#install.packages(c('png','jpeg')) You need to do this only once.
library(png)
library(jpeg)

#setwd('...') replace ... by the name of th subfolder where you have the images. 
x = readPNG('toucantrans.png')
str(x)
plot(as.raster(x))
plot(as.raster(x),xlim=c(105,110),ylim=c(80,86),inter=F)
plot(as.raster(x[,,1]))
x = readJPEG('gorkhey.jpg')
dim(x)
plot(as.raster(x))
plot(as.raster(x),xlim=c(1570,1600),ylim=c(1150,1200),inter=F)
p = locator(1)

###Let's do some simple image processing: reducing the red component to half.

x[,,1] = x[,,1]/2
plot(as.raster(x))