org.apache.pdfbox.pdmodel.graphics.color.ColorSpaceCMYK Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of pdfbox Show documentation
The Apache PDFBox library is an open source Java tool for working with PDF documents.
There is a newer version: 3.0.2
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.pdfbox.pdmodel.graphics.color;

import java.awt.color.ColorSpace;

/**
 * This class represents a CMYK color space.
 *
 * @author Andreas Lehmkühler
 * @version $Revision: 1.0 $
 */
public class ColorSpaceCMYK extends ColorSpace
{
    /**
     * IDfor serialization.
     */
    private static final long serialVersionUID = -6362864473145799405L;
    
    /**
     * Constructor.
     */
    public ColorSpaceCMYK()
    {
        super(ColorSpace.TYPE_CMYK,4);
    }

    /**
     *  Converts colorvalues from RGB-colorspace to CIEXYZ-colorspace.
     *  @param rgbvalue RGB colorvalues to be converted.
     *  @return Returns converted colorvalues.
     */
    private float[] fromRGBtoCIEXYZ(float[] rgbvalue) 
    {
        ColorSpace colorspaceRGB = ColorSpace.getInstance(CS_sRGB);
        return colorspaceRGB.toCIEXYZ(rgbvalue);
    }
    
    /**
     *  Converts colorvalues from CIEXYZ-colorspace to RGB-colorspace.
     *  @param rgbvalue CIEXYZ colorvalues to be converted.
     *  @return Returns converted colorvalues.
     */
    private float[] fromCIEXYZtoRGB(float[] xyzvalue) 
    {
        ColorSpace colorspaceXYZ = ColorSpace.getInstance(CS_CIEXYZ);
        return colorspaceXYZ.toRGB(xyzvalue);
    }

    /**
     * {@inheritDoc}
     */
    public float[] fromCIEXYZ(float[] colorvalue) 
    {
        if (colorvalue != null && colorvalue.length == 3)
        {
            // We have to convert from XYV to RGB to CMYK
            return fromRGB(fromCIEXYZtoRGB(colorvalue));
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public float[] fromRGB(float[] rgbvalue) 
    {
        if (rgbvalue != null && rgbvalue.length == 3) 
        {
            // First of all we have to convert from RGB to CMY
            float c = 1 - rgbvalue[0];
            float m = 1 - rgbvalue[1];
            float y = 1 - rgbvalue[2];
            // Now we have to convert from CMY to CMYK
            float varK = 1;
            float[] cmyk = new float[4];
            if ( c < varK )
            {
                varK = c;
            }
            if ( m < varK )
            {
                varK = m;
            }
            if ( y < varK ) 
            {
                varK = y;
            }
            if ( varK == 1 ) 
            {
                cmyk[0] = cmyk[1] = cmyk[2] = 0;
            }
            else 
            {
                cmyk[0] = ( c - varK ) / ( 1 - varK );
                cmyk[1] = ( m - varK ) / ( 1 - varK );
                cmyk[2] = ( y - varK ) / ( 1 - varK );
            }
            cmyk[3] = varK;
            return cmyk;
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public float[] toCIEXYZ(float[] colorvalue) 
    {
        if (colorvalue != null && colorvalue.length == 4)
        {
            // We have to convert from CMYK to RGB to XYV
            return fromRGBtoCIEXYZ(toRGB(colorvalue));
        }
        return null;
    }

    /**
     * {@inheritDoc}
     */
    public float[] toRGB(float[] colorvalue) 
    {
        if (colorvalue != null && colorvalue.length == 4) 
        {
            // First of all we have to convert from CMYK to CMY
            float k = colorvalue[3];
            float c = ( colorvalue[0] * ( 1 - k ) + k );
            float m = ( colorvalue[1] * ( 1 - k ) + k );
            float y = ( colorvalue[2] * ( 1 - k ) + k );
            // Now we have to convert from CMY to RGB
            return new float[] { 1 - c, 1 - m, 1 - y };
        }
        return null;
    }

}