This app allows you to create UltraHDR images from 10-bit HDR, and conversely, create 10-bit HDR from UltraHDR images.
If your camera app supports 10-bit HDR video recording but not UltraHDR recording, this app allows you to create UltraHDR images from video.
You can also do the reverse: convert to 10-bit HDR to create dazzling videos.
This app is open source. You can view the source code.
https://github.com/takusan23/andAikacaroid