Even Rouault

> It seems that latest version requires gcc >= 13? what makes you think so ? CMakeLists.txt shows: ``` set_property(TARGET ${GEOTIFF_LIBRARY_TARGET} PROPERTY C_STANDARD 99) ```

@wblangdon Assuming this PR pass the tests, can you give it a try on your side to measure the performance?

On my system, with a RelWithDebInfo build (-O2), ``hyperfine --warmup 5 './bin/bench_proj_trans -p "+proj=pipeline +step +inv +proj=cart" 4189946.586317880544811 146316.158923541981494 4790634.218430089764297'`` runs in 441 ms, vs 497 ms with master, so...

> :-) I am out of the office next week, but do not hesitate to let me know if I can help when I get back, eg timings yes, you're...

https://github.com/OSGeo/libgeotiff/issues/126 is probably a preliminary step. I'm pretty sure there might be other details we'd find out on the road if we engage this. Probably the type of question to...

I would suggest you use proj_trans_bounds() : https://proj.org/en/9.4/development/reference/functions.html#c.proj_trans_bounds

I don't confirm that using plain GDAL command line (3.8.5 or master): ``` $ CPL_VSIL_SHOW_NETWORK_STATS=YES GDAL_DISABLE_READDIR_ON_OPEN=EMPTY_DIR CPL_DEBUG=ON gdalinfo /vsicurl/https://sentinel-cogs.s3.us-west-2.amazonaws.com/sentinel-s2-l2a-cogs/15/T/VK/2023/10/S2B_15TVK_20231008_0_L2A/TCI.tif HTTP: libcurl/7.68.0 GnuTLS/3.6.13 zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3...

you may want to break into GTiffDataset::LookForProjectionFromXML() . Normally papszSiblingFiles = GetSiblingFiles() should be such that papszSiblingFiles != nullptr and papszSiblingFiles[0] == nullptr if GDAL_DISABLE_READDIR_ON_OPEN=EMPTY_DIR

> is `LookForProjectionFromXML` something that changed between gdal 3.6 and 3.7? it has been introduced in 3.7

should be resolved per https://github.com/OSGeo/gdal/pull/10957