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Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF.
/*
* 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.
*/
/* $Id: BitmapImageUtil.java 953952 2010-06-12 08:19:48Z jeremias $ */
package org.apache.fop.util.bitmap;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.IndexColorModel;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
/**
* Utility method for dealing with bitmap images.
*/
public class BitmapImageUtil {
/**
* Indicates whether an image is a monochrome (1 bit black and white) image.
* @param img the image
* @return true if it's a monochrome image
*/
public static final boolean isMonochromeImage(RenderedImage img) {
return (getColorIndexSize(img) == 2);
}
/**
* Indicates whether a zero bit indicates a black/dark pixel for a monochrome image.
* @param img the image (must be 1 bit monochrome)
* @return true if a zero bit indicates a black/dark pixel, false for a white/bright pixel
*/
public static final boolean isZeroBlack(RenderedImage img) {
if (!isMonochromeImage(img)) {
throw new IllegalArgumentException("Image is not a monochrome image!");
}
IndexColorModel icm = (IndexColorModel)img.getColorModel();
int gray0 = convertToGray(icm.getRGB(0));
int gray1 = convertToGray(icm.getRGB(1));
return gray0 < gray1;
}
/**
* Convert an RGB color value to a grayscale from 0 to 100.
* @param r the red component
* @param g the green component
* @param b the blue component
* @return the gray value
*/
public static final int convertToGray(int r, int g, int b) {
return (r * 30 + g * 59 + b * 11) / 100;
}
/**
* Convert an RGB color value to a grayscale from 0 to 100.
* @param rgb the RGB value
* @return the gray value
*/
public static final int convertToGray(int rgb) {
int r = (rgb & 0xFF0000) >> 16;
int g = (rgb & 0xFF00) >> 8;
int b = rgb & 0xFF;
return convertToGray(r, g, b);
}
/**
* Returns the size of the color index if the given image has one.
* @param img the image
* @return the size of the color index or 0 if there's no color index
*/
public static final int getColorIndexSize(RenderedImage img) {
ColorModel cm = img.getColorModel();
if (cm instanceof IndexColorModel) {
IndexColorModel icm = (IndexColorModel)cm;
return icm.getMapSize();
} else {
return 0;
}
}
/**
* Indicates whether an image is a grayscale image.
* @param img the image
* @return true if it's a grayscale image
*/
public static final boolean isGrayscaleImage(RenderedImage img) {
return (img.getColorModel().getColorSpace().getNumComponents() == 1);
}
/**
* Converts an image to sRGB. Optionally, the image can be scaled.
* @param img the image to be converted
* @param targetDimension the new target dimensions or null if no scaling is necessary
* @return the sRGB image
*/
public static final BufferedImage convertTosRGB(RenderedImage img,
Dimension targetDimension) {
return convertAndScaleImage(img, targetDimension, BufferedImage.TYPE_INT_RGB);
}
/**
* Converts an image to a grayscale (8 bits) image. Optionally, the image can be scaled.
* @param img the image to be converted
* @param targetDimension the new target dimensions or null if no scaling is necessary
* @return the grayscale image
*/
public static final BufferedImage convertToGrayscale(RenderedImage img,
Dimension targetDimension) {
return convertAndScaleImage(img, targetDimension, BufferedImage.TYPE_BYTE_GRAY);
}
/**
* Converts an image to a monochrome 1-bit image. Optionally, the image can be scaled.
* @param img the image to be converted
* @param targetDimension the new target dimensions or null if no scaling is necessary
* @return the monochrome image
*/
public static final BufferedImage convertToMonochrome(RenderedImage img,
Dimension targetDimension) {
return toBufferedImage(convertToMonochrome(img, targetDimension, 0.0f));
}
/**
* Converts an image to a monochrome 1-bit image. Optionally, the image can be scaled.
* @param img the image to be converted
* @param targetDimension the new target dimensions or null if no scaling is necessary
* @param quality Defines the desired quality level for the conversion.
