Abstract
In the previous report, a method to extract circular pattern has been proposed. The method utilizes geometrical property of circle, and can detect circular patterns very fast (100 particles within 1 second). The method was applied to particle image, but the method did not consider overlapped particle. In this paper, the method further improved to be able to count particle which are overlapped. The performance of the new method is examined by applying images of crowded particles groups that contain various size of particles.
