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Re: why is imagelines performance so bad?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg127514] Re: why is imagelines performance so bad?
  • From: Matthias Odisio <matthias at wolfram.com>
  • Date: Mon, 30 Jul 2012 22:16:17 -0400 (EDT)
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  • References: <20120728063939.E30F9684B@smc.vnet.net>

Larry,

On 7/28/12 1:39 , larry wrote:
> Why is ImageLines performance so bad when I have cleaned up an image to have thick checkerboard pattern but ImageLines produces a lot of extra lines. I don't see where it's getting it.
> Can we add images here?
> 

It would be nice to see the problematic image; perhaps with suitable
settings of the parameters and the method option the results could be
improved.

For example on this checkerboard the automatic settings work just fine:

img = ImageResize[
  Image[ArrayPad[IdentityMatrix[2], 3, "Reflected"], "Bit"], 256,
  Resampling -> "Nearest"]

e = EdgeDetect[img]

l = ImageLines[e];

Show[img, Graphics[{Blue, Thick, Line /@ l}]]


Matthias Odisio
Wolfram Research




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