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 org.apache.pdfbox.pdmodel.graphics.image; import java.awt.Transparency; import java.awt.color.ColorSpace; import java.awt.color.ICC_ColorSpace; import java.awt.image.BufferedImage; import java.awt.image.ColorConvertOp; import java.awt.image.Raster; import java.awt.image.WritableRaster; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.InputStream; import java.io.IOException; import java.io.OutputStream; import java.util.Iterator; import javax.imageio.IIOImage; import javax.imageio.ImageIO; import javax.imageio.ImageReader; import javax.imageio.ImageTypeSpecifier; import javax.imageio.ImageWriteParam; import javax.imageio.ImageWriter; import javax.imageio.metadata.IIOMetadata; import javax.imageio.plugins.jpeg.JPEGImageWriteParam; import javax.imageio.stream.ImageInputStream; import javax.imageio.stream.ImageOutputStream; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.pdfbox.cos.COSArray; import org.apache.pdfbox.cos.COSInteger; import org.apache.pdfbox.cos.COSName; import org.apache.pdfbox.filter.MissingImageReaderException; import org.apache.pdfbox.io.IOUtils; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.pdmodel.graphics.color.PDColorSpace; import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceCMYK; import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceGray; import org.apache.pdfbox.pdmodel.graphics.color.PDDeviceRGB; import org.w3c.dom.Element; /** * Factory for creating a PDImageXObject containing a JPEG compressed image. * @author John Hewson */ public final class JPEGFactory { private static final Log LOG = LogFactory.getLog(JPEGFactory.class); private JPEGFactory() { } /** * Creates a new JPEG Image XObject from an input stream containing JPEG data. * * The input stream data will be preserved and embedded in the PDF file without modification. * @param document the document where the image will be created * @param stream a stream of JPEG data * @return a new Image XObject * * @throws IOException if the input stream cannot be read */ public static PDImageXObject createFromStream(PDDocument document, InputStream stream) throws IOException { return createFromByteArray(document, IOUtils.toByteArray(stream)); } /** * Creates a new JPEG Image XObject from a byte array containing JPEG data. * * @param document the document where the image will be created * @param byteArray bytes of JPEG image * @return a new Image XObject * * @throws IOException if the input stream cannot be read */ public static PDImageXObject createFromByteArray(PDDocument document, byte[] byteArray) throws IOException { // copy stream ByteArrayInputStream byteStream = new ByteArrayInputStream(byteArray); Dimensions meta = retrieveDimensions(byteStream); PDColorSpace colorSpace; switch (meta.numComponents) { case 1: colorSpace = PDDeviceGray.INSTANCE; break; case 3: colorSpace = PDDeviceRGB.INSTANCE; break; case 4: colorSpace = PDDeviceCMYK.INSTANCE; break; default: throw new UnsupportedOperationException("number of data elements not supported: " + meta.numComponents); } // create PDImageXObject from stream PDImageXObject pdImage = new PDImageXObject(document, byteStream, COSName.DCT_DECODE, meta.width, meta.height, 8, colorSpace); if (colorSpace instanceof PDDeviceCMYK) { COSArray decode = new COSArray(); decode.add(COSInteger.ONE); decode.add(COSInteger.ZERO); decode.add(COSInteger.ONE); decode.add(COSInteger.ZERO); decode.add(COSInteger.ONE); decode.add(COSInteger.ZERO); decode.add(COSInteger.ONE); decode.add(COSInteger.ZERO); pdImage.setDecode(decode); } return pdImage; } private static class Dimensions { private int width; private int height; private int numComponents; } private static Dimensions retrieveDimensions(ByteArrayInputStream stream) throws IOException { // find suitable image reader Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName("JPEG"); ImageReader reader = null; while (readers.hasNext()) { reader = readers.next(); if (reader.canReadRaster()) { break; } } if (reader == null) { throw new MissingImageReaderException( "Cannot