Abstract (EN):
The main goals of the present work are to automatically extract the contour of an
object and to simulate its deformation using a physical approach. In this work, to segment an
object represented in an image, an initial contour is manually defined for it that will then
automatically evolve until it reaches the border of the desired object. In this approach, the
contour is modelled by a physical formulation using the finite element method, and its
temporal evolution to the desired final contour is driven by internal and external forces. The
internal forces are defined by the intrinsic characteristics of the material adopted for the
physical model and the interrelation between its nodes. The external forces are determined in
function of the image features most suitable for the object to be segmented. To build the
physical model of the contour used in the segmentation process, the isoparametric finite
element proposed by Sclaroff is adopted, and to obtain its evolution towards the object border
the methodology presented by Nastar is used, that consists in solving the dynamic equilibrium
equation between two consecutive instants.
To simulate the deformation between two different instances of an object, after they each have
their contours properly modelled, modal analysis, complemented with global optimization
techniques, is employed to establish the correspondence between their nodes (data points).
After this matching phase, the displacements field between the two contours is simulated
using the dynamic equilibrium equation that balances the internal forces defined by the
physical model, and the external forces determined by the distance between the two contours.
Language:
English
Type (Professor's evaluation):
Scientific
Contact:
www.fe.up.pt/~tavares
Notes:
O texto encontrado tem mais páginas do que o que está inserido nesta publicação.
No. of pages:
9
License type: