Custom header - enable adding several header images in bulk

[mark-k]

Right now in order to have several header images to be randomly displayed you need to add each image individually as a header image. This process can be improved by enabling uploading several images at the same time and just cropping them one by one. Maybe some clever UI design can achieve cropping all of the images at a single page.

[mark-k]

Actually it even applies to selection from the media library.

[ocean90]

Maybe some clever UI design can achieve cropping all of the images at a single page.

This seems to be very tricky. An idea would be to select first the images and then the UI will let you crop each image one after another, automatically.

Related: #21785

[mark-k]

Actually, since the time I opened the ticket I worked a little if the HTML5 filereader interface and canvas. You can basically do cropping at client side and upload only the cropped image (or the original+crop coordinates) without having to upload the image to the server. This should make handling number of images at the same time much easier.

[SergeyBiryukov]

Related: #27202

[celloexpressions]

Even with the new UI in the Customizer, you need to add images one-by-one, but they each have a crop step anyway, so bulk-selection probably isn't worth the large development effort it would require. Closing for now due to lack of activity/interest.