/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.styling;
import org.opengis.filter.expression.Expression;
import org.opengis.style.ContrastMethod;
/**
* The ContrastEnhancement object defines contrast enhancement for a channel of
* a false-color image or for a color image. Its format is:
* <pre>
* <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"/>
* </pre>
* 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
*
* @source $URL$
*
*/
public interface ContrastEnhancement extends org.opengis.style.ContrastEnhancement {
/**
* Used to set the contrast enhancement method used.
* @param method
*/
public void setMethod( ContrastMethod method );
/**
* @param type Should be a Literal of "Normalize" or "Histogram" or "None", if null supplied "None" is assumed
* @deprecated Please use setMethod
*/
public void setType(Expression type);
/**
* Returns a literal expression (one of NORMALIZE, HISTOGRAM, NONE)
* indicating which ContrastMethod value is to be used.
*
* @deprecated Please use getMethod
*/
public Expression getType();
/**
* @param gamma How much to brighten (greater than 1) or dim (less than 1) this channel; use 1.0 to indicate no change.
*/
public void setGammaValue(Expression gamma);
/**
* 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).
*
* @return Expression, if <code>null</code> a value of 1.0 is assumed indicating no change
*/
public Expression getGammaValue();
/**
* @deprecated Please use setMethod( ContrastMethodt.NORMALIZE )
*/
@Deprecated
public void setNormalize();
/**
* @deprecated Please use setMethod( ContrastMethodt.HISTOGRAM )
*/
@Deprecated
public void setHistogram();
/**
* @deprecated Please use setMethod; please note Logarithmic is not currently supported
*/
@Deprecated
public void setLogarithmic();
/**
* @deprecated Please use setMethod; please note Exponential is not currently supported
*/
public void setExponential();
/**
* Traversal of the style data structure.
* @param visitor
*/
public void accept(StyleVisitor visitor);
}