title: Segmentation of multivariate mixed data via Lossy data coding and compression.
abstract: In this paper, based on ideas from lossy data coding and compression, we present a simple but effective technique for segmenting multivariate mixed data that are drawn from a mixture of Gaussian distributions, which are allowed to be almost degenerate. The goal is to find the optimal segmentation that minimizes the overall coding length of the segmented data, subject to a given distortion. By analyzing the coding length/rate of mixed data, we formally establish some strong connections of data segmentation to many fundamental concepts in lossy data compression and rate distortion theory. We show that a deterministic segmentation is approximately the (asymptotically) optimal solution for compressing mixed data. We propose a very simple and effective algorithm which depends on a single parameter, the allowable distortion. At any given distortion, the algorithm automatically determines the corresponding number and dimension of the groups and does not involve any parameter estimation. Simulation results reveal intriguing phase-transition-like behaviors of the number of segments when changing the level of distortion or the amount of outliers. Finally, we demonstrate how this technique can be readily applied to segment real imagery and bioinformatic data.
authors.affiliation: Electrical and Computer Engineering Department, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. yima@uiuc.edu
authors.forename: Yi
authors.initials: Y
authors.lastname: Ma
authors.forename: Harm
authors.initials: H
authors.lastname: Derksen
authors.forename: Wei
authors.initials: W
authors.lastname: Hong
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001185:Artificial Intelligence; D003198:Computer Simulation; D044962:Data Compression / Q000379:methods*; D003627:Data Interpretation, Statistical; D015233:Models, Statistical; D015999:Multivariate Analysis; D016011:Normal Distribution; D010363:Pattern Recognition, Automated / Q000379:methods*