read JPEG image: a suitable JAI I/O image filter is not installed"); } try (ImageInputStream iis = ImageIO.createImageInputStream(stream)) { reader.setInput(iis); Dimensions meta = new Dimensions(); meta.width = reader.getWidth(0); meta.height = reader.getHeight(0); // PDFBOX-4691: get from image metadata (faster because no decoding) try { meta.numComponents = getNumComponentsFromImageMetadata(reader); if (meta.numComponents != 0) { return meta; } LOG.warn("No image metadata, will decode image and use raster size"); } catch (IOException ex) { LOG.warn("Error reading image metadata, will decode image and use raster size", ex); } // Old method: get from raster (slower) ImageIO.setUseCache(false); Raster raster = reader.readRaster(0, null); meta.numComponents = raster.getNumDataElements(); return meta; } finally { stream.reset(); reader.dispose(); } } private static int getNumComponentsFromImageMetadata(ImageReader reader) throws IOException { IIOMetadata imageMetadata = reader.getImageMetadata(0); if (imageMetadata == null) { return 0; } Element root = (Element) imageMetadata.getAsTree("javax_imageio_jpeg_image_1.0"); if (root == null) { return 0; } try { XPath xpath = XPathFactory.newInstance().newXPath(); String numScanComponents = xpath.evaluate("markerSequence/sos/@numScanComponents", root); if (numScanComponents.isEmpty()) { return 0; } return Integer.parseInt(numScanComponents); } catch (NumberFormatException | XPathExpressionException ex) { LOG.warn(ex.getMessage(), ex); return 0; } } /** * Creates a new JPEG PDImageXObject from a BufferedImage. * <p> * Do not read a JPEG image from a stream/file and call this method; you'll get more speed and * quality by calling {@link #createFromStream(org.apache.pdfbox.pdmodel.PDDocument, * java.io.InputStream) createFromStream()} instead. * * @param document the document where the image will be created * @param image the BufferedImage to embed * @return a new Image XObject * @throws IOException if the JPEG data cannot be written */ public static PDImageXObject createFromImage(PDDocument document, BufferedImage image) throws IOException { return createFromImage(document, image, 0.75f); } /** * Creates a new JPEG PDImageXObject from a BufferedImage and a given quality. * <p> * Do not read a JPEG image from a stream/file and call this method; you'll get more speed and * quality by calling {@link #createFromStream(org.apache.pdfbox.pdmodel.PDDocument, * java.io.InputStream) createFromStream()} instead. * * The image will be created with a dpi value of 72 to be stored in metadata. * @param document the document where the image will be created * @param image the BufferedImage to embed * @param quality The desired JPEG compression quality; between 0 (best * compression) and 1 (best image quality). See * {@link ImageWriteParam#setCompressionQuality(float)} for more details. * @return a new Image XObject * @throws IOException if the JPEG data cannot be written */ public static PDImageXObject createFromImage(PDDocument document, BufferedImage image, float quality) throws IOException { return createFromImage(document, image, quality, 72); } /** * Creates a new JPEG Image XObject from a BufferedImage, a given quality and dpi metadata. * <p> * Do not read a JPEG image from a stream/file and call this method; you'll get more speed and * quality by calling {@link #createFromStream(org.apache.pdfbox.pdmodel.PDDocument, * java.io.InputStream) createFromStream()} instead. * * @param document the document where the image will be created * @param image the BufferedImage to embed * @param quality The desired JPEG compression quality; between 0 (best * compression) and 1 (best image quality). See * {@link ImageWriteParam#setCompressionQuality(float)} for more details. * @param dpi the desired dpi (resolution) value of the JPEG to be stored in metadata. This * value has no influence on image content or size. * @return a new Image XObject * @throws IOException if the JPEG data cannot be written */ public static PDImageXObject createFromImage(PDDocument document, BufferedImage