smart crop feature

[aaronpk]

This is a great library, but I'm really missing a "smart crop" feature! There's a handful of PHP libraries that do this, but it would be great to be integrated into this code.

Here's some example code for doing just the smart crop: https://github.com/xymak/smartcrop.php

Here's an example of an alternative image processing library that has smart crop built in: https://kosinix.github.io/grafika/smart-crop.html

This is a lighter weight version of doing full on face detection as described in #75 since it is just looking for "interestingness" in the image.

It'd be super great if this were built in!

[olivervogel]

Sounds like a good idea. I'm just worried that it won't be possible to implement it properly. For example the library mentioned iterates through every single pixel of the image, which can quickly run into the millions and become very resource-intensive.

[Gummibeer]

Hey, I've added something like that to a league/glide wrapper I've made.
https://github.com/Astrotomic/pixpipe/blob/main/src/Analyzers/FocusPointAnalyzer.php
It returns the focus point and then the proper crop offset is calculated to crop the image.
https://github.com/Astrotomic/pixpipe/blob/main/src/Manipulators/Size.php
All using plain PHP & intervention image logic.

Regarding performance - it's definitely not super fast, VIPS smartcrop is significantly faster. But I think that's not the point here and I think no one expects a smartcrop to be lightning fast. Having any kind of cache/persistence in front of the manipulation would be needed. But it's also not super slow and doable, even with 4K images on a simple HTTP request level as the image is first downscaled. So the number of iterations is predictable and more or less consistent. A 4K image takes a little longer because of the downscale but not because of the loops.

I haven't completely checked the VIPS source code, but from some issues I've seen, it appears that they are also using downscale and blur. And the best thing: the VIPS driver could implement smartcrop just natively.

[olivervogel]

Thanks @Gummibeer

It appears that the repo Astrotomic/pixpipe is private. Is there any way you could share the code? I'd love to take a look at it.

[Gummibeer]

@olivervogel sorry, it should be public anyway. So it is now.