Class ContrastEnhancementImpl

  • All Implemented Interfaces:
    ContrastEnhancement, ContrastEnhancement

    public class ContrastEnhancementImpl
    extends Object
    implements ContrastEnhancement
    The ContrastEnhancement object defines contrast enhancement for a channel of a false-color image or for a color image. Its format is:
     <xs:element name="ContrastEnhancement">
           <xs:choice minOccurs="0">
             <xs:element ref="sld:Normalize"/>
             <xs:element ref="sld:Histogram"/>
           <xs:element ref="sld:GammaValue" minOccurs="0"/>
     <xs:element name="Normalize">
     <xs:element name="Histogram">
     <xs:element name="GammaValue" type="xs:double"/>
    In the case of a color image, the relative grayscale brightness of a pixel color is used. ?Normalize? means to stretch the contrast so that the dimmest color is stretched to black and the brightest color is stretched to white, with all colors in between stretched out linearly. ?Histogram? means to stretch the contrast based on a histogram of how many colors are at each brightness level on input, with the goal of producing equal number of pixels in the image at each brightness level on output. This has the effect of revealing many subtle ground features. A ?GammaValue? tells how much to brighten (value greater than 1.0) or dim (value less than 1.0) an image. The default GammaValue is 1.0 (no change). If none of Normalize, Histogram, or GammaValue are selected in a ContrastEnhancement, then no enhancement is performed.