Mutual information (MI) is a widely used similarity metric for multimodality image registration. However, it involves an extremely high computational time especially when it is applied to volume images. Moreover, its robustness is affected by existence of local maxima. The multi-resolution pyramid approaches have been proposed to speed up the registration process and increase the accuracy of th...

Abstract Optical flow estimation in human facial video, which provides 2D correspondences between adjacent frames, is a fundamental pre-processing step for many applications, like expression capture and recognition. However, it quite challenging as images contain large areas of similar textures, rich expressions, rotations. These characteristics also result the scarcity large, annotated real-wo...

Background: One of the challenges of PET/MRI combined systems is to derive an attenuation map to correct the PET image. For that, the pseudo-CT image could be used to correct the attenuation. Until now, most existing scientific researches construct this pseudo-CT image using the registration techniques. However, these techniques suffer from the local minima of the non-rigid deformation energy f...

UNLABELLED In lung cancer, (18)F-FDG PET, CT, and (18)F-FDG PET/CT are used for noninvasive staging and therapy planning. Even with improved image registration techniques-especially in the modern hybrid PET/CT scanners-inaccuracies in the fusion process may occur, leading to errors in image interpretation. The aim of this study was to investigate by an intraindividual analysis whether, in compa...

BACKGROUND [18F]fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) is a valuable tool for monitoring response to therapy in oncology. In longitudinal studies, however, patients are not scanned in exactly the same position. Rigid and non-rigid image registration can be applied in order to reuse baseline volumes of interest (VOI) on consecutive studies of the same patient. The...

BACKGROUND AND PURPOSE Bone-subtraction techniques have been shown to enhance CT angiography (CTA) interpretation, but motion can lead to incomplete bone removal. The aim of this study was to evaluate 2 novel registration techniques to compensate for patient motion. MATERIALS AND METHODS Fifty-four patients underwent bone-subtraction CTA (BSCTA) for the evaluation of the neck vessels with 64-...

This paper presents the application of a signal intensity independent similarity criterion for rigid and non-rigid body registration of binary objects. The criterion is defined as the weighted ratio image of two images. The ratio is computed on a voxel per voxel basis and weighting is performed by setting the raios between signal and background voxels to a standard high value. The mean squared ...

In this paper, we propose a new similarity measure to combine multiple views of 3-D objects for non-rigid registration. It is a metric that integrates multiple 2-D view features representing a visual identity of a 3-D object seen from different viewpoints. The robustness to non-rigid distortions is achieved by the proximity correspondence manner. The human face, a typical non-rigid object, was ...