A parallel unmixing algorithm for hyperspectral images

Stefan A. Robila, Lukasz G. Maciak

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

16 Scopus citations


We present a new algorithm for feature extraction in hyperspectral images based on source separation and parallel computing. In source separation, given a linear mixture of sources, the goal is to recover the components by producing an unmixing matrix. In hyperspectral imagery, the mixing transform and the separated components can be associated with endmembers and their abundances. Source separation based methods have been employed for target detection and classification of hyperspectral images. However, these methods usually involve restrictive conditions on the nature of the results such as orthogonality (in Principal Component Analysis - PCA and Orthogonal Subspace Projection - OSP) of the endmembers or statistical independence (in Independent Component Analysis - ICA) of the abundances nor do they fully satisfy all the conditions included in the Linear Mixing Model. Compared to this, our approach is based on the Nonnegative Matrix Factorization (NMF), a less constraining unmixing method. NMF has the advantage of producing positively defined data, and, with several modifications that we introduce also ensures addition to one. The endmember vectors and the abundances are obtained through a gradient based optimization approach. The algorithm is further modified to run in a parallel environment. The parallel NMF (P-NMF) significantly reduces the time complexity and is shown to also easily port to a distributed environment. Experiments with in-house and Hydice data suggest that NMF outperforms ICA, PCA and OSP for unsupervised endmember extraction. Coupled with its parallel implementation, the new method provides an efficient way for unsupervised unmixing further supporting our efforts in the development of a real time hyperspectral sensing environment with applications to industry and life sciences.

Original languageEnglish
Title of host publicationIntelligent Robots and Computer Vision XXIV
Subtitle of host publicationAlgorithms, Techniques, and Active Vision
StatePublished - 2006
EventIntelligent Robots and Computer Vision XXIV: Algorithms, Techniques, and Active Vision - Boston, MA, United States
Duration: 2 Oct 20064 Oct 2006

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherIntelligent Robots and Computer Vision XXIV: Algorithms, Techniques, and Active Vision
Country/TerritoryUnited States
CityBoston, MA


  • Blind source separation
  • Hyperspectral images
  • Image processing
  • Linear mixing model
  • Nonnegative matrix factorization
  • Parallel processing


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