texture_image_background.R

library(tidyverse)
library(magick)

width = 800 
height = 500

img <- image_read("https://i.dlpng.com/static/png/6920336_preview.png")
pomo_bg <- magick::image_resize(img, paste0(width, "x", height, "!"))
pomo_bg <- magick::image_crop(pomo_bg, paste0(width, "x", height))

pomo_img <- magick::image_composite(pomo_bg, gg_fig)

df <- tibble(
  trt = c("a", "b", "c"),
  outcome = c(2.3, 1.9, 3.2))

pomo_gg <- ggplot(df, aes(trt, outcome)) +
  geom_bar(stat = "identity", fill = "seagreen", alpha = .5) +
  theme_void() +
  ggplot2::theme(plot.background = 
                   ggplot2::element_rect(fill = 'transparent', colour = NA))
  
gg_fig <- magick::image_graph(width, height, bg = "transparent", pointsize = 16)
print(pomo_gg)
dev.off()

magick::image_composite(pomo_bg, gg_fig)