15.5.529 scale

scale(image [, low, high][, /fullrange, /zoom])

Returns an linearly intensity-scaled version of image. If low and high are defined, then low and smaller numbers are mapped to !scalemin, and high and greater numbers to !scalemax, except when keyword /fullrange is specified, which forces the numbers to be scaled to the full range of colors. If x windows are used, then this range is from 0 to one less than the maximum number of distinguishable colors in the currently selected display style, and if x windows are not used, then the range is from 0 to 255 (inclusive). If the range is 256 or less (e.g., on an 8-bit display), then the result has type byte. If the range is 65536 or less (e.g., on 9 through 16-bit displays), then the result is word, and otherwise (e.g., on 17 through 32-bit displays) it is long.

If low and high are not explicitly specified, and if /zoom is specified, then the values of !zoomlow and !zoomhigh are taken for them, respectively; otherwise they default to the lowest and highest values in image.

See also: scalerange, !scalemin, !scalemax, !zoomlow, !zoomhigh