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Hi,<br>
<br>
I put the following question on the GRASS user list. It isn't possible
with GRASS (or the programs mentioned by Glynn), but if someone on this
list can help me further, I would be very grateful. I have been
struggling for some time with this problem, and I'll have to process
lots of scanned old maps in the near future.<br>
<br>
Jan<br>
<br>
<br>
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style="font-family: -moz-fixed; font-size: 13px;" lang="x-western">
<pre wrap="">Jan Hartmann wrote:
</pre>
<blockquote type="cite" style="color: rgb(0, 0, 0);">
<pre wrap=""><span class="moz-txt-citetags">> </span>I am working with series of old topographical maps, ranging from 10 to
<span class="moz-txt-citetags">> </span>600 map sheets per map. Each sheet is discolored a bit from age. How can
<span class="moz-txt-citetags">> </span>I process a complete series in such a way that there are no differences
<span class="moz-txt-citetags">> </span>visible any more between map sheets? Preferably I would like to
<span class="moz-txt-citetags">> </span>downsample them to 8 bits color table, as the originals only have a
<span class="moz-txt-citetags">> </span>small set of colors. In other words: how do I calibrate set of maps to
<span class="moz-txt-citetags">> </span>the same optimal color table?
</pre>
</blockquote>
<pre wrap="">This is probably better done with general image-processing software,
e.g. pnmquant (from the Netpbm package) or "convert -colors ..." (from
ImageMagick).
<div class="moz-txt-sig">--
Glynn Clements <a class="moz-txt-link-rfc2396E"
href="mailto:glynn@gclements.plus.com"><glynn@gclements.plus.com></a>
</div></pre>
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