Re: importing image and getting numbers from the gray intensity
- To: mathgroup at smc.vnet.net
- Subject: [mg49427] Re: importing image and getting numbers from the gray intensity
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Mon, 19 Jul 2004 07:46:19 -0400 (EDT)
- Organization: The University of Western Australia
- References: <cd5okp$b2c$1@smc.vnet.net> <cd8b5g$olp$1@smc.vnet.net> <cdb1pf$aka$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <cdb1pf$aka$1 at smc.vnet.net>,
sean_incali at yahoo.com (sean kim) wrote:
> I can't seem to get this to work.
>
> I copied, pasted, converted and renamed it to pixel.
pixel or pixels?
Did the renamed cell, look like
pixels = Show[Graphics[
{AbsoluteThickness[1],GrayLevel[1],
Polygon[{{4, 4},{148, 4},{148, 307},{4, 307},{4, 4}}],
RasterArray[{{
RGBColor[0.980392, 0.968627, 1],
...
}},
{{4, 4}, {148, 307}}]}],
AspectRatio->2.10417,
PlotRange->{{4, 148}, {4, 307}},
ImageSize->{144, 303}]
or did it have Raster instead (this may be version dependent)?
> but when i go...
>
> In[74]:=
> pixels=First[
> Cases[pixels,RasterArray[x__]:>x,Infinity]]/.RGBColor[r_,g_,
> b_]:>(r+g+b)/3
>
> From In[74]:=
> First::first: {} has a length of zero and no first element.
This would happen if you named it pixel instead of pixels, or if you get
a Raster object instead of a RasterArray.
Cheers,
Paul
--
Paul Abbott Phone: +61 8 9380 2734
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