libvips 8.18

[jcupitt]

Hello, we've just done a feature-freeze ready for the release of libvips 8.18. There's a tracking issue here:

libvips/libvips#4770

The new bit of API is get_gainmap():

https://github.com/libvips/libvips/blob/master/libvips/iofuncs/header.c#L1069-L1107

You need this if you want to implement your own uhdr support, there's a new chapter in the docs for this feature:

https://github.com/libvips/libvips/blob/master/doc/uhdr.md

lua-vips might want to wrap this function.

Note that get_gainmap() does not make a new reference, the caller "borrows" the pointer from the image. You'd probably want to add a g_object_ref() when adding a method to lua-vips. I can make a PR if that'd be helpful.

[rolandlo]

Thanks for the info. That's an interesting feature. The implementation looks relatively straightforward, so I don't necessarily need help with it.

[rolandlo]

Note that get_gainmap() does not make a new reference, the caller "borrows" the pointer from the image. You'd probably want to add a g_object_ref() when adding a method to lua-vips.

This info is outdated after libvips/libvips@e56eb32? has been merged, right?
Could you please take a look at #95 to check if I got it right?

[jcupitt]

Yes, we did a little swerve on the API right at the end :( sorry.

Nice, I'll have a look at the PR!

[jcupitt]

I used this test for pyvips fwiw:

https://github.com/libvips/pyvips/blob/master/tests/test_image.py#L397-L418

might be relevant.