[gdal-dev] WEBP in GEOTIFF

[Even Rouault]

Andreas,

> Interesting - thanks for the hint about turbo-jpeg.
> 
> I found out that my gdal is linked against libjpeg.so.8 and not against
> libturbojpeg.so.0 which is also present on my system.
> 
> Would I have to tell gdal to compile against libturbojpeg with the
> --with-jpeg= flag in order to benefit from turbo-jpeg?

Ubuntu has shipped for a long time libjpeg-turbo as the system libjpeg.so.8. It has the same 
ABI and behaviour as the corresponding IJG version, so it can be used as a complete 
replacement.

If you want to check:
objdump -T /usr/lib/x86_64-linux-gnu/libjpeg.so.8 | grep LIBJPEGTURBO

0000000000000000 g    DO *ABS*	0000000000000000  LIBJPEGTURBO_8.0 
LIBJPEGTURBO_8.0

(libturbojpeg.so uses a slightly different API, that is only useful for applications directly 
targetted at it. Not used by GDAL. More details at
https://libjpeg-turbo.org/About/TurboJPEG)

> 
> And yes, the mask thing is what I was struggling with JPEG compression
> and RGB images, but I got the mask to work by using the following
> 
> gdal_translate command:
> |gdal_translate -b 1 -b 2 -b 3 -b mask -of COG --config
> 
> GDAL_DISABLE_READDIR_ON_OPEN TRUE\ -co COMPRESS=JPEG -co BIGTIFF=YES -co
> NUM_THREADS=4 -a_srs EPSG:2056\ infile.vrt outfile.tif|

Hum, normally the COG driver makes the internal necessary steps to convert an alpha band to 
a mask band when using JPEG compression

Even

-- 
Spatialys - Geospatial professional services
http://www.spatialys.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/gdal-dev/attachments/20201010/e3f26a2c/attachment.html>