[Insight-users] CannyEdgefilter

[Karthik Krishnan]

On Thu, Mar 12, 2009 at 4:35 PM, Wen Shi <wsa18 at sfu.ca> wrote:

> Hi Ghassan and guys,
>
> As we discussed before, for the cannyedgedetectionfilter, since it deals
> with noise by first convolve the image with a Guassian filter,
> I supposed that maybe the data from the output filter can be a good measure
> for the edges.
> But when I tried a brain image with the filter, I saw lots of noisy edges
> in the processed image.
> Even in the region in which the original image has nothing(no edge clues
> there) there, the processed image has a lot of short bright edges.


Try any of the following

- Increase the hysteresis / strength thresholds on the canny filter, so it
picks up the stronger edges.
- Increase the sigma being used by the canny filter, so it picks up the
edges at a larger scale.
- Smooth the images prior to canny, perhaps with anisotropic diffusion etc.

--
karthik
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