A high speed systolic architecture for labeling connected components in an image

Connected components detection and labeling is an essential step in many image analysis techniques. The efficiency of the connected components labeling algorithm is critical for many image processing and machine vision applications that require real time response. The advances in the areas of parallel processing and VLSI technology can be exploited in designing hardware algorithms of high speed and throughput. In this paper, the authors propose a systolic algorithm and architecture for finding connected components in an image. The architecture is simple and can be implemented as a special purpose VLSI chip. Although, the algorithm has a time complexity of O(N/sup 2/), this is in terms of the actual clock cycle which is estimated as 25 nano seconds. The proposed hardware can process a 128/spl times/128 image in 0.85 msec and uses 128 processors whereas the MPP requires 94.6 msec with 16384 processors. The only special purpose hardware that exists requires 300 msec to label a 512/spl times/512 image which can be accomplished in 13.5 msec using the authors' proposed hardware. >