Alicevision has a modified fork of vlfeat

[dkogan]

Hello. Alicevision currently includes a modified fork of VLFeat here: https://github.com/alicevision/AliceVision/tree/develop/src/nonFree/sift

There are several things that would be nice to address:

• In the code, this is referred to as "vlsift", not "vlfeat". Probably should be "vlfeat"
• It installs a library called "vlsift", which is confusing, because "vlsift" isn't a thing. This is a part of Alicevision, so I'm patching it to call it "aliceVision_vlsift".
• Is it nonfree? The SIFT patent expired long ago
• Can the patches be handled better? Can you contribute them upstream? If not, can you move them to Alicevision proper, so that the normal vlfeat can be used?
• There's a missing -lm. Patch: https://salsa.debian.org/science-team/alicevision/-/blob/master/debian/patches/vlsift-needs-to-link-with-lm.patch?ref_type=heads