How to save a plot as a B&W (no gray pixel) image in R?

Question

I am generating some test images which are supposed to have foreground and background colors only. I created my plots using ggplot2, and I saved them using the methods jpeg() and png(). But I realized that the output is not B&W. Below you can see a sample image and the issue as well.

[A sample image]

[Zoomed-in to show the none B&W output]

How can I save a plot like that as a B&W image? (I prefer to stick to JPEG format.)

Answer 1

You can use the option antialias = "none". For example

library(ggplot2)
library(cowplot)
png(antialias = "none")
ggplot(data.frame(x=1:100, y=sin((1:100/10))), aes(x,y)) +
  geom_line() 
dev.off()