an image data obtaining unit that obtains image data including pixel data corresponding to {TAIL ~ a plurality} of {HEAD ~ pixels} forming the image 
an image data obtaining unit that obtains image data including pixel data corresponding to { TAIL ~ a plurality } of { HEAD ~ pixels } forming the image
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH