Webp

WebP, the one format that is not writable everywhere.

Android and a browser encode it. The JDK ships no WebP writer, and Apple's ImageIO reads WebP on systems where it will not write it, so both refuse with dev.jordond.filmstrip.FilmstripError.UnsupportedStillFormat naming the target rather than handing back a file that is not WebP. Ask for Png or Jpeg in code that has to run on all four.