pdfbox/src/main/java/org/apache/pdfbox/pdmodel/graphics/color/PDLab.java - pdfbox - Git at Google

 /*
  * 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 org.apache.pdfbox.cos.COSArray;
 import org.apache.pdfbox.cos.COSBase;
 import org.apache.pdfbox.cos.COSDictionary;
 import org.apache.pdfbox.cos.COSFloat;
 import org.apache.pdfbox.cos.COSName;
 import org.apache.pdfbox.pdmodel.common.PDRange;
 import java.awt.color.ColorSpace;
 import java.awt.image.BufferedImage;
 import java.awt.image.WritableRaster;
 import java.io.IOException;

 /**
  * A Lab colour space is a CIE-based ABC colour space with two transformation stages.
  *
  * @author Ben Litchfield
  * @author John Hewson
  */
 public final class PDLab extends PDCIEBasedColorSpace
 {
     private static final ColorSpace CIEXYZ = ColorSpace.getInstance(ColorSpace.CS_CIEXYZ);

     private final COSDictionary dictionary;
     private PDColor initialColor;

     // we need to cache whitepoint values, because using getWhitePoint()
     // would create a new default object for each pixel conversion if the original
     // PDF didn't have a whitepoint array
     private float wpX = 1;
     private float wpY = 1;
     private float wpZ = 1;

     /**
      * Creates a new Lab color space.
      */
     public PDLab()
     {
         array = new COSArray();
         dictionary = new COSDictionary();
         array.add(COSName.LAB);
         array.add(dictionary);
     }

     /**
      * Creates a new Lab color space from a PDF array.
      * @param lab the color space array
      */
     public PDLab(COSArray lab)
     {
         array = lab;
         dictionary = (COSDictionary)array.getObject(1);

         // init whitepoint cache
         PDTristimulus whitepoint = getWhitepoint();
         wpX = whitepoint.getX();
         wpY = whitepoint.getY();
         wpZ = whitepoint.getZ();
     }

     @Override
     public String getName()
     {
         return COSName.LAB.getName();
     }

     //
     // WARNING: this method is performance sensitive, modify with care!
     //
     @Override
     public BufferedImage toRGBImage(WritableRaster raster) throws IOException
     {
         int width = raster.getWidth();
         int height = raster.getHeight();

         BufferedImage rgbImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
         WritableRaster rgbRaster = rgbImage.getRaster();

         float minA = getARange().getMin();
         float maxA = getARange().getMax();
         float minB = getBRange().getMin();
         float maxB = getBRange().getMax();

         // always three components: ABC
         float[] abc = new float[3];
         for (int y = 0; y < height; y++)
         {
             for (int x = 0; x < width; x++)
             {
                 raster.getPixel(x, y, abc);

                 // 0..255 -> 0..1
                 abc[0] /= 255;
                 abc[1] /= 255;
                 abc[2] /= 255;

                 // scale to range
                 abc[0] *= 100;
                 abc[1] = minA + (abc[1] * (maxA - minA));
                 abc[2] = minB + (abc[2] * (maxB - minB));

                 float[] rgb = toRGB(abc);

                 // 0..1 -> 0..255
                 rgb[0] *= 255;
                 rgb[1] *= 255;
                 rgb[2] *= 255;

                 rgbRaster.setPixel(x, y, rgb);
             }
         }

         return rgbImage;
     }

     @Override
     public float[] toRGB(float[] value)
     {
         // CIE LAB to RGB, see http://en.wikipedia.org/wiki/Lab_color_space

         // L*
         float lstar = (value[0] + 16f) * (1f / 116f);

         // TODO: how to use the blackpoint? scale linearly between black & white?

