gdkDrawGrayImage: gdkDrawGrayImage
In RGtk2: R Bindings for Gtk 2.8.0 and Above

Draws a grayscale image in the drawable.

1	gdkDrawGrayImage(object, gc, x, y, width, height, dith, buf)

`object`	The `GdkDrawable` to draw in (usually a `GdkWindow`).
`gc`	The graphics context.
`x`	The x coordinate of the top-left corner in the drawable.
`y`	The y coordinate of the top-left corner in the drawable.
`width`	The width of the rectangle to be drawn.
`height`	The height of the rectangle to be drawn.
`dith`	A `GdkRgbDither` value, selecting the desired dither mode.
`buf`	The pixel data, represented as 8-bit gray values.