CN111126169A - Face recognition method and system based on orthogonalization graph regular nonnegative matrix decomposition - Google Patents

Face recognition method and system based on orthogonalization graph regular nonnegative matrix decomposition Download PDF

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CN111126169A
CN111126169A CN201911221189.6A CN201911221189A CN111126169A CN 111126169 A CN111126169 A CN 111126169A CN 201911221189 A CN201911221189 A CN 201911221189A CN 111126169 A CN111126169 A CN 111126169A
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王国胤
喻君武
夏书银
彭道万
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Chongqing University of Post and Telecommunications
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    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/16Human faces, e.g. facial parts, sketches or expressions
    • G06V40/161Detection; Localisation; Normalisation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F18/00Pattern recognition
    • G06F18/20Analysing
    • G06F18/24Classification techniques
    • G06F18/241Classification techniques relating to the classification model, e.g. parametric or non-parametric approaches
    • G06F18/2413Classification techniques relating to the classification model, e.g. parametric or non-parametric approaches based on distances to training or reference patterns
    • G06F18/24147Distances to closest patterns, e.g. nearest neighbour classification
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T3/00Geometric image transformation in the plane of the image
    • G06T3/40Scaling the whole image or part thereof
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00Image enhancement or restoration
    • G06T5/40Image enhancement or restoration by the use of histogram techniques
    • G06T5/70
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00Arrangements for image or video recognition or understanding
    • G06V10/40Extraction of image or video features
    • G06V10/42Global feature extraction by analysis of the whole pattern, e.g. using frequency domain transformations or autocorrelation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/16Human faces, e.g. facial parts, sketches or expressions
    • G06V40/168Feature extraction; Face representation
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06VIMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V40/00Recognition of biometric, human-related or animal-related patterns in image or video data
    • G06V40/10Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
    • G06V40/16Human faces, e.g. facial parts, sketches or expressions
    • G06V40/172Classification, e.g. identification
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/10Image acquisition modality
    • G06T2207/10004Still image; Photographic image
    • GPHYSICS
    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00Indexing scheme for image analysis or image enhancement
    • G06T2207/30Subject of image; Context of image processing
    • G06T2207/30196Human being; Person
    • G06T2207/30201Face

Abstract

The invention discloses a face recognition method and a face recognition system based on orthogonalization graph regular nonnegative matrix decomposition. The method comprises the following steps: 1) preprocessing a face image; 2) extracting the human face characteristics by utilizing an orthogonalized image regular non-negative matrix decomposition; 3) extracting the characteristics of the face image to be tested; 4) and carrying out face recognition detection by using a nearest neighbor classifier. The method makes the result of the non-negative matrix decomposition more robust by utilizing orthogonalization, and improves the accuracy of face recognition.

