NGVF: An improved external force field for active contour model

2007 ◽  
Vol 28 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Ning Jifeng ◽  
Wu Chengke ◽  
Liu Shigang ◽  
Yang Shuqin
Keyword(s):  
Force Field ◽  
External Force ◽  
Active Contour ◽  
Active Contour Model ◽  
External Force Field ◽  
Contour Model

scholarly journals Improved Algorithm for Gradient Vector Flow Based Active Contour Model Using Global and Local Information

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jianhui Zhao ◽  
Bingyu Chen ◽  
Mingui Sun ◽  
Wenyan Jia ◽  
Zhiyong Yuan
Keyword(s):  
Force Field ◽  
External Force ◽  
Active Contour ◽  
Active Contours ◽  
Active Contour Model ◽  
Computational Cost ◽  
Local Information ◽  
Gradient Vector Flow ◽  
Gradient Vector ◽  
External Force Field

Active contour models are used to extract object boundary from digital image, but there is poor convergence for the targets with deep concavities. We proposed an improved approach based on existing gradient vector flow methods. Main contributions of this paper are a new algorithm to determine the false part of active contour with higher accuracy from the global force of gradient vector flow and a new algorithm to update the external force field together with the local information of magnetostatic force. Our method has a semidynamic external force field, which is adjusted only when the false active contour exists. Thus, active contours have more chances to approximate the complex boundary, while the computational cost is limited effectively. The new algorithm is tested on irregular shapes and then on real images such as MRI and ultrasound medical data. Experimental results illustrate the efficiency of our method, and the computational complexity is also analyzed.

EFFICIENT CONTOUR DETECTION BASED ON IMPROVED SNAKE MODEL

2004 ◽  
Vol 18 (02) ◽  
pp. 197-209 ◽  
Author(s):  
FRANK Y. SHIH ◽  
KAI ZHANG
Keyword(s):  
Force Field ◽  
Active Contour ◽  
Active Contour Model ◽  
Contour Detection ◽  
Initial Contour ◽  
Object Boundary ◽  
Edge Preserving ◽  
Snake Model ◽  
External Force Field ◽  
Gravitation Force

Active contour model, also called snake, adapts to edges in an image. A snake is defined as an energy minimizing spline – the snake's energy depends on its shape and location within the image. Problems associated with initialization and poor convergence to boundary concavities, however, have limited its utility. In this paper, we present a new external force field, named gravitation force field, for the snake model. We associate this force field with edge preserving smoothing to drive the snake for solving the problems. Our gravitation force field uses gradient values as particles to construct force field in the whole image. This force field will attract the active contour toward the edge boundary. The locations of the initial contour are very flexible, such that they can be very far away from the objects and can be inside, outside, or the mixture. The improved snake can converge toward the object boundary in a fast pace.

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