Boosted Mean Shift Clustering

Mean shift is a nonparametric clustering technique that does not require the number of clusters in input and can find clusters of arbitrary shapes. While appealing, the performance of the mean shift algorithm is sensitive to the selection of the bandwidth, and can fail to capture the correct clustering structure when multiple modes exist in one cluster. DBSCAN is an efficient density based clustering algorithm, but it is also sensitive to its parameters and typically merges overlapping clusters. In this paper we propose Boosted Mean Shift Clustering (BMSC) to address these issues. BMSC partitions the data across a grid and applies mean shift locally on the cells of the grid, each providing a number of intermediate modes (iModes). A mode-boosting technique is proposed to select points in denser regions iteratively, and DBSCAN is utilized to partition the obtained iModes iteratively. Our proposed BMSC can overcome the limitations of mean shift and DBSCAN, while preserving their desirable properties. Complexity analysis shows its potential to deal with large-scale data and extensive experimental results on both synthetic and real benchmark data demonstrate its effectiveness and robustness to parameter settings.