Point-based registration of high-resolution histological slices for navigation purposes in virtual microscopy

Automatic registration methods for histological images in virtual microscopy are presented. Point-based approaches with outlier filtering by RANSAC and multibody factorization are investigated. The algorithms are tested on high-resolution biopsy images of the gastrointestinal tract. Quantitative evaluation is performed at different resolution levels. The results reveal the superiority of Harris feature points over SIFT features, in our setting. At low resolutions or when only subsequent slices are aligned, favorable registration results are obtained using only raw feature matching and Delaunay-based interpolation of the transformation parameters. Outlier filtering is necessary to obtain stable results in more difficult scenarios, i.e. when registering nonconsecutive slices.