Efficient symmetry-based screening strategy to speed up randomized circle-detection

Randomized approaches for circle detections are often used for the advantages of less computational time and memory requirements. However, randomized approaches involve examining a large number of candidate circles and may not be suitable for real-time applications. In this paper, a screening strategy based on the symmetric property of the circle is adopted to select the promising candidates for further investigation, resulting in substantial reduction in the computational time while maintaining the accuracy. Empirical results show that, under the same accuracy level, the proposed symmetry-based method achieves the improvement ratios of 40%–90% on the execution-time when compared to four state-of-the-art randomized methods.

► A symmetry-based strategy has been presented to discard invalid candidate circles.
► Four new methods have been developed by combining the symmetry-based strategy with four existing methods.
► Four new methods have 40%–90% execution-time improvement ratios.