         // XYZ
         float x = wpX * inverse(lstar + value[1] * (1f / 500f));
         float y = wpY * inverse(lstar);
         float z = wpZ * inverse(lstar - value[2] * (1f / 200f));

         // toRGB() malfunctions with negative values
         // XYZ must be non-negative anyway:
         // http://ninedegreesbelow.com/photography/icc-profile-negative-tristimulus.html
         if (x < 0)
         {
             x = 0;
         }
         if (y < 0)
         {
             y = 0;
         }
         if (z < 0)
         {
             z = 0;
         }

         // XYZ to RGB
         return CIEXYZ.toRGB(new float[] { x, y, z });
     }

     // reverse transformation (f^-1)
     private float inverse(float x)
     {
         if (x > 6.0 / 29.0)
         {
             return x * x * x;
         }
         else
         {
             return (108f / 841f) * (x - (4f / 29f));
         }
     }

     @Override
     public int getNumberOfComponents()
     {
         return 3;
     }

     @Override
     public float[] getDefaultDecode(int bitsPerComponent)
     {
         PDRange a = getARange();
         PDRange b = getARange();
         return new float[] { 0, 100, a.getMin(), a.getMax(), b.getMin(), b.getMax() };
     }

     @Override
     public PDColor getInitialColor()
     {
         if (initialColor == null)
         {
             initialColor = new PDColor(new float[] {
                     0,
                     Math.max(0, getARange().getMin()),
                     Math.max(0, getBRange().getMin()) });
         }
         return initialColor;
     }

     /**
      * This will return the whitepoint tristimulus.
      * As this is a required field this will never return null.
      * A default of 1,1,1 will be returned if the pdf does not have any values yet.
      * @return the whitepoint tristimulus
      */
     public PDTristimulus getWhitepoint()
     {
         COSArray wp = (COSArray)dictionary.getDictionaryObject(COSName.WHITE_POINT);
         if(wp == null)
         {
             wp = new COSArray();
             wp.add(new COSFloat(1.0f));
             wp.add(new COSFloat(1.0f));
             wp.add(new COSFloat(1.0f));
         }
         return new PDTristimulus(wp);
     }

     /**
      * This will return the BlackPoint tristimulus.
      * This is an optional field but has defaults so this will never return null.
      * A default of 0,0,0 will be returned if the pdf does not have any values yet.
      * @return the blackpoint tristimulus
      */
     public PDTristimulus getBlackPoint()
     {
         COSArray bp = (COSArray)dictionary.getDictionaryObject(COSName.BLACK_POINT);
         if(bp == null)
         {
             bp = new COSArray();
             bp.add(new COSFloat(0.0f));
             bp.add(new COSFloat(0.0f));
             bp.add(new COSFloat(0.0f));
         }
         return new PDTristimulus(bp);
     }

     /**
      * creates a range array with default values (-100..100 -100..100).
      * @return the new range array.
      */
     private COSArray getDefaultRangeArray()
     {
         COSArray range = new COSArray();
         range.add(new COSFloat(-100));
         range.add(new COSFloat(100));
         range.add(new COSFloat(-100));
         range.add(new COSFloat(100));
         return range;
     }

     /**
      * This will get the valid range for the "a" component.
      * If none is found then the default will be returned, which is -100..100.
      * @return the "a" range.
      */
     public PDRange getARange()
     {
         COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
         if (rangeArray == null)
         {
             rangeArray = getDefaultRangeArray();
         }
         return new PDRange(rangeArray, 0);
     }

     /**
      * This will get the valid range for the "b" component.
      * If none is found  then the default will be returned, which is -100..100.
      * @return the "b" range.
      */
     public PDRange getBRange()
     {
         COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
         if (rangeArray == null)
         {
             rangeArray = getDefaultRangeArray();
         }
         return new PDRange(rangeArray, 1);
     }

     /**
      * This will set the whitepoint tristimulus.
      * As this is a required field this null should not be passed into this function.
      * @param whitepoint the whitepoint tristimulus
      */
     public void setWhitePoint(PDTristimulus whitepoint)
     {
         COSBase wpArray = whitepoint.getCOSObject();
         if(wpArray != null)
         {
             dictionary.setItem(COSName.WHITE_POINT, wpArray);
         }

