Re: Image Analysis: identifying objects with Mathematica 7.0
- To: mathgroup at smc.vnet.net
- Subject: [mg98714] Re: Image Analysis: identifying objects with Mathematica 7.0
- From: dh <dh at metrohm.com>
- Date: Thu, 16 Apr 2009 04:20:09 -0400 (EDT)
- References: <grupo8$m7$1@smc.vnet.net>
Hi Gideon,
if I understand correctly, you want to find where a "subpicture" occurs
in a larger picture.
If you consider the picture as a numerrical array, then the correlation
is large at places ahere the subpicture appears.
Here is a simple example where we place a subpicture in the middle of a
larger array:
m1 = SparseArray[{{10, 10} -> 1, {10, 11} -> 1, {11, 10} ->
1, {11, 11} -> 1}, {20, 20}];
m2 = {{1, 1}, {1, 1}};
ListCorrelate[m2, m1] // MatrixForm
hope this helps, Daniel
GidiL wrote:
> Hi All!
>
> I would appreciate any input on the following problem:
>
> After scanning my samples with TEM, I get images (JPEG or TIFF) which
> contain many dimmers, e.g. gold nanoparticles connected via some
> other molecule.
> Approximately half of the popoulation is that of dimmers, while the
> other half contains trimmers, monomers, etc. I would like to run some
> statistics on the samples.
> I read Theodore Gray's post in the Wolfram Blog about the new
> capabilities of image processing in Mathematica 7.0.1 and I would like
> to ask if it is possible to do the following in Mathematica:
>
> Pick out a square that contains the dimmers, define that square as a
> new image, and then let Mathematica search for such an image within
> the original image.
>
> I know that Mathematica has a new function MorphologicalComponents
> that is apparently the key to getting this done, but I don't really
> understand how to use it. It is also supposed to return the
> coordinates of the located images, but I don't know how to extract
> this output from the function.
>
> Thanks,
>
> Gideon
>