determining means for determining whether {HEAD ~ each pixel signal} read by the image reading means represents a white pixel and for generating a white pixel signal representing {TAIL ~ the white pixel} 
determining means for determining whether { HEAD ~ each pixel signal } read by the image reading means represents a white pixel and for generating a white pixel signal representing { TAIL ~ the white pixel }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL