CN111581852B - Optimal design method of joint time vertex node variable graph filter - Google Patents

Optimal design method of joint time vertex node variable graph filter Download PDF

Info

Publication number
CN111581852B
CN111581852B CN202010474645.4A CN202010474645A CN111581852B CN 111581852 B CN111581852 B CN 111581852B CN 202010474645 A CN202010474645 A CN 202010474645A CN 111581852 B CN111581852 B CN 111581852B
Authority
CN
China
Prior art keywords
filter
matrix
node
dimensional
graph
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
Application number
CN202010474645.4A
Other languages
Chinese (zh)
Other versions
CN111581852A (en
Inventor
蒋俊正
冯海荣
欧阳缮
谢跃雷
卢军志
池源
黄炟鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guilin University of Electronic Technology
Original Assignee
Guilin University of Electronic Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Guilin University of Electronic Technology filed Critical Guilin University of Electronic Technology
Priority to CN202010474645.4A priority Critical patent/CN111581852B/en
Publication of CN111581852A publication Critical patent/CN111581852A/en
Application granted granted Critical
Publication of CN111581852B publication Critical patent/CN111581852B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00Computer-aided design [CAD]
    • G06F30/20Design optimisation, verification or simulation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00Image enhancement or restoration
    • G06T5/70Denoising; Smoothing

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Evolutionary Computation (AREA)
  • Geometry (AREA)
  • General Engineering & Computer Science (AREA)
  • Complex Calculations (AREA)
  • Processing Or Creating Images (AREA)

Abstract

The invention discloses an optimal design method of a joint time vertex node variable graph filter, which comprises the steps of firstly providing the joint time vertex node variable graph filter, then providing an effective filter optimal design method, and the method is used for attributing the design of the joint time vertex node variable graph filter into a least square optimization problem, solving the joint time vertex node variable graph filter with larger design freedom and better overall performance, and applying the filter obtained by design to an inverse filtering denoising problem. The filter designed according to the method has higher design freedom degree and better overall characteristic, and has better effect when carrying out inverse filtering denoising on the network measured data.

