[gdal-dev] FLIR thermal with embedded image

[Even Rouault]

Javier,

I've just added a commit in your pull request to replace your image with 
a smaller one. I've started from autotest/gdrivers/data/jpeg/flir/FLIR.jpg
and then hacked record 2 of type 32 (FLIR_REC_CAMERA_INFO) with data at 
offset 0xC7E + 1352 by replacing it by type 14 (FLIR_REC_EMBEDDEDIMAGE), 
and then I copied & pasted the content of a 2x1 JPEG image at offset 
0xC7E + 1352 + 32. This resulting image is of course non sensical, but 
enough for our purposes.

Even

Le 02/02/2026 à 18:39, Javier Jimenez Shaw a écrit :
> Hi Even
>
> I was not able to achieve that, sorry. So finally I made the PR with 
> an original image.
> If anybody has one image that works I can still replace mine.
>
> Thanks
>
> On Sat, 31 Jan 2026 at 03:20, Even Rouault 
> <even.rouault at spatialys.com> wrote:
>
>     Javier,
>
>     What about the hard core GDAL contributor way of starting with a
>     small JPEG image and then adding the needed bytes with your
>     favorite hexadecimal editor :-) ?
>
>     Otherwise, still a bit of use of your hexadecimal editor, but just
>     to find out a couple offfset/lenghts, you may try the trick of
>     starting from an existing file, keeping the begin in a part, the
>     end in the other part, and omitting most of the embedded image
>     using a /vsisparse/ .XML file and replacing it with a
>     <ConstantRegion> at zero. Like
>     https://github.com/OSGeo/gdal/blob/master/autotest/gdrivers/data/grib/rotated_pole.grb2.xml
>      and then you use "/vsisparse/your.xml" as a valid JPEG dataset name.
>
>     Or variation of the above, perhaps a bit less convoluted, start
>     with your initial image, set to the zero byte unneeded ranges, and
>     zip it.
>
>     Even
>
>     Le 30/01/2026 à 10:43, Javier Jimenez Shaw via gdal-dev a écrit :
>>     Hi
>>
>>     TL;DR: I need a "small" FLIR image file for a unit test in GDAL.
>>     Do you have one?
>>
>>     I am working on GDAL's thermal jpeg code, to read an embedded RGB
>>     image that some FLIR cameras are including inside the JPEG, in
>>     addition to the thermal information/image.
>>
>>     I want to add a unit test with a real image, but unfortunately I
>>     only have "big" images, around 4 or 5 MB.
>>
>>     It would be great if anybody has a smaller image that can be
>>     included in the GDAL tests code (with the copyright/license
>>     permissions that it has).
>>     The model "FLIR T640" I think produces images of about 1.5 MB
>>     only. But it can be other models as well.
>>
>>     To check if it has the Embedded Image, just run this:
>>
>>     exiftool -EmbeddedImage filename.jpg
>>
>>     If you see any output, please contact me.
>>
>>     Thank you!
>>
>>     _______________________________________________
>>     gdal-dev mailing list
>>     gdal-dev at lists.osgeo.org
>>     https://lists.osgeo.org/mailman/listinfo/gdal-dev
>
>     -- 
>     http://www.spatialys.com
>     My software is free, but my time generally not.
>
-- 
http://www.spatialys.com
My software is free, but my time generally not.
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