Snakes: Active contour models

Abstract

A snake is an energy-minimizing spline guided by external constraint forces and influenced by image forces that pull it toward features such as lines and edges. Snakes are active contour models: they lock onto nearby edges, localizing them accurately. Scale-space continuation can be used to enlarge the capture region surrounding a feature. Snakes provide a unified account of a number of visual problems, including detection of edges, lines, and subjective contours; motion tracking; and stereo matching. We have used snakes successfully for interactive interpretation, in which user-imposed constraint forces guide the snake near features of interest.

Application of automatic statistical post-processing method for analysis of ultrasonic and digital dermatoscopy images

“…Edge detection technique is not effective when applying on skin images, because of the additional details, such as hair. Active contours [38] and snake’s method [39] are less attractive due to the complex shape of the melanoma suspicious lesions. Since thresholding does not present any of these disadvantages [40], it could be used in order to get the reliable results.…”

Fully automated segmentation and morphometrical analysis of muscle fiber images

“…The core algorithm for separating the muscle fibers from the connective tissue is based on active contour models as introduced by Kass et al (9). The method makes use of the level set technique known from Refs.…”

Smoothness-based forces for deformable models: a long-range force and a corner fitting force

“…A deformable model is a surface model with a generalized spline subject to internal and external constraints expressed by energies or forces [1,3]. Image segmentation is carried out by fitting the deformable model to image data under the influence of the model's internal and external constraints.…”

“…Deformable models, originally proposed by Terzopoulos et al [1,2] and Kass et al [3] in 1988, have been used widely in medical image segmentation. However, they manifest certain well known limitations that significantly restrict the scope of their applications.…”

“…Several long range forces have been introduced to overcome the limitation. The elastic spring force [3,[5][6][7][8] pulls model nodes towards object boundary (high gradient) voxels. Its strength depends on the distance from the model node to its corresponding boundary voxel, vanishing when that distance becomes zero.…”