TAG_Y_CB_CR_POSITIONING top-level constant

String const TAG_Y_CB_CR_POSITIONING

The position of chrominance components in relation to the luminance component. This field is designated only for JPEG compressed data or uncompressed YCbCr data. The TIFF default is Y_CB_CR_POSITIONING_CENTERED; but when Y:Cb:Cr = 4:2:2 it is recommended in this standard that Y_CB_CR_POSITIONING_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 (Y_CB_CR_POSITIONING_CENTERED) is recommended. If the Exif/DCF reader does not have the capability of supporting both kinds of positioning, it shall follow the TIFF default regardless of the value in this field. It is preferable that readers can support both centered and co-sited positioning.

Implementation

const String TAG_Y_CB_CR_POSITIONING = "YCbCrPositioning";