What was the nodata value in the original?<br><br><div class="gmail_quote">On Fri, Oct 28, 2011 at 11:28 PM, Hermann Peifer <span dir="ltr"><<a href="mailto:peifer@gmx.eu">peifer@gmx.eu</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;">
On 27/10/2011 10:58, Chaitanya kumar CH wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<br>
A vrt file can implement your requirements. It can create a 'lookup<br>
table' to translate your pixel values...<br>
</blockquote>
<br>
Chaitanya,<br>
<br>
I just tried to translate an Int32 GeoTIFF with pixel values 111..523 into a byte-type GeoTIFF with values 1..44, using the LUT as indicated below.<br>
<br>
I noted that in the resulting GeoTIFF, the previous NODATA areas have now a pixel value of 1. Is this expected behaviour or rather some sort of "over-extrapolation" of my lookup table (as I would assume) ?<br>
<br>
Thanks in advance, Hermann<br>
<br>
<br>
<br>
<VRTDataset rasterXSize="8786" rasterYSize="6443"><br>
...<br>
<VRTRasterBand dataType="Int32" band="1"><br>
<NoDataValue>0.<u></u>00000000000000E+00</<u></u>NoDataValue><br>
<ColorInterp>Gray</<u></u>ColorInterp><br>
<ComplexSource><br>
<SourceFilename relativeToVRT="1">ch00_form.<u></u>tif</SourceFilename><br>
<SourceBand>1</SourceBand><br>
<SourceProperties RasterXSize="8786" RasterYSize="6443" DataType="Int32" BlockXSize="256" BlockYSize="256" /><br>
<SrcRect xOff="0" yOff="0" xSize="8786" ySize="6443" /><br>
<DstRect xOff="0" yOff="0" xSize="8786" ySize="6443" /><br>
<LUT>111:1,112:2,121:3,122:4,<u></u>123:5,124:6,131:7,132:8,...</<u></u>LUT><br>
</ComplexSource><br>
</VRTRasterBand><br>
</VRTDataset><br>
</blockquote></div><br><br clear="all"><br>-- <br>Best regards,<br>Chaitanya kumar CH.<br><br>+91-9494447584<br>17.2416N 80.1426E<br>