Method for improving the visibility of poor contrast line structures in a digital image

摘要

An original digital image has superimposed on it an amplitude image which is determined by using a star-shaped filter mask by summing the image values of the original image along the directional stripes of this filter mask. To smooth this amplitude image, a directional image is determined which allocates to each pixel the maximum of all its directional sums, and the image values of the amplitude image are corrected as a function of the amplitudes of adjacent image values with an approximately parallel direction. The method is particularly suitable for improving the visibility of the finest blood vessels in medical images.