Quaternion-based disorientation coloring of orientation maps

The authors of the present work propose a color coding technique using quaternions for the display of crystallographic orientation data such as EBSD maps. The main difference to existing color coding techniques in this field is that it creates a color space, within which the perceived color differences are approximately proportional to Euclidean distances in the corresponding 3D quaternion vector space, and thus approximately proportional to mutual disorientation angles. Since all disorientation parameters (axis and angle pairs, but represented as quaternions) are taken into account, color ambiguities appearing in maps created by other techniques are successfully avoided, and the sub-grain orientation differences within grains can be unambiguously visualized.