title: Saving raster in R using png() and levelplot results in strange lines
body: <p>I think I may have discovered a bug. I'm using levelplot in rasterVis, when I plot the rasters they show up fine in the raster window, however when I try and save them using <code>png()</code> the raster has lines through it. </p>
  
  <pre><code>library(raster)
  library(rasterVis)
  library(RColorBrewer)
  col&lt;-rasterTheme(region=brewer.pal(8,"YlOrRd"))
  r&lt;-raster(ncol=40,nrow=20)
  r[] &lt;- rnorm(n=ncell(r))
  b&lt;-"Title"
  
  png(file=paste0(path,"\\",b,".png"), width=1800, height=1800, res=300)
  plot&lt;-levelplot(r,main=b,par.settings=col, margin=FALSE, scales=list(draw=FALSE))
  print(plot)
  dev.off()
  </code></pre>
  
  <p>In the plot window it shows up as it should:
  <a href="https://i.stack.imgur.com/Ev4Sk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ev4Sk.png" alt="enter image description here"></a></p>
  
  <p>But saved using <code>png()</code>:
  <a href="https://i.stack.imgur.com/qcOd8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qcOd8.png" alt="enter image description here"></a></p>