Plot data over background image with ggplot

Question

I\'m trying to plot some data over a background image. The problem is that both layers end up using the same scale. This is unfortunately problematic.

An example.<

Answer 1

Try this, (or alternatively annotation_raster)

library(ggplot2)
library(jpeg)
library(grid)

img <- readJPEG("image.jpg")

df <- data.frame(x=sample(1:64, 1000, replace=T), 
                 y=sample(1:64, 1000, replace=T))

ggplot(df, aes(x,y)) + 
  annotation_custom(rasterGrob(img, width=unit(1,"npc"), height=unit(1,"npc")), 
                    -Inf, Inf, -Inf, Inf) +
  stat_bin2d() +
  scale_x_continuous(expand=c(0,0)) +
  scale_y_continuous(expand=c(0,0))