This method detects dark lines (gray value valleys) on a bright background and contours between bright regions.

Parameter

Description

Sigma

Degree of smoothing of input image before detection of valleys. The smoothing factor can be used to influence the sensitivity of recognition. If a low value is set, lots of valleys are detected. Fewer valleys are detected with a high value.

Threshold

Curvature at the valley bottom high/low. Depending on the setting made, weakly pronounced valleys are also detected, or only ones that are strongly pronounced.