Glossary for Geospatial Science

HIS:Hue, Intensity, and Saturation.� Sometimes called HLS, for Hue, Luminance and Saturation.� The system of defining video output color from hue, intensity and saturation characteristics.� HIS controls are commonly used with color television sets.� Most computer displays use RGB (red/green/blue) color mixing information instead.

The hue-intensity-saturation color model uses a double cone (with its greatest circumference at the midpoint of the z-axis) to describe specific colors.� On any horizontal slice of the cone, the hue varies as you move around the slice and the saturation increases as you move outward from the center.� Intensity is the z-axis of the model.� The shades of gray are found along the z-axis, where hue and saturation equal zero.� (See also: HBS, RGB.)