[mapserver-users] Raster parameter PROCESSING "BANDS=..." and ECW files

[Armin Burger]

On 04/09/2011 19:07, Frank Warmerdam wrote:
> On 11-09-04 09:33 AM, Armin Burger wrote:
>> Hi all
>>
>> I noticed a strange behaviour of MapServer (5.6.7 and 6.0.1) when
>> defining for
>> a raster layer based on an ECW file a processing parameter for the
>> bands order
>> like
>>
>> PROCESSING "BANDS=3,2,1"
>>
>> The order of the bands does not have any effect. The image is always
>> displayed
>> in the original band order 1,2,3, whatever I define for the BANDS
>> value. If I
>> just define a single band, like
>> "BANDS=3" or "BANDS=1"
>> then it's displaying it correctly using the right band.
>>
>> This problem seems just to appear for ECW files, not e.g. for Tiff
>> files. If I
>> wrap a VRT image around the ECW and use this VRT in the DATA tag of
>> the map
>> file then the BANDS order is taken into account, just not when
>> defining the
>> DATA using the pure ECW file.
>>
>> Any ideas what's going wrong?
>
> Armin,
>
> I suspect that the special interleaved read method in the GDAL ECW driver
> is not properly honouring the list of bands passed in to it. If this is
> the problem then it might not have come up with earlier mapserver versions
> that didn't do such reads in one interleaved request.
>
> If this is the issue then please test with GDAL "trunk" and if the problem
> persists file a ticket against GDAL.
>
> Best regards,


Frank,

thanks for the quick reply. I tested the same configuration using the 
GDAL trunk from today and the problem persists. I filed a ticket for it 
on GDAL Trac (#4234).

Armin