Thanks I have tried it ,and I found each transfered vector map is not compatible with the real color position of the image......<br><br><div class="gmail_quote">2009/6/18 Moritz Lennert <span dir="ltr"><<a href="mailto:mlennert@club.worldonline.be">mlennert@club.worldonline.be</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="im">On 18/06/09 14:59, maven apache wrote:<br>
><br>
><br>
> 2009/6/18 Moritz Lennert <<a href="mailto:mlennert@club.worldonline.be">mlennert@club.worldonline.be</a><br>
</div>> <mailto:<a href="mailto:mlennert@club.worldonline.be">mlennert@club.worldonline.be</a>>><br>
<div><div></div><div class="h5">><br>
> On 18/06/09 14:31, maven apache wrote:<br>
> > Also I found that I can see only five color from the tiff<br>
> > swi.tiff, and yesterday I get five category with the same<br>
> > steps(import and composite then calculate ), they are<br>
> > "0<br>
> > 9321 26425 31744 32736 ";, but today it change to six!!<br>
> ><br>
> > Maybe I remembered it wrongly. (*^__^*)<br>
> ><br>
> ><br>
> > And acturlly I want to extract each color and export them<br>
> to a<br>
> > vector map, I am looking the proper commond.<br>
> ><br>
> > It seems that there is no corresponding command to achieve this<br>
> goal£¿<br>
><br>
><br>
> Please start by reading:<br>
><br>
> <a href="http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html" target="_blank">http://grass.osgeo.org/grass64/manuals/html64_user/rasterintro.html</a><br>
> <a href="http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html" target="_blank">http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html</a><br>
><br>
> The command you are looking for is r.to.vect (I see it is not mentioned<br>
> in the rasterintro. Should be...).<br>
><br>
> It seems that the r.to.vect is to transfer the hole raster map to a<br>
> vector,but I want to transfer each category to a vector....<br>
<br>
</div></div>The easiest solution is probably a combination of r.to.vect + v.extract.<br>
<font color="#888888"><br>
Moritz<br>
</font></blockquote></div><br>