Sperm's tail identification and discrimination in microscopic images of stained human semen smear

Correct estimating of a man's fertility potential has long been of great interest to researchers. Sperm morphology is assessed routinely as part of standard laboratory analysis in the diagnosis of human male infertility. The evaluation of sperm size, shape and morphological smear characteristics should be assesed by carefully observing a stained sperm sample under a microscope. In order to avoid subjectivity, numerous studies that incorporate image analysis techniques in the assessment of sperm morphology have been proposed appeared. In this paper, we have proposed a new method to identify sperm's tail through some points which are placed on the sperm's tail, accurately. These estimated points could be used to verify the morphological characteristics of sperm's tail such as length, shape and etc. At first, sperm's head and mid-piece are segmented. Then, a pixel which is placed at the end of sperm's mid-piece, is selected as an initial point. At the next step, the proposed method finds the other pixels which are placed on the sperm's tail using structural similarity index in an iterative scheme. In order to stop the algorithm automatically at the end of sperm's tail, local entropy is estimated and used as a feature to determine if a point is located on the sperm's tail or not ,and also to determine the end of sperm's tail.