Connected Components Labeling on Bitonal Images

Federico Bolelli, Stefano Allegretti, Costantino Grana

Abstract: Several algorithmic solutions for the optimization of Connected Components Labeling have been proposed in literature. Among them, one of the most effective is a block-based mask to drastically reduce the number of memory accesses during the labeling procedure. This paper proposes a systematic approach for labeling multiple pixels at once, automatically generating the actions to be performed on the current pixel/block given the mask values. The proposed strategy allows to extend existing techniques for the generation of optimal decision trees to much more complex masks, where the connectivity between pixels inside a block is not guaranteed. A showcase application, consisting in the design of an efficient CCL algorithm for bitonal images, demonstrates the effectiveness of our proposal in terms of speed and memory footprint.