Guillaume,
yes, what you've observed is consistant with the source code of the driver.
To improve the situation, I've added in r15687 support for setting metadata at
the raster band level (that is to say with GDALRasterBand::GetMetadata)
Here's the new output :
$ apps/gdalinfo dimap/DN000340T_
I have some trouble getting some meta data using DIMAP Driver.
gdalinfo --version
> GDAL 1.6.0dev, FWTools 2.2.8, released 2008/10/29
>
Sample data can be found here :
ftp://ftp.dmcii.com/samples/32m_MS_L1R/DN000340T_L1R.zip
The meta data file contains this data :
...
>
>
>