classPhoto<Sequel::ModelincludeShrine::Attachment(:image)end

photo=Photo.create(image: file)photo.image#=> #<Shrine::UploadedFile>photo.image_url#=> "https://my-bucket.s3.amazonaws.com/6bfafe89748ee135.jpg"photo.image.id#=> "6bfafe89748ee135.jpg"photo.image.storage#=> #<Shrine::Storage::S3>photo.image.metadata#=> { "size" => 749238, "mime_type" => "image/jpeg", "filename" => "nature.jpg" }

Shrine::Attacher.derivatives:thumbnailsdo |original|  magick=ImageProcessing::MiniMagick.source(original)  { large:  magick.resize_to_limit!(800,800),    medium: magick.resize_to_limit!(500,500),    small:  magick.resize_to_limit!(300,300) }end

photo.image_derivatives#=># { large:  #<Shrine::UploadedFile id="4ed847866c71a5bf.jpg" ...>,#   medium: #<Shrine::UploadedFile id="7bc41b1c24afe81d.jpg" ...>,#   small:  #<Shrine::UploadedFile id="cccdd4052261633b.jpg" ...> }

Shrine.derivation:thumbnaildo |file, width, height|  magick=ImageProcessing::MiniMagick.source(original)  magick.resize_to_limit!(width.to_i, height.to_i)end

photo.image.derivation_url(:thumbnail,600,400)#=> ".../thumbnail/600/400/eyJpZCI6ImZvbyIsInN0b3JhZ2UiOiJzdG9yZSJ9?signature=..."