src by scaling by
scale.x and scale.y then translating by offset.x and offset.y.
This gives an image in the coordinates of the destination pixbuf.
The rectangle (dest.x, dest.y, dest.width, dest.height)
is then composited onto the corresponding rectangle of the
original destination image.gdkPixbufComposite(object, dest, dest.x, dest.y, dest.width, dest.height, offset.x, offset.y, scale.x, scale.y, interp.type, overall.alpha)dest.xdest.ydest.widthdest.heightoffset.xoffset.yscale.xscale.yinterp.typeGdkInterpType] the interpolation type for the transformation.overall.alphaCompositing of pixbufs