Optimization of Numerical Calculations of Geometric Features of a Curve Describing Preprocessed X-Ray Images of Bones as a Starting Point for Syntactic Analysis of Finger Bone Contours

摘要

Analysis of bone contours in X-ray images is crucial for the detection of pathological changes such as erosions and osteophytes. The analysis is done by using shape languages. In this approach the contour received from the preprocessing procedure is segmented into fragments according to geometrical properties of the contour. The properties are characterized by monotonicity and convexity of the contour. Two aforementioned features are deduced by using the first and second derivatives that are calculated numerically. On the one hand the used numerical procedure can smooth the analyzed contour. On the other hand, however, the more smoothed the contour is, the more chance that the small pathological changes remain undetected. Finding the optimal numerical procedure for X-ray hand images is the aim of this paper. (This paper was supported by the AGH - University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection as a part of the statutory project).