Description

Optimal design method of joint time vertex node variable graph filter
Technical Field
The invention relates to the technical field of graph signal processing, in particular to an optimal design method of a joint time vertex node graph-changing filter.
Background
The graph signal processing is an important signal processing theoretical framework for processing data in irregular fields such as a sensor network, a temperature network and the like, and extends a plurality of important concepts of traditional signal processing to graph fields, including graph Fourier transform, graph filters, graph filter banks and the like, wherein the graph filters are powerful tools for processing graph signals, and have wide application in aspects of classification, denoising, interpolation and the like of the graph signals. A common form of graph filter is a polynomial filter with respect to the graph laplacian matrix, and the corresponding graph spectral kernel is also a polynomial form. However, the polynomial-diagram filter has a limited degree of freedom in design, and it is difficult to realize a filter having good characteristics both at the diagram vertices and in the frequency domain. Based on the method, the node mapping filter with higher design freedom and better local characteristics is used for processing the problems of network data coding, clustering and the like.
However, the graph filter described above is mainly used for analyzing static signals on a graph, and in an actual network, most of the signals are changed with time axis changes, such as temperature data recorded at successive time points, traffic flow data, and the like. The time-varying signals on the graph need to be processed in the vertex and time domains, such as the correlation of the graph topology and the evolution of the characteristics in the time axis. To analyze the time-varying signals on the graph, a two-dimensional joint-time vertex graph filter, i.e., a two-dimensional polynomial filter, is obtained by extending the product graph model from the graph vertex domain to the joint-time vertex domain. The current two-dimensional polynomial filter is a bivariate function with respect to the matrix polynomial, and the corresponding frequency response is also a bivariate polynomial with respect to the time-frequency domain and the graph-frequency domain. Although the research on the two-dimensional polynomial filter is developed rapidly and plays an important role in practical applications such as continuous time sequence prediction, dynamic image denoising, video restoration and the like, the two-dimensional polynomial filter is mainly designed under the condition of non-node change on the joint time vertex domain, the research is less under the condition of node change, the degree of freedom of node design is low, the design characteristics are not flexible enough, and the joint time vertex graph filter with good characteristics on the joint time vertex domain and the joint frequency domain is difficult to design, so that a more generalized joint time vertex node graph filter is to be proposed under the condition of node change on the joint time vertex domain.
Disclosure of Invention
The invention aims at overcoming the defects of the prior art and provides an optimal design method of a joint time vertex node variable graph filter. The filter designed according to the method has higher design freedom degree and better overall characteristic, and has better effect when carrying out inverse filtering denoising on the network measured data.
The technical scheme for realizing the aim of the invention is as follows:
the optimization design method of the joint time vertex node variable graph filter is different from the prior art in that the method comprises the following steps:
1) Defining a joint time vertex node variogram filter: first, a two-dimensional polynomial graph filter is defined as follows:
Figure BDA0002515476560000021
in the middle of
Figure BDA0002515476560000022
Is a directed circulation diagram->
Figure BDA0002515476560000023
Laplacian matrix in time domain, wherein +.>
Figure BDA0002515476560000024
Is a unitary matrix->
Figure BDA0002515476560000025
Is an adjacency matrix;
Figure BDA0002515476560000026
Is a common figure->
Figure BDA0002515476560000027
Normalized Laplace matrix on vertex domain, wherein +.>
Figure BDA0002515476560000028
Is a unitary matrix->
Figure BDA0002515476560000029
For the degree matrix->
Figure BDA00025154765600000210
