{HEAD ~ The first block generating means} splits the output picture into {TAIL ~ a plurality} of blocks of a specified size which are then outputted sequentially 
{ HEAD ~ The first block generating means } splits the output picture into { TAIL ~ a plurality } of blocks of a specified size which are then outputted sequentially
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH