In the online demo, the default val

In the online demo, the default value for the standard deviation σ h is 0.35, which reasonably models the blurriness of typical images.
The first two examples demonstrate the contour estimation. At every pixel in the image, the best-fitting stencil is determined, and a small line is drawn to indicate the estimated contour C S ? (k)
modeled by the stencil. The stencil set includes lines, parabolas, corners, and the circle, so the method is able to distinguish these different geometric features. The lines are colored according to the type of feature.
In the first image, straight lines are selected as the contour model for most of the image and parabolas and some corners are used along the curving edge of the star.