Capture device output as a raster image
dev.capture captures the current contents of a graphics device
as a raster (bitmap) image.
Not all devices support capture of the output as raster bitmaps. Typically, only image-based devices do and even not all of them.
NULL if the device does not support capture, otherwise a
matrix of color names (for
native = FALSE) or a
nativeRaster object (for
native = TRUE).