[gdal-dev] Proposal: gdal_muladd.py

[Antonio Valentino]

Hi Matt,

Il giorno Mon, 25 Jan 2010 20:57:58 -0600
Matt Klaric <matt at klaric.com> ha scritto:

> On Mon, Jan 25, 2010 at 8:38 PM, Frank Warmerdam
> <warmerdam at pobox.com>wrote:
> 
> > I don't think the VRT approach supports actually adding
> > different images together, only overlaying and rescaling.
> >
> >
> However, pixel functions could be used in a VRT file to accomplish the
> desired outcome.
> 
> --matt

Indeed, it would require a pixel function for sum and the ScaleRatio
property of ComplexSource.

I have just submitted a patch 

http://trac.osgeo.org/gdal/ticket/3367

that provides a set of standard pixel functions, including sum (of 2
or more raster bands).

Using this set of functions it should be quite easy to write a python
program that performs generic bands arithmetic.

Best regards.

-- 
Antonio Valentino