11 research outputs found
Fast fluid registration of medical images
. This paper offers a new fast algorithm for non-rigid Viscous Fluid Registration of medical images that is at least an order of magnitude faster than the previous method by Christensen et al. [4]. The core algorithm in the fluid registration method is based on a linear elastic deformation of the velocity field of the fluid. Using the linearity of this deformation we derive a convolution filter which we use in a scalespace framework. We also demonstrate that the 'demon'-based registration method of Thirion [13] can be seen as an approximation to the fluid registration method and point to possible problems. 1 Introduction Non-rigid registration of two medical images is performed by applying global and/or local transformations to one of the images (which we will call the template T ) in such a way that it matches the other image (the study S). It is important to understand that the aim of the transformation is to map the template completely onto the study in such a way that informatio..
Fast Fluid Registration of Medical Images
Abstract. This paper o�ers a new fast algorithm for non�rigid Viscous Fluid Registration of medical images that is at least an order of mag� nitude faster than the previous method by Christensen et al. �4�. The core algorithm in the �uid registration method is based on a linear elas� tic deformation of the velocity �eld of the �uid. Using the linearity of this deformation we derive a convolution �lter which we use in a scale� space framework. We also demonstrate that the �demon��based registra� tion method of Thirion �13 � can be seen as an approximation to the �uid registration method and point to possible problems.
Non-Rigid Image Registration using Bone Growth Model
. Non-rigid registration has traditionally used physical models like elasticity and fluids. These models are very seldom valid models of the difference between the registered images. This paper presents a non-rigid registration algorithm, which uses a model of bone growth as a model of the change between time sequence images of the human mandible. By being able to register the images, this paper at the same time contributes to the validation of the growth model, which is based on the currently available medical theories and knowledge. This paper studies the process of bone growth in the human mandible. Based on the available medical knowledge, a bone growth model is established, and experiments are carried out to determine the validity of the model. These experiments uses a unique data set containing three voxel images of the mandible of a child, taken at different times. Being able to model the growth of the facial bones is both interesting for understanding the development of the cra..
RobVision - Visually Guiding a Walking Robot through a Ship Structure
The EU funded ROBVISION project develops a vision system that finds and measures the location of 3D structures with respect to a CAD-model. The main objective is to build an integrated vision system capable of providing adequate information to navigate a walking robot through a ship structure. The key aspect is the integration of a CAD-model to visual measurement and the direct feedback of the measurement results. The objective is to render visual processing robust to deviations in parts and environmental conditions. To achieve this goal a technique is developed that integrates different cues of images to obtain confidence of the measurement result. 1 Project Overview Industries using a CAD-system to design parts or working areas need a means of feedback to enable a comparison of designed and manufactured structures. Using vision based on the CAD information is an effective tool to establish this link. For example, the autonomy of a robotic vehicle is needed in several applications in building and inspecting of large structures, such as ship bodies. The navigation of a walking robot will be demonstrated using this vision tool. Furthermore, the vision tool can be used for the task of dimensional measurements of parts