[gdal-dev] Troubles with PAM file

[Even Rouault]

Dominique,
> 
> I'm trying to read a raster georeferenced with ArcGIS. It's a jpg file
> coming with a PAM file (.aux.xml) that store GCPs and define a polynomial
> transformation of order 3. Unfortunately GDAL does not take the PAM file
> into account and gdalinfo does not report GCPs. After some investigations,
> I found this commit
> <https://github.com/OSGeo/gdal/commit/f8822eb50466fb740e228b8c6a7f066b916faa
> 0a> that suggest PAM files are supported by GDAL but only for TIFF dataset.

Not really. PAM files are supported for most formats, included JPEG, but the 
ESRI specific GCP decoding was limited for now to the GTiff format, mostly 
because of the oddity you noticed: in the case for which this was developed 
for
(see https://lists.osgeo.org/pipermail/gdal-dev/2017-January/045854.html and 
the related email thread), pixel coordinates were indeed surprisingly in 
inches and from the bottom left origin. So I couldn't/didn't want to 
generalize that to core PAM processing.

> 
> I'm a bit confused with theses PAM files, is there any technical doc from
> ESRI? 

Not to my knowledge. Initially PAM was developed for GDAL itself, but it seems 
ESRI developed some extensions on top of it, like the one you are facing to.

> The file can be downloaded here :
> https://drive.google.com/drive/folders/1hZXncJhcfZI0Uem-oCfUsruO9mPwWD0U?usp
> =sharing

You didn't include the most interesting part, that is the .aux.xml file itself

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com