[vtkusers] Read PNG from in-memory buffer?

[Elvis Stansvik]

I'd like to read a PNG from an in-memory buffer. Looking at
vtkPNGReader, it seems it only works with files in the file system. In
general, is there some way to use the reader classes in VTK with
in-memory data, or would I have to write my own custom reader?

My need for this is not great, I was simply hoping to be able to keep
this particular PNG in the Qt resource system (so in the end, embedded
in my executable), load it using Qt file facilities, and use VTK on
the read in-memory data.

Elvis