Bug#1016870: gdal-bin: Support for KEA format is somewhat hidden

[Phil Endecott]

Package: gdal-bin
Version: 3.2.2+dfsg-2+deb11u1
Severity: minor

Dear Maintainer,

Dear Maintainer,

I was going to file a bug saying "Please enable support for KEA 
format in GDAL" - but then I discovered that this format actually is
supported, but that support is far from obvious.

I'm attempting to process some elevation data from New Zealand. 
The KEA format download is about 9 GB, compared to about 14 GB for 
GeoTIFF. So I am motivated to use KEA if possible.

Searching, I found that GDAL does support KEA format since version  
2.0:

  https://gdal.org/drivers/raster/kea.html

But is this support enabled in the Debian package? It is not    
mentioned in the list of drivers in the --long-usage output, and 
libkea does not seem to be a dependency of GDAL (in fact it seems 
not to be in Debain at all), and KEA is not mentioned in the   
configure flags at https://sources.debian.org/src/gdal/3.5.1%2Bdfsg-1/debian/rules/

So I was all ready to file a bug, but I thought I'd better try 
anyway and I got this:

$ gdalinfo lds-tile-cj-KEA/CJ.kea 
Driver: HDF5Image/HDF5 Dataset
Files: lds-tile-cj-KEA/CJ.kea
Size is 8192, 8192
Corner Coordinates:
Upper Left  (    0.0,    0.0)
Lower Left  (    0.0, 8192.0)
Upper Right ( 8192.0,    0.0)
Lower Right ( 8192.0, 8192.0)
Center      ( 4096.0, 4096.0)
Band 1 Block=256x256 Type=Float32, ColorInterp=Undefined
  Metadata:
    BAND1_DATA_BLOCK_SIZE=256 
    BAND1_DATA_CLASS=IMAGE
    BAND1_DATA_IMAGE_VERSION=1.2


???!!! So KEA format IS supported - but using the HDF5 driver.

https://gdal.org/drivers/raster/hdf5.html has no indication that 
HDF5 and KEA are related.

Really I'm not sure what the right fix for this is. One thing 
that would have helped me would have been if `gdal_translate --long-usage 
| grep -i kea` reported something, e.g. "HDF5: Hierarchical Data Format 5 
(including KEA)". But actually, now that I look, --long-usage doesn't 
even mention HDF5 - it only mentions HDF4. (It doesn't help that it isn't 
sorted.)

It would also have been useful if https://gdal.org/drivers/raster/kea.html 
had said something about HDF5, but that's not your responsibility!

Note I'm using 3.2.2 on bullseye.

Thanks for reading.

Regards, Phil.