Nonrigid Registration Using Free-Form Deformations

Introduction This paper presents an algorithm for non-rigid registration of contrast-enhanced breast MR image sequences. The authors propose a model incorporating both global transformations (represented by affine transformation) as well as local transformation (free-form deformation represented using B-splines). Normalized mutual information was used as the similarity measure across images. The authors demonstrate the algorithm’s superior performance compared to the rigid and affine registration techniques. ...

October 24, 2018 · 3 min · Kumar Abhishek

A Minimum Description Length Approach to Statistical Shape Modeling

Introduction This paper presents an algorithm for generating statistical shape models by addressing it as a correspondence problem of finding the parameterization of each shape in the training set, instead of manually annotating a set of “landmark” points for each image in the training set. The authors demonstrate the robustness of the algorithm by applying it to a variety of training image sets - infarcts, kidneys, knee cartilages, hand outlines, hip prostheses, and left ventricles. The proposed minimum description length model leads to good compactness, specificity and generalizes well, outperforming the contemporary gold standard - manual landmarking. Moreover, the authors also show that this model can be extended to work with 3-D images. ...

October 17, 2018 · 3 min · Kumar Abhishek

Active Shape Models

Introduction This paper presents an algorithm for modeling rigid objects in the presence of noise, clutter, and occlusion and overcomes the problems facing the contemporary algorithms - sacrificing specificity to accommodate variability. The proposed models permits deformations only consistent with the class of objects it represents. The authors demonstrate the robustness of the algorithm by applying it to a variety of training image sets - resistors, heart, hand, and worm models. ...

October 17, 2018 · 3 min · Kumar Abhishek

Multiscale Vessel Enhancement Filtering

Introduction This paper presents a method for vessel enhancement filtering which relies on local structure. Using information about the second order ellipsoid, this is an improvement over previous works that exhibits robustness to noise and background for vessel enhancement in the experiments with two clinical image modalities - 2D DSA images and 3D MRA images. ...

October 17, 2018 · 3 min · Kumar Abhishek

Graph Cuts for Image Segmentation

Introduction This paper presents a graph cut approach to the image segmentation task. Considering the image to be a directed graph with two nodes representing the source (object) and the sink (background), the authors propose a combinatorial optimization framework for image segmentation using $s/t$ graph cuts. This is the first global optimization object extraction technique that is extensible to beyond 2-D images. ...

October 10, 2018 · 4 min · Kumar Abhishek