Markov chain based edge detection algorithm for evaluation of capillary microscopic images

Abstract

Nailfold capillaroscopy is a non invasive, simple examination, which provides exact information on the assessment of the microcirculation. The peripheral blood circulation is very sensible for certain illnesses e.g.: autoimmune diseases, diabetes. In many cases there exists a pattern specific for certain illnesses, therefore this test is capable of differentiate between them. Our aim is to develop a computer aided evaluation system for capillary microscopic images. The fist step of the evaluation is the detection of capillaries, which is done by edge detection. Classical edge detectors resulted in unsatisfactory output, therefore we tried a different approach, which is able to take into account not only the local properties of the image, but also the relations of pixels. During the test of the algorithm we obtained that with a suitable post processing procedure the capillaries shown in the picture can be detected robustfully, hence our procedure is applicable as the first step of the evaluation of these images.