Is a weighted adjacency matrix; k (K) t And K g For the filter length in the joint temporal vertex domain, a k,l For the filter coefficients +.>
Figure BDA00025154765600000211
For the Cronecker product, from equation (1), it can be derived that each node on the product graph of the two-dimensional polynomial filter is given the same weight coefficient a k,l I.e. filter coefficient a k,l The effect is the same for all nodesExpressed as a non-node-dependent characteristic of a two-dimensional polynomial filter, the degree of freedom of design is only (K t +1)×(K g +1), the flexible design characteristics of the filter are limited, in order to improve the design freedom of the joint time vertex graph filter and improve the overall performance of the filter, a more general joint time vertex graph filter is provided, and the joint time vertex node graph filter is defined as follows:
Figure BDA00025154765600000212
in the method, in the process of the invention,
Figure BDA00025154765600000213
is a vector of NT×1, N and T each represent a normal map +.>
Figure BDA00025154765600000214
And directed cyclic graph->
Figure BDA00025154765600000215
Is of the size of diag (a) (k,l) ) Representing a diagonal matrix, the diagonal elements being represented by the vector a (k,l) In the composition, in the formula (2), a joint time vertex node change graph filter can be obtained, that is, the degree of freedom of the two-dimensional node change graph filter is NT× (K t +1)(K g +1), far greater than the degree of freedom of the two-dimensional polynomial filter, in addition, it can be seen that the two-dimensional node-change filter weights different +.>
Figure BDA00025154765600000216
Endowed on each node of the product graph, which ensures flexibility and performance of the filter design;
2) Definition of two-dimensional node-change-map filter H 2D,NV (((i-1) n+j)) behavior:
Figure BDA00025154765600000217
where T represents a transpose of the vector or matrix, and the ranges of i and j are i=1, …, T, j=1, …, N, respectively;
Figure BDA0002515476560000031
{e i } T×1 sum { e } j } N×1 The standard basis vector is represented, that is, the elements other than the ith and jth elements in the vector are all 0, and for convenience in designing the filter, the following formula is defined:
Figure BDA0002515476560000032
Figure BDA0002515476560000033
Figure BDA0002515476560000034
based on the above formula (4), formula (5), formula (6), formula (3) can be expressed as:
Figure BDA0002515476560000035
wherein I is NT Is an identity matrix with the size of NT x NT;
3) Design of two-dimensional node change-map filter H 2D,NV : design of two-dimensional node-varying filter H 2D,NV Approximating an ideal filter operator
Figure BDA0002515476560000036
The following optimization problems are summarized:
Figure BDA0002515476560000037
wherein F represents the F norm of the matrix, a (k,l) Representing a filter to be solvedThe coefficients, according to equation (3) and equation (7) in step 2), equation (8) can be equivalently the least squares optimization problem as follows:
Figure BDA0002515476560000038
by solving the optimization problem, equation (9), the filter coefficients can be obtained as:
Figure BDA0002515476560000039
in the method, in the process of the invention,
Figure BDA00025154765600000310
thereby obtaining the approximate ideal filter operator +.>
Figure BDA00025154765600000311
Is a two-dimensional node-change filter;
4) Application of two-dimensional node variable filter in inverse filtering denoising: assuming that a noise-containing mapping signal with size n×t is y=x+n, where X and N are an original signal and a noise signal, respectively, when the original signal and the noise signal are vectorized, y=vec (Y) =x+n, the dimensions of X and N are nt×1, and the inverse filtering denoising problem is expressed as the following unconstrained optimization problem:
Figure BDA00025154765600000312
in the method, in the process of the invention,
Figure BDA00025154765600000313
for the polynomial of the joint Laplace matrix, μ is a weight factor, the relation between the first term and the second term in the optimization problem can be adjusted, and the inverse filtering problem, namely formula (11), is solved to obtain the optimal solution as follows:
Figure BDA0002515476560000041
wherein I is NT Is an identity matrix with the size of NT x NT,
Figure BDA0002515476560000042
is an ideal inverse filter operator;
5) Inverse filtering denoising: in combination with the optimization problem (9) in step 3) and the equation (10) for solving the filter coefficients, an ideal inverse filter operator approximating step 4) can be designed
