In [[multivariate statistics]] and the [[cluster analysis|clustering]] of data, '''spectral clustering'''<ref> U. von Luxburg, "A tutorial on spectral clustering", Stat. Comp. Vol. 17, Issue 4 , 395-416 (2007), [http://papercore.org/vonLuxburg2007 Papercore summary http://papercore.org/vonLuxburg2007 ] </ref> techniques make use of the [[Spectrum of a matrix|spectrum]] ([[eigenvalues]]) of the [[similarity matrix]] of the data to perform [[dimensionality reduction]] before clustering in fewer dimensions. The similarity matrix is provided as an input and consists of a quantitative assessment of the relative similarity of each pair of points in the dataset.
In application to image segmentation, spectral clustering is known as [[segmentation-based object categorization]].
