Fig. 1.

Examples of 100% position-symmetric patterns with different luminance-polarity arrangements. (A) Symmetric pattern in which elements across the vertical axis are matched in luminance polarity. (B) Anti-symmetric pattern in which the matched pairs across the symmetry axis have opposite luminance-polarity. (C) Polarity-grouped anti-symmetric pattern in which each half of the pattern is of different luminance-polarity. Note, each of the patterns contains the same amount of positional information but they differ in regard to their luminance-polarity arrangement.