org.geotools.styling
Class ContrastEnhancementImpl

java.lang.Object
  org.geotools.event.AbstractGTComponent
      org.geotools.styling.ContrastEnhancementImpl

All Implemented Interfaces:

ContrastEnhancement, GTComponent

public class ContrastEnhancementImpl

extends AbstractGTComponent

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:complexType>
     <xs:sequence>
       <xs:choice minOccurs="0">
         <xs:element ref="sld:Normalize"/>
         <xs:element ref="sld:Histogram"/>
       </xs:choice>
       <xs:element ref="sld:GammaValue" minOccurs="0"/>
     </xs:sequence>
   </xs:complexType>
 </xs:element>
 <xs:element name="Normalize">
   <xs:complexType/>
 </xs:element>
 <xs:element name="Histogram">
   <xs:complexType/>
 </xs:element>
 <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.

Author:

iant

Field Summary

Fields inherited from class org.geotools.event.AbstractGTComponent

notification

Constructor Summary

ContrastEnhancementImpl()

ContrastEnhancementImpl(FilterFactory factory)

Method Summary

Expression	getGammaValue()
Expression	getType()
void	setFilterFactory(FilterFactory factory)
void	setGammaValue(Expression gamma)
void	setHistogram()
void	setNormalize()
void	setType(Expression type)

Methods inherited from class org.geotools.event.AbstractGTComponent

changed, clone, fireChanged, fireChildChanged, getNote, getParent, removed, setNote

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.geotools.event.GTComponent

changed, getNote, getParent, removed, setNote

Constructor Detail

ContrastEnhancementImpl

public ContrastEnhancementImpl()

ContrastEnhancementImpl

public ContrastEnhancementImpl(FilterFactory factory)

Method Detail

setFilterFactory

public void setFilterFactory(FilterFactory factory)

getGammaValue

public Expression getGammaValue()

Specified by:

getGammaValue in interface ContrastEnhancement

getType

public Expression getType()

Specified by:

getType in interface ContrastEnhancement

setGammaValue

public void setGammaValue(Expression gamma)

Specified by:

setGammaValue in interface ContrastEnhancement

setHistogram

public void setHistogram()

Specified by:

setHistogram in interface ContrastEnhancement

setNormalize

public void setNormalize()

Specified by:

setNormalize in interface ContrastEnhancement

setType

public void setType(Expression type)

Specified by:

setType in interface ContrastEnhancement