DESCRIPTION
A Gtk2::Gdk::Image is a 2-D array of pixel values in client-side memory. It can optionally use shared memory with the X server for fast copying to or from a window or pixmap.
If you're thinking of using this then look at Gtk2::Gdk::Pixbuf first. GdkPixbuf has many more features, in particular file read and write (PNG, JPEG, etc). But a GdkImage lets you work directly in pixel values instead of expanding to RGB components.
See Gtk2::Gdk::Drawable for draw_image, get_image and copy_to_image methods to draw or fetch images to or from a window or pixmap.
The various get methods are Gtk 2.22 style. For previous versions they're direct field access.