Right now decodeImageFromPixels only supports rgba8888 and bgra8888 of an unspecified colorspace (assumed to be sRGB).

We could:

1. Add a colorspace argument
2. Add support for pixel formats that can represent extended sRGB values
3. Both

Design doc:
https://docs.google.com/document/d/1JUvx3N21Dq-GmzveNOUDixVL0hUKyrkDL5WCuPUPudQ/edit#