Как скопировать Ximage в CLIPBOARD?

Как вообще копируют:
The full technical documentation for this stuff is in the X11R6 Inter-Client Communication Conventions Manual,
section 2: ``Peer-to-Peer Communication by Means of Selections."
https://www.x.org/releases/X11R7.6/doc/xorg-docs/specs/ICCCM/icccm.html#peer_...

Что такое Ximage:
https://en.wikipedia.org/wiki/XImage
The structure of an XImage as defined by the X Window core protocol
https://en.wikipedia.org/wiki/X_Window_core_protocol

Что такое Xlib:
https://www.x.org/releases/X11R7.6/doc/libX11/specs/libX11/libX11.html
C Language X Interface

При чём тут Xlib:
http://web.archive.org/web/20150717082859/https://tronche.com/gui/x/xlib/grap...
Xlib provides functions that you can use to transfer images between a client and the server.
Xlib provides an image object that fully describes the data in memory and that provides for basic operations on that data.
To initialize the image manipulation routines of an image structure, use XInitImage().
To combine an image with a rectangle of a drawable on the display, use XPutImage().
To return the contents of a rectangle in a given drawable on the display, use XGetImage().
To copy the contents of a rectangle on the display to a location within a preexisting image structure, use XGetSubImage().