circos.raster(
    image, x, y,
    width, height,
    facing = c("inside", "outside", "reverse.clockwise", "clockwise",
    "downward", "bending.inside", "bending.outside"),
    niceFacing = FALSE,
    sector.index = get.current.sector.index(),
    track.index = get.current.track.index(),
    scaling = 1)

require(png)
image = system.file("extdata", "Rlogo.png", package = "circlize")
image = as.raster(readPNG(image))
circos.initialize(letters[1:8], xlim = c(0, 1))
circos.track(ylim = c(0, 1), panel.fun = function(x, y) {
    circos.raster(image, CELL_META$xcenter, CELL_META$ycenter, width = "2cm", 
        facing = "inside", niceFacing = TRUE)
})
circos.clear()

if(FALSE) {
# NOTE: following takes quite a long time to run
load(system.file("extdata", "doodle.RData", package = "circlize"))
circos.par("cell.padding" = c(0, 0, 0, 0))
circos.initialize(letters[1:16], xlim = c(0, 1))
circos.track(ylim = c(0, 1), panel.fun = function(x, y) {
    img = img_list[[CELL_META$sector.numeric.index]]
    circos.raster(img, CELL_META$xcenter, CELL_META$ycenter, width = 1, 
        height = 1, facing = "bending.inside")
}, track.height = 0.25, bg.border = NA)
circos.track(ylim = c(0, 1), panel.fun = function(x, y) {
    img = img_list[[CELL_META$sector.numeric.index + 16]]
    circos.raster(img, CELL_META$xcenter, CELL_META$ycenter, width = 1, 
        height = 1, facing = "bending.inside")
}, track.height = 0.25, bg.border = NA)
circos.clear()
}