Note that you can technically do this right now, if you use Chrome on your android device, and point it to the PhotoStructure instance running on your LAN: then just click the “cast” button.
A beta user did some preliminary research for me to implement this as a native chromecast channel (which wouldn’t require an android device to “drive” the UI):
To implement Chromecast requires:
A sender. There is a JS framework. Integrate Cast SDK into Your Web Sender App | Google for Developers Requires the user to be running Chrome. As best as I can understand, the Chrome App, is just a webapp. Fortunately, you’re already doing that on port
A receiver. To support images appears to need a custom receiver. Again, this is also a JS app.
Custom receiver
If your app provides content such as an image gallery, requires DRM, or custom business logic, then you need to build a custom receiver application. A custom receiver is an HTML5 app that you host on your own servers and that must be implemented using the JavaScript CAF Receiver API.
For details about how to build your receiver application with the Receiver API, see the Create a Basic CAF Receiver guide.
Cast supports JPEG and other image formats. Supported Media for Google Cast | Google for Developers
Another beta user wrote this blog post (complete with demo):
https://fjordaan.medium.com/wanted-my-photo-library-on-a-connected-tv-ae272c68abec
As an aside, I’m a bit hesitant to build on (any!) Google API, given how joyfully they kill their own products, but at least for now, it seems to be the simplest way to broadcast to a TV.