I. Introduction
Studying sperm cells and their motion characteristics is of utmost importance in fertility assessment and other applications such as artificial insemination and In-Vitro Fertilization (IVF) [1]. Due to the large number of sperm cells involved, using machine vision is a must. The most common is Computer Assisted Sperm Analysis (CASA), which refers to the hardware (microscope, camera, PC) and software needed to analyze sperm motion characteristics [2]. CASA is used to make an objective analysis of sperm motion as a measure of fertility assessment and quality assurance of semen for artificial insemination. It is also used in research, to gain a better understanding of the motion of sperm and the mechanisms responsible for sperm progression to a female egg [2].