CN112464010A - Automatic image labeling method based on Bayesian network and classifier chain - Google Patents

Automatic image labeling method based on Bayesian network and classifier chain Download PDF

Info

Publication number
CN112464010A
CN112464010A CN202011493104.2A CN202011493104A CN112464010A CN 112464010 A CN112464010 A CN 112464010A CN 202011493104 A CN202011493104 A CN 202011493104A CN 112464010 A CN112464010 A CN 112464010A
Authority
CN
China
Prior art keywords
bayesian network
label
image
classifier
subset
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202011493104.2A
Other languages
Chinese (zh)
Other versions
CN112464010B (en
Inventor
王振武
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.)
China University of Mining and Technology Beijing CUMTB
Original Assignee
China University of Mining and Technology Beijing CUMTB
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 China University of Mining and Technology Beijing CUMTB filed Critical China University of Mining and Technology Beijing CUMTB
Priority to CN202011493104.2A priority Critical patent/CN112464010B/en
Publication of CN112464010A publication Critical patent/CN112464010A/en
Application granted granted Critical
Publication of CN112464010B publication Critical patent/CN112464010B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/50Information retrieval; Database structures therefor; File system structures therefor of still image data
    • G06F16/58Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually
    • G06F16/5866Retrieval characterised by using metadata, e.g. metadata not derived from the content or metadata generated manually using information manually generated, e.g. tags, keywords, comments, manually generated location and time information
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/50Information retrieval; Database structures therefor; File system structures therefor of still image data
    • G06F16/55Clustering; Classification

Abstract

The invention discloses an image automatic labeling method based on a Bayesian network and a classifier chain, which is characterized in that a Bayesian network structure is learned by utilizing an improved BIC scoring function method, labels are clustered through a DBSCAN algorithm, a Bayesian network is learned for each label subset, feature selection is carried out through the Bayesian network between the labels and features, the classifier chain is constructed according to the topological sequence of the Bayesian network, and an image prediction label set is constructed through the Bayesian network and the classifier chain algorithm, so that all types of images can be labeled, and the method is strong in universality; meanwhile, the method can process the image containing continuous features and discrete features, has good adaptability, and effectively improves the robustness and accuracy of image labeling.