Figure BDA0002515476560000043
Is a two-dimensional node-change filter H 2D,NV Finally, the method is used for solving the problem of denoising of the inverse filter.
The optimization problem formula (9) in the step 3) is a least square optimization problem, the formula (9) is solved by adopting a method for solving the least square problem, and a solution of the filter coefficient, namely the formula (10), is obtained, so that the two-dimensional node mapping filter is obtained.
In the step 4) of the method,
Figure BDA0002515476560000044
where q represents the joint Laplace matrix +.>
Figure BDA0002515476560000045
To the power q of (2).
In step 4), an ideal inverse filter operator
Figure BDA0002515476560000046
I NT Represents an identity matrix of size NT.times.NT, mu is the weighting factor,/is the weight factor>
Figure BDA0002515476560000047
Compared with the prior art, the technical scheme adopts an optimization method to design the joint time vertex node graph changing filter, the design problem of the filter is reduced to be a least square problem, the objective function is the approximation of the two-dimensional node graph changing filter to an ideal inverse filter operator, and the optimization problem is split into the approximation of each row of the two-dimensional node graph changing filter and each row of the ideal inverse filter operator to obtain the solution of the filter coefficient, thereby obtaining the two-dimensional node graph changing filter.
The two-dimensional node variable filter designed according to the method has larger design freedom, more flexible design characteristics and better overall performance, and has better effect and is closer to the denoising level of an ideal inverse filter operator when the ideal inverse filter operator is approximately denoised, namely, the synthesized time-varying data or the actually measured time-varying network signal is denoised, compared with the existing method.
Detailed Description
The following describes the invention in further detail with reference to examples, but is not intended to limit the invention.
Examples:
an optimization design method of a joint time vertex node variable graph filter comprises the following steps:
1) Defining a joint time vertex node variogram filter: first, a two-dimensional polynomial graph filter is defined as follows:
Figure BDA0002515476560000048
in the middle of
Figure BDA0002515476560000049
Is a directed circulation diagram->
Figure BDA00025154765600000410
Laplacian matrix in time domain, wherein +.>
Figure BDA00025154765600000411
Is a unitary matrix->
Figure BDA00025154765600000412
Is an adjacency matrix;
Figure BDA00025154765600000413
Is a common figure->
Figure BDA00025154765600000414
Normalized Laplace matrix on vertex domain, wherein +.>
Figure BDA00025154765600000415
Is a unitary matrix->
Figure BDA00025154765600000416
For the degree matrix->
Figure BDA00025154765600000417
Is a weighted adjacency matrix; k (K) t And K g For the filter length in the joint temporal vertex domain, a k,l For the filter coefficients +.>
Figure BDA0002515476560000051
For the Cronecker product, from equation (1), it can be derived that each node on the product graph of the two-dimensional polynomial filter is given the same weight coefficient a k,l I.e. filter coefficient a k,l The effect is the same for all nodes, the non-node-varying characteristic expressed as a two-dimensional polynomial filter, the degree of freedom of design is only (K t +1)×(K g +1), the flexible design characteristics of the filter are limited, in order to improve the design freedom of the joint time vertex graph filter and improve the overall performance of the filter, a more general joint time vertex graph filter is provided, and the joint time vertex node graph filter is defined as follows:
Figure BDA0002515476560000052
in the method, in the process of the invention,
Figure BDA0002515476560000053
is a vector of NT×1, N and T each represent a normal map +.>
Figure BDA0002515476560000054
And directed cyclic graph->
Figure BDA0002515476560000055
Is of the size of diag (a) (k,l) ) Representing a diagonal matrix, the diagonal elements being represented by the vector a (k,l) In the composition, in the formula (2), a joint time vertex node change graph filter can be obtained, that is, the degree of freedom of the two-dimensional node change graph filter is NT× (K t +1)(K g +1), far greater than the degree of freedom of the two-dimensional polynomial filter, in addition, it can be seen that the two-dimensional node-change filter weights different +.>
