[mapserver-dev] RE: MapServer and MultiBand-IMG

[Frank Warmerdam]

Steve Lime wrote:
> Hi Stepan/Oliver: This will be a great addition but I'd like  to run it
> by Frank Warmerdam first since he's our raster guru and I don't know if
> he had something else in mind (or already working in 3.7). I've cc'd the
> developers list for feedback.
> 
> Steve
> 
> Stephen Lime
> Data & Applications Manager
> 
> Minnesota DNR
> 500 Lafayette Road
> St. Paul, MN 55155
> 651-297-2937
> 
>>>>"Stepan Kafka" <stepan.kafka at centrum.cz> 11/05/02 16:56 PM >>>
>>>
> Hi Oliver,
>   I am sending you my changes in Mapserver source code to enable
> selecting
> raster bands. Only GDAL formats are supported. Originaly I tried it with
> 3.6
> dev. code, I haven't try actual Mapserver version yet!
> In map file the bands are supproted with LAYER COLOR parameter:
> 
> LAYER
>   NAME mylyr
>   DATA landsat.tif
>   COLOR 7 4 2  # the R G B channels
>   ...
> END
> 
> It would be better to use e.g. BANDS parameter, but I don't know, how to
> introduce it.

Folks,

I like the change, but I would like to go a little further:

  o I would like to introduce a BANDS parameter instead of using COLOR.

  o I would like it to support 1, 2, 3 or 4 bands which would be interpreted
    as:
     1: single greyscale or paletted band.
     2: as above plus an alpha band.
     3: R/G/B
     $: R/G/B/Alpha

If there is no problem with this I will incorporate it into 3.7 soon.
In the meantime using the suggested patches in local versions should be
fine.

Actually, when I think about it, does anyone thing that this sort of control
should be done through layer metadata?  There are other aspects of raster
control, like the scaling used for >8bit bands that I would like to add
but doing it all via specific keywords seems cumbersome.  I had been thinking
of doing it via layer metadata but I wonder if that is an abuse/misuse of
layer metadata?

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