ContrastEnhancementImpl (Geotools modules 21.0 API)

Object
- ContrastEnhancementImpl

All Implemented Interfaces:

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: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

Constructor Summary

Constructors
Constructor and Description
`ContrastEnhancementImpl()`
`ContrastEnhancementImpl(ContrastEnhancement contrastEnhancement)`
`ContrastEnhancementImpl(FilterFactory factory)`
`ContrastEnhancementImpl(FilterFactory2 factory, Expression gamma, ContrastMethod method)`
`ContrastEnhancementImpl(FilterFactory factory, ContrastMethod method)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`accept(StyleVisitor visitor)` Traversal of the style data structure.
`Object`	`accept(StyleVisitor visitor, Object extraData)` calls the visit method of a StyleVisitor
`void`	`addOption(String key, Expression value)` Store a vendor option
`boolean`	`equals(Object obj)`
`Expression`	`getGammaValue()` How much to brighten (values greater than 1.0) or dim (values less than 1.0) an image.
`ContrastMethod`	`getMethod()` We use a codeList to enable more enchancement type possibilities.
`Expression`	`getOption(String key)`
`Map<String,Expression>`	`getOptions()` Return vendor options relating to the enhancement method
`int`	`hashCode()`
`boolean`	`hasOption(String key)` check if vendor option key is available
`void`	`setFilterFactory(FilterFactory factory)`
`void`	`setGammaValue(Expression gamma)`
`void`	`setMethod(ContrastMethod method)` Used to set the contrast enhancement method used.
`void`	`setMethod(ContrastMethodStrategy method)` Convenience method to allow users to pass in a `ContrastEnhancementMethod` to update `Method` and `Options` in one go.
`void`	`setOptions(Map<String,Expression> options)`

Methods inherited from class Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ContrastEnhancementImpl
```
public ContrastEnhancementImpl()
```
  - ContrastEnhancementImpl
```
public ContrastEnhancementImpl(FilterFactory factory)
```
  - ContrastEnhancementImpl
```
public ContrastEnhancementImpl(FilterFactory factory,
                               ContrastMethod method)
```
  - ContrastEnhancementImpl
```
public ContrastEnhancementImpl(ContrastEnhancement contrastEnhancement)
```
  - ContrastEnhancementImpl
```
public ContrastEnhancementImpl(FilterFactory2 factory,
                               Expression gamma,
                               ContrastMethod method)
```
- Method Detail
  - setFilterFactory
```
public void setFilterFactory(FilterFactory factory)
```
  - getGammaValue
```
public Expression getGammaValue()
```
    Description copied from interface: ContrastEnhancement
    
    How much to brighten (values greater than 1.0) or dim (values less than 1.0) an image. The default GammaValue is 1.0 (no change).
    
    Specified by:
    
    getGammaValue in interface ContrastEnhancement
    
    Returns:
    
    Expression, if null a value of 1.0 is assumed indicating no change
  - setGammaValue
```
public void setGammaValue(Expression gamma)
```
    Parameters:
    
    gamma - How much to brighten (greater than 1) or dim (less than 1) this channel; use 1.0 to indicate no change.
  - getMethod
```
public ContrastMethod getMethod()
```
    Description copied from interface: ContrastEnhancement
    
    We use a codeList to enable more enchancement type possibilities.
    
    Specified by:
    
    getMethod in interface ContrastEnhancement
  - accept
```
public Object accept(StyleVisitor visitor,
                     Object extraData)
```
    Description copied from interface: ContrastEnhancement
    
    calls the visit method of a StyleVisitor
    
    Specified by:
    
    accept in interface ContrastEnhancement
    
    Parameters:
    
    visitor - the style visitor
  - accept
```
public void accept(StyleVisitor visitor)
```
    Description copied from interface: ContrastEnhancement
    
    Traversal of the style data structure.
  - setMethod
```
public void setMethod(ContrastMethod method)
```
    Description copied from interface: ContrastEnhancement
    
    Used to set the contrast enhancement method used.
  - getOptions
```
public Map<String,Expression> getOptions()
```
    Description copied from interface: ContrastEnhancement
    
    Return vendor options relating to the enhancement method
    
    Returns:
    
    a Map containing expressions with string keys.
  - hasOption
```
public boolean hasOption(String key)
```
    Description copied from interface: ContrastEnhancement
    
    check if vendor option key is available
    
    Parameters:
    
    key - - the name of the option to check
    
    Returns:
    
    true if present
  - getOption
```
public Expression getOption(String key)
```
    Returns:
    
    An expression for the matching VendorOption
  - addOption
```
public void addOption(String key,
                      Expression value)
```
    Description copied from interface: ContrastEnhancement
    
    Store a vendor option
    
    Parameters:
    
    key - - the name of the option
    
    value - an expression that evaluates to it's value
  - setOptions
```
public void setOptions(Map<String,Expression> options)
```
    Parameters:
    
    options - a Map of VendorOptions
  - setMethod
```
public void setMethod(ContrastMethodStrategy method)
```
    Description copied from interface: ContrastEnhancement
    
    Convenience method to allow users to pass in a ContrastEnhancementMethod to update Method and Options in one go.
    
    Parameters:
    
    method - the ContrastEnhancementMethod that underlies this enhancement
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object

Class ContrastEnhancementImpl

Constructor Summary

Method Summary

Methods inherited from class Object

Constructor Detail

ContrastEnhancementImpl

ContrastEnhancementImpl

ContrastEnhancementImpl

ContrastEnhancementImpl

ContrastEnhancementImpl

Method Detail

setFilterFactory

getGammaValue

setGammaValue

getMethod

accept

accept

setMethod

getOptions

hasOption

getOption

addOption

setOptions

setMethod

hashCode

equals