Figure BDA0002515476560000056
The method has the advantages that the flexibility and the performance of the filter design are guaranteed by the method on each node of the product graph, compared with a two-dimensional polynomial filter, the two-dimensional node variable filter has higher degree of freedom and the like, but the difficulty is also increased for the design of the filter;
2) Definition of two-dimensional node-change-map filter H 2D,NV (((i-1) n+j)) behavior:
Figure BDA0002515476560000057
where T represents a transpose of the vector or matrix, and the ranges of i and j are i=1, …, T, j=1, …, N, respectively;
Figure BDA0002515476560000058
{e i } T×1 sum { e } j } N×1 The standard basis vector is represented, that is, the elements other than the ith and jth elements in the vector are all 0, and for convenience in designing the filter, the following formula is defined:
Figure BDA0002515476560000059
Figure BDA0002515476560000061
Figure BDA0002515476560000062
based on the above formula (4), formula (5), formula (6), formula (3) can be expressed as:
Figure BDA0002515476560000063
wherein I is NT Is an identity matrix with the size of NT x NT;
3) Design of two-dimensional node change-map filter H 2D,NV : design of two-dimensional node-varying filter H 2D,NV Approximating an ideal filter operator
Figure BDA0002515476560000064
The following optimization problems are summarized:
Figure BDA0002515476560000065
wherein F represents the F norm of the matrix, a (k,l) Representing the filter coefficients to be solved, according to equations (3) and (7) in step 2), equation (8) may be equivalently the following least squares optimization problem:
Figure BDA0002515476560000066
by solving the optimization problem, equation (9), the filter coefficients can be obtained as:
Figure BDA0002515476560000067
in the method, in the process of the invention,
Figure BDA0002515476560000068
thereby obtaining the approximate ideal filter operator +.>
Figure BDA0002515476560000069
Is a two-dimensional node-change filter;
4) Application of two-dimensional node variable filter in inverse filtering denoising: assuming that a noise-containing mapping signal with size n×t is y=x+n, where X and N are an original signal and a noise signal, respectively, when the original signal and the noise signal are vectorized, y=vec (Y) =x+n, the dimensions of X and N are nt×1, and the inverse filtering denoising problem is expressed as the following unconstrained optimization problem:
Figure BDA00025154765600000610
in the method, in the process of the invention,
Figure BDA00025154765600000611
for the polynomial of the joint Laplace matrix, μ is a weight factor, the relation between the first term and the second term in the optimization problem can be adjusted, and the inverse filtering problem, namely formula (11), is solved to obtain the optimal solution as follows:
Figure BDA00025154765600000612
wherein I is NT Is an identity matrix with the size of NT x NT,
Figure BDA00025154765600000613
is an ideal inverse filter operator;
5) Inverse filtering denoising: in combination with the optimization problem (9) in step 3) and the equation (10) for solving the filter coefficients, an ideal inverse filter operator approximating step 4) can be designed
Figure BDA0002515476560000071
Is a two-dimensional node-change filter H 2D,NV Finally, the method is used for solving the problem of denoising of the inverse filter.
The optimization problem formula (9) in the step 3) is a least square optimization problem, the formula (9) is solved by adopting a method for solving the least square problem, and a solution of the filter coefficient, namely the formula (10), is obtained, so that the two-dimensional node mapping filter is obtained.
In the step 4) of the method,
Figure BDA0002515476560000072
where q represents the joint Laplace matrix +.>
Figure BDA0002515476560000073
To the power q of (2).
In step 4), an ideal inverse filter operator
Figure BDA0002515476560000074
I NT Represents an identity matrix of size NT.times.NT, mu is the weighting factor,/is the weight factor>
Figure BDA0002515476560000075
Specifically:
simulation case 1:
using two-dimensional node-change filters H 2D,NV Approximate ideal inverse filter operator
Figure BDA0002515476560000076
