How to fix Rails Active Storage thumbnails orientation

fix-orientation.md

If you use Active Storage variants to generate thumbs and your thumbnails are sometimes misoriented, you may have EXIF metadata problems For example:

• the original image can have an EXIF metadata specifying a 90° rotation
• when resizing by default libvips will apply this rotation to the pixels
• HOWEVER it will also preserve the EXIF metadata including this rotation info
• so the thumbnail is doubly rotated

a solution is to remove all EXIF metadata from the generated thumbs by using saver: { strip: true } in the config:

  has_many_attached :photos do |attachable|
    attachable.variant :medium, resize_to_limit: [800, 800], saver: { strip: true }
  end

this documentation is quite hard to understand