         // update cached values
         wpX = whitepoint.getX();
         wpY = whitepoint.getY();
         wpZ = whitepoint.getZ();
     }

     /**
      * This will set the BlackPoint tristimulus.
      * As this is a required field this null should not be passed into this function.
      * @param blackpoint the BlackPoint tristimulus
      */
     public void setBlackPoint(PDTristimulus blackpoint)
     {
         COSBase bpArray = null;
         if(blackpoint != null)
         {
             bpArray = blackpoint.getCOSObject();
         }
         dictionary.setItem(COSName.BLACK_POINT, bpArray);
     }

     /**
      * This will set the a range for the "a" component.
      * @param range the new range for the "a" component,
      * or null if defaults (-100..100) are to be set.
      */
     public void setARange(PDRange range)
     {
         COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
         if (rangeArray == null)
         {
             rangeArray = getDefaultRangeArray();
         }
         //if null then reset to defaults
         if(range == null)
         {
             rangeArray.set(0, new COSFloat(-100));
             rangeArray.set(1, new COSFloat(100));
         }
         else
         {
             rangeArray.set(0, new COSFloat(range.getMin()));
             rangeArray.set(1, new COSFloat(range.getMax()));
         }
         dictionary.setItem(COSName.RANGE, rangeArray);
         initialColor = null;
     }

     /**
      * This will set the "b" range for this color space.
      * @param range the new range for the "b" component,
      * or null if defaults (-100..100) are to be set.
      */
     public void setBRange(PDRange range)
     {
         COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
         if (rangeArray == null)
         {
             rangeArray = getDefaultRangeArray();
         }
         //if null then reset to defaults
         if(range == null)
         {
             rangeArray.set(2, new COSFloat(-100));
             rangeArray.set(3, new COSFloat(100));
         }
         else
         {
             rangeArray.set(2, new COSFloat(range.getMin()));
             rangeArray.set(3, new COSFloat(range.getMax()));
         }
         dictionary.setItem(COSName.RANGE, rangeArray);
         initialColor = null;
     }
 }
	/*
	* 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 org.apache.pdfbox.cos.COSArray;
	import org.apache.pdfbox.cos.COSBase;
	import org.apache.pdfbox.cos.COSDictionary;
	import org.apache.pdfbox.cos.COSFloat;
	import org.apache.pdfbox.cos.COSName;
	import org.apache.pdfbox.pdmodel.common.PDRange;
	import java.awt.color.ColorSpace;
	import java.awt.image.BufferedImage;
	import java.awt.image.WritableRaster;
	import java.io.IOException;

	/**
	* A Lab colour space is a CIE-based ABC colour space with two transformation stages.
	*
	* @author Ben Litchfield
	* @author John Hewson
	*/
	public final class PDLab extends PDCIEBasedColorSpace
	{
	private static final ColorSpace CIEXYZ = ColorSpace.getInstance(ColorSpace.CS_CIEXYZ);

	private final COSDictionary dictionary;
	private PDColor initialColor;

	// we need to cache whitepoint values, because using getWhitePoint()
	// would create a new default object for each pixel conversion if the original
	// PDF didn't have a whitepoint array
	private float wpX = 1;
	private float wpY = 1;
	private float wpZ = 1;

	/**
	* Creates a new Lab color space.
	*/
	public PDLab()
	{
	array = new COSArray();
	dictionary = new COSDictionary();
	array.add(COSName.LAB);
	array.add(dictionary);
	}

	/**
	* Creates a new Lab color space from a PDF array.
	* @param lab the color space array
	*/
	public PDLab(COSArray lab)
	{
	array = lab;
	dictionary = (COSDictionary)array.getObject(1);

	// init whitepoint cache
	PDTristimulus whitepoint = getWhitepoint();
	wpX = whitepoint.getX();
	wpY = whitepoint.getY();
	wpZ = whitepoint.getZ();
	}

