We introduce a novel continuous surface deformation method which relies on a time-dependent vector field over a triangular mesh. For every time step the piecewise linear vector field is obtained by leastsquares minimization of the metric distortion induced by integration subject to boundary conditions. As an integral part of the approach, we introduce a new measure to describe local metric dist...

In this work, we study the problem of anonymity-preserving data publishing in moving objects databases. In particular, the trajectory of a mobile user on the plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface: we know that the trajectory of the mobile user is within this surface, but we do not know exactly where. We transform the surface’s boundary...

Introduction Echo-planar imaging (EPI) is a group of fast data acquisition methods commonly used in fMRI studies. It acquires multiple image lines in k-space after a single excitation, which leads to a very short scan time. A well-known problem with EPI is that it is more sensitive to distortions due to the used encoding scheme. Source of distortion is inhomogeneity in the static B0 field that ...

Introduction: Geometric distortion, an important parameter in neurology and oncology. The current study aimed to design and construct a new three-dimensional (3D) phantom using a 3D printer in order to measure geometric distortion and its 3D reproducibility. Material and Methods: In this study, a new phantom ...

This paper describes a new method for determining corneal surface detail utilizing a modified Zeiss photo slit lamp. This system projects a grid onto the cornea through a cobalt blue filter. The tear film is stained with fluorescein, causing the projected grid pattern to be visible on the corneal surface. A video image of the grid is then digitized by an image processor which calculates surface...

In this paper we present a novel application which uses 2D barcode for object tracking and event detection. We analyze the relationship between the spatial efficiency of a marker and its robustness against defocusing. Based on our analysis we design a spatially efficient and robust 2D barcode, M-Code (MarkerCode) which can be attached to the surface of static or moving objects. Compared with tr...

Photometric Stereo can recover dense (at pixel-level) local surface orientation, but the subsequent reconstruction procedures used to obtain 3D shape of the scene are prone to low frequency geometric distortion. This geometric distortion is mainly due to assumption of collimated light source, to overcome the error due to collimated light source we propose a novel calibration process to dynamica...

In this paper, we propose a hand-held mobile projection system that can freely project keystone free content on a general flat surface without any markings. Such a projection system can give the user great freedom of control of the display such as viewing angle and distance without suffering from distortion. We attach a camera to the projector to form a stereo pair. The correction of the displa...

There has been a dramatic increase in the handling of geospatial information, and also in the production of maps. However, because the Earth is three-dimensional, geo-referenced data must be projected on a two-dimensional surface. Depending on the area being mapped, the projection process generates a varying amount of distortion, especially for continental and world maps. Geospatial users have ...