Moving away from Microsoft HD Photo
Consuming as little network bandwidth as possible has always been a priority. The Feed Viewer client downloads a lot of images, which are preprocessed by the Feed Viewer online service. Tile images are resized and encoded into the JPEG XR format. This format is very good but is limited to Windows devices only. There is a lack of image libraries that support this format. Windows 10 is inconsistent because Live Tiles still lack JPEG XR support. Feed Viewer will be available on another platform soon, and adopting a portable image format is necessary.
JPEG is still much more efficient than PNG with color quantization. There is an option of HEIF in the future. Everything is about finding the center of gravity of the triangle with three vertices – quality, compression ratio, and cost of implementation. The backend was designed to serve different file formats to different devices, but the latest and currently planned features are almost impossible to implement with this design decision.
Feed Viewer has always been limited by hardware performance, operating system restrictions, and backend running costs. Portability is another boundary that must be considered. Choosing a 25-year-old technology in IT must have a serious reason. When you look around, everybody would like to use a better format, but there is just not a better alternative yet.