Java tutorial
/* * 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 com.ackpdfbox.app.imageio; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import javax.imageio.ImageWriteParam; import javax.imageio.metadata.IIOInvalidTreeException; import javax.imageio.metadata.IIOMetadata; import javax.imageio.metadata.IIOMetadataNode; import java.awt.image.BufferedImage; import static com.ackpdfbox.app.imageio.MetaUtil.SUN_TIFF_FORMAT; import static com.ackpdfbox.app.imageio.MetaUtil.debugLogMetadata; /** * Used by ImageIOUtil to write TIFF files. * @author Tilman Hausherr */ final class TIFFUtil { private static final Log LOG = LogFactory.getLog(TIFFUtil.class); private static String tagSetClassName = "com.sun.media.imageio.plugins.tiff.BaselineTIFFTagSet"; private TIFFUtil() { } static { try { String alternateClassName = "com.github.jaiimageio.plugins.tiff.BaselineTIFFTagSet"; Class.forName(alternateClassName); tagSetClassName = alternateClassName; } catch (ClassNotFoundException ex) { // ignore } } /** * Sets the ImageIO parameter compression type based on the given image. * @param image buffered image used to decide compression type * @param param ImageIO write parameter to update */ public static void setCompressionType(ImageWriteParam param, BufferedImage image) { // avoid error: first compression type is RLE, not optimal and incorrect for color images // TODO expose this choice to the user? if (image.getType() == BufferedImage.TYPE_BYTE_BINARY && image.getColorModel().getPixelSize() == 1) { param.setCompressionType("CCITT T.6"); } else { param.setCompressionType("LZW"); } } /** * Updates the given ImageIO metadata with Sun's custom TIFF tags, as described in * the <a href="https://svn.apache.org/repos/asf/xmlgraphics/commons/tags/commons-1_3_1/src/java/org/apache/xmlgraphics/image/writer/imageio/ImageIOTIFFImageWriter.java">org.apache.xmlgraphics.image.writer.ImageIOTIFFImageWriter * sources</a>, * the <a href="http://download.java.net/media/jai-imageio/javadoc/1.0_01/com/sun/media/imageio/plugins/tiff/package-summary.html">com.sun.media.imageio.plugins.tiff * package javadoc</a> * and the <a href="http://partners.adobe.com/public/developer/tiff/index.html">TIFF * specification</a>. * * @param image buffered image which will be written * @param metadata ImageIO metadata * @param dpi image dots per inch * @throws IIOInvalidTreeException if something goes wrong */ static void updateMetadata(IIOMetadata metadata, BufferedImage image, int dpi) throws IIOInvalidTreeException { debugLogMetadata(metadata, SUN_TIFF_FORMAT); if (!SUN_TIFF_FORMAT.equals(metadata.getNativeMetadataFormatName())) { LOG.debug("Using unknown TIFF image writer: " + metadata.getNativeMetadataFormatName()); return; } IIOMetadataNode root = new IIOMetadataNode(SUN_TIFF_FORMAT); IIOMetadataNode ifd; if (root.getElementsByTagName("TIFFIFD").getLength() == 0) { ifd = new IIOMetadataNode("TIFFIFD"); ifd.setAttribute("tagSets", tagSetClassName); root.appendChild(ifd); } else { ifd = (IIOMetadataNode) root.getElementsByTagName("TIFFIFD").item(0); } // standard metadata does not work, so we set the DPI manually ifd.appendChild(createRationalField(282, "XResolution", dpi, 1)); ifd.appendChild(createRationalField(283, "YResolution", dpi, 1)); ifd.appendChild(createShortField(296, "ResolutionUnit", 2)); // Inch ifd.appendChild(createLongField(278, "RowsPerStrip", image.getHeight())); ifd.appendChild(createAsciiField(305, "Software", "PDFBOX")); if (image.getType() == BufferedImage.TYPE_BYTE_BINARY && image.getColorModel().getPixelSize() == 1) { // set PhotometricInterpretation WhiteIsZero // because of bug in Windows XP preview ifd.appendChild(createShortField(262, "PhotometricInterpretation", 0)); } metadata.mergeTree(SUN_TIFF_FORMAT, root); debugLogMetadata(metadata, SUN_TIFF_FORMAT); } private static IIOMetadataNode createShortField(int tiffTagNumber, String name, int val) { IIOMetadataNode field, arrayNode, valueNode; field = new IIOMetadataNode("TIFFField"); field.setAttribute("number", Integer.toString(tiffTagNumber)); field.setAttribute("name", name); arrayNode = new IIOMetadataNode("TIFFShorts"); field.appendChild(arrayNode); valueNode = new IIOMetadataNode("TIFFShort"); arrayNode.appendChild(valueNode); valueNode.setAttribute("value", Integer.toString(val)); return field; } private static IIOMetadataNode createAsciiField(int number, String name, String val) { IIOMetadataNode field, arrayNode, valueNode; field = new IIOMetadataNode("TIFFField"); field.setAttribute("number", Integer.toString(number)); field.setAttribute("name", name); arrayNode = new IIOMetadataNode("TIFFAsciis"); field.appendChild(arrayNode); valueNode = new IIOMetadataNode("TIFFAscii"); arrayNode.appendChild(valueNode); valueNode.setAttribute("value", val); return field; } private static IIOMetadataNode createLongField(int number, String name, long val) { IIOMetadataNode field, arrayNode, valueNode; field = new IIOMetadataNode("TIFFField"); field.setAttribute("number", Integer.toString(number)); field.setAttribute("name", name); arrayNode = new IIOMetadataNode("TIFFLongs"); field.appendChild(arrayNode); valueNode = new IIOMetadataNode("TIFFLong"); arrayNode.appendChild(valueNode); valueNode.setAttribute("value", Long.toString(val)); return field; } private static IIOMetadataNode createRationalField(int number, String name, int numerator, int denominator) { IIOMetadataNode field, arrayNode, valueNode; field = new IIOMetadataNode("TIFFField"); field.setAttribute("number", Integer.toString(number)); field.setAttribute("name", name); arrayNode = new IIOMetadataNode("TIFFRationals"); field.appendChild(arrayNode); valueNode = new IIOMetadataNode("TIFFRational"); arrayNode.appendChild(valueNode); valueNode.setAttribute("value", numerator + "/" + denominator); return field; } }