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1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.pdfbox.pdmodel.graphics.color;
18
19 import java.awt.color.ColorSpace;
20
21 /**
22 * This class represents a CMYK color space.
23 *
24 * @author <a href="mailto:andreas@lehmi.de">Andreas Lehmkühler</a>
25 * @version $Revision: 1.0 $
26 */
27 public class ColorSpaceCMYK extends ColorSpace
28 {
29 /**
30 * IDfor serialization.
31 */
32 private static final long serialVersionUID = -6362864473145799405L;
33
34 /**
35 * Constructor.
36 */
37 public ColorSpaceCMYK()
38 {
39 super(ColorSpace.TYPE_CMYK,4);
40 }
41
42 /**
43 * Converts colorvalues from RGB-colorspace to CIEXYZ-colorspace.
44 * @param rgbvalue RGB colorvalues to be converted.
45 * @return Returns converted colorvalues.
46 */
47 private float[] fromRGBtoCIEXYZ(float[] rgbvalue)
48 {
49 ColorSpace colorspaceRGB = ColorSpace.getInstance(CS_sRGB);
50 return colorspaceRGB.toCIEXYZ(rgbvalue);
51 }
52
53 /**
54 * Converts colorvalues from CIEXYZ-colorspace to RGB-colorspace.
55 * @param rgbvalue CIEXYZ colorvalues to be converted.
56 * @return Returns converted colorvalues.
57 */
58 private float[] fromCIEXYZtoRGB(float[] xyzvalue)
59 {
60 ColorSpace colorspaceXYZ = ColorSpace.getInstance(CS_CIEXYZ);
61 return colorspaceXYZ.toRGB(xyzvalue);
62 }
63
64 /**
65 * {@inheritDoc}
66 */
67 public float[] fromCIEXYZ(float[] colorvalue)
68 {
69 if (colorvalue != null && colorvalue.length == 3)
70 {
71 // We have to convert from XYV to RGB to CMYK
72 return fromRGB(fromCIEXYZtoRGB(colorvalue));
73 }
74 return null;
75 }
76
77 /**
78 * {@inheritDoc}
79 */
80 public float[] fromRGB(float[] rgbvalue)
81 {
82 if (rgbvalue != null && rgbvalue.length == 3)
83 {
84 // First of all we have to convert from RGB to CMY
85 float c = 1 - rgbvalue[0];
86 float m = 1 - rgbvalue[1];
87 float y = 1 - rgbvalue[2];
88 // Now we have to convert from CMY to CMYK
89 float varK = 1;
90 float[] cmyk = new float[4];
91 if ( c < varK )
92 {
93 varK = c;
94 }
95 if ( m < varK )
96 {
97 varK = m;
98 }
99 if ( y < varK )
100 {
101 varK = y;
102 }
103 if ( varK == 1 )
104 {
105 cmyk[0] = cmyk[1] = cmyk[2] = 0;
106 }
107 else
108 {
109 cmyk[0] = ( c - varK ) / ( 1 - varK );
110 cmyk[1] = ( m - varK ) / ( 1 - varK );
111 cmyk[2] = ( y - varK ) / ( 1 - varK );
112 }
113 cmyk[3] = varK;
114 return cmyk;
115 }
116 return null;
117 }
118
119 /**
120 * {@inheritDoc}
121 */
122 public float[] toCIEXYZ(float[] colorvalue)
123 {
124 if (colorvalue != null && colorvalue.length == 4)
125 {
126 // We have to convert from CMYK to RGB to XYV
127 return fromRGBtoCIEXYZ(toRGB(colorvalue));
128 }
129 return null;
130 }
131
132 /**
133 * {@inheritDoc}
134 */
135 public float[] toRGB(float[] colorvalue)
136 {
137 if (colorvalue != null && colorvalue.length == 4)
138 {
139 // First of all we have to convert from CMYK to CMY
140 float c = ( colorvalue[0] * ( 1 - colorvalue[3] ) + colorvalue[3] );
141 float m = ( colorvalue[1] * ( 1 - colorvalue[3] ) + colorvalue[3] );
142 float y = ( colorvalue[2] * ( 1 - colorvalue[3] ) + colorvalue[3] );
143 // Now we have to convert from CMY to RGB
144 float[] rgbvalues = new float[3];
145 rgbvalues[0] = 1 - c;
146 rgbvalues[1] = 1 - m;
147 rgbvalues[2] = 1 - y;
148 return rgbvalues;
149 }
150 return null;
151 }
152
153 }