[gdal-dev] Re: Proposal: gdal_muladd.py

[Frank Warmerdam]

Antonio Valentino wrote:
> Anyway, IMHO the point here is not to decide if we have to
> *modify* the diff function so that it returns abs(b1-b2).
> Greg asked to add a new one ( abs(b1-b2) ) to the *base set* of pixel
> functions.
> Stated that there is no technical difficulty to do this I'm wondering
> what is the Frank's mind about the question.

Antonio,

I think including abs(b1-b2) just demonstrates that we haven't come
up with a convenient way of stacking more basic operations (difference
and abs).

Honestly, I'm a bit ambivalent about fleshing out the use of
pixel operations in VRT files and I've never used them myself.
I think I would prefer to wait for a more generalized expression
evaluation mechanism for VRT or possibly as a distinct driver.

However, if there are other GDAL developers keen on this functionality,
and willing to take responsibility for integration, documentation and
support then I'm willing to let them proceed.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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