Create a new GDK.Image object. The firstargument is either 0, which
indicates that you want a 'slow' image. If you use '1', you
indicate that you want a 'fast' image. Fast images are stored in
shared memory, and thus are not sent over any network. But please
limit your usage of fast images, they use up a possibly limited
system resource set. See the man page for shmget(2) for more
information on the limits on shared segments on your system.
A 'fast' image will automatically revert back to 'slow' mode if no
shared memory is available.
If the second argument is specified, it is the actual image data.
GDK.Image