	@Override
	public String getName()
	{
	return COSName.LAB.getName();
	}

	//
	// WARNING: this method is performance sensitive, modify with care!
	//
	@Override
	public BufferedImage toRGBImage(WritableRaster raster) throws IOException
	{
	int width = raster.getWidth();
	int height = raster.getHeight();

	BufferedImage rgbImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
	WritableRaster rgbRaster = rgbImage.getRaster();

	float minA = getARange().getMin();
	float maxA = getARange().getMax();
	float minB = getBRange().getMin();
	float maxB = getBRange().getMax();

	// always three components: ABC
	float[] abc = new float[3];
	for (int y = 0; y < height; y++)
	{
	for (int x = 0; x < width; x++)
	{
	raster.getPixel(x, y, abc);

	// 0..255 -> 0..1
	abc[0] /= 255;
	abc[1] /= 255;
	abc[2] /= 255;

	// scale to range
	abc[0] *= 100;
	abc[1] = minA + (abc[1] * (maxA - minA));
	abc[2] = minB + (abc[2] * (maxB - minB));

	float[] rgb = toRGB(abc);

	// 0..1 -> 0..255
	rgb[0] *= 255;
	rgb[1] *= 255;
	rgb[2] *= 255;

	rgbRaster.setPixel(x, y, rgb);
	}
	}

	return rgbImage;
	}

	@Override
	public float[] toRGB(float[] value)
	{
	// CIE LAB to RGB, see http://en.wikipedia.org/wiki/Lab_color_space

	// L*
	float lstar = (value[0] + 16f) * (1f / 116f);

	// TODO: how to use the blackpoint? scale linearly between black & white?

	// XYZ
	float x = wpX * inverse(lstar + value[1] * (1f / 500f));
	float y = wpY * inverse(lstar);
	float z = wpZ * inverse(lstar - value[2] * (1f / 200f));

	// toRGB() malfunctions with negative values
	// XYZ must be non-negative anyway:
	// http://ninedegreesbelow.com/photography/icc-profile-negative-tristimulus.html
	if (x < 0)
	{
	x = 0;
	}
	if (y < 0)
	{
	y = 0;
	}
	if (z < 0)
	{
	z = 0;
	}

	// XYZ to RGB
	return CIEXYZ.toRGB(new float[] { x, y, z });
	}

	// reverse transformation (f^-1)
	private float inverse(float x)
	{
	if (x > 6.0 / 29.0)
	{
	return x * x * x;
	}
	else
	{
	return (108f / 841f) * (x - (4f / 29f));
	}
	}

	@Override
	public int getNumberOfComponents()
	{
	return 3;
	}

	@Override
	public float[] getDefaultDecode(int bitsPerComponent)
	{
	PDRange a = getARange();
	PDRange b = getARange();
	return new float[] { 0, 100, a.getMin(), a.getMax(), b.getMin(), b.getMax() };
	}

	@Override
	public PDColor getInitialColor()
	{
	if (initialColor == null)
	{
	initialColor = new PDColor(new float[] {
	0,
	Math.max(0, getARange().getMin()),
	Math.max(0, getBRange().getMin()) });
	}
	return initialColor;
	}

	/**
	* This will return the whitepoint tristimulus.
	* As this is a required field this will never return null.
	* A default of 1,1,1 will be returned if the pdf does not have any values yet.
	* @return the whitepoint tristimulus
	*/
	public PDTristimulus getWhitepoint()
	{
	COSArray wp = (COSArray)dictionary.getDictionaryObject(COSName.WHITE_POINT);
	if(wp == null)
	{
	wp = new COSArray();
	wp.add(new COSFloat(1.0f));
	wp.add(new COSFloat(1.0f));
	wp.add(new COSFloat(1.0f));
	}
	return new PDTristimulus(wp);
	}

