ThumbHash
Each Source record has a thumb_hash field, which holds a short string
that can be used to render a blurred placeholder while the real image loads.
By default it is a ThumbHash, base64
encoded.
Install the thumbhash extra (see Installation) to enable the default
hasher. Without it, thumb_hash stays empty.
The hash is generated when the first thumbnail of a source image is created and
is available through Thumbnailer.get_thumb_hash(). For sources that
already have thumbnails, generate the missing hashes with
thumbnail thumb_hash.
Custom hashers
Set THUMBNAIL_HASHER to the dotted path
of a function that takes the PIL source image and returns a string (at most 64
characters) or None:
THUMBNAIL_HASHER = 'myapp.hashers.blurhash'
Set it to None to disable hashing.