And (3) carrying out inverse filtering denoising experiments on the synthesized time-varying graph signals: in the simulation, a random sensor network diagram with a node n=100 is firstly constructed by using a nearest distance algorithm, and then a time-varying diagram signal x= [ X ] of 100×30 is generated 1 ,x 2 ,…,x 30 ]Its picture signal at time t is set to +.>
Figure BDA0002515476560000077
Wherein the initial signal x 1 Is a low frequency signal f t Vectorizing X to a white Gaussian noise signalWith x=vec (X), the signal size range is [ -19.39,38.31]The noise signal n is [ -sigma, sigma]Obeying uniform distribution, sigma is a standard noise factor, the weight factor is set to mu=0.6, and the filter length is set to K t =K g =2 and let->
Figure BDA0002515476560000078
Table 1 shows the filter design of the method of the present example and the prior method 1 (two-dimensional polynomial graph filter) in approximately ideal inverse filter operator +.>
Figure BDA0002515476560000079
Performance comparison of inverse filtering denoising is carried out on the time-varying graph signals, wherein Input (containing noise) represents Input signal-to-noise ratio, and Explicit (denoising) represents the noise between ideal inverse filtering operator +.>
Figure BDA00025154765600000710
The denoising signal-to-noise ratio obtained below.
TABLE 1
σ 1 2 5 10 15
Input (with noise) 24.85 18.83 10.87 4.85 1.33
Explicit (denoising) 26.21 20.48 12.61 6.60 3.08
Existing method 1 (denoising) 21.73 18.80 12.41 6.67 3.20
This example method (denoising) 24.02 19.91 12.66 6.74 3.24
As can be seen from Table 1, the two-dimensional node variable filter designed by the method of the present example approximates to an ideal inverse filter operator
Figure BDA00025154765600000711
When the noise factor sigma is smaller, the denoising performance of the time-varying graph signal is better than that of a two-dimensional polynomial filter, and is closer to an ideal inverse filtering operator +.>
Figure BDA0002515476560000081
This also verifies the two-dimensional node transformation graph filtering designed by the methodThe wave filter has a larger design degree and is superior to a two-dimensional polynomial filter in the overall denoising performance.
Simulation case 2:
in the simulation, actual measurement data, namely global sea level pressure data, is used for verifying the validity of the designed two-dimensional node variable filter in processing real data. The global sea level pressure data includes sea level pressure data from 1984 to 2010, and the recorded pressure data for each time period is average pressure data every five days. In this simulation, a graph model is constructed on sea level pressure data of node n=500 by a nearest distance algorithm, then average sea level data of last 100 days in 2010 is selected as an original time-varying graph signal x, that is, average pressure data of every five days in 100 days is taken as pressure data at one moment, that is, t=20, x ranges from 95.2762kPa to 106.9132kPa, a weighting factor μ=0.4 is set, and other parameters such as filter length and L are set p Etc. are set as in simulation case 1.
TABLE 2
σ 5 10 1 20 25
Input (with noise) 30.84 24.82 21.30 18.80 16.86
Explicit (denoising) 32.21 26.20 22.67 20.18 18.24
Existing method 1 (denoising) 27.17 24.33 21.78 19.68 17.94
This example method (denoising) 29.28 25.33 22.32 20.01 18.18
Table 2 reflects the comparison of the present example method with the prior art method 1 (two-dimensional polynomial graph filter)
Figure BDA0002515476560000082
And when the sea level pressure data is similar, performing inverse filtering denoising performance comparison on the actually measured sea level pressure data. As can be seen from Table 2, the two-dimensional node variable filter is closer to the ideal inverse filter operator when denoising the measured data>
Figure BDA0002515476560000083
Is to be subjected to denoisingThe performance of the two-dimensional node variable filter is better than that of a two-dimensional polynomial filter, and the effect of denoising the measured network data by the two-dimensional node variable filter designed by the example is also shown. The two simulation examples show that the filter designed by the method has better denoising performance than a two-dimensional polynomial filter in the aspect of processing the synthesized time-varying diagram signals and the actual network data, and can be closer to the denoising effect of an ideal filtering operator, and the two-dimensional node variable filter designed by the method is verified from the side to have larger design freedom, more flexible design characteristics and better overall performance. />