	/**
	* This will return the BlackPoint tristimulus.
	* This is an optional field but has defaults so this will never return null.
	* A default of 0,0,0 will be returned if the pdf does not have any values yet.
	* @return the blackpoint tristimulus
	*/
	public PDTristimulus getBlackPoint()
	{
	COSArray bp = (COSArray)dictionary.getDictionaryObject(COSName.BLACK_POINT);
	if(bp == null)
	{
	bp = new COSArray();
	bp.add(new COSFloat(0.0f));
	bp.add(new COSFloat(0.0f));
	bp.add(new COSFloat(0.0f));
	}
	return new PDTristimulus(bp);
	}

	/**
	* creates a range array with default values (-100..100 -100..100).
	* @return the new range array.
	*/
	private COSArray getDefaultRangeArray()
	{
	COSArray range = new COSArray();
	range.add(new COSFloat(-100));
	range.add(new COSFloat(100));
	range.add(new COSFloat(-100));
	range.add(new COSFloat(100));
	return range;
	}

	/**
	* This will get the valid range for the "a" component.
	* If none is found then the default will be returned, which is -100..100.
	* @return the "a" range.
	*/
	public PDRange getARange()
	{
	COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
	if (rangeArray == null)
	{
	rangeArray = getDefaultRangeArray();
	}
	return new PDRange(rangeArray, 0);
	}

	/**
	* This will get the valid range for the "b" component.
	* If none is found then the default will be returned, which is -100..100.
	* @return the "b" range.
	*/
	public PDRange getBRange()
	{
	COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
	if (rangeArray == null)
	{
	rangeArray = getDefaultRangeArray();
	}
	return new PDRange(rangeArray, 1);
	}

	/**
	* This will set the whitepoint tristimulus.
	* As this is a required field this null should not be passed into this function.
	* @param whitepoint the whitepoint tristimulus
	*/
	public void setWhitePoint(PDTristimulus whitepoint)
	{
	COSBase wpArray = whitepoint.getCOSObject();
	if(wpArray != null)
	{
	dictionary.setItem(COSName.WHITE_POINT, wpArray);
	}

	// update cached values
	wpX = whitepoint.getX();
	wpY = whitepoint.getY();
	wpZ = whitepoint.getZ();
	}

	/**
	* This will set the BlackPoint tristimulus.
	* As this is a required field this null should not be passed into this function.
	* @param blackpoint the BlackPoint tristimulus
	*/
	public void setBlackPoint(PDTristimulus blackpoint)
	{
	COSBase bpArray = null;
	if(blackpoint != null)
	{
	bpArray = blackpoint.getCOSObject();
	}
	dictionary.setItem(COSName.BLACK_POINT, bpArray);
	}

	/**
	* This will set the a range for the "a" component.
	* @param range the new range for the "a" component,
	* or null if defaults (-100..100) are to be set.
	*/
	public void setARange(PDRange range)
	{
	COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
	if (rangeArray == null)
	{
	rangeArray = getDefaultRangeArray();
	}
	//if null then reset to defaults
	if(range == null)
	{
	rangeArray.set(0, new COSFloat(-100));
	rangeArray.set(1, new COSFloat(100));
	}
	else
	{
	rangeArray.set(0, new COSFloat(range.getMin()));
	rangeArray.set(1, new COSFloat(range.getMax()));
	}
	dictionary.setItem(COSName.RANGE, rangeArray);
	initialColor = null;
	}

	/**
	* This will set the "b" range for this color space.
	* @param range the new range for the "b" component,
	* or null if defaults (-100..100) are to be set.
	*/
	public void setBRange(PDRange range)
	{
	COSArray rangeArray = (COSArray) dictionary.getDictionaryObject(COSName.RANGE);
	if (rangeArray == null)
	{
	rangeArray = getDefaultRangeArray();
	}
	//if null then reset to defaults
	if(range == null)
	{
	rangeArray.set(2, new COSFloat(-100));
	rangeArray.set(3, new COSFloat(100));
	}
	else
	{
	rangeArray.set(2, new COSFloat(range.getMin()));
	rangeArray.set(3, new COSFloat(range.getMax()));
	}
	dictionary.setItem(COSName.RANGE, rangeArray);
	initialColor = null;
	}
	}