This does not change size of the image in pixels, nor does it affect
appearance -- it is lossless compression. This requires the program
optipng
to be installed.
shrink(filename)
Character vector containing the path of images to resize. Must be PNG files.
If other operations like resizing are performed, shrinking should occur as the last step. Otherwise, if the resizing happens after file shrinking, it will be as if the shrinking didn't happen at all.
if (interactive()) {
webshot("https://www.r-project.org/", "r-shrink.png") %>%
shrink()
}