indicates a color difference signal between blue (B) and a luminance component, as part of a luminance (Y) and chrominance (C) color model. It has different meanings depending on the exact model used: U in YUV, a generic model used for analog and digital image formats Cb in YCbCr, used for digital images and video Pb in YPbPr, used in analog component video Db in YDbDr, used in analog SECAM
See also R-Y – The corresponding signal for red