Description

Automatic image labeling method based on Bayesian network and classifier chain
Technical Field
The invention relates to the technical field of image retrieval, in particular to an automatic image labeling method based on a Bayesian network and a classifier chain.
Background
With the gradual development of technologies such as multimedia and image information, the image database is becoming larger and larger, which makes the management of visual information important, and the image retrieval technology can play a role in visual information management. The traditional manual image labeling method has large workload, and the subjectivity and the inaccuracy are inevitably brought, so that the automatic image labeling of a computer is imperative. The automatic image annotation is to make the computer automatically add the semantic keywords capable of reflecting the content of the image to the image, and the use of the automatic annotation can effectively improve the difficulty of the current image retrieval. The Bayesian network algorithm is a common probability graph model, correlation among the obtained labels is fully considered, and the classifier chain algorithm is a model for fully utilizing the correlation among the labels, so that how to provide an automatic image labeling method based on the Bayesian network and the classifier chain is a technical problem to be solved urgently at present.
Disclosure of Invention
The invention aims to provide an automatic image labeling method based on a Bayesian network and a classifier chain, which aims to solve the technical problems in the prior art, can label images of all types, has strong universality and adaptability, and effectively improves the robustness and accuracy of automatic image labeling.
In order to achieve the purpose, the invention provides the following scheme: the invention provides an automatic image labeling method based on a Bayesian network and a classifier chain, which comprises the following steps:
s1, obtaining a sample image, extracting the characteristics of the sample image to form a training set and a test set, obtaining the label of the sample image, and constructing a total label set;
s2, normalizing the characteristics of the sample images in the training set and the test set;
step S3, constructing a Bayesian network through a score searching method of an improved Bayesian information criterion BIC score function based on each label in the total label set and the characteristics of the sample image after normalization processing, and performing characteristic selection through the Bayesian network to obtain a characteristic subset corresponding to each label;
step S4, based on the feature subset corresponding to each label, clustering the labels in the total label set by adopting density clustering DBSCAN to generate a label subset;
step S5, respectively constructing a Bayesian network structure for each label subset based on the improved BIC scoring function scoring search method;
step S6, extracting a topological sequence of the Bayesian network structure constructed by each label subset, and constructing a classifier chain based on the topological sequence; and training and testing each base classifier in the classifier chain through the training set and the testing set to obtain the trained classifier chain, and performing class prediction on the image to be tested through the trained classifier chain to finish automatic labeling of the image.
Preferably, in step S3, each label l is assignedqConstruction of a Bayesian network
Figure BDA0002841309370000021
Wherein f iswwIn order to provide an improved scoring function,
Figure BDA0002841309370000022
on datasets for Bayesian network G
Figure BDA0002841309370000023
The value of the score function to be given,
Figure BDA0002841309370000024
is meant to make
Figure BDA0002841309370000031
A maximum bayesian network; finally, each label l is obtainedqCorresponding feature subset
Figure BDA0002841309370000032
d=1,2,…,Dq,DqIs a label lqThe number of features of the corresponding feature subset.
Preferably, in the step S3, the solution is performed by a hill climbing method so that
Figure BDA0002841309370000033
The largest network structure.
Preferably, the step S5 specifically includes:
according to the scoring function in the step S3, nodes representing labels are continuously added in the initial Bayesian network;
randomly selecting a label as a starting point of mountain climbing search;
and constructing the Bayesian network structure by adding edges, subtracting edges or overturning.
Preferably, in the process of constructing the bayesian network structure, a condition of maximizing a scoring function is satisfied, and the bayesian network structure corresponding to each tag subset is obtained.
Preferably, in step S6, the training of each base classifier in the classifier chain through the training set includes:
based on each tag subset Lr(r ═ 1,2, … s) corresponding bayesian network, constructing a label dependent dictionary dependency _ factr={<keyq,valueq>},keyqValue for the q-th tag in the subset of tagsqA parent node set of the q label in the label subset; relying tags on keys in a dictionaryqCorresponding feature subset and valueqAnd splicing to form a new feature set, and finishing the training of the base classifier.
Preferably, the base classifier employs a logistic regression model.
Preferably, in step S6, the method for performing class prediction on an image to be detected by using a trained classifier chain includes:
inputting the characteristics of each image to be detected into a base classifier corresponding to the non-precursor node label to obtain a prediction result; and inputting the prediction result into other base classifiers of the classifier chain, and integrating all output sets into a final image prediction result set to finish automatic annotation of the image.
The invention discloses the following technical effects:
the method learns the Bayesian network structure by using an improved BIC scoring function method, clusters the labels by using a DBSCAN algorithm, learns the Bayesian network for each label subset, selects the characteristics by using the Bayesian network among the labels and the characteristics, constructs a classifier chain according to the topological sequence of the Bayesian network, constructs an image prediction label set by using the Bayesian network and the classifier chain algorithm, and has strong universality, wherein all types of images can be labeled; meanwhile, the method can process the image containing continuous features and discrete features, has good adaptability, and effectively improves the robustness and accuracy of image labeling.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a flowchart of an automatic image annotation method based on a Bayesian network and a classifier chain according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Referring to fig. 1, the present embodiment provides an automatic image annotation method based on a bayesian network and a classifier chain, which specifically includes the following steps:
