Edge Detection and Manual Thresholds
Fri, 05/31/2013 - 02:07 pm
I am trying to understand the edge detection algorithm and specifically the use of the /S and /T flags.
My Problem: I have height data over an array and it is easily thought of as an image where height is now the Z value. What I am trying to detect are areas of sudden height variation and using the image processing tools and the edge detection seems an appropriate route.
The data I have is in microns and is floating point and I convert that to an unsigned byte since the functions require an imagematrix as an input. All is well and good and I can create an new image and test various combinations of the builtin methods. Thus far the Canny seems to be working out the best.
What I would like to do is be more precise in the threshold for the detection and the sensitivity. It appears that the /S and /T are my tools and I would like to better understand how they play.
For /T I have been testing values in the 1-10 range How does this relate to the base imagematrix which is 0-255 in value? Is it looking for change in value >=T and if so over what length scale?
/S how should I think about this factor relative to my imagematrix? How is the smoothing done? Does it impact the length scale over which a change in value is measured against?
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