Jan,<br><br>If you are just going to shift the image, just the GeoTransform element should be enough. You don't need the GCPs.<br><br><div class="gmail_quote">On Thu, Jul 7, 2011 at 3:04 PM, Jan Hartmann <span dir="ltr"><<a href="mailto:j.l.h.hartmann@uva.nl">j.l.h.hartmann@uva.nl</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><u></u>
<div text="#000000" bgcolor="#ffffff">
<font face="Times New Roman, Times, serif">Hi all,<br>
<br>
This has come up before, but I'm still struggling for an answer. I
want to rubbersheet an already projected image with control
points, so as to remove small errors.On a suggestion by Frank
(<a href="http://lists.osgeo.org/pipermail/gdal-dev/2009-February/019775.html" target="_blank">http://lists.osgeo.org/pipermail/gdal-dev/2009-February/019775.html</a>)
I produced a VRT file of the georeferenced image and added control
points to shift the image 1000m to the right. (see below).
However, GDALWARP ignores the control points and returns the
original georeferenced image. When I remove the georeferencing
information, it does use the control points, but returns a raw
image shifted to the right.<br>
<br>
Is it possible to rubbersheet a georeferenced image with control
points, or am I chasing a red herring?<br>
<br>
Thanks,<br>
<br>
Jan<br>
<br>
<VRTDataset rasterXSize="310" rasterYSize="343"><br>
<SRS>PROJCS[&quot;Amersfoort / RD
New&quot;,GEOGCS[&quot;Amersfoort&quot;,DATUM[&quot;Amersfoort&quot;,SPHEROID[&quot;Bessel
1841&quot;,6377397.155,299.1528128000008,AUTHORITY[&quot;EPSG&quot;,&quot;7004&quot;]],AUTHORITY[&quot;EPSG&quot;,&quot;6289&quot;]],PRIMEM[&quot;Greenwich&quot;,0],UNIT[&quot;degree&quot;,0.0174532925199433],AUTHORITY[&quot;EPSG&quot;,&quot;4289&quot;]],PROJECTION[&quot;Oblique_Stereographic&quot;],PARAMETER[&quot;latitude_of_origin&quot;,52.15616055555555],PARAMETER[&quot;central_meridian&quot;,5.38763888888889],PARAMETER[&quot;scale_factor&quot;,0.9999079],PARAMETER[&quot;false_easting&quot;,155000],PARAMETER[&quot;false_northing&quot;,463000],UNIT[&quot;metre&quot;,1,AUTHORITY[&quot;EPSG&quot;,&quot;9001&quot;]],AUTHORITY[&quot;EPSG&quot;,&quot;28992&quot;]]</SRS><br>
<GeoTransform> -8.5000000000000000e+03,
1.0000000000000000e+03, 0.0000000000000000e+00,
2.8750000000000000e+05, 0.0000000000000000e+00,
1.0000000000000000e+03</GeoTransform><br>
<Metadata /><br>
<Metadata domain="IMAGE_STRUCTURE"><br>
<MDI key="INTERLEAVE">BAND</MDI><br>
</Metadata><br>
<GCPList><br>
<GCP Id="" Pixel="0.0000" Line="0.0000"
X="1.000000000000E+03" Y="0.000000000000E+00" /><br>
<GCP Id="" Pixel="1000.0000" Line="0.0000"
X="2.000000000000E+03" Y="0.000000000000E+00" /><br>
<GCP Id="" Pixel="1000.0000" Line="1000.0000"
X="2.000000000000E+03" Y="2.000000000000E+03" /><br>
<GCP Id="" Pixel="0.0000" Line="1000.0000"
X="1.000000000000E+03" Y="1.000000000000E+03" /><br>
</GCPList><br>
<VRTRasterBand dataType="Float64" band="1"><br>
<Metadata /><br>
<ColorInterp>Gray</ColorInterp><br>
<SimpleSource><br>
<SourceFilename
relativeToVRT="1">test.tif</SourceFilename><br>
<SourceBand>1</SourceBand><br>
<SourceProperties RasterXSize="310" RasterYSize="343"
DataType="Float64" BlockXSize="310" BlockYSize="3" /><br>
<SrcRect xOff="0" yOff="0" xSize="310" ySize="343" /><br>
<DstRect xOff="0" yOff="0" xSize="310" ySize="343" /><br>
</SimpleSource><br>
</VRTRasterBand><br>
</VRTDataset><br>
</font>
</div>
<br>_______________________________________________<br>
gdal-dev mailing list<br>
<a href="mailto:gdal-dev@lists.osgeo.org">gdal-dev@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/gdal-dev" target="_blank">http://lists.osgeo.org/mailman/listinfo/gdal-dev</a><br></blockquote></div><br><br clear="all"><br>-- <br>Best regards,<br>Chaitanya kumar CH.<br>
/tʃaɪθənjə/ /kʊmɑr/ <br>+91-9494447584<br>17.2416N 80.1426E<br>