Detection of the bone contours of the knee joints on medical X-ray images

Detection of objects of interest is a crucial step in the automatic analysis of the medical X-ray images. However, medical X-rays are often characterized by the low contrast as well as great variability in range of colours, which makes it more difficult to be analysed by the common methods based on the regions homogeneity principles. In our paper, we present an alternative approach to the contours detection problem that does not require the homogeneity criteria to be satisfied. Our method is based on the identification of edge fragments and elimination of discontinuities between them. Moreover, we describe a numeric criterion for quality evaluation of contours detection. The obtained results can used for diagnosis of abnormalities and diseases, and also as an intermediate step for more sophisticated methods of image analysis.