library(jpeg)
moon <- jpeg::readJPEG(system.file("extra", "GPN-2000-000473.jpg",
                             package="RGraphics"))


grid.raster(moon, x=0, y=1, height=.5, just=c("left", "top"))
grid.raster(moon, x=1, y=.75, 
            width=.5, height=.25, just="right")
for (i in seq(10, 90, 10)) {
  pushViewport(viewport(x=i/100, y=.25, width=.2, height=.2, 
                        angle=i - 10))
  grid.raster(moon)
  popViewport()
}