Advisory Committee Chair
Arie Nakhmani
Advisory Committee Members
Allan Dobbins
Ho-Wook Jun
Document Type
Thesis
Date of Award
2016
Degree Name by School
Master of Biomedical Engineering (MBE) School of Engineering
Abstract
The active contour model has good performance in boundary extraction for medical images; particularly, Gradient Vector Flow (GVF) active contour model shows good performance at concavity convergence and insensitivity to initialization, yet it is susceptible to edge leaking, deep and narrow concavities, and has some issues handling noisy images. This paper proposes a novel external force, called Iterative Weighted Average Diffusion (IWAD), which used in tandem with parametric active contours, provides superior performance in images with high values of concavity. The image gradient is first turned into an edge image, smoothed, and modified with enhanced corner detection, then the IWAD algorithm diffuses the force at a given pixel based on its 3x3 pixel neighborhood. A forgetting factor, φ, is employed to ensure that forces being spread away from the boundary of the image will attenuate. The experimental results show better behavior in high curvature regions, faster convergence, and less edge leaking than GVF when both are compared to expert manual segmentation of the images.
Recommended Citation
Mirov, Ilya Sergeyevich, "Iterative Weighted Average Diffusion as a Novel External Force in the Active Contour Model" (2016). All ETDs from UAB. 2477.
https://digitalcommons.library.uab.edu/etd-collection/2477