How to Make Graphics with Transparent Background in R Using Ggplot2

How to make graphics with transparent background in R using ggplot2?

Create the initial plot:

library(ggplot2)
d <- rnorm(100)
df <- data.frame(
  x = 1,
  y = d,
  group = rep(c("gr1", "gr2"), 50)
)
p <- ggplot(df) + stat_boxplot(
  aes(
    x = x,
    y = y,
    color = group
  ), 
  fill = "transparent" # for the inside of the boxplot
)

The fastest way to modify the plot above to have a completely transparent background is to set theme()'s rect argument, as all the rectangle elements inherit from rect:

p <- p + theme(rect = element_rect(fill = "transparent"))
          
p

A more controlled way is to set theme()'s more specific arguments individually:

p <- p + theme(
  panel.background = element_rect(fill = "transparent",
                                  colour = NA_character_), # necessary to avoid drawing panel outline
  panel.grid.major = element_blank(), # get rid of major grid
  panel.grid.minor = element_blank(), # get rid of minor grid
  plot.background = element_rect(fill = "transparent",
                                 colour = NA_character_), # necessary to avoid drawing plot outline
  legend.background = element_rect(fill = "transparent"),
  legend.box.background = element_rect(fill = "transparent"),
  legend.key = element_rect(fill = "transparent")
)

p

---

ggsave() offers a dedicated argument bg to set the

Background colour. If NULL, uses the plot.background fill value from the plot theme.

To write a ggplot object p to filename on disk using a transparent background:

ggsave(
  plot = p,
  filename = "tr_tst2.png",
  bg = "transparent"
)

Transparent background graph with ggplot2 in high resolution, R

You need to specify the dimension and resolution in png. This works for me

png("graph.png", width=20, height=15, units="cm", res=800, bg="transparent")
    gridExtra::grid.arrange(o1, o2, ncol=1)
dev.off()

You can also use ggsave. Here I use cowplot::plot_grid to combind o1 & o2

o3 <- cowplot::plot_grid(o1, o2, nrow = 2)

ggsave(plot = o3, file = "graph2.png", 
       type = "cairo-png",  bg = "transparent",
       width = 20, height = 15, units = "cm", dpi = 800)

R/ggplot2: Add png with transparency info

I think that the alpha channel is being respected here. It's just that inset_element draws a white canvas element first. What you are trying to do arguably isn't an inset, more of an annotation.

I think using annotation_custom from ggplot2 is more appropriate here (and means one less package to load).

library(ggplot2)
library(png)

img1 <- grid::rasterGrob(readPNG("bg.png"))
img2 <- grid::rasterGrob(readPNG("image1.png"))

ggp <- ggplot(data.frame()) +
  geom_point() + 
  theme_void() +
  annotation_custom(img1) +
  annotation_custom(img2, xmax = 0.5, ymax = 0.5)

ggp

Panel transparency in ggplot

Well, the trick is obvious. I have misunderstood what panel and plot background is. So this one should work:

# third option
 p <- p + theme(
   panel.grid.minor = element_blank(), 
   panel.grid.major = element_blank(),
   plot.background = element_rect(fill = "transparent", colour = NA)
 )

Add png to {ggplot2} that has transparent background and was rotated via {magick}

This doesn't really have anything to do with ggplot specifically. The rotate changes the size of the image but does not set the background transparent. The image will always have a rectangular shape. You need to set the background so magick knows what to fill in the newly created space with

img_rot <- magick::image_read(url) %>%
  magick::image_background("none") %>% 
  magick::image_rotate(30) %>% 
  grid::rasterGrob()

ggplot's transparent background changes after ShinyApp resizing

It seems as though when you run a plot in shiny with renderPlot it saves the plot as a variable so that when you resize the page the plot is not rerendered, it just shows the image again. This seems to be having issues with the transparent background (maybe due to a background being set when it is saved as a variable? I'm not sure on this point). To prevent this, set the execOnResize option to TRUE in renderPlot, this will redraw the plot instead of resize the saved image. For example:

output$boxplot <- renderPlot({
ggplot(df, aes(x=id, y=a, group=id)) + 
  geom_boxplot(aes(fill=id)) +
  facet_grid(~id, margins = T) +
  theme(rect=element_blank(),
        panel.grid = element_blank(),
        panel.background= element_blank(),
        plot.background = element_blank()
  )
}, bg="transparent", execOnResize = TRUE)

ggplot2 png file without background

set the bg argument to "white", e.g.

ggsave("test.png", dpi = 300, bg = "white")

This argument will be passed to grDevices::png via the ... argument. bg controls the background of the device.

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