Search results for "Flux optique"
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Quantitative study of cardiac wall motion from cine-MRI using frequency-based optical flow methods
2010
The aim of this thesis is to study parietal desynchronisation of the left ventricle from conventional cine-MRI. The first part of our work consisted in the quantification of the left ventricle wall motion of the heart directly from conventional retrospective SSFP type cine-MRI sequences used in the study of cardiac function. The developed methods for measuring displacements within the images are frequency-based optical flow methods. These techniques seem to be particularly adapted to MRI specificities. We have demonstrated their robustness in the event of Rician noise and pixel intensity variations as a function of time. These variations are often associated with the through-plane motion of…
Visual scale factor for speed perception rendering in car driving simulation
2010
Speed perception is an important task that the driver must perform continuously to control his/her vehicle. It appears that many factors influence this perception: height of the point of view, field of view, realism of the environment, but also realism of audio and proprioceptive rendering. If some high-performance car driving simulators are able to render motion satisfactorily according to all these criteria, it is not always the case. As a result, speed perception is thus often under estimated, leading into producing higher speeds than in real conditions. Perceptual validity is then not good enough to study driver's behavior. To solve this problem, a technique has recently seen the light,…