How do I overlay an image on to a ggplot?

Question

I\'d like to read an image from the web. e.g.

http://api.altmetric.com/donut/502878_64x64.png

and insert it into the top right of a ggplot

Answer 1

The correct solution was this:

# This was one of my issues, reading a png from the web
my_image <-  readPNG(getURLContent('http://path.to/image.png'))
p1 + annotation_raster(my_image, ymin = 4,ymax= 5,xmin = 30,xmax = 40)