A ContrastEnhancement is a Symbolizer used to style Rasters by modifying the contrast.
You can create a ContrastEnhancement using the normalize method:
 def c = new ContrastEnhancement("normalize")
 
 Or you can create a ContrastEnhancement using the normalize histogram method and a gamma value:
 def c = new ContrastEnhancement("histogram", 0.5)
  | Fields inherited from class | Fields | 
|---|---|
class Symbolizer | 
                            filterFactory, styleBuilder, styleFactory, styleOptions | 
                        
| Type | Name and description | 
|---|---|
private Expression  | 
                            gammaValueThe gamma value  | 
                        
private java.lang.String  | 
                            methodThe method: Normalize or Histogram  | 
                        
| Constructor and description | 
|---|
                                ContrastEnhancement
                                (java.lang.String method, java.lang.Object gammaValue)Create a new ContrastEnhancement  | 
                        
                                ContrastEnhancement
                                () | 
                        
| Type Params | Return Type | Name and description | 
|---|---|---|
 | 
                            protected void | 
                            apply(Symbolizer sym)Apply this Symbolizer to the GeoTools Symbolizer 
  | 
                        
 | 
                            protected ContrastEnhancement | 
                            createContrastEnhancement()Create a GeoTools ContrastEnhancement 
  | 
                        
 | 
                            protected void | 
                            prepare(Rule rule)Prepare the GeoTools Rule by applying this Symbolizer 
  | 
                        
 | 
                            java.lang.String | 
                            toString()The string representation 
  | 
                        
| Methods inherited from class | Name | 
|---|---|
class RasterSymbolizer | 
                            apply, geometry, opacity, overlap, prepare, setGeometry, setOpacity, setOverlap, toString | 
                        
class Symbolizer | 
                            and, apply, asSLD, asSLD, buildString, composite, createGeoToolsSymbolizer, getDefault, getDefault, getGeoToolsSymbolizers, getGtStyle, getSld, plus, prepare, prepare, range, range, sortBy, sortBy, where, zindex | 
                        
The gamma value
The method: Normalize or Histogram
Create a new ContrastEnhancement
method -  The methodgammaValue -  The gamma valueApply this Symbolizer to the GeoTools Symbolizer
sym -  The GeoTools SymbolizerCreate a GeoTools ContrastEnhancement
Prepare the GeoTools Rule by applying this Symbolizer
rule -  The GeoTools RuleThe string representation
Groovy Documentation