[GRASS-user] can the grass calculate the area of different color for a image(tiff or other?)

[maven apache]

2009/6/18 Moritz Lennert <mlennert at club.worldonline.be>

> On 18/06/09 15:26, maven apache wrote:
> > Thanks I have tried it ,and I found each transfered vector map is
> > not compatible with the real color position of the image......
>
>
> You will have to give us more info than that if you want any help. What
> do you mean by "not compatible" ?

I imported the swi.tiff to grass,got four raster ,r g b and other ,then I
composite them ,
The composited raster have five category:
0
9321
26425
31744
32736
And I use the r.to.vect commond to change it to to a vecor layer.
then extract:
v.extract input=swivec at PERMANENT output=swi_32736 type=point,area layer=1
new=-1 list=32736 --overwrite
then I display the  swi_32736 ,its shape is not close to which in the tiff.

>
> Have you set your working region correctly ? Try g.region
> rast=YourRasterMap before r.to.vect (or maybe with res= to set to a
> finer resolution).

I create new location for the tiff,so I think the region is not a problem

>
>
> Moritz
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/grass-user/attachments/20090618/457f0ec1/attachment.html