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