s1, obtaining a sample image, extracting the characteristics of the sample image to form a training set and a test set, obtaining the label of the sample image, and constructing a total label set;
in this embodiment, the training set and the test set are respectively expressed as:
Figure BDA0002841309370000051
wherein m is the number of samples in the training set, n is the number of samples in the testing set, i is the image number,
Figure BDA0002841309370000052
for the ith image xiD is the total number of features,
Figure BDA0002841309370000053
representing the ith image xiThe D-th feature of (1, 2., D);
Figure BDA0002841309370000054
for the ith image xiThe corresponding label vector of the label set of (a),
Figure BDA0002841309370000055
L={l1,l2,...,lQas the total label set, lqQ is the Q-th tag in L, and Q is the total number of tags.
S2, normalizing the characteristics of the sample images in the training set and the test set;
in this example, the normalization process is shown as follows:
Figure BDA0002841309370000061
in the formula (I), the compound is shown in the specification,
Figure BDA0002841309370000062
respectively representing the d-th feature x of the image xdMaximum and minimum values of, xd:normRepresenting the d-th feature x of the image xdThe result of normalization.
Step S3, based on each label l in the total label setqAnd the characteristic x of the normalized sample imaged :normThe Bayesian network G is constructed by the improved score search method of the BIC (Bayesian Information Criterion) score functionqThrough a Bayesian network GqSelecting features to obtain a feature subset corresponding to each label;
in this embodiment, eachFor each label lqConstruction of a Bayesian network
Figure BDA0002841309370000063
For representing a label lqAnd the relationship between the characteristic variables; wherein f iswwIn order to provide an improved scoring function,
Figure BDA0002841309370000064
on datasets for Bayesian network G
Figure BDA0002841309370000065
The value of the score function to be given,
Figure BDA0002841309370000066
refer to all possible Bayesian networks such that
Figure BDA0002841309370000067
A maximum bayesian network; by extracting the network GqGet each label/qCorresponding feature subset
Figure BDA0002841309370000068
d=1,2,…,Dq,DqIs a label lqThe number of features of the corresponding feature subset.
The specific method for constructing the Bayesian network structure based on the score search method of the improved BIC score function comprises the following steps:
s3-1, definition
Figure BDA0002841309370000069
Wherein
Figure BDA00028413093700000610
T represents the number of nodes in the Bayesian network, JtIs node NtNumber of parent node, KtIs node Ntη is a regulation parameter, in this embodiment, η is 10, m is the number of samples in the training set, UtIs node NtNumber of parent node, counttjkRepresenting a data set
Figure BDA0002841309370000071
Middle node NtIs k, and the parent node state quantity is j, and
Figure BDA0002841309370000072
Figure BDA0002841309370000073
represents NtAnd u, normalized mutual information quantity;
Figure BDA0002841309370000074
represents NtAnd u, H () represents the solution information entropy, and p () represents the solution probability.
S3-2, adopting hill climbing method to obtain the optimum structure of all Bayesian network structures
Figure BDA0002841309370000075
Step S4, Based on the feature subset corresponding to each label, Clustering the labels in the total label set by using Density-Based Clustering of Applications with Noise (Density-Based Clustering method) to generate a label subset L1,L2,...,LsAnd s is the number of tag subsets.
Step S5, respectively, the score searching method based on the improved BIC score function is used for each label subset Lr(r ═ 1,2, … s) to construct a bayesian network structure Gr(ii) a The method specifically comprises the following steps:
according to the scoring function defined in the step S3-1, nodes representing labels are continuously added in an initial network, wherein the initial network is a disconnected empty network;
selecting a label lq(Q1, 2, …, Q) as the starting point for hill climbing search to ensure that there must be a label l in the networkq(since the number of features is huge and the hill-climbing search arrival scoring function increment is smaller than1e-8, the search is stopped, so the network between the tag and the feature contains only part of the feature); wherein Q is the total number of the tags; constructing a Bayesian network structure by adding edges, subtracting edges or overturning, wherein the constructed Bayesian network structure comprises characteristic nodes which are labels lqCorresponding feature subset
Figure BDA0002841309370000081
d=1,2,…,Dq,DqIs a label lqThe number of features of the corresponding feature subset; and in the construction process of the network structure, the maximization of the scoring function is met, and the Bayesian network structure is obtained.
Step S6, Bayesian network structure G constructed for each label subsetrExtracting a topological sequence, and constructing a classifier chain based on the topological sequence; and training and testing each base classifier in the classifier chain through the training set and the testing set to obtain the trained classifier chain, and performing class prediction on the image to be tested through the trained classifier chain to finish automatic labeling of the image.
Parsing the bayesian network structure G corresponding to each tag subset Lr (r ═ 1,2, … S) in step S5rConstructing a tag dependent dictionary dependency _ factr={<keyq,valueq>},r=1,2,…s,q=1,2,…Qr,QrIs a subset L of tagsrNumber of tags owned, keyqValue for the q-th tag in the subset of tagsqA parent node set of the q label in the label subset; since some tags do not have a parent tag (root node in the tag network), such tags do not have a tag that needs to be relied upon, with value null.
The process of training each base classifier in the classifier chain through the training set includes:
each subset of tags Lr(r ═ 1,2, … s) are all given the label dependent dictionary dependency _ factr={<keyq,valueq>}; for each key in the tag-dependent dictionary, its corresponding feature subset
Figure BDA0002841309370000082
d=1,2,…,DqAnd its dependency _ factrValue (l) ofq1,lq2,...,lqn) Splicing to form a new feature set; wherein q isnFor the number of tags in value, tag lqTraining a base classifier for each key as a prediction target; the base classifier uses a logistic regression model, and in this embodiment, the classification threshold is 0.5.
The method for carrying out category prediction on the image to be detected through the trained classifier chain comprises the following steps:
inputting the characteristics of each image to be detected into a base classifier corresponding to the non-precursor node label to obtain a prediction result; and inputting the prediction result into other corresponding base classifiers, and synthesizing all output sets into a final image prediction result set to finish automatic annotation of the image.
The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims (8)

