Previous Next Table of Contents . The Sparkle plug-in has a number of user controlled features to manipulate images: . ... Levels for the pixel intensity threshold, the intensity of the flares which radiate out from the center of the sparkle, and the opacity (the amount the sparkle will blend with the original image). ... Variable or constant saturation for spikes. Length of spike. ... All of these features is discussed at length in the section titled The Sparkle Dialog Box . ...