The command does the same thing
as the Stretch Contrast command,
except that it works in HSV color space, rather than RGB color space,
and it preserves the Hue. Thus, it independently stretches the ranges of
the Hue, Saturation and Value components of the colors. Occasionally the
results are good, often they are a bit odd. “Stretch HSV”
operates on layers from RGB and Indexed images. If the image is
Grayscale, the menu entry is insensitive and grayed out.
8.12.1.
Activate the Command
8.12.2.
“Stretch HSV” example