1. An automatic image labeling method based on a Bayesian network and a classifier chain is characterized by comprising the following steps:
s1, obtaining a sample image, extracting the characteristics of the sample image to form a training set and a test set, obtaining the label of the sample image, and constructing a total label set;
s2, normalizing the characteristics of the sample images in the training set and the test set;
step S3, constructing a Bayesian network through a score searching method of an improved Bayesian information criterion BIC score function based on each label in the total label set and the characteristics of the sample image after normalization processing, and performing characteristic selection through the Bayesian network to obtain a characteristic subset corresponding to each label;
step S4, based on the feature subset corresponding to each label, clustering the labels in the total label set by adopting density clustering DBSCAN to generate a label subset;
step S5, respectively constructing a Bayesian network structure for each label subset based on the improved BIC scoring function scoring search method;
step S6, extracting a topological sequence of the Bayesian network structure constructed by each label subset, and constructing a classifier chain based on the topological sequence; and training and testing each base classifier in the classifier chain through the training set and the testing set to obtain the trained classifier chain, and performing class prediction on the image to be tested through the trained classifier chain to finish automatic labeling of the image.
2. The Bayesian network and classifier chain-based image automatic labeling method as claimed in claim 1, wherein in step S3, a Bayesian network is constructed for each label lq respectively
Figure FDA0002841309360000021
Wherein f iswwIn order to provide an improved scoring function,
Figure FDA0002841309360000022
on datasets for Bayesian network G
Figure FDA0002841309360000023
The value of the score function to be given,
Figure FDA0002841309360000024
is meant to make
Figure FDA0002841309360000025
A maximum bayesian network; finally, each label l is obtainedqCorresponding feature subset
Figure FDA0002841309360000026
DqIs a label lqThe number of features of the corresponding feature subset.
3. The Bayesian network and classifier chain-based image automatic labeling method as claimed in claim 2, wherein in step S3, solving is performed by hill climbing so that
Figure FDA0002841309360000027
The largest network structure.
4. The automatic image annotation method based on the bayesian network and the classifier chain as claimed in claim 3, wherein said step S5 specifically comprises:
according to the scoring function in the step S3, nodes representing labels are continuously added in the initial Bayesian network;
randomly selecting a label as a starting point of mountain climbing search;
and constructing the Bayesian network structure by adding edges, subtracting edges or overturning.
5. The Bayesian network and classifier chain-based image automatic labeling method according to claim 4, wherein in the Bayesian network structure construction process, a condition of maximizing a scoring function is satisfied, and a Bayesian network structure corresponding to each tag subset is obtained.
6. The Bayesian network and classifier chain-based image automatic labeling method of claim 4, wherein in the step S6, the training of each base classifier in the classifier chain through the training set comprises:
based on each tag subset Lr(r ═ 1,2, … s) corresponding bayesian network, constructing a label dependent dictionary dependency _ factr={<keyq,valueq>},keyqValue for the q-th tag in the subset of tagsqA parent node set of the q label in the label subset; will be provided withKey in tag dependency dictionaryqCorresponding feature subset and valueqAnd splicing to form a new feature set, and finishing the training of the base classifier.
7. The Bayesian network and classifier chain based image automatic labeling method of claim 6, wherein the base classifier employs a logistic regression model.
8. The Bayesian network and classifier chain-based image automatic labeling method of claim 6, wherein in the step S6, the method for performing class prediction on the image to be tested through the trained classifier chain comprises:
inputting the characteristics of each image to be detected into a base classifier corresponding to the non-precursor node label to obtain a prediction result; and inputting the prediction result into other base classifiers of the classifier chain, and integrating all output sets into a final image prediction result set to finish automatic annotation of the image.
CN202011493104.2A 2020-12-17 2020-12-17 Automatic image labeling method based on Bayesian network and classifier chain Active CN112464010B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011493104.2A CN112464010B (en) 2020-12-17 2020-12-17 Automatic image labeling method based on Bayesian network and classifier chain

