[SciPy-User] Edge Detection

Zachary Pincus zachary.pincus@yale....
Tue Nov 10 10:48:51 CST 2009

References: Start around just looking at the top google hits for  
"image processing edge detection" -- that should be a pretty good  
start. Also, google any unfamiliar terms below... I really find that  
there's a ton of good basic image-processing information available  

Code: Look at what's available in scipy.ndimage. There are functions  
for getting gradient magnitudes, as well as standard filters like  
Sobel etc. (which you'll learn about from the above), plus  
morphological operators for modifying binarized image regions (e.g.  
like erosion etc.; useful for getting rid of stray noise-induced  
edges), plus some basic functions for image smoothing like median  
filters, etc.

For exploratory analysis, you might want some ability to interactively  
visualize images; you could use matplotlib or the imaging scikit,  
which is still pre-release but making fast progress: http://github.com/stefanv/scikits.image

I've attached basic code for Canny edge detection, which should  
demonstrate a bit about how ndimage works, plus it's useful in its own  
right. There is also some code floating around for anisotropic  
diffusion and bilateral filtering, which are two noise-reduction  
methods that can be better than simple median filtering.


On Nov 10, 2009, at 11:37 AM, Dan Yamins wrote:

> Hi,
> I'm looking into using SciPy for a couple of edge-detection  
> problems, involving detection of edges in images of text (in simple,  
> clean fonts).   If someone on this list could point me to a relevant  
> resource / function, that would be excellent.   (I have essentially  
> no background in image processing, but am reasonably comfortable  
> mathematically, and I would be happy to dive into something fairly  
> technical.)
> thanks,
> Dan
> _______________________________________________
> SciPy-User mailing list
> SciPy-User@scipy.org
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