Abstract—This paper presents an automated method for
counting red blood cells present in a blood sample. The proposed
method addresses the problems of holes present in blood cells and
overlapping characteristics of the red blood cells. The procedure
is quite simple and straightforward, which utilizes mathematical
morphological operations of erosion and dilation for performing
different steps. It first thresholds a gray scale image to obtain
the binary image using the Otsu thresholding method, and then,
performs the hole filling process on the red blood cells if they
have holes. Then, the process moves on to the job of counting the
red blood cells. For this, each red blood cell is extracted and its
shape analysis is performed to decide whether it is circular, noncircular,
overlapping or just partially present in the sample. If a
cell is only partially present in the image, then it is discarded. In
case of overlapping, the number of cells in the overlapped area is
determined. Several experimental results have been presented to
establish the effectiveness of the method. One of the important
findings is that the proposed method gives accurate count of red
blood cells of the blood sample, and classifies each cell into one
of the four categories mentioned above.