Template-Based Active Contours

by   Jayanth Krishna Mogali, et al.

We develop a generalized active contour formalism for image segmentation based on shape templates. The shape template is subjected to a restricted affine transformation (RAT) in order to segment the object of interest. RAT allows for translation, rotation, and scaling, which give a total of five degrees of freedom. The proposed active contour comprises an inner and outer contour pair, which are closed and concentric. The active contour energy is a contrast function defined based on the intensities of pixels that lie inside the inner contour and those that lie in the annulus between the inner and outer contours. We show that the contrast energy functional is optimal under certain conditions. The optimal RAT parameters are computed by maximizing the contrast function using a gradient descent optimizer. We show that the calculations are made efficient through use of Green's theorem. The proposed formalism is capable of handling a variety of shapes because for a chosen template, optimization is carried with respect to the RAT parameters only. The proposed formalism is validated on multiple images to show robustness to Gaussian and Poisson noise, to initialization, and to partial loss of structure in the object to be segmented.


page 6

page 9

page 10

page 11

page 12

page 13


A Simple Method to improve Initialization Robustness for Active Contours driven by Local Region Fitting Energy

Active contour models based on local region fitting energy can segment i...

Detection and Visualization of Endoleaks in CT Data for Monitoring of Thoracic and Abdominal Aortic Aneurysm Stents

In this paper we present an efficient algorithm for the segmentation of ...

Globally Optimal Joint Image Segmentation and Shape Matching Based on Wasserstein Modes

A functional for joint variational object segmentation and shape matchin...

State-of-The-Art Fuzzy Active Contour Models for Image Segmentation

Image segmentation is the initial step for every image analysis task. A ...

An Efficiently Coupled Shape and Appearance Prior for Active Contour Segmentation

This paper proposes a novel training model based on shape and appearance...

Active Contour with A Tangential Component

Conventional edge-based active contours often require the normal compone...

A Mutual Reference Shape for Segmentation Fusion and Evaluation

This paper proposes the estimation of a mutual shape from a set of diffe...

Please sign up or login with your details

Forgot password? Click here to reset