TY - CONF
T1 - Bilateral symmetry of object silhouettes under perspective projection
T2 - 19th International Conference on Pattern Recognition, 2008. ICPR 2008
Y1 - 2008
A1 - Bitsakos,K.
A1 - Yi,H.
A1 - Yi,L.
A1 - FermÃ¼ller, Cornelia
KW - Automation
KW - bilateral symmetry
KW - Computer vision
KW - Frequency
KW - Image analysis
KW - Image coding
KW - Image reconstruction
KW - Internet
KW - Internet images
KW - Object detection
KW - object silhouettes
KW - perspective distortion
KW - perspective projection
KW - SHAPE
KW - symmetric objects
AB - Symmetry is an important property of objects and is exhibited in different forms e.g., bilateral, rotational, etc. This paper presents an algorithm for computing the bilateral symmetry of silhouettes of shallow objects under perspective distortion, exploiting the invariance of the cross ratio to projective transformations. The basic idea is to use the cross ratio to compute a number of midpoints of cross sections and then fit a straight line through them. The goodness-of-fit determines the likelihood of the line to be the axis of symmetry. We analytically estimate the midpointpsilas location as a function of the vanishing point for a given object silhouette. Hence finding the symmetry axis amounts to a 2D search in the space of vanishing points. We present experiments on two datasets as well as Internet images of symmetric objects that validate our approach.
JA - 19th International Conference on Pattern Recognition, 2008. ICPR 2008
PB - IEEE
SN - 978-1-4244-2174-9
M3 - 10.1109/ICPR.2008.4761501
ER -