Описание тега canny-operator
The Canny edge detector is an edge detection operator that uses a multi-stage algorithm to detect a wide range of edges in images. It was developed by John F. Canny in 1986. Canny also produced a computational theory of edge detection explaining why the technique works.
Canny's aim was to discover the optimal edge detection algorithm. In this situation, an "optimal" edge detector means:
good detection – the algorithm should mark as many real edges in the image as possible.
good localization – edges marked should be as close as possible to the edge in the real image.
- minimal response – a given edge in the image should only be marked once, and where possible, image noise should not create false edges.
To satisfy these requirements Canny used the calculus of variations – a technique which finds the function which optimizes a given functional. The optimal function in Canny's detector is described by the sum of four exponential terms, but it can be approximated by the first derivative of a Gaussian.