[Mapserver-users] proccessing 4-Band Tiif

[Aaron D. Hunt]

Thank you for you info, I do not know much about python, but I may give 
grass a try.

Aaron

Frank Warmerdam wrote:

> Aaron D. Hunt wrote:
>
>> Can I use mapserver to make a NDVI map from a four band tiff.
>> ie.
>> NDVI = (Band 4 - Band 3)/(Band 3 + Band 4)
>>
>> Or does anybody know of a program that can.
>
>
> Aaron,
>
> There is no way to do this kind of calculation directly in MapServer.
> There are lots of programs that can do it externally such as GRASS or
> various commercial offerings.  You could also write a Python script that
> uses GDAL to read and write the results and "Numeric" to do the 
> computation.
>
> Within GDAL the gdal/pymod/samples/fft.py script shows how to use GDAL 
> and
> Numeric to compute an FFT.  NDVI should be somewaht simpler.
>
> Someday I would like to implement a kind of "virtual file" in GDAL 
> where you
> can supply Python expressions for how the results should be computed from
> other source files but that is a ways out.
>
> Best regards,
>