title: How to add logo on ggplot2 footer
body: <p>How to add image logo outside the plotting areas for ggplot2. Tried rasterGrob function from 'grid' package, but that keep's the image inside plot area. </p>
  
  <p>Here is the starter script:</p>
  
  <pre><code>library(ggplot2)
  library(png)
  library(gridExtra)
  library(grid)
  
  gg &lt;- ggplot(df1, aes(x = mpg, y = wt)) + 
         theme_minimal() +
          geom_count() + 
          labs(title = "Title Goes Here", x = "", y = "")
  
  img &lt;- readPNG("fig/logo.png")
  </code></pre>
  
  <p>Here is the outcome I am looking for. </p>
  
  <p><a href="https://i.stack.imgur.com/pZkd5.png" rel="noreferrer"><img src="https://i.stack.imgur.com/pZkd5.png" alt="enter image description here"></a></p>
  
  <p>I can add the annotation on the right side, but the logo on the left is where I am getting challenged.</p>