dev.capture captures the current contents of a graphics device
as a raster (bitmap) image.dev.capture(native = FALSE)FALSE the result is a matrix of R
color names, if TRUE the output is returned as a
nativeRaster object which is more efficient for plotting, but
not portable.NULL if the device does not support capture, otherwise a
matrix of color names (for native = FALSE) or a
nativeRaster object (for native = TRUE).