Automatic Counting of Leukocytes in Giemsa-Stained Images of Peripheral Blood Smear

There are many different classes of leukocyte in peripheral blood image. Leukocyte count is used to determine the presence of an infection in the human body. To be able to observe and recognize the different kinds of leukocyte, you must stain them. For this purpose, normally Giemsa stain is used. There are two difficult issues in image segmentation which common segmentation algorithms can not overcome them. Nucleus which is laid inside white cell is the darkest part of image which can be used to count cells. Since Giemsa staining is done by humans, intensity of images is slightly different from each others. Neutrophils are kinds of leukocytes which have segmented and distinctive nucleus. These reasons cause a considerable error in counting. In this paper, we have proposed to use histogram of images and intensity of red cells which are major objects in images to select appropriate point for thresholding. And then the distances among centers of the extracted nuclei have been calculated, according to the specified size of leukocytes, we merge the nuclei which those distances are less than the diameter of one leukocyte. Experimental results show that our approach is very efficient.