JEITA  CP-3451 - 19 - JPEG compressed data or uncompressed YCbCr data. The TIFF default is 1 (centered); but when Y:Cb:Cr = 4:2:2 it is recommended in this standard that 2 (co-sited) be used to record data, in order to improve the image quality when viewed on TV systems. When this field does not exist, the reader shall assume the TIFF default. In the case of  Y:Cb:Cr  =  4:2:0,  the  TIFF  default  (centered)  is  recommended.  If  the  reader  does  not  have  the  capability  of supporting both kinds of YCbCrPositioning, it shall follow the TIFF default regardless of the value in this field. It is preferable that readers be able to support both centered and co-sited positioning.   Tag = 531 (213.H) Type = SHORT Count = 1 Default = 1 1 = centered 2 = co-sited Other = reserved Figure 8    YCbCrPositioning XResolution The number of pixels per ResolutionUnit in the ImageWidth direction. When the image resolution is unknown, 72 [dpi] is designated. Tag = 282 (11A.H) Type = RATIONAL Count = 1 Default = 72 YResolution The  number  of  pixels  per  ResolutionUnit  in  the  ImageLength  direction.  The  same  value  as  XResolution  is designated. Tag = 283 (11B.H) Type = RATIONAL Count = 1 YCbCrPositioning = 1 (centered) YCbCrPositioning = 2 (co-sited) Luminance Sample Chrominance Sample a) Y:Cb:Cr = 4:2:2 b) Y:Cb:Cr = 4:2:0 YCbCrPositioning = 1 (centered) YCbCrPositioning = 2 (co-sited)