Specify blur area: with_blur

[zx8754]

See related SO post:

• How to blur part of a plot in ggplot?

Something like below:

library(ggplot2)
library(ggfx)

ggplot(mtcars, aes(x = disp, y = mpg)) +
  with_blur(
    geom_line(),
    sigma = unit(1, 'mm'),
    xmin = 100, xmax = 200, ymin = 15, ymax = 30 # specify rectangular area
  )