Enhanced dark block extraction method performed automatically to determine the number of clusters in unlabeled data sets

Abstract

One of the major issues in data cluster analysis is to decide the number of clusters or groups from a set of unlabeled data. In addition, the presentation of cluster should be analyzed to provide the accuracy of clustering objects. This paper propose a new method called Enhanced-Dark Block Extraction (E-DBE), which automatically identifies the number of objects groups in unlabeled datasets. The proposed algorithm relies on the available algorithm for visual assessment of cluster tendency of a dataset, by using several common signal and image processing techniques. The method includes the following steps: 1.Generating an Enhanced Visual Assessment Tendency (E-VAT) image from a dissimilarity matrix which is the input for E-DBE algorithm. 2. Processing image segmentation on E-VAT image to obtain a binary image then performs filter techniques. 3. Performing distance transformation to the filtered binary image and projecting the pixels in the main diagonal alignment of the image to figure a projection signal. 4. Smoothing the outcrop signal, computing its first-order derivative and then detecting major peaks and valleys in the resulting signal to acquire the number of clusters. E-DBE is a parameter-free algorithm to perform cluster analysis. Experiments of the method are presented on several UCI, synthetic and real world datasets. © 2006-2013 by CCC Publications.