Cropping to faces

[brendon]

I currently have a paperclip processor called face_cropper. It makes a local call to a little express app that I wrote that uses @vladmandic/human to find the primary face in the image and then sets the centre of the crop to that face. It works well.

I want to do the same thing with Active Storage, for example:

image.variant(resize_to_fill: [932, 466, crop: :face])

I'm using vips currently and wondered if image_processing would be the correct layer to attempt to add this processor?

[janko]

The image_processing pipeline relies on building a single ImageMagick/Vips command with the given operations. In your case, you'd need to call your local processor and image_processing separately. I'm not sure you'd customize that with Active Storage.

[brendon]

Thanks @janko. I'm thinking down the path of an extension to the ImageAnalyzer that adds some metadata on where the primary face is. This can then be used to inform the crop call I suspect. (hopefully!)

[brendon]

I've managed to make some good progress and have extended the Active Storage ImageAnalyzer to also find the focal point which is just an array of two 0..1 floats indicating the X and Y location of the most prominent face. I'd like to convert this into the css object-position as percentages along with an image that is resized to cover a minimum pixel area. Unfortunately it seems that resize_to_fill with crop: :none resizes the image down so that it's contained within those two dimensions rather than creating an image that covers the two dimensions. Is that by design, and if so, would you consider a PR that adds a resize_to_cover method? :)

[brendon]

I've gone ahead and had a first attempt at this. It works, but the tests are where I'm stuck:

#120