Non-maximum suppression in canny edge detection

1. What is non maximum suppression in canny edge detection?
2. What is non maximal separation in edge detection?
3. What kind of edges would the Canny edge detector generate without doing the non maximum suppression step?
4. What are the 3 basic objective of canny edge detection?

What is non maximum suppression in canny edge detection?

Non-maximum supression is often used along with edge detection algorithms. The image is scanned along the image gradient direction, and if pixels are not part of the local maxima they are set to zero. This has the effect of supressing all image information that is not part of local maxima.

What is non maximal separation in edge detection?

Non max suppression is a technique used mainly in object detection that aims at selecting the best bounding box out of a set of overlapping boxes. In the following image, the aim of non max suppression would be to remove the yellow, and blue boxes, so that we are left with only the green box.

What kind of edges would the Canny edge detector generate without doing the non maximum suppression step?

Step 4 - Non Maximum Suppression

The image magnitude produced results in thick edges. Ideally, the final image should have thin edges.

What are the 3 basic objective of canny edge detection?

Find the intensity gradients of the image. Apply non-maximum suppression to get rid of spurious response to edge detection. Apply double threshold to determine potential edges.