Description

Face recognition method and system based on orthogonalization graph regular nonnegative matrix decomposition
Technical Field
The invention belongs to the field of face recognition, and particularly relates to a face recognition method based on orthogonalization graph regular nonnegative matrix decomposition.
Background
In the field of computer vision, the face recognition technology has become a popular research direction, and a great amount of innovation is applied to the face recognition technology every year, so that the face recognition accuracy rate is continuously refreshed. The application scene of the face recognition is also very wide, and people can scan faces to get in a station, recognize faces in offices to punch cards, and use the face recognition to carry out criminal investigation and case solving and the like when riding a car. Face recognition is expected to be more promising in the future.
non-Negative Matrix Factorization (NMF) is an algorithm proposed by Lee and Seung in 2000. Under the condition that the matrix elements are not negative, the NMF algorithm decomposes the matrix X into X ═ UV, where U and V are the feature matrix and the weight matrix, respectively. The face features extracted by the NMF can be expressed as a linear combination of feature matrixes, wherein the feature matrixes can express local features of eyes, noses and the like of the face. Deng Cai et al proposed a canonical nonnegative matrix decomposition (GNMF) based on NMF, which considers that if two points in the original eigenspace are close, then in the new eigenspace after matrix decomposition, the two points should remain close, and then GNMF incorporates geometric information into NMF.
Existing methods of non-negative matrix factorization may continue to improve. Experiments on clustering show that the limitation of orthogonalization can optimize the clustering effect. Because the matrix resulting from the matrix decomposition is more sparse after applying the orthogonalizing terms. In order to enhance the sparse representation capability of the matrix, an orthogonalization term is added on the basis of GNMF. The whole OGNMF model can well keep the structure information and sparsity of an original matrix, can decompose a more robust base matrix and a more robust coefficient matrix, and can effectively improve the face recognition rate.
Disclosure of Invention
The present invention is directed to solving the above problems of the prior art. A face recognition method based on orthogonalization graph regular non-negative matrix decomposition is provided. The technical scheme of the invention is as follows:
a face recognition method based on orthogonalization graph regular nonnegative matrix decomposition comprises the following steps:
step S1, carrying out size normalization, filtering denoising and gray normalization pretreatment on the training and testing face image;
step S2, carrying out one-dimensional treatment on the images of the training set, splicing the images into a matrix, then obtaining a new base matrix by utilizing orthogonal image regular nonnegative matrix decomposition, and extracting the human face characteristics;
step S3, on the basis of step S2, projecting the face data set matrix to be tested to a base matrix to obtain a corresponding feature vector;
and step S3, face recognition detection is carried out by utilizing the nearest neighbor classifier.
Further, the step S1 includes the following steps:
step S1.1: size normalization: scaling the facial image to a uniform size;
step S1.2: filtering and denoising: removing noise in the face image by using median filtering;
step S1.3: gray level normalization: and carrying out gray level transformation on the image by utilizing histogram equalization so that the face image follows similar gray level distribution.
Further, the step S2 of extracting the face features by using an orthogonalized regular non-negative matrix decomposition of the graph includes the following steps:
step S2.1: supposing that n training samples are provided, each sample is unidimensionalized to form a training sample matrix of X ═ X1,x2,...,xn]Wherein x isiIs a single face image;
step S2.2: calculating a laplacian matrix L ═ D-W of the matrix for the sample matrix X, wherein D is a degree matrix of the sample matrix and W is an adjacency matrix of the sample matrix;
step S2.3: the maximum iteration number t, the smoothing parameter λ and the orthogonality parameter μ are set, and the weights are updated by minimizing the following objective function:
Figure RE-GDA0002407566680000021
wherein U and V are respectively a feature matrix and a weight matrix obtained by decomposing the sample matrix X, which are non-negative matrices, | · toryFIs a Frobenius paradigm, the parameter lambda is more than or equal to 0 to control the smoothness degree of matrix decomposition, the parameter mu is more than or equal to 0 to control the orthogonality of U and V decomposed by the matrix, and I is a unit matrix;
the matrices U and V are updated according to the following multiplicative iterative formula:
Figure RE-GDA0002407566680000031
Figure RE-GDA0002407566680000032
after t iterations, the U and V updates are complete.
Further, the step S3 of extracting the features of the face image to be tested includes the following steps:
s3.1: preprocessing the face image to be detected in the step S1 to obtain a matrix q;
s3.2: projecting the face image matrix q onto a feature space, wherein the obtained projected feature vector is as follows:
p=UTq。
further, in step S4, the euclidean distance between p and the face image of the training sample is calculated by using the nearest neighbor algorithm:
di=||p-Vi||2,i=1,2,...,n
suppose dkIs diIf the number of the face to be detected is the k-th face in the training sample, the face to be detected belongs to the k-th face in the training sample.
A face recognition system based on orthogonalized graph regular non-negative matrix factorization, comprising:
a preprocessing module: carrying out size normalization, filtering denoising and gray normalization pretreatment on the training and testing face images;
the face feature extraction module: carrying out one-dimensional treatment on the images of the training set, splicing the images into a matrix, then decomposing by utilizing an orthogonalized image regular nonnegative matrix to obtain a new base matrix, and extracting the human face characteristics;
an extraction and identification module: projecting the face data set matrix to be tested to a base matrix to obtain a corresponding feature vector; and carrying out face recognition detection by using the nearest neighbor classifier.
The invention has the following advantages and beneficial effects:
on the basis of graph regular non-negative matrix decomposition, the invention firstly considers the constraint of orthogonality to improve the decomposition result of the non-negative matrix decomposition, and provides an OGNMF model. The OGNMF model can well keep the structural information and sparsity of an original matrix and enhance the sparse expression capacity of the matrix, so that the face recognition rate can be effectively improved.
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FIG. 1 is a flow chart of a face recognition method based on orthogonalized graph regular non-negative matrix factorization according to a preferred embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described in detail and clearly with reference to the accompanying drawings. The described embodiments are only some of the embodiments of the present invention.
The technical scheme for solving the technical problems is as follows:
as shown in fig. 1, a face recognition method based on orthogonalization graph regular non-negative matrix decomposition includes the following steps:
1.1 scaling the face image to a uniform size;
1.2 removing noise in the face image by using median filtering;
1.3, carrying out gray level transformation on the image by utilizing histogram equalization so that the face image follows similar gray level distribution;
2.1 assume that there are n training samples, each of which is unidimensionalized to form a training sample matrix of X ═ X1,x2,...,xn]Wherein x isiIs a single face image;
2.2 calculate the laplacian matrix L ═ D-W of the matrix for the sample matrix X, where D is the degree matrix of the sample matrix and W is the adjacency matrix of the sample matrix;
2.3 set the maximum number of iterations t, the smoothing parameter λ and the orthogonality parameter μ.
The matrices U and V are updated according to the following multiplicative iterative formula:
Figure RE-GDA0002407566680000041
Figure RE-GDA0002407566680000042
after t iterations, the U and V updates are complete.
3.1, preprocessing the face image to be detected in the step 1 to obtain a matrix q;
3.2 projecting the face image matrix q to a feature space to obtain projected feature vectors as follows: p is UTq;
And 4, calculating the Euclidean distance between p and the face image of the training sample by using a nearest neighbor algorithm, wherein the minimum distance is the category.
The above examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure. After reading the description of the invention, the skilled person can make various changes or modifications to the invention, and these equivalent changes and modifications also fall into the scope of the invention defined by the claims.

