Particle Detection Algorithms for Complex Plasmas

Abstract

The floating micrometer sized particles in complex plasmas are usually individually visible and can be recorded by digital video cameras. To analyze the dynamics of single particles, reliable algorithms are required to accurately determine their positions to sub-pixel accuracy from the recorded images. Here, we present an improved algorithm for blob detection, and combine it with common techniques for image processing, such as pre- and post-processing methods, and an automatic threshold detection. We further compare several algorithms with regard to particle features in complex plasmas, and the presence of image noise. This leads to an extensive comparison of the influence of every step on the positioning error of the detection, and also shows the limits of the practicality. The presented results quantitatively show that each algorithm and method has its own advantage, often depending on the problem at hand.