COLORSCALE creates a color scale for use with an integer-valued image which has been encoded and quantized via a monotonic transformation from a real-valued array. The original array has physically meaningful units, but the image does not. The transformed image has been displayed with a direct mapping to the figure's colormap. (That is, the IMAGE object has a CDATAMAPPING of 'direct'.) The image and/or color scale may not use the entire colormap. The colormap may contain special values for null data areas, and these special values may be excluded from the scale bar. Or, the colormap may be deliberately partitioned and shared with a different image in the same figure, and that image may have its own, entirely distinct, color scale. In these cases, unlike the standard COLORBAR function, COLORSCALE can limit the displayed colors to the appropriate interval within the figure's colormap.