[Gdal-dev] How to flat multiple bands image into single band image?

[Frank Warmerdam]

Huajun Zhang wrote:
> 
> Hi folks,
> 
> I want to flat a multiple band image with geotiff format into a single 
> band image, do you have any idea how to do it with GDAL or other FWTools?

Huajun,

What sort of merging do you want to do?  Do you want to average all the bands?
Or perhaps you just want to extract a single band?  You can extract single
bands with something like:

  gdal_translate -b 1 in.tif out.tif

But there is no ready mechanism to average bands into one result band.  The
easiest way to do this would be to write a python script using numeric to
do the averaging.

Best regards,
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