A New Tensor Network: Tubal Tensor Train and Its Applications
Authors: Salman Ahmadi-Asl, Valentin Leplat, Anh-Huy Phan, Andrzej Cichocki
Organizations: Lab of Machine Learning and Knowledge Representation, Innopolis University, Innopolis, Russia · Innopolis University, Innopolis, Russia · Skolkovo Institute of Science and Technology, Center for Artificial Intelligence Technology, Moscow, Russia · Systems Research Institute of Polish Academy of Science, Warsaw, Poland
We introduce the tubal tensor train (TTT) decomposition, a tensor-network model that combines the t-product algebra of the tensor singular value decomposition (T-SVD) with the low-order core structure of the tensor train (TT) format. For an order-(N+1) tensor with a distinguished tube mode, the proposed representation consists of two third-order boundary cores and N−2 fourth-order interior cores linked through the t-product. As a result, for bounded tubal ranks, the storage scales linearly with the number of modes, in contrast to direct high-order extensions of T-SVD. We present two computational strategies: a sequential fixed-rank construction, called TTT-SVD, and a Fourier-slice alternating scheme based on the alternating two-cores update (ATCU). We also state a TT-SVD-type error bound for TTT-SVD and illustrate the practical performance of the proposed model on image compression, video compression, tensor completion, and hyperspectral imaging.
Figures & tables
Figure 1: T-SVD and truncated T-SVD for a third-order tensor.
Figure 2: Tubal tensor train structure and tube-wise evaluation.
Figure 3: Benchmark images used in our experiments.
TT-Based
Proposed method
Images
MSE
PSNR (dB)
SSIM
MSE
PSNR (dB)
SSIM
Kodim03
251
24.12
0.6649
114.09
27.52
0.7806
Kodim23
251.40
24.13
0.7042
127.27
27.08
0.8096
Kodim04
239.25
24.34
0.5940
93.46
28.42
0.7117
Airplane
874.30
18.71
0.6081
351.47
22.67
0.6921
Kodim15
380.32
22.33
0.6178
159.13
26.11
0.7673
Table 1: The experimental results obtained by the proposed algorithm and the TT-based method for images and error bound of 0.15 .
Figure 4: The reconstructed images using the proposed TTT model and the TT-based model for an upper error bound of 0.15 .
Method
Airplane
Barbara
Kodim02
Kodim03
Kodim04
Kodim15
Kodim20
TTT
22.67
27.30
29.90
27.52
28.42
26.11
23.35
TT
18.71
23.37
26.62
24.12
24.34
22.33
21.73
TC
20.85
26.01
27.78
26.34
26.75
25.04
21.17
Table 2: PSNR values obtained by TTT, TT, and TC for tolerance 0.15 on seven representative benchmark RGB images.
TT-based model
Proposed method
Video
Rel. err.
Time (s)
Comp. factor
Rel. err.
Time (s)
Comp. factor
News_qcif
0.1
23.80
13.34
0.1
21.73
12.44
Akiyo_qcif
0.1
27.49
7.68
0.1
22.30
64.64
Tempete_cif
0.1
32.16
2.3283
0.1
30.33
2.3284
Table 3: Experimental results for the proposed TTT algorithm and the TT-based baseline on the video data sets.
T-SVD
Proposed method
Video
Rel. err.
Time (s)
Comp. factor
Rel. err.
Time (s)
Comp. factor
Waterfall_cif
0.1
10.34
5.04
0.1
20.73
20.10
Foreman_qcif
0.1
9.34
4.42
0.1
24.56
11.44
Stephan_qcif
0.1
11.28
2.50
0.1
24.90
2.53
Table 4: Experimental results for the proposed TTT algorithm and the T-SVD baseline on the video data sets.
Figure 5: The PSNR and SSIM of the reconstructed frames by the proposed TTT model and TT decomposition for the relative approximation error bound of 0.1 for the “Akiyo” video (left) and the “News” video datasets.
Figure 6: Illustration of the reference data, the incomplete observations with 70% of entries removed at random, and the reconstructions obtained with the proposed model and T-SVD for Example 3 . The displayed triplets correspond to ( MSE, PSNR, SSIM ).
