Re: [gdal-dev] gdalwarp's default nodata value

Joaquim, On Wed, May 12, 2010 at 5:07 AM, Joaquim Luis wrote: > Hi, > > Before filling a ticket I would like to ask here if this gdalwarp behavior > is the intended one. > When I convert a grid from geogs to UTM the nodatavalues are filled with > zeros. > I get the expected behaviour if I use th

Re: [gdal-dev] gdalwarp's default nodata value

On 12-05-2010 05:55, Chaitanya kumar CH wrote: Joaquim, On Wed, May 12, 2010 at 5:07 AM, Joaquim Luis > wrote: Hi, Before filling a ticket I would like to ask here if this gdalwarp behavior is the intended one. When I convert a grid from geogs to UTM the

Re: [gdal-dev] gdalwarp's default nodata value

Joaquim, GDALSetRasterNoDataValue() sets only the metadata. It doesn't actually change the nodata pixels. We need to process each pixel to do this. Or you could just create a VRT mentioning the source and vrt nodata values. http://www.gdal.org/gdal_vrttut.html http://www.gdal.org/gdalbuildvrt.htm

Re: [gdal-dev] gdalwarp's default nodata value

On 12-05-2010 15:58, Chaitanya kumar CH wrote: Joaquim, GDALSetRasterNoDataValue() sets only the metadata. It doesn't actually change the nodata pixels. We need to process each pixel to do this. Or you could just create a VRT mentioning the source and vrt nodata values. Chaitanya, Thanks,

Re: [gdal-dev] gdalwarp's default nodata value

Joaquim, I believe what you see is the expected behaviour. You must keep in mind that there are 2 notions : 1) nodata value --> setting it is no more than just setting a "tag" on the raster band. It doesn't change the pixel values by itself as Chaintanya explained 2) initialization of the pixel

Re: [gdal-dev] gdalwarp's default nodata value

Even, Thanks, I understand it better now and made some advances but I'm still facing some troubles. For example, if I do this papszWarpOptions = CSLSetNameValue(papszWarpOptions, "INIT_DEST", "300" ); psWO->papszWarpOptions = CSLDuplicate(papszWarpOptions); than it works fine. However, if I

Re: [gdal-dev] gdalwarp's default nodata value

Le Wednesday 12 May 2010 23:15:08 Joaquim Luis, vous avez écrit : > Even, > > Thanks, I understand it better now and made some advances but I'm still > facing some troubles. > > For example, if I do this > > papszWarpOptions = CSLSetNameValue(papszWarpOptions, "INIT_DEST", "300" ); > psWO->papszWar

Re: [gdal-dev] gdalwarp's default nodata value

papszWarpOptions = CSLSetNameValue(papszWarpOptions, "INIT_DEST", "nan" ); than I get zeros again in place of the nodata. Works for me. You'll have to use your debugger I'm afraid For the rec, VS2010 and a quite recent trunk version. papszWarpOptions = CSLSetNameValue(papszWarpOp

Re: [gdal-dev] gdalwarp's default nodata value

Joaquim, > > For the rec, VS2010 and a quite recent trunk version. Ah, this is the reason for the different results we got. On Windows, atof("nan") returns 0... but on Linux it returns a nan number. I've pushed quite a few changes to trunk to improve the situation on Windows and other changes

Re: [gdal-dev] gdalwarp's default nodata value

On 13-05-2010 18:38, Even Rouault wrote: Joaquim, For the rec, VS2010 and a quite recent trunk version. Ah, this is the reason for the different results we got. On Windows, atof("nan") returns 0... but on Linux it returns a nan number. I've pushed quite a few changes to trunk to imp