Hyperspectral image band selection method and system based on latent feature fusion
A hyperspectral image band selection method based on latent feature fusion comprises: S 11 , inputting a hyperspectral image cube and segmenting the inputted hyperspectral image cube into several regions by superpixel segmentation; S 12 , learning low-dimensional latent features corresponding to the several regions from the several regions respectively to obtain a latent feature matrix of all the regions; S 13 , calculating an average Laplacian matrix and an average latent feature matrix of the hyperspectral image cube; S 14 , fusing the latent feature matrix, the average Laplacian matrix, and the average latent feature matrix of all the regions to obtain a low-dimensional self-representation matrix of the hyperspectral image cube; and S 15 , clustering the low-dimensional self-representation matrix by a k-means algorithm to obtain an optimal band subset of the hyperspectral image cube.
1 . A hyperspectral image band selection method based on latent feature fusion, comprising:
S1, inputting a hyperspectral image cube and segmenting the hyperspectral image cube into N regions by superpixel segmentation to obtain segmented regions;
S2, learning low-dimensional latent features corresponding to the N regions from the N regions respectively to obtain a latent feature matrix of all the regions;
S3, calculating an average Laplacian matrix and an average latent feature matrix of the hyperspectral image cube;
S4, fusing the latent feature matrix, the average Laplacian matrix, and the average latent feature matrix of all the regions to obtain a low-dimensional self-representation matrix of the hyperspectral image cube; and
S5, clustering the low-dimensional self-representation matrix by a k-means algorithm to obtain an optimal band subset of the hyperspectral image cube.
2 . The hyperspectral image band selection method according to claim 1 , wherein in S1, the hyperspectral image cube into the N regions by superpixel segmentation is segmented by adopting an ERS entropy rate superpixel segmentation algorithm.
3 . The hyperspectral image band selection method according to claim 2 , wherein in S1, a number of the segmented regions is represented as:
N
=
5
0
0
×
N
z
P
+
4
0
×
N
z
N
b
×
res
wherein N represents an optimal segmentation number for the hyperspectral image cube; N z represents a number of non-zero regions at an edge of a detected hyperspectral image; P represents pixels contained in each band; N b represents a fixed constant; res represents a spatial resolution of the detected hyperspectral image.
4 . The hyperspectral image band selection method according to claim 1 , wherein in S2, the low-dimensional latent features corresponding to the N regions are learned from the N regions respectively to obtain the latent feature matrix of all the segmented regions, expressed as:
max
Y
(
i
)
Tr
(
Y
(
i
)
T
E
(
i
)
Y
(
i
)
)
s
.
t
.
Y
(
i
)
T
Y
(
i
)
=
I
wherein Y (i) represents a low-dimensional latent feature matrix corresponding to an i-th segmented region; E (i) represents a Laplacian matrix corresponding to the i-th segmented region; I represents an identity matrix;
the Laplacian matrix corresponding to each of the segmented regions is specifically represented as follows:
E
(
i
)
=
D
-
1
2
WD
-
1
2
wherein W represents a similarity matrix between samples in each of the segmented regions; D represents a diagonal matrix, represented as:
D
jj
=
∑
W
:
,
j
wherein j represents a j-th sample in the segmented regions; D jj represents elements in a j-th row and j-th column of the diagonal matrix
D
;
∑
W
:
,
j
represents a sum of all elements in a j-th column of the similarity matrix W.
5 . The hyperspectral image band selection method according to claim 4 , wherein in S4, the latent feature matrix, the average Laplacian matrix, and the average latent feature matrix of all the regions are fused to obtain the low-dimensional self-representation matrix of the hyperspectral image cube, expressed as:
max
F
,
R
,
γ
Tr
(
F
T
∑
i
=
1
N
γ
i
Y
(
i
)
R
(
i
)
)
+
λ
Tr
(
F
T
F
_
)
+
β
Tr
(
F
T
LF
)
s
.
t
.
F
T
F
=
I
d
,
R
(
i
)
T
R
(
i
)
=
I
d
,
∑
i
=
1
N
γ
i
2
=
1
,
γ
i
≥
0
wherein F represents a low-dimensional self-representation matrix of a fused hyperspectral image; γ i represents a contribution rate of each of the segmented regions; Y (i) represents a low-dimensional latent feature matrix corresponding to the i-th segmented region; R (i) represents a rotation matrix corresponding to the i-th segmented region; F represents an average latent feature matrix; L represents an average Laplacian matrix; λ and β both represent equilibrium parameters; T represents a transposition of a matrix; I d represents an identity matrix with a size of d*d.
