Abstract The implementation of digital image processing system of blood cell images has the potential to decrease the cost of making clinical decisions, while at the same time giving a more reliable result for red blood cells (RBCs) counting. In this chapter discuss the development of a novel system for the automatic detection and segmentation of RBCs in microscopic blood smear images which play an increasing important role in medical diagnosis. The aim of this study is creating a graphical user interface (GUI) to analyze and evaluate the concept of automated RBC segmentation based on the marker-controlled watershed algorithm for an identification and segmentation technique. The GUI was constructed and developed to allow user interaction with various applications through graphical icons and visual indicators, such as secondary notation instead of text. The user is given options to visually analyze the blood image, process it, and get an accurate count of the total RBC.