A high-accuracy circle detection method using a multi-angle rotating equilateral triangle
Opard. Chai-Ruage, Wannida Sae-Tang · International Workshop on Advanced Imaging Technology (IWAIT) 2022 · 2022
Nowadays, visual inspection is widely used in manufacturing industries such as electronic industries, and the most common shape detection is circle detection. Although, there were many methods proposed for circle detection, there is a room to improve the detection accuracy. This paper then proposes a high-accuracy circle detection method using a multiangle rotating equilateral triangle. The main idea is to fit the equilateral triangle into the circle with various rotation angles to select the most accurate circle center. Triangles with various rotation angles are fitted into the circle by iteratively adjusting the ratios of the triangle bases to another sides. The triangles which cannot be adjusted to be equilateral are then discarded, because those isosceles triangles, which occur when a detected triangle corner (s) is not on the circumference but on noises inside the circle, are the cause of inaccurately detected circle centers. The experimental results show that the proposed method is superior to the conventional methods in terms of accuracy and processing time.