* Valid values: a value between 0.0f (fastest) and 1.0f (best)
* @return the monochrome image
*/
public static final RenderedImage convertToMonochrome(RenderedImage img,
Dimension targetDimension, float quality) {
if (!isMonochromeImage(img)) {
if (quality >= 0.5f) {
BufferedImage bi;
Dimension orgDim = new Dimension(img.getWidth(), img.getHeight());
if (targetDimension != null && !orgDim.equals(targetDimension)) {
//Scale only before dithering
ColorModel cm = img.getColorModel();
BufferedImage tgt = new BufferedImage(cm,
cm.createCompatibleWritableRaster(
targetDimension.width, targetDimension.height),
cm.isAlphaPremultiplied(), null);
transferImage(img, tgt);
bi = tgt;
} else {
bi = toBufferedImage(img);
}
//Now convert to monochrome (dithering if available)
MonochromeBitmapConverter converter = createDefaultMonochromeBitmapConverter();
if (quality >= 0.8f) {
//Activates error diffusion if JAI is available
converter.setHint("quality", Boolean.TRUE.toString());
//Need to convert to grayscale first since otherwise, there may be encoding
//problems later with the images JAI can generate.
bi = convertToGrayscale(bi, targetDimension);
}
try {
return converter.convertToMonochrome(bi);
} catch (Exception e) {
//Provide a fallback if exotic formats are encountered
bi = convertToGrayscale(bi, targetDimension);
return converter.convertToMonochrome(bi);
}
}
}
return convertAndScaleImage(img, targetDimension, BufferedImage.TYPE_BYTE_BINARY);
}
private static BufferedImage convertAndScaleImage(RenderedImage img,
Dimension targetDimension, int imageType) {
Dimension bmpDimension = targetDimension;
if (bmpDimension == null) {
bmpDimension = new Dimension(img.getWidth(), img.getHeight());
}
BufferedImage target = new BufferedImage(bmpDimension.width, bmpDimension.height,
imageType);
transferImage(img, target);
return target;
}
/**
* Returns a BufferedImage based on the given RenderedImage. In the easiest case,
* this is a simple typecast. Otherwise, the image is converted to a BufferedImage.
* @param img the original image
* @return the buffered image
*/
public static BufferedImage toBufferedImage(RenderedImage img) {
if (img instanceof BufferedImage) {
return (BufferedImage)img;
} else {
WritableRaster wr = img.getColorModel().createCompatibleWritableRaster(
img.getWidth(), img.getHeight());
boolean premult = img.getColorModel().isAlphaPremultiplied();
return new BufferedImage(img.getColorModel(), wr, premult, null);
}
}
private static void transferImage(RenderedImage source, BufferedImage target) {
Graphics2D g2d = target.createGraphics();
try {
g2d.setBackground(Color.white);
g2d.setColor(Color.black);
g2d.clearRect(0, 0, target.getWidth(), target.getHeight());
AffineTransform at = new AffineTransform();
if (source.getWidth() != target.getWidth()
|| source.getHeight() != target.getHeight()) {
double sx = target.getWidth() / (double)source.getWidth();
double sy = target.getHeight() / (double)source.getHeight();
at.scale(sx, sy);
}
g2d.drawRenderedImage(source, at);
} finally {
g2d.dispose();
}
}
public static MonochromeBitmapConverter createDefaultMonochromeBitmapConverter() {
MonochromeBitmapConverter converter = null;
try {
String clName = "org.apache.fop.util.bitmap.JAIMonochromeBitmapConverter";
Class clazz = Class.forName(clName);
converter = (MonochromeBitmapConverter)clazz.newInstance();
} catch (ClassNotFoundException cnfe) {
// Class was not compiled so is not available. Simply ignore.
} catch (LinkageError le) {
// This can happen if fop was build with support for a
// particular provider (e.g. a binary fop distribution)
// but the required support files (i.e. JAI) are not
// available in the current runtime environment.
// Simply continue with the backup implementation.
} catch (InstantiationException e) {
// Problem instantiating the class, simply continue with the backup implementation
} catch (IllegalAccessException e) {
// Problem instantiating the class, simply continue with the backup implementation
}
if (converter == null) {
converter = new DefaultMonochromeBitmapConverter();
}
return converter;
}
}