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011493104.2A CN112464010B (en) 2020-12-17 2020-12-17 Automatic image labeling method based on Bayesian network and classifier chain

Publications (2)

Publication Number Publication Date
CN112464010A true CN112464010A (en) 2021-03-09
CN112464010B CN112464010B (en) 2021-08-27

Family

ID=74802917

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011493104.2A Active CN112464010B (en) 2020-12-17 2020-12-17 Automatic image labeling method based on Bayesian network and classifier chain

Country Status (1)

Country Link
CN (1) CN112464010B (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101256641A (en) * 2008-03-11 2008-09-03 浙江大学 Gene chip data analysis method based on model of clustering means and Bayesian network means
CN109003279A (en) * 2018-07-06 2018-12-14 东北大学 Fundus retina blood vessel segmentation method and system based on K-Means clustering labeling and naive Bayes model
US10311442B1 (en) * 2007-01-22 2019-06-04 Hydrojoule, LLC Business methods and systems for offering and obtaining research services
CN110704624A (en) * 2019-09-30 2020-01-17 武汉大学 Geographic information service metadata text multi-level multi-label classification method
CN111402224A (en) * 2020-03-12 2020-07-10 广东电网有限责任公司广州供电局 Target identification method for power equipment
WO2020144525A1 (en) * 2019-01-09 2020-07-16 Chevron Usa Inc. System and method for deriving high-resolution subsurface reservoir parameters
CN111783831A (en) * 2020-05-29 2020-10-16 河海大学 Complex image accurate classification method based on multi-source multi-label shared subspace learning

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10311442B1 (en) * 2007-01-22 2019-06-04 Hydrojoule, LLC Business methods and systems for offering and obtaining research services
CN101256641A (en) * 2008-03-11 2008-09-03 浙江大学 Gene chip data analysis method based on model of clustering means and Bayesian network means
CN109003279A (en) * 2018-07-06 2018-12-14 东北大学 Fundus retina blood vessel segmentation method and system based on K-Means clustering labeling and naive Bayes model
WO2020144525A1 (en) * 2019-01-09 2020-07-16 Chevron Usa Inc. System and method for deriving high-resolution subsurface reservoir parameters
CN110704624A (en) * 2019-09-30 2020-01-17 武汉大学 Geographic information service metadata text multi-level multi-label classification method
CN111402224A (en) * 2020-03-12 2020-07-10 广东电网有限责任公司广州供电局 Target identification method for power equipment
CN111783831A (en) * 2020-05-29 2020-10-16 河海大学 Complex image accurate classification method based on multi-source multi-label shared subspace learning

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
L. ENRIQUE SUCAR: "Multi-label classification with Bayesian network-based chain classifiers", 《PATTERN RECOGNITION LETTERS 41 (2014) 14–22》 *
PING ZHANG: "Approaching Multi-dimensional Classification by Using Bayesian Network Chain Classifiers", 《2014 SIXTH INTERNATIONAL CONFERENCE ON INTELLIGENT HUMAN-MACHINE SYSTEMS AND CYBERNETICS》 *
侯漫丽: "基于贝叶斯网络的多类标分类算法研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》 *

Also Published As

Publication number Publication date
CN112464010B (en) 2021-08-27

Similar Documents

Publication Publication Date Title
CN111325326A (en) Link prediction method based on heterogeneous network representation learning
CN112507699B (en) Remote supervision relation extraction method based on graph convolution network
CN109408743B (en) Text link embedding method
US20220253477A1 (en) Knowledge-derived search suggestion
CN112819023A (en) Sample set acquisition method and device, computer equipment and storage medium
CN109816015B (en) Recommendation method and system based on material data
CN103778206A (en) Method for providing network service resources
CN111078835A (en) Resume evaluation method and device, computer equipment and storage medium
CN108595411B (en) Method for acquiring multiple text abstracts in same subject text set
CN115688024A (en) Network abnormal user prediction method based on user content characteristics and behavior characteristics
CN115982403A (en) Multi-mode hash retrieval method and device
CN109582868A (en) The search recommended method of preference is clicked based on term vector weighting, support vector regression and user
CN116662565A (en) Heterogeneous information network keyword generation method based on contrast learning pre-training
CN110196995B (en) Complex network feature extraction method based on biased random walk
CN117271767A (en) Operation and maintenance knowledge base establishing method based on multiple intelligent agents
CN111428502A (en) Named entity labeling method for military corpus
CN114328800A (en) Text processing method and device, electronic equipment and computer readable storage medium
CN113535949A (en) Multi-mode combined event detection method based on pictures and sentences
TW201243627A (en) Multi-label text categorization based on fuzzy similarity and k nearest neighbors
Kobyshev et al. Hybrid image recommendation algorithm combining content and collaborative filtering approaches
CN112464010B (en) Automatic image labeling method based on Bayesian network and classifier chain
CN114896514B (en) Web API label recommendation method based on graph neural network
CN114372148A (en) Data processing method based on knowledge graph technology and terminal equipment
Zhang et al. Imbalanced networked multi-label classification with active learning
CN112269877A (en) Data labeling method and device

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