In audio visual speech recognition and lipreading, the widely used ASM (Active Shape Model) for lip contour extraction suffers from the lack of robustness and cannot extract the exact lip contours due to the various mouth shape changes when uttering.

A novel scheme for the contour detection is proposed based on gradient vector flow (GVF) snakes and multiscale analysis.

The contour extraction and condensation of RP based CT image;

Geometric active contour method based on support value transform for contour extraction;

Face contour extraction using level sets;

This paper introduces usual method for keeping curves in computer and usual method of outline extraction in image recognition.

The key of the Light-sectioning Method is the outline extraction.