Controlled Active Vision/Image
Processing with Applications to Medical Image Computing
Allen Tannenbaum, Comprehensive Cancer Center / ECE, UAB
Abstract:
In this talk, we will describe some theory and practice of
controlled active vision The applications range from visual tracking
(e.g., laser tracking in turbulence, flying in formation of
UAVs, etc.), nanoparticle flow control, and sedation control in the
intensive care unit. Our emphasis will be on the medical side,
especially image guided therapy and surgery. This includes projects
such as radiation planning in cancer therapy, traumatic brain
injury, and left atrial fibrillation. Accordingly, we will describe
several models of active contours for which both local (edge-based)
and global (statistics-based) information may be
included for various segmentation tasks. We will indicate how
statistical estimation and prediction ideas (e.g., particle
ltering) may be naturally combined with this methodology. A novel
model of directional active contour models based on the Finsler
metric will be considered that may be employed for white
matter brain tractography. Very importantly, we will describe some
ideas from feedback control that may be used to close the loop
around and robustify the typical open-loop segmentation algorithms
in computer vision. In addition to segmentation, the second key
component of many active vision
tasks is registration. The registration problem (especially in the
elastic case) is still one of the great challenges in vision and
medical image processing. Registration is the process of
establishing a common geometric reference frame between two or more
data sets obtained by possibly dierent imaging modalities. Reg-
istration has a substantial literature devoted to it, with numerous
approaches ranging from optical flow to computational fluid
dynamics. For this purpose, we propose using ideas from optimal mass
transport (Monge-Kantorovich). The optimal mass transport approach
has strong connections to optimal control, and can be the basis for
a geometric observer theory for tracking in which shape information
is explicitly taken into account. Finally, we will describe how mass
transport ideas may be utilized to generate hexahedral meshes with
applications to problems in biomechanics. The talk is designed to be
accessible to a general applied mathematical/engineering audience
with an interest in vision, control, and image processing. We will
demonstrate our techniques on a wide variety of data sets from
various medical imaging modalities.