a) In a digital video system, the sampling is quincunx if the luminance and color-difference samples are generated from pixels arranged on one of two congruent rectilinear grids, the one being displaced horizontally from the other by half the horizontal pixel spacing.

The alternate grid is usually chosen for alternate lines, but may instead be chosen for alternate field/frames. b) In a digital video system, a sampling structure with an array of samples wherein alternate rows of pixel samples are displaced horizontally in the grid by half of the pitch of the pixel samples along the remaining rows.