[UMN_MAPSERVER-USERS] How to use Nasa Blue Marble raw images

[Paco Regodón]

Hello, i downloaded a 10GB raw image from Nasa Earth Observatory - Blue
Marble (http://earthobservatory.nasa.gov/Newsroom/BlueMarble/)

It is a world image at 500m/pixel resolution in raw rgb format,
86400x42600 pixels.

I want to use it with mapserver, and have created a gdal VRT file:

<VRTDataset rasterXSize="86400" rasterYSize="42600">
<SRS></SRS>
<GeoTransform></GeoTransform>
<VRTRasterBand dataType="Byte" band="1" subClass="VRTRawRasterBand">
<ColorInterp>Red</ColorInterp>
<SourceFilename
relativetoVRT="1">world.topo.bathy.200407.3x86400x43200.bin</SourceFilename>
<ImageOffset>0</ImageOffset>
<PixelOffset>3</PixelOffset>
<LineOffset>259200</LineOffset>
</VRTRasterBand>
<VRTRasterBand dataType="Byte" band="2" subClass="VRTRawRasterBand">
<ColorInterp>Green</ColorInterp>
<SourceFilename
relativetoVRT="1">world.topo.bathy.200407.3x86400x43200.bin</SourceFilename>
<ImageOffset>1</ImageOffset>
<PixelOffset>3</PixelOffset>
<LineOffset>259200</LineOffset>
</VRTRasterBand>
<VRTRasterBand dataType="Byte" band="3" subClass="VRTRawRasterBand">
<ColorInterp>Blue</ColorInterp>
<SourceFilename
relativetoVRT="1">world.topo.bathy.200407.3x86400x43200.bin</SourceFilename>
<ImageOffset>2</ImageOffset>
<PixelOffset>3</PixelOffset>
<LineOffset>259200</LineOffset>
</VRTRasterBand>
</VRTDataset>

I still need to georeference the image. How can i fill the SRS and
GeoTransform labels?

Also, is there some tool to convert this too big file into a tile of
smaller files?

thanks for your help,

Paco Regodón

[Frank Warmerdam]

Post by Paco Regodón
I still need to georeference the image. How can i fill the SRS and
GeoTransform labels?

<SRS>WGS84</SRS>
<GeoTransform>-180, 0.00416666666, 0, 90, 0, -0.00416666666</GeoTransform>

Post by Paco Regodón
Also, is there some tool to convert this too big file into a tile of
smaller files?

You could use multiple gdal_translate invocations to pull out
different subwindows using the -srcwin option. But it might
be better to translate it to one big file in an internally tiled
format, like Erdas Imagine format. You also might want
to build overviews for it.

I would add that the big blue marble image is well suited
to handling as a jpeg2000 or ecw file. I believe one or more
of the big blue marble images are available in ECW format
from http://www.geotorrents.org .

Best regards,
--
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I set the clouds in motion - turn up | Frank Warmerdam, ***@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | Geospatial Programmer for Rent