Motivated by the snake approach of Terzopoulos and others,
we seek to study a new class of forces that we call
profile forces
for detecting edges
in images. Basically, an edge is regarded as
a curve segment C in the image plane. At each point P on
the curve segment, we take a finite cross section of the image
in the transverse direction. This is the profile
of the curve C at P.
In the ideal case, these profiles have a ramp
or ridge shape. The profile is regarded as
a 1-dimensional signal F with a nominal center (or origin)
denoted O. One idea is to match F to some closest
ideal profile F* with center O*.
This distance between O and O* constitute
the profile force
that tends to push O towards O*.
We also investigate the idea of relative differences
of profiles as another source of force.
We apply these forces to snake-like objects
which automatically seek edges. An important aspect of
the theory of edges is their classification.
The simplest kinds of edges has a consistent profile
throughout the extent of the curve. More complicated edges may have
systematic variations along the curve, for instance, dotted lines.
We develop such snake-like that are specialized to seek out certain classes
of edges. Another aspect of our research is to develop
a qualitative theory of confirmation, where we propose to be able to
confirm or deny the presence of edges. It is qualitative
in the sense that we try to avoid arbitrary threshholding.
For further information, please contact one of us: Chee Yap and Ting-Jen Yen.