6 . A hyperspectral image band selection system based on latent feature fusion, comprising a processor comprising:
a hyperspectral image segmentation module, used for inputting a hyperspectral image cube and segmenting the hyperspectral image cube into N regions by superpixel segmentation to obtain segmented regions;
a latent feature learning module, used for learning low-dimensional latent features corresponding to the N regions from the N regions respectively to obtain a latent feature matrix of all the regions;
a calculation module, used for calculating an average Laplacian matrix and an average latent feature matrix of the hyperspectral image cube;
a latent feature fusion module, used for fusing the latent feature matrix, the average Laplacian matrix, and the average latent feature matrix of all the regions to obtain a low-dimensional self-representation matrix of the hyperspectral image cube; and
a hyperspectral band selecting module, used for clustering the low-dimensional self-representation matrix by a k-means algorithm to obtain an optimal band subset of the hyperspectral image cube.
7 . The hyperspectral image band selection system according to claim 6 , wherein in the hyperspectral image segmentation module, the inputted hyperspectral image cube into the N regions by superpixel segmentation is segmented by adopting an ERS entropy rate superpixel segmentation algorithm.
8 . The hyperspectral image band selection system according to claim 7 , wherein in the hyperspectral image segmentation module, a number of the segmented regions is represented as:
N
=
5
0
0
×
N
z
P
+
4
0
×
N
z
N
b
×
res
wherein N represents an optimal segmentation number for the hyperspectral image cube; N z represents a number of non-zero regions at an edge of a detected hyperspectral image; P represents pixels contained in each band; N b represents a fixed constant; res represents a spatial resolution of the detected hyperspectral image.
9 . The hyperspectral image band selection system according to claim 6 , wherein in the latent feature learning module, the low-dimensional latent features corresponding to the N regions are learned from the N regions respectively to obtain the latent feature matrix of all the segmented regions, expressed as:
max
Y
(
i
)
Tr
(
Y
(
i
)
T
E
(
i
)
Y
(
i
)
)
s
.
t
.
Y
(
i
)
T
Y
(
i
)
=
I
wherein Y (i) represents a low-dimensional latent feature matrix corresponding to an i-th segmented region; E (i) represents a Laplacian matrix corresponding to the i-th segmented region; I represents an identity matrix;
the Laplacian matrix corresponding to each of the segmented regions is specifically represented as follows:
E
(
i
)
=
D
-
1
2
WD
-
1
2
wherein W represents a similarity matrix between samples in each of the segmented regions; D represents a diagonal matrix, represented as:
D
jj
=
∑
W
:
,
j
wherein j represents a j-th sample in the segmented regions; D jj represents elements in a j-th row and j-th column of the diagonal matrix
D
;
∑
W
:
,
j
represents a sum of all elements in a j-th column of the similarity matrix W.
10 . The hyperspectral image band selection system according to claim 9 , wherein in the latent feature fusion module, the latent feature matrix, the average Laplacian matrix, and the average latent feature matrix of all the regions are fused to obtain the low-dimensional self-representation matrix of the hyperspectral image cube, expressed as:
max
F
,
R
,
γ
Tr
(
F
T
∑
i
=
1
N
γ
i
Y
(
i
)
R
(
i
)
)
+
λ
Tr
(
F
T
F
_
)
+
β
Tr
(
F
T
LF
)
s
.
t
.
F
T
F
=
I
d
,
R
(
i
)
T
R
(
i
)
=
I
d
,
∑
i
=
1
N
γ
i
2
=
1
,
γ
i
≥
0
wherein F represents a low-dimensional self-representation matrix of a fused hyperspectral image; γ i represents a contribution rate of each of the segmented regions; Y (i) represents a low-dimensional latent feature matrix corresponding to the i-th segmented region; R (i) represents a rotation matrix corresponding to the i-th segmented region; F represents an average latent feature matrix; L represents an average Laplacian matrix; λ and β both represent equilibrium parameters; T represents a transposition of a matrix; I d represents an identity matrix with a size of d*d.