Input
The input operation specifies what image will be used as the source of the image processing. This can either be a path to a file on your storage bucket, a remote URL, or allow the extension to create an image on the fly.
Google Cloud Storage
This is a valid google cloud storage url of an existing image. For example:
{ "operation": "input", "type": "gcs", "source": "gs://bucket/path/to/file" }