Claims (6)

1. A face recognition method based on orthogonalization graph regular nonnegative matrix decomposition is characterized by comprising the following steps:
step S1, preprocessing the training and testing face image including size normalization, filtering denoising and gray normalization;
s2, on the basis of S1, images of the training set are subjected to one-dimensional processing and spliced into a matrix, then a new base matrix is obtained by utilizing orthogonal image regular non-negative matrix decomposition, and the human face features are extracted;
step S3, on the basis of step S2, projecting the face data set matrix to be tested to a base matrix to obtain a corresponding feature vector;
in step S4, face recognition detection is performed using the nearest neighbor classifier in addition to step S3.
2. The face recognition method based on orthogonalized graph regular non-negative matrix factorization of claim 1, wherein the preprocessing of the step S1 comprises the following steps:
step S1.1: size normalization: scaling the facial image to a uniform size;
step S1.2: filtering and denoising: removing noise in the face image by using median filtering;
step S1.3: gray level normalization: and carrying out gray level transformation on the image by utilizing histogram equalization so that the face image follows similar gray level distribution.
3. The face recognition method based on orthogonalized graph regular non-negative matrix factorization of claim 1, wherein the step S2 of extracting face features by utilizing orthogonalized graph regular non-negative matrix factorization comprises the following steps:
step S2.1: supposing that n training samples are provided, each sample is unidimensionalized to form a training sample matrix of X ═ X1,x2,...,xn]Wherein x isiIs a single face image;
step S2.2: calculating a laplacian matrix L ═ D-W of the matrix for the sample matrix X, wherein D is a degree matrix of the sample matrix and W is an adjacency matrix of the sample matrix;
step S2.3: the maximum iteration number t, the smoothing parameter λ and the orthogonality parameter μ are set, and the weights are updated by minimizing the following objective function:
Figure FDA0002300899740000011
wherein U and V are respectively a feature matrix and a weight matrix obtained by decomposing the sample matrix X, which are non-negative matrices, | · toryFIs a Frobenius paradigm, the parameter lambda is more than or equal to 0 to control the smoothness degree of matrix decomposition, the parameter mu is more than or equal to 0 to control the orthogonality of U and V decomposed by the matrix, and I is a unit matrix;
the matrices U and V are updated according to the following multiplicative iterative formula:
Figure FDA0002300899740000021
Figure FDA0002300899740000022
after t iterations, the U and V updates are complete.
4. The face recognition method based on orthogonalized graph regular non-negative matrix factorization of claim 3, wherein the step S3 of extracting the features of the face image to be tested comprises the following steps:
s3.1: preprocessing the face image to be detected in the step S1 to obtain a matrix q;
s3.2: projecting the face image matrix q onto a feature space, wherein the obtained projected feature vector is as follows:
p=UTq。
5. the face recognition method based on orthogonalized regular nonnegative matrix factorization of graph according to claim 4, wherein the step S4 is to calculate the Euclidean distance between p and the face image of the training sample by using the nearest neighbor algorithm:
di=||p-Vi||2,i=1,2,...,n
suppose dkIs diIf the number of the face to be detected is the k-th face in the training sample, the face to be detected belongs to the k-th face in the training sample.
6. A face recognition system based on orthogonalized graph regular non-Negative Matrix Factorization (NMF), comprising:
a preprocessing module: carrying out size normalization, filtering denoising and gray normalization pretreatment on the training and testing face images;
the face feature extraction module: carrying out one-dimensional treatment on the images of the training set, splicing the images into a matrix, then decomposing by utilizing an orthogonalized image regular nonnegative matrix to obtain a new base matrix, and extracting the human face characteristics;
an extraction and identification module: the face image testing device is used for extracting the features of a face image to be tested; and carrying out face recognition detection by using the nearest neighbor classifier.
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