[Gdal-dev] IKONOS

[Frank Warmerdam]

On 6/22/05, Bjoern Ruff <br at forstware.de> wrote:
> Hello,
> 
> since I have not yet worked with gdal,
> may be someone can tell me if I can do the following using gdal
> before I start trying:
> 
>         I get a Ikonos Multispectral image (4 bands in 4 separate files) as
> GEOTIFF 11 Bits per pixel
>         (1 m resolution, 50 km2 szene)

Bjoern, 

You can use the gdal_merge.py script distributed with GDAL
to "stack" individual files into a multispectral image.  

eg. 

gdal_merge.py -seperate -o stack.tif band1.tif band2.tif band3.tif band4.tif

Then use gdal_translate to extract subwindows:

gdal_translate -subwin 0 0 512 512 stack.tif  subwindow.tif

This assumes you want to select your window in terms of pixel
coordinates (or projected coordinates with -projwin).  But if you
want to extract the rectangle graphically you will need a GUI app.
This can be accomplished with OpenEV for instance.  In fact, I think
OpenEV includes a "stacking" mechanism.

>         Merge the 4 bands to get a color image,
>         select rectangles in the merged picture and store them as GeoTiff or
> some other georeferenced format.

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