FPGA-based BLOB Detection Using Dual-pipelining (Abstract Only)

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Binary Large OBject (BLOB) detection is utilized in various fields such as car cameras, traffic sign recognition and surveillance systems. Although labeling is an important component in BLOB detection, it is difficult to be parallelized using a look-up table (LUT) in terms of data dependency. Since BLOB detection takes a long time, recognition speed and accuracy need to be improved. This research aims to detect BLOBs as fast as possible by using dual-pipelining image processing on the FPGA. Dual-pipelining is to perform pipeline processing in parallel to the upper and lower portions of an original image after dividing it into two portions. We have to consider the timing of each module around the borderline because of the data dependency in label generation. The image processing consists of Gaussian filtering, binarization, labeling, and BLOB analysis. Generally, labeling uses a LUT to combine multiple numbers for one object into the smallest number of temporary labels. In order to simplify the labeling, the connected components of each BLOB are stored and revised just in the LUT. In our approach, a BLOB can be detected when multiple temporary labels are stored in a same entry of the LUT, thus enabling us to detect BLOBs by dual-pipelining. Although our labeling method does not revise temporary labels into a unified label, BLOBs can be detected and their numbers, areas, and centroids are correctly computed. We compared our approach with a related work, which consists of three steps: identifying the connected pixels in each row, labeling the counted pixels in different rows, computing the area and centroid. Experimental results show that the dual-pipelining system using FPGA can detect BLOBs in 0.06 ms, which is 3.92 times faster than the related work and 1.83 times faster than a single-pipelining system. The dual-pipelining system utilized 1.5% of Registers, 8.4% of LUT, 24.3% of LUT-FF pairs, 91.9% of BRAM in Virtex V. The dual-pipelining system is about twice as large as the single-pipelining system. Our approach can be applied for the other areas such as traffic sign recognition and vehicle detection.