dump png to stdout instead of savefig()?

when using the GD backed, you can write directly to a

    > stream (in your case could be sys.stdout).. the same
    > functionality has not been implemented for agg yet (last
    > time i checked).. i needed this before, and hacked it up
    > for GD in the early days (didn't even have agg back
    > then).. i think it would be great to have this implemented
    > for agg, but i think noone got around to doing it yet...

Finally I did - long overdue. The agg backend now will print png to
a file object, including sys.stdout.

Give it a whirl...