Abstract (EN):
Human motion analysis in images is thoroughly related with the development
of computational techniques capable of automatically identify, track and
analyze relevant structures of the body. In fact, in any system designed for human
motion analysis from image sequences, the first processing step concerns the identification
of the structures to be analyzed in each of the sequence images, being
this step commonly referred as image segmentation. Here, a widely used database,
the CASIA Gait Database, is used to build Point Distribution Models (PDMs) of
the human silhouette, including specific joints. The training image dataset used includes
14 subjects walking in four different directions, and each shape of the training
set was represented by a set of labeled landmark points. The contours of the
silhouettes were obtained with the purpose of automatically extract 100 silhouette
points together with additional 13 anatomic joint points, such as elbows, knees and
feet, to be used as landmarks. In order to obtain the mean shape of the silhouette
as well as its admissible shape variations PDMs for each direction were built. The
PDMs built were finally used in the construction of Active Shape Models (ASMs),
which combine the shape model with grey level profiles, with the purpose of further
segment the modeled silhouettes in new images. The referred technique is an
iterative optimization scheme for PDMs allowing initial estimates of pose, scale
and shape of an object to be refined in a new image. The experiments conducted
using this segmentation technique has revealed very encouraging results.
Language:
English
Type (Professor's evaluation):
Scientific
Contact:
www.fe.up.pt/~tavares
No. of pages:
1
License type: