org.opengis.style

Interface ContrastEnhancement

All Known Subinterfaces:

ContrastEnhancement

All Known Implementing Classes:

ContrastEnhancementImpl

@XmlElement(value="ContrastEnhancement")
public interface ContrastEnhancement

The ContrastEnhancement object defines contrast enhancement for a channel of a false-color image or for a color image.

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.

Since:

GeoAPI 2.2

Author:

Open Geospatial Consortium, Ian Turton, CCG, Johann Sorel (Geomatys)

Method Summary

Modifier and Type	Method and Description
Object	accept(StyleVisitor visitor, Object extraData) calls the visit method of a StyleVisitor
Expression	getGammaValue() A "GammaValue" tells 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.

Method Detail

getMethod

@XmlElement(value="Normalize,Histogram,Logarithmic,Exponential")
ContrastMethod getMethod()

We use a codeList to enable more enchancement type possibilities.

getGammaValue

@XmlElement(value="GammaValue")
Expression getGammaValue()

A "GammaValue" tells 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).

Returns:

Expression to control gamma adjustment, null or Expression.NIL handled as the value 1.0

accept

@Extension
Object accept(StyleVisitor visitor,
                         Object extraData)

calls the visit method of a StyleVisitor

Parameters:

visitor - the style visitor