An FPGA implementation of real-time K-means clustering for color images

Abstract

K-means clustering is a very popular clustering technique, which is used in numerous applications. In the k-means clustering algorithm, each point in the dataset is assigned to the nearest cluster by calculating the distances from each point to the cluster centers. The computation of these distances is a very time-consuming task, particularly for large dataset and large number of clusters. In order to achieve high performance, we need to reduce the number of the distance calculations for each point efficiently. In this paper, we describe an FPGA implementation of k-means clustering for color images based on the filtering algorithm. In our implementation, when calculating the distances for each point, clusters which are apparently not closer to the point than other clusters are filtered out using kd-trees which are dynamically generated on the FPGA in each iteration of k-means clustering. The performance of our system for 512 × 512 and 640 × 480  pixel images (24-bit full color RGB) is more than 30 fps, and 20–30 fps for 756 × 512 pixel images in average when dividing to 256 clusters.