Now the adaptive criterion is applied to the luminance resuls to select the direction of further processing. (The entire reconstruction, i.e. both Y and C components, or any portion thereof, e.g. just Y or C components, can be used to select the appropriate direction.) Therefore, if 2|YL -YR |???|YT -YB |, (the factor 2 is needed since twice as many terms are in YT and YB as are in YL and YR), the