A Resource-Efficient Hardware Architecture for Connected Component Analysis

A resource-efficient hardware architecture for connected component analysis (CCA) of streamed video data is presented, which reduces the required hardware resources, especially for larger image widths. On-chip memory requirements increase with image width and dominate the resources of state-of-the-art CCA single-pass hardware architectures. A reduction in on-chip memory resources is essential to meet the ever increasing image sizes of high-definition (HD) and ultra-HD standards. The proposed architecture is resource efficient due to several innovations. An improved label recycling scheme detects the last pixel of an image object in the video stream only a few clock cycles after its occurrence, allowing the reuse of a label in the following image row. The coordinated application of these techniques leads to significant memory savings of more than two orders in magnitude compared with classical two-pass connected component labeling architectures. Compared with the most memory-efficient state-of-the-art single-pass CCA hardware architecture, 42% or more of on-chip memory resources are saved depending on the features extracted. Based on these savings, it is possible to realize an architecture processing video streams of larger images sizes, or to use a smaller and more energy-efficient field-programmable gate array device, or to increase the functionality of already existing image processing pipelines in reconfigurable computing and embedded systems.