Linear hyperspectral unmixing (LHU) aims to decompose mixed pixels into endmembers and abundance vectors, and it has important applications in terrain classification, mineral recognition and quantification, agricultural monitoring, and military surveillance. Because the data-fidelity term couples the endmember and abundance variables, the original formulation is nonconvex. After a principal components analysis (PCA)-based dimensionality reduction and the inverse transformation $ Q = M^{-1} $, we obtain a smooth reduced model on the nonsingular domain. We first apply the adaptive moments method (ADAM) to this transformed LHU model and then develop a stochastic adaptive moments method (SADAM) based on mini-batch gradients to reduce the computational cost for large data sets. For SADAM, we provide a conditional convergence analysis to stationary points under smoothness, boundedness, and moment-tracking assumptions. Numerical experiments on four real hyperspectral data sets show that SADAM can reduce computational time while maintaining competitive unmixing accuracy.
Citation: Zhewei Zhang, Fangfang Xu. Adaptive moments method for linear hyperspectral unmixing[J]. AIMS Mathematics, 2026, 11(10): 32839-32859. doi: 10.3934/math.20261288
Linear hyperspectral unmixing (LHU) aims to decompose mixed pixels into endmembers and abundance vectors, and it has important applications in terrain classification, mineral recognition and quantification, agricultural monitoring, and military surveillance. Because the data-fidelity term couples the endmember and abundance variables, the original formulation is nonconvex. After a principal components analysis (PCA)-based dimensionality reduction and the inverse transformation $ Q = M^{-1} $, we obtain a smooth reduced model on the nonsingular domain. We first apply the adaptive moments method (ADAM) to this transformed LHU model and then develop a stochastic adaptive moments method (SADAM) based on mini-batch gradients to reduce the computational cost for large data sets. For SADAM, we provide a conditional convergence analysis to stationary points under smoothness, boundedness, and moment-tracking assumptions. Numerical experiments on four real hyperspectral data sets show that SADAM can reduce computational time while maintaining competitive unmixing accuracy.
| [1] |
F. Xu, Y. Wang, Y. Li, L. Liu, T. Tian, Gradient type methods for linear hyperspectral unmixing, CSIAM Trans. Appl. Math., 3 (2022), 109–132. https://doi.org/10.4208/csiam-am.SO-2021-0001 doi: 10.4208/csiam-am.SO-2021-0001
|
| [2] |
R. Bro, A. K. Smilde, Principal component analysis, Anal. Methods, 6 (2014), 2812–2831. https://doi.org/10.1039/c3ay41907j doi: 10.1039/c3ay41907j
|
| [3] | J. Duchi, S. Shalev-Shwartz, Y. Singer, T. Chandra, Efficient projections onto the $\ell_1$-ball for learning in high dimensions, Proceedings of the 25th International Conference on Machine Learning, 2008,272–279. https://doi.org/10.1145/1390156.1390191 |
| [4] | W. Wang, M. A. Carreira-Perpiñán, Projection onto the probability simplex: an efficient algorithm with a simple proof, and an application, arXiv, 2013. https://doi.org/10.48550/arXiv.1309.1541 |
| [5] | X. Chen, S. Liu, R. Sun, M. Hong, On the convergence of a class of Adam-type algorithms for non-convex optimization, arXiv, 2018. https://doi.org/10.48550/arXiv.1808.02941 |
| [6] | D. P. Kingma, J. Ba, Adam: a method for stochastic optimization, arXiv, 2014. https://doi.org/10.48550/arXiv.1412.6980 |
| [7] |
W. B. Powell, A unified framework for stochastic optimization, Eur. J. Oper. Res., 275 (2019), 795–821. https://doi.org/10.1016/j.ejor.2018.07.014 doi: 10.1016/j.ejor.2018.07.014
|
| [8] | S. J. Reddi, S. Kale, S. Kumar, On the convergence of Adam and beyond, arXiv, 2018. https://doi.org/10.48550/arXiv.1904.09237 |
| [9] | X. Li, A. Milzarek, A unified convergence theorem for stochastic optimization methods, arXiv, 2022. https://doi.org/10.48550/arXiv.2206.03907 |
| [10] | H. Robbins, D. Siegmund, A convergence theorem for non negative almost supermartingales and some applications, In: Optimizing methods in statistics, New York: Academic Press, 1971,233–257. https://doi.org/10.1016/B978-0-12-604550-5.50015-8 |
| [11] | F. Zhu, Y. Wang, B. Fan, G. Meng, C. Pan, Effective spectral unmixing via robust representation and learning-based sparsity, arXiv, 2014. https://doi.org/10.48550/arXiv.1409.0685 |
| [12] |
F. Zhu, Y. Wang, B. Fan, S. Xiang, G. Meng, C. Pan, Spectral unmixing via data-guided sparsity, IEEE Trans. Image Process., 23 (2014), 5412–5427. https://doi.org/10.1109/TIP.2014.2363423 doi: 10.1109/TIP.2014.2363423
|
| [13] |
F. Zhu, Y. Wang, S. Xiang, B. Fan, C. Pan, Structured sparse method for hyperspectral unmixing, ISPRS J. Photogramm. Remote Sens., 88 (2014), 101–118. https://doi.org/10.1016/j.isprsjprs.2013.11.014 doi: 10.1016/j.isprsjprs.2013.11.014
|
| [14] |
J. Li, X. Li, L. Zhao, Hyperspectral unmixing via projected mini-batch gradient descent, IEEE International Geoscience and Remote Sensing Symposium (IGARSS), 2017, 1133–1136. https://doi.org/10.1109/IGARSS.2017.8127157 doi: 10.1109/IGARSS.2017.8127157
|
| [15] |
F. Zhu, P. Honeine, Online nonnegative matrix factorization based on kernel machines, 2015 23rd European Signal Processing Conference (EUSIPCO), 2015, 2381–2385. https://doi.org/10.1109/EUSIPCO.2015.7362811 doi: 10.1109/EUSIPCO.2015.7362811
|
| [16] |
X. Li, F. Xu, Y. H. Dai, A stochastic proximal gradient method for linear hyperspectral unmixing, J. Appl. Numer. Optim., 6 (2024), 323–338. https://doi.org/10.23952/jano.6.2024.3.02 doi: 10.23952/jano.6.2024.3.02
|
| [17] |
Y. Qian, S. Jia, J. Zhou, A. Robles-Kelly, Hyperspectral unmixing via $l_{1/2}$ sparsity-constrained nonnegative matrix factorization, IEEE Trans. Geosci. Remote Sens., 49 (2011), 4282–4297. https://doi.org/10.1109/TGRS.2011.2144605 doi: 10.1109/TGRS.2011.2144605
|
| [18] |
Y. Dai, F. Xu, L. Zhang, Alternating direction method of multipliers for linear hyperspectral unmixing, Math. Methods Oper. Res., 97 (2023), 289–310. https://doi.org/10.1007/s00186-023-00815-2 doi: 10.1007/s00186-023-00815-2
|