[gdal-dev] Reading DNG files with GDAL

[Even Rouault]

Le mercredi 21 novembre 2012 19:56:31, Scott Arko a écrit :
> Hello,
> 
> 
> I have run into a strange issue that I haven't been able to sort out.  I
> have a number of digital negative (.dng) files collected by an Aeryon Scout
> UAV.  They are three band images with the bands being UInt16.  However,
> when I read these images with the python gdal binding, they read as Byte
> bands and half resolution.  When I use gdalinfo I get something like:
> 
> Driver: GTiff/GeoTIFF
> Files: 2012-11-06-flight_005-012.dng
> Size is 1296, 972
> Coordinate System is `'
> Metadata:
>   TIFFTAG_DATETIME=2012:11:06 16:24:42
>   TIFFTAG_SOFTWARE=Aeryon_Scout_DNG
> Image Structure Metadata:
>   INTERLEAVE=PIXEL
> Corner Coordinates:
> Upper Left  (    0.0,    0.0)
> Lower Left  (    0.0,  972.0)
> Upper Right ( 1296.0,    0.0)
> Lower Right ( 1296.0,  972.0)
> Center      (  648.0,  486.0)
> Band 1 Block=1296x2 Type=Byte, ColorInterp=Red
> Band 2 Block=1296x2 Type=Byte, ColorInterp=Green
> Band 3 Block=1296x2 Type=Byte, ColorInterp=Blue
> 
> In reality, the data are 2592X1944 and the bands are UInt16.  I can read
> the files with ufraw and they read fine.  Interestingly, Python Imaging
> Library (PIL) also reads them like gdal.
> 
> Running gdal 1.9.0 on a MBP with Snow Leopard
> 
> Would appreciate any thoughts folks might have.

I'm not a specialist of DNG files but I somehow remember that they are a kind 
of "weird"/unusual TIFF Files. It might be possible that GDAL (or probably 
libtiff) has found a overview instead of the full resolution imagery. Perhaps 
you could provide a sample for examination.


> 
> 
> Thanks,