This val allows creation of polygot png files by uploading a reference image and a file.

A polygot png is a valid png file that also contains arbitrary data. This can be used to create files that serve a different purpose depending on their file extensions. PDF and ZIP files are known to work with polygot png images, although not every software supports the resulting files.

The conversion happens entirely on the client side.

The logic behind the conversion is entirely based on DavidBuchanan314/tweetable-polyglot-png and ported to JavaScript.