0079] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0080] Step 1: Calculate the gradient values ​​of the interferogram fringes;

[0081] Step 2: Calculate the fringe density map based on the fringe gradient values;

[0082] Step 3: Calculate the vertical reliability value and the horizontal reliability value using the fringe density map;

[0083] Step 4: Sort the reliability values ​​obtained in Step 3 in descending order;

[0084] Step 5: Guide the relative unpacking of two adjacent pixels based on the reliability value position;

[0085] Step 6: Repeat step 5 until unpacking is complete, and obtain the pointer graph.

[0086] For specific limitations on each step, please refer to the limitations of the fast unpacking method for stripe direction angle based on reliability sorting mentioned above, which will not be repeated here.

[0087] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0088] Step 1: Calculate the gradient values ​​of the interferogram fringes;

[0089] Step 2: Calculate the fringe density map based on the fringe gradient values;

[0090] Step 3: Calculate the vertical reliability value and the horizontal reliability value using the fringe density map;

[0091] Step 4: Sort the reliability values ​​obtained in Step 3 in descending order;

[0092] Step 5: Guide the relative unpacking of two adjacent pixels based on the reliability value position;

[0093] Step 6: Repeat step 5 until unpacking is complete, and obtain the pointer graph.

[0094] For specific limitations on each step, please refer to the limitations of the fast unpacking method for stripe direction angle based on reliability sorting mentioned above, which will not be repeated here.

[0095] As a specific example, the invention will be further verified and illustrated in one embodiment.

[0096] This invention relates to a fast unpacking algorithm for stripe direction angles based on reliability ranking, comprising the following:

[0097] 1. First, calculate the fringe gradient using the interferogram, as shown in the interferogram below. Figure 3 As shown, the gradient algorithm is used for... Figure 3 The calculated fringe pattern is as follows Figure 4 As shown.

[0098] 2. Calculate the fringe density map from the fringe gradient, such as... Figure 5 As shown.

[0099] 3. The reliability value is obtained by adding the stripe density values ​​of adjacent pixels, such as... Figure 6 As shown.

[0100] 4. For example Figure 2 As shown, the orientation angles of two adjacent pixels with reliability values ​​are unpacked.

[0101] 5. Iterate through all reliability values ​​from largest to smallest until unpacking is complete, thus obtaining the unpacking result. Wrap the unpacking result in [-π, π] to form a pointer graph, as shown below. Figure 7 As shown.

[0102] The expansion path used in this invention is a discontinuous path, which unpacks the same size orientation pattern, resulting in a faster unpacking speed and smaller propagation error affected by the path.

[0103] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention without departing from its spirit and scope should be included within the protection scope of the present invention.

Claims

1. A fast unpacking method for stripe direction angles based on reliability ranking, characterized in that, Includes the following steps: Step 1: Calculate the gradient values ​​of the interferogram fringes; Step 2: Calculate the fringe density map based on the fringe gradient values; Step 3: Calculate the vertical reliability value and the horizontal reliability value using the fringe density map; Step 4: Guide the relative unpacking of two adjacent pixels based on the reliability value position; Step 5: Repeat step 4 until unpacking is complete, and obtain the pointer graph; Step 3, which involves calculating the horizontal and vertical reliability values ​​using the fringe density map, specifically involves: Calculate the horizontal reliability value : ; Calculate vertical reliability value : ; In the formula, Indicating the interferometric image in Horizontal reliability value at the location, Indicates the image in Vertical reliability value at the location, Indicates the interferometric image in The stripe density value at the location; Step 4, which guides the relative unpacking of two adjacent pixels based on the reliability value location, specifically includes: Before unpacking, group all pixels separately: find two pixels A and B with adjacent reliability values, assuming A belongs to... Group B belongs to Group, calculate the difference in direction angle between two points. Determine if groups A and B are the same. If they are the same, skip this reliability value; otherwise, determine... Is it greater than zero? If it is greater than zero, then let Otherwise ; judge Is the number of group elements greater than The number of elements in the group; if so, then All azimuth angles within the group plus And join to Group, otherwise All azimuth angles within the group plus And join to Group; Before step 5 is executed, the following also includes execution: Sort the reliability values ​​obtained in step 3 in descending order.

2. The fast unpacking method for stripe direction angle based on reliability ranking according to claim 1, characterized in that, Step 1, which involves calculating the gradient values ​​of the interferogram fringes, specifically includes: Calculate the horizontal gradient of the interferometric image : ;in , Interference images at , Pixel value at the location; Calculate the vertical gradient of the interferometric image : .

3. The fast unpacking method for stripe direction angle based on reliability ranking according to claim 2, characterized in that, Step 2, which involves calculating the fringe density map based on the fringe gradient values, specifically includes: In the formula, Indicates the interferometric image in The fringe density value at the location, symbol This represents the convolution operator. Indicates the kernel size as Gaussian filter.

4. The fast unpacking method for stripe direction angle based on reliability ranking according to claim 3, characterized in that, Step 5 involves repeating step 4 until unpacking is complete, resulting in a pointing graph. Specifically, this involves sequentially unpacking all edge values ​​for all direction angles and wrapping the unpacking results in a... The area between them is the pointing diagram.

5. A fast unpacking system for stripe orientation angles based on reliability ranking, based on the method of any one of claims 1 to 4, characterized in that, The system includes sequential execution of: The first module is used to calculate the gradient values ​​of the interferogram fringes; The second module is used to calculate the fringe density map based on the fringe gradient value; The third module is used to calculate the vertical reliability value and the horizontal reliability value using the stripe density map; The fourth module is used to guide the relative unpacking of two adjacent pixels based on the location of the reliability value; The fifth module is used to repeatedly run the fourth module until the unpacking is complete, and obtain the pointer graph.

6. The fast unpacking system for stripe direction angle based on reliability ranking according to claim 5, characterized in that, The system also includes the following steps prior to the execution of the fourth module: The sixth module is used to sort the reliability values ​​obtained from the third module in descending order.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 4.

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