What was the nodata value in the original? On Fri, Oct 28, 2011 at 11:28 PM, Hermann Peifer <pei...@gmx.eu> wrote:
> On 27/10/2011 10:58, Chaitanya kumar CH wrote: > >> >> A vrt file can implement your requirements. It can create a 'lookup >> table' to translate your pixel values... >> > > Chaitanya, > > 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. > > 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) ? > > Thanks in advance, Hermann > > > > <VRTDataset rasterXSize="8786" rasterYSize="6443"> > ... > <VRTRasterBand dataType="Int32" band="1"> > <NoDataValue>0.**00000000000000E+00</**NoDataValue> > <ColorInterp>Gray</**ColorInterp> > <ComplexSource> > <SourceFilename relativeToVRT="1">ch00_form.**tif</SourceFilename> > <SourceBand>1</SourceBand> > <SourceProperties RasterXSize="8786" RasterYSize="6443" > DataType="Int32" BlockXSize="256" BlockYSize="256" /> > <SrcRect xOff="0" yOff="0" xSize="8786" ySize="6443" /> > <DstRect xOff="0" yOff="0" xSize="8786" ySize="6443" /> > <LUT>111:1,112:2,121:3,122:4,**123:5,124:6,131:7,132:8,...</**LUT> > </ComplexSource> > </VRTRasterBand> > </VRTDataset> > -- Best regards, Chaitanya kumar CH. +91-9494447584 17.2416N 80.1426E
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