1. A method of registering biomedical images to reduce imaging artifacts caused by object movement, the method comprising: a) providing at least a first and a second digital or digitalized images or set of cross-sectional images of the same object, each image being formed by a two or three dimensional array of pixels or voxels; b) defining within the first image or set of images a number of landmarks or features by selecting a number of pixels or voxels which are set as landmarks or features, and generating a list of said features to be tracked; c) tracking the position of each pixel or voxel selected as a feature from the first to the second image or set of images by determining an optical flow vector from the first to the second image or set of images for each pixel or voxel of the list; d) registering the first and the second image or set of images by applying an inverse optical flow vector to the pixels or voxels of the second image or set of images, wherein an automatic feature selection step is carried out comprising: B1) defining a pixel or voxel neighborhood around each pixel or voxel of the first image or first set of cross-sectional images, the pixel or voxel neighborhood comprising a limited number of pixels or voxels, wherein a two dimensional neighborhood is chosen for a single image, and wherein a three dimensional neighborhood is chosen for the set of cross-sectional images; and B2) for each pixel or voxel of the first image or first set of cross-sectional images, determining a mean signal intensity value of all pixels or voxels within the neighborhood; B3) defining a mean signal intensity value threshold; B4) comparing the mean signal intensity value determined for each pixel or voxel neighborhood at step B2 and comparing the said mean signal intensity value with the mean signal intensity value threshold; and B5) if the mean signal intensity value of one neighborhood is higher than the threshold at step B4, the pixels or voxels of the one neighborhood are defined as a feature to be tracked, which is added to the list of features to be tracked.