{HEAD ~ An object} of {TAIL ~ the present invention} is to reduce the brightness of the background to improve the contrast 
of
{ HEAD ~ An object } of { TAIL ~ the present invention } is to reduce the brightness of the background to improve the contrast
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH