Jaroslav Kĝivánek

Improving Performance and Accuracy of Local PCA

Computer Graphics Forum (Proc. of Pacific Graphics)


Václav Gassenbauer
IRISA Rennes, France
 
Jaroslav Kĝivánek
Charles Univesrity in Prague
Faculty of Mathematics and Physics
Kadi Bouatouch
IRISA Rennes, France
Christian Bouville
IRISA Rennes, France
Mickaël Ribardiere
IRISA Rennes, France


Abstract

Local Principal Component Analysis (LPCA), also known as Clustered PCA (CPCA), is one of the popular techniques for dimensionality reduction and data compression of large data sets encountered in computer graphics. The LPCA algorithm is a variant of k-means clustering where the repetitive classification of high dimensional data points to their nearest cluster leads to long execution times. The focus of this paper is on improving the efficiency and accuracy of LPCA. We propose a novel SortCluster LPCA algorithm that significantly reduces the cost of the point-cluster classification stage, achieving a speed-up of up to 20. To improve the approximation accuracy, we investigate different initialization schemes for LPCA and find that the k-means++ algorithm [AV07] yields best results, however at a high computation cost. We show that similar ideas that lead to the efficiency of our SortCluster LPCA algorithm can be used to accelerate k-means++. The resulting initialization algorithm is faster than purely random seeding while producing substantially more accurate data approximation.


Publication

Václav Gassenbauer, Jaroslav Kĝivánek, Kadi Bouatouch, Christian Bouville, and Mickaël Ribardiere Improving Performance and Accuracy of Local PCA. Computer Graphics Forum (Pacific Graphics), vol. 30, no. 7, 2011. ... DOI | BibTeX.


Downloads

 
paper
presentation
slides
 
video
 3.8MB pdf  2MB pptx | 0.7MB pdf  1.4MB avi