(INFO
". A map is regular if the control points are evenly "
"spaced along the domain, and hence their position isn't "
"explicitly represented in the map; the axis min, axis "
"max, and number of points determine their location. "
"The map can be a 1D nrrd (for \"grayscale\"), "
"in which case the "
"output has the same dimension as the input, "
"or a 2D nrrd (for \"color\"), in which case "
"the output has one more dimension than the input. In "
"either case, the output is the result of linearly "
"interpolating between map points, either scalar values "
"(\"grayscale\"), or scanlines along axis 0 "
"(\"color\").")