Claims (2)

1. The optimal design method of the joint time vertex node variable graph filter is characterized by comprising the following steps of:
1) Defining a joint time vertex node variogram filter: first, a two-dimensional polynomial graph filter is defined as follows:
Figure FDA0002515476550000011
in the middle of
Figure FDA0002515476550000012
Is a directed circulation diagram->
Figure FDA0002515476550000013
Laplacian matrix in time domain, wherein +.>
Figure FDA0002515476550000014
Is a matrix of units which is a matrix of units,
Figure FDA0002515476550000015
is an adjacency matrix;
Figure FDA0002515476550000016
Is a common figure->
Figure FDA0002515476550000017
Normalized Laplace matrix on vertex domain, wherein +.>
Figure FDA0002515476550000018
Is a unitary matrix->
Figure FDA0002515476550000019
For the degree matrix->
Figure FDA00025154765500000110
Is a weighted adjacency matrix; k (K) t And K g For the filter length in the joint temporal vertex domain, a k,l For the filter coefficients +.>
Figure FDA00025154765500000111
For the Cronecker product, from equation (1), it can be derived that each node on the product graph of the two-dimensional polynomial filter is given the same weight coefficient a k,l I.e. filter coefficient a k,l The effect is the same for all nodes, the non-node-varying characteristic expressed as a two-dimensional polynomial filter, the degree of freedom of design is only (K t +1)×(K g +1) then defining a joint temporal vertex node variogram filter as:
Figure FDA00025154765500000112
in the method, in the process of the invention,
Figure FDA00025154765500000113
is a vector of NT×1, N and T each represent a normal map +.>
Figure FDA00025154765500000114
And directed cyclic graph->
Figure FDA00025154765500000115
Is of the size of diag (a) (k,l) ) Representing a diagonal matrix, the diagonal elements being represented by the vector a (k,l) Composition;
2) Definition of two-dimensional node-change-map filter H 2D,NV (((i-1) n+j)) behavior:
Figure FDA00025154765500000116
where T represents a transpose of the vector or matrix, and the ranges of i and j are i=1, …, T, j=1, …, N, respectively;
Figure FDA00025154765500000117
{e i } T×1 sum { e } j } N×1 The standard basis vector, i.e. the vector has 0 for all elements except the i and j elements except 1, defines the following formula:
Figure FDA0002515476550000021
Figure FDA0002515476550000022
Figure FDA0002515476550000023
based on the above formula (4), formula (5), formula (6), formula (3) can be expressed as:
Figure FDA0002515476550000024
wherein I is NT Is an identity matrix with the size of NT x NT;
3) Design of two-dimensional node change-map filter H 2D,NV : design of two-dimensional node-varying filter H 2D,NV Approximating an ideal filter operator
Figure FDA0002515476550000025
The following optimization problems are summarized:
Figure FDA0002515476550000026
wherein F represents the F norm of the matrix, a (k,l) Representing the filter coefficients to be solved, according to equations (3) and (7) in step 2), equation (8) may be equivalently the following least squares optimization problem:
Figure FDA0002515476550000027
by solving the optimization problem, equation (9), the filter coefficients can be obtained as:
Figure FDA0002515476550000028
in the method, in the process of the invention,
Figure FDA0002515476550000029
thereby obtaining the approximate ideal filter operator
Figure FDA00025154765500000210
Is a two-dimensional node-change filter;
4) Application of two-dimensional node variable filter in inverse filtering denoising: assuming that a noise-containing mapping signal with size n×t is y=x+n, where X and N are an original signal and a noise signal, respectively, when the original signal and the noise signal are vectorized, y=vec (Y) =x+n, the dimensions of X and N are nt×1, and the inverse filtering denoising problem is expressed as the following unconstrained optimization problem:
Figure FDA00025154765500000211
in the method, in the process of the invention,
Figure FDA00025154765500000212
for the polynomial of the joint Laplace matrix, μ is a weight factor, the relation between the first term and the second term in the optimization problem can be adjusted, and the inverse filtering problem, namely formula (11), is solved to obtain the optimal solution as follows:
Figure FDA0002515476550000031
wherein I is NT Is an identity matrix with the size of NT x NT,
Figure FDA0002515476550000032
is an ideal inverse filter operator;
5) Inverse filtering denoising: combining the optimization problem (9) in step 3) and the equation (10) for solving the filter coefficients, the ideal inverse filter operator approximating step 4) can be obtained
Figure FDA0002515476550000033
Is a two-dimensional node-change filter H 2D,NV Finally, the method is used for solving the inverse filtering denoising.
2. The method for optimizing design of joint-time vertex node variogram filter as in claim 1, wherein in step 4), ideal inverse filter operator
Figure FDA0002515476550000034
I NT Represents an identity matrix of size NT.times.NT, mu is the weighting factor,/is the weight factor>
Figure FDA0002515476550000035
CN202010474645.4A 2020-05-29 2020-05-29 Optimal design method of joint time vertex node variable graph filter Active CN111581852B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010474645.4A CN111581852B (en) 2020-05-29 2020-05-29 Optimal design method of joint time vertex node variable graph filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010474645.4A CN111581852B (en) 2020-05-29 2020-05-29 Optimal design method of joint time vertex node variable graph filter

