When uploading images, instead of uploading the actual image files to Cloudinary, you can also specify a remote HTTP URL of existing images. This method allows for much faster uploading. You can also specify an S3 URL of an existing image. The S3 URL should be from whitelisted S3 buckets we define for your Cloudinary account. This way, you can upload images to Cloudinary directly from an existing S3 bucket and then dynamically deliver transformed and resized versions to your users via a fast CDN.
More information about uploading to Cloudinary can be found here: http://cloudinary.com/documentation/upload_images
Another option is to use Cloudinary's fetch or auto-upload functionalities for transforming and delivering images from remote sources on the fly.
Fetching involves appending an image URL to a Cloudinary URL "prefix". An example URL prefix for an uploaded image would be `https://res.cloudinary.com/demo/upload/`. You can replace `upload` with `fetch` and append an image URL to take that remote image and store it on your account like this: https://res.cloudinary.com/demo/image/fetch/https://upload.wikimedia.org/wikipedia/commons/1/13/Benedict_Cumberbatch_2011.png
Auto-uploading makes lazy migration of your assets from a remote URL or S3 bucket possible as well.
More information about fetching and auto-uploading can be found here: https://cloudinary.com/documentation/fetch_remote_images