In computer graphics, a drop shadow is a visual effect consisting of drawing that looks like the shadow of an object, giving the impression that the object is raised above the objects behind it. The drop shadow is often used for elements of a graphical user interface such as windows or menus, and for simple text. The text label for icons on desktops in many desktop environments has a drop shadow, as this effect effectively distinguishes the text from any colored background it may be in front of.
A simple way of drawing a drop shadow of a rectangular object is to draw a gray or black area underneath and offset from the object. In general, a drop shadow is a copy in black or gray of the object, drawn in a slightly different position. Realism may be increased by:
- Darkening the colors of the pixels where the shadow casts instead of making them gray. This can be done with alpha blending the shadow with the area it is cast on.
- Softening the edges of the shadow. This can be done by adding Gaussian blur to the shadow's alpha channel before blending.
Famous quotes containing the words drop and/or shadow:
“Birds which are the same color as the foliage in which they nest are less likely to be disturbed by other birds who want to drop in and chat, and therefore last longer.”
—Robert Benchley (1889–1945)
“A perfect beauty of a sunflower! a perfect excellent lovely sunflower existence! a sweet natural eye to the new hip moon, woke up alive and excited grasping in the sunset shadow sunrise golden monthly breeze”
—Allen Ginsberg (b. 1926)