Method
Runtime (sec.)
PSNR (dB)
RMSE
ERGAS
SAM
UIQI
#Paras
Best value
0
∞
0
0
0
1
0
Data set - ROSIS Pavia Univ. - N=14 - Relative error fixed and set to 0.08
TTT
61.26
35.89
130.02
10.77
3.01
0.97
12454744
TT
42.93
35.89
130.03
10.71
2.82
0.97
13600746
Data set - ROSIS Pavia Univ. - N=14 - "equal" number of parameters
TTT
52.78
36.33
123.52
10.26
2.84
0.97
13565592
Table 5: Comparison of tensor decomposition models on the ROSIS Pavia Univ. data set. The table reports the quantitative quality detailed in Section A.2.1 .
Appendix figures & tables11 assets
Supplementary material from the paper’s appendix.
Appendix
Method
Runtime (sec.)
PSNR (dB)
RMSE
ERGAS
SAM
UIQI
#Paras
Best value
0
∞
0
0
0
1
0
Data set - HYDICE Urban - N=13 - Relative error fixed and set to 0.08
TTT
39.12
33.67
16.41
10.31
3.18
0.97
9010360
TT
22.04
33.80
16.42
10.08
3.02
0.98
10670310
Data set - HYDICE Urban - N=13 - "equal" number of parameters
TTT
23.81
35.92
12.71
7.95
2.60
0.98
10559780
Appendix
Table 6: Comparison of tensor decomposition models on the HYDICE Urban data set. The table reports the quantitative quality detailed in Section A.2.1 .
Method
Runtime (sec.)
PSNR (dB)
RMSE
ERGAS
SAM
UIQI
#Paras
Best value
0
∞
0
0
0
1
0
Data set - Moffett - N=10 - Relative error fixed and set to 0.02
TTT
0.68
39.72
0.01
4.90
6.22
1.00
362150
TT
0.28
40.61
0.01
3.10
5.78
1.00
418905
Data set - Moffett - N=10 - "equal" number of parameters
TTT
0.66
44.15
0.00
2.93
4.06
1.00
407975
Appendix
Table 7: Comparison of tensor decomposition models on the AVIRIS Moffett data set. The table reports the quantitative quality detailed in Section A.2.1 .
Method
Runtime (sec.)
PSNR (dB)
RMSE
ERGAS
SAM
UIQI
#Paras
Best value
0
∞
0
0
0
1
0
Data set - K.S.C. - N=14 - Relative error fixed and set to 0.05
TTT
19.39
39.99
130.13
86.88
25.16
0.49
8534545
TT
26.90
38.28
130.35
119.49
37.73
0.32
3484834
Data set - K.S.C. - N=14 - Relative error fixed and set to 0.02
TTT
19.28
45.83
51.52
47.42
16.73
0.58
9188870
Appendix
Table 8: Comparison of tensor decomposition models on the AVIRIS Kennedy Space Center data set. The table reports the quantitative quality detailed in Section A.2.1 .
Figure 7: SAM maps for HYDICE Urban data set for both stages of the test procedure detailed in Section A.2 , the values for sam quality measurement are limited to the interval [0;20].
Figure 8: SAM maps for ROSIS Pavia University data set for both stages of the test procedure detailed in Section A.2 , the values for sam quality measurement are limited to the interval [0;20].
Figure 9: SAM maps for AVIRIS Moffett data set for both stages of the test procedure detailed in Section A.2 , the values for sam quality measurement are limited to the interval [0;20].
Figure 10: Structure of the TT decomposition for an N -th order tensor.
Figure 11: The truncated T-SVD of a tensor X as a sum of tubal rank-1 terms.
Figure 12: The truncated T-SVD of a third-order and a fourth-order tensor.
Figure 13: The procedure of the TTT-SVD for decomposing a tensor into the TTT format.
Figure 14: (Upper) The visualization of the structure of the proposed tubal TC/TR decomposition. The connection between the core tensors is the T-product. (Bottom) A tube of the original tensor is obtained through a sequence of t-products involving sub-tensors of the TTC/TTR cores.