Why MORPH_ELLIPSE kernel is slower than MORPH_RECT and others?

asked 2016-12-29 11:33:12 -0600

stalin
1 ●1

updated 2016-12-29 11:34:09 -0600

I was doing some dilation and erosion operations and noticed that MORPH_ELLIPSE kernel takes much more time than MORPH_RECT and MORPH_CROSS kernel. A similar question and finding is also posted in StackOverflow here.

Can somebody tell why this is so?

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answered 2016-12-29 12:14:31 -0600

LBerger
9317 ●2 ●20 ●88 http://www.traimaocv.fr

updated 2016-12-29 13:55:57 -0600

Try to write algorithm. For a rect I look for extremun in rectangle (or line for cross). I can use previous result for a pixel to calculate new pixel. Rect and cross are separable filter

Now I cannot do like this for MORPH_ELLIPS I have to scan two arrays. I cannot use previous results For each pixel I need to scan all neighbouhood It is not a separable filter