Publications (2)

Publication Number Publication Date
CN111581852A CN111581852A (en) 2020-08-25
CN111581852B true CN111581852B (en) 2023-05-16

Family

ID=72123700

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010474645.4A Active CN111581852B (en) 2020-05-29 2020-05-29 Optimal design method of joint time vertex node variable graph filter

Country Status (1)

Country Link
CN (1) CN111581852B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112865748B (en) * 2021-01-13 2022-05-10 西南大学 Method for constructing online distributed multitask graph filter based on recursive least squares
CN113191978B (en) * 2021-04-30 2022-07-26 南京邮电大学 Asynchronous implementation method of distributed constraint edge-varying FIR (finite impulse response) graph filter

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109586688A (en) * 2018-12-07 2019-04-05 桂林电子科技大学 Time-varying based on iterative calculation can divide the design method of non-lower sampling figure filter group

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070037540A1 (en) * 2005-08-15 2007-02-15 Research In Motion Limited Joint Space-Time Optimum Filters (JSTOF) Using Singular Value Decompositions (SVD)
US8027547B2 (en) * 2007-08-09 2011-09-27 The United States Of America As Represented By The Secretary Of The Navy Method and computer program product for compressing and decompressing imagery data
US8705809B2 (en) * 2010-09-30 2014-04-22 King Saud University Method and apparatus for image generation

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109586688A (en) * 2018-12-07 2019-04-05 桂林电子科技大学 Time-varying based on iterative calculation can divide the design method of non-lower sampling figure filter group

Also Published As

Publication number Publication date
CN111581852A (en) 2020-08-25

Similar Documents

Publication Publication Date Title
CN104159003B (en) A kind of cooperateed with based on 3D filters the video denoising method rebuild with low-rank matrix and system
CN111581852B (en) Optimal design method of joint time vertex node variable graph filter
Gupta et al. Review of different local and global contrast enhancement techniques for a digital image
Lamberti et al. CMBFHE: a novel contrast enhancement technique based on cascaded multistep binomial filtering histogram equalization
CN112132758B (en) Image restoration method based on asymmetric optical system point spread function model
CN107274379B (en) Image quality evaluation method and system
Hel-Or et al. The role of redundant bases and shrinkage functions in image denoising
CN111461999B (en) SAR image speckle suppression method based on super-pixel similarity measurement
Kumar et al. Image denoising based on fractional gradient vector flow and overlapping group sparsity as priors
Bhattacharya et al. Brain image segmentation technique using Gabor filter parameter
Park et al. False contour reduction using neural networks and adaptive bi-directional smoothing
CN107590781A (en) Adaptive weighted TGV image deblurring methods based on primal dual algorithm
Tseng et al. Distributed implementation of heat kernel smoothing for graph signal denoising
CN111340741A (en) Particle swarm optimization gray level image enhancement method based on quaternion and L1 norm
Wang et al. Super-resolution image reconstruction method using homotopy regularization
Su et al. Deconvolution of defocused image with multivariate local polynomial regression and iterative wiener filtering in DWT domain
Su et al. Defocused image restoration using RBF network and iterative Wiener filter in wavelet domain
Lin et al. An iterative enhanced super-resolution system with edge-dominated interpolation and adaptive enhancements
Mironov et al. Comparative Analysis of Local Adaptive LMS Image Filtration
Mironov Local Adaptive 2D Recursive Sliding Mean Filtration of Halftone Images
Zhang et al. Frequency Domain Filtering
Ozkan et al. LMMSE restoration of blurred and noisy image sequences
Su Defocused Image Restoration with Local Polynomial Regression and IWF
Srinivasa et al. Vector median filter methods for denoising of digital color images: A review
Ko et al. Image sequence enhancement based on adaptive symmetric order statistics

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
EE01 Entry into force of recordation of patent licensing contract

Application publication date: 20200825

Assignee: Guangxi wisdom Valley Technology Co.,Ltd.

Assignor: GUILIN University OF ELECTRONIC TECHNOLOGY

Contract record no.: X2023980046615

Denomination of invention: An Optimization Design Method for Joint Time Vertex Node Variable Graph Filter

Granted publication date: 20230516

License type: Common License

Record date: 20231108

EE01 Entry into force of recordation of patent licensing contract