INTRODUCTION Over the recent decades various marker­based video capture systems have been developed in order to estimate segment kinematics in biomechanics applications. It may not be a disproportionate statement to claim that this method is regarded as the gold standard in laboratory based settings. Inherent problems to these systems include adequate marker placement, skin movement artefacts a...

Digital video stabilization approaches typically degrade their performances in presence of periodic patterns. Any kind of matching between consecutive frames is not usually able to work in presence of these kind of signals: the motion estimation engine is deceived and its performances degrade abruptly. In this paper we propose a fast fuzzy classifier able to recognize periodic and aperiodic pat...

This paper presents an enhanced version of our previous algorithm for point-wise tracking and analysis of cardiac motion based on 3D active mesh model. In the present software, a new 3D active surface model based on curve evolution techniques and level sets is used for automatizing the segmentation of endocardial boundary in the left ventricle in the first phase of cardiac cycle. Furthermore, c...

Facial features play an important role in expressing grammatical information in signed languages, including American Sign Language (ASL). Gestures such as raising or furrowing the eyebrows are key indicators of constructions such as yes-no questions. Periodic head movements (nods and shakes) are also an essential part of the expression of syntactic information, such as negation (associated with...

Traditional plane alignment techniques are typically performed between pairs of frames. In this paper we present a method for extending existing two-frame planar-motion estimation techniques into a simultaneous multi-frame estimation, by exploiting multi-frame geometric constraints of planar surfaces. The paper has three main contributions: (i) we show that when the camera calibration does not ...

In statistical pattern recognition, parameters of distributions are usually estimated from training samples. It is well known that shortage of training samples causes estimation errors which reduce recognition accuracy. By studying estimation errors of eigenvalues, various methods of avoiding recognition accuracy reduction have been proposed. However, estimation errors of eigenvectors have not ...

ACstract--In the eight-point linear algorithm for determining 3-D motion/structure from two perspective views using point correspondences, the E matrix occupies a central role. The E matrix is defined as a skew-symmetrical matrix (containing the translation components) postmultiplied by a rotation matrix. In this correspondence, we show that a necessary and sufficient condition for a 3 x 3 matr...

Background Feature tracking (FT) software packages measure myocardial wall motion deformation parameters through the cardiac cycle. Myocardial tagging technique is currently considered the gold standard for myocardial deformation measurements. This study compares 2 FT-software packages with a tagging software package and investigates the differences in strain deformation parameters measured in ...