Relative orientation between the RHT-H angle expectation value and the GRAD-L direction angle (magenta-blue-green) overlaid on the surface brightness map (shades of gray) for Region 1 (left) and Region 2 (right). The relative orientation goes from fully parallel (green, 0°) to fully perpendicular (magenta, 90°). As in Fig. 4, the angles have been calculated for the pixels that are in common to the RHT-H and GRAD-L cases.