library(imager)
file <- system.file('extdata/parrots.png',package='imager')
#system.file gives the full path for a file that ships with a R package
#if you already have the full path to the file you want to load just run:
#im <- load.image("/somedirectory/myfile.png")
im <- load.image(file)
plot(im) #Parrots!