Source Code Cross Referenced for ContrastEnhancement.java in  » GIS » GeoTools-2.4.1 » org » geotools » styling » Java Source Code / Java DocumentationJava Source Code and Java Documentation

01:        /*
02:         *    GeoTools - OpenSource mapping toolkit
03:         *    http://geotools.org
04:         *    (C) 2002-2006, GeoTools Project Managment Committee (PMC)
05:         *
06:         *    This library is free software; you can redistribute it and/or
07:         *    modify it under the terms of the GNU Lesser General Public
08:         *    License as published by the Free Software Foundation;
09:         *    version 2.1 of the License.
10:         *
11:         *    This library is distributed in the hope that it will be useful,
12:         *    but WITHOUT ANY WARRANTY; without even the implied warranty of
13:         *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14:         *    Lesser General Public License for more details.
15:         */
16:        package org.geotools.styling;
17:
18:        import org.opengis.filter.expression.Expression;
19:        import org.geotools.event.GTComponent;
20:
21:        /**
22:         * The ContrastEnhancement object defines contrast enhancement for a channel of
23:         * a false-color image or for a color image. Its format is:
24:         * <pre>
25:         * &lt;xs:element name="ContrastEnhancement"&gt;
26:         *   &lt;xs:complexType&gt;
27:         *     &lt;xs:sequence&gt;
28:         *       &lt;xs:choice minOccurs="0"&gt;
29:         *         &lt;xs:element ref="sld:Normalize"/&gt;
30:         *         &lt;xs:element ref="sld:Histogram"/&gt;
31:         *       &lt;/xs:choice&gt;
32:         *       &lt;xs:element ref="sld:GammaValue" minOccurs="0"/&gt;
33:         *     &lt;/xs:sequence&gt;
34:         *   &lt;/xs:complexType&gt;
35:         * &lt;/xs:element&gt;
36:         * &lt;xs:element name="Normalize"&gt;
37:         *   &lt;xs:complexType/&gt;
38:         * &lt;/xs:element&gt;
39:         * &lt;xs:element name="Histogram"&gt;
40:         *   &lt;xs:complexType/&gt;
41:         * &lt;/xs:element&gt;
42:         * &lt;xs:element name="GammaValue" type="xs:double"/&gt;
43:         * </pre>
44:         * In the case of a color image, the relative grayscale brightness of a pixel
45:         * color is used. ?Normalize? means to stretch the contrast so that the
46:         * dimmest color is stretched to black and the brightest color is stretched to
47:         * white, with all colors in between stretched out linearly. ?Histogram? means
48:         * to stretch the contrast based on a histogram of how many colors are at each
49:         * brightness level on input, with the goal of producing equal number of
50:         * pixels in the image at each brightness level on output.  This has the
51:         * effect of revealing many subtle ground features. A ?GammaValue? tells how
52:         * much to brighten (value greater than 1.0) or dim (value less than 1.0) an
53:         * image. The default GammaValue is 1.0 (no change). If none of Normalize,
54:         * Histogram, or GammaValue are selected in a ContrastEnhancement, then no
55:         * enhancement is performed.
56:         *
57:         * @author iant
58:         * @source $URL: http://svn.geotools.org/geotools/tags/2.4.1/modules/library/api/src/main/java/org/geotools/styling/ContrastEnhancement.java $
59:         */
60:        public interface ContrastEnhancement extends GTComponent {
61:            public void setType(Expression type);
62:
63:            public Expression getType();
64:
65:            public void setGammaValue(Expression gamma);
66:
67:            public Expression getGammaValue();
68:
69:            public void setNormalize();
70:
71:            public void setHistogram();
72:        }