image, float quality, int dpi) throws IOException { return createJPEG(document, image, quality, dpi); } // returns the alpha channel of an image private static BufferedImage getAlphaImage(BufferedImage image) { if (!image.getColorModel().hasAlpha()) { return null; } if (image.getTransparency() == Transparency.BITMASK) { throw new UnsupportedOperationException( "BITMASK Transparency JPEG compression is not" + " useful, use LosslessImageFactory instead"); } WritableRaster alphaRaster = image.getAlphaRaster(); if (alphaRaster == null) { // happens sometimes (PDFBOX-2654) despite colormodel claiming to have alpha return null; } BufferedImage alphaImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_BYTE_GRAY); alphaImage.setData(alphaRaster); return alphaImage; } // Creates an Image XObject from a BufferedImage using JAI Image I/O private static PDImageXObject createJPEG(PDDocument document, BufferedImage image, float quality, int dpi) throws IOException { // extract alpha channel (if any) BufferedImage awtColorImage = getColorImage(image); BufferedImage awtAlphaImage = getAlphaImage(image); // create XObject ByteArrayOutputStream baos = new ByteArrayOutputStream(); encodeImageToJPEGStream(awtColorImage, quality, dpi, baos); ByteArrayInputStream byteStream = new ByteArrayInputStream(baos.toByteArray()); PDImageXObject pdImage = new PDImageXObject(document, byteStream, COSName.DCT_DECODE, awtColorImage.getWidth(), awtColorImage.getHeight(), 8, getColorSpaceFromAWT(awtColorImage)); // alpha -> soft mask if (awtAlphaImage != null) { PDImage xAlpha = JPEGFactory.createFromImage(document, awtAlphaImage, quality); pdImage.getCOSObject().setItem(COSName.SMASK, xAlpha); } return pdImage; } private static ImageWriter getJPEGImageWriter() throws IOException { ImageWriter writer = null; Iterator<ImageWriter> writers = ImageIO.getImageWritersBySuffix("jpeg"); while (writers.hasNext()) { if (writer != null) { writer.dispose(); } writer = writers.next(); if (writer == null) { continue; } // PDFBOX-3566: avoid CLibJPEGImageWriter, which is not a JPEGImageWriteParam if (writer.getDefaultWriteParam() instanceof JPEGImageWriteParam) { return writer; } } throw new IOException("No ImageWriter found for JPEG format"); } private static void encodeImageToJPEGStream(BufferedImage image, float quality, int dpi, OutputStream out) throws IOException { // encode to JPEG ImageOutputStream ios = null; ImageWriter imageWriter = null; try { // find JAI writer imageWriter = getJPEGImageWriter(); ios = ImageIO.createImageOutputStream(out); imageWriter.setOutput(ios); // add compression ImageWriteParam jpegParam = imageWriter.getDefaultWriteParam(); jpegParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); jpegParam.setCompressionQuality(quality); // add metadata ImageTypeSpecifier imageTypeSpecifier = new ImageTypeSpecifier(image); IIOMetadata data = imageWriter.getDefaultImageMetadata(imageTypeSpecifier, jpegParam); Element tree = (Element) data.getAsTree("javax_imageio_jpeg_image_1.0"); Element jfif = (Element) tree.getElementsByTagName("app0JFIF").item(0); jfif.setAttribute("Xdensity", Integer.toString(dpi)); jfif.setAttribute("Ydensity", Integer.toString(dpi)); jfif.setAttribute("resUnits", "1"); // 1 = dots/inch // write imageWriter.write(data, new IIOImage(image, null, null), jpegParam); } finally { // clean up IOUtils.closeQuietly(out); if (ios != null) { ios.close(); } if (imageWriter != null) { imageWriter.dispose(); } } } // returns a PDColorSpace for a given BufferedImage private static PDColorSpace getColorSpaceFromAWT(BufferedImage awtImage) { if (awtImage.getColorModel().getNumComponents() == 1) { // 256 color (gray) JPEG return PDDeviceGray.INSTANCE; } ColorSpace awtColorSpace = awtImage.getColorModel().getColorSpace(); if (awtColorSpace instanceof ICC_ColorSpace && !awtColorSpace.isCS_sRGB()) { throw new UnsupportedOperationException("ICC color spaces not implemented"); } switch (awtColorSpace.getType()) { case ColorSpace.TYPE_RGB: return PDDeviceRGB.INSTANCE; case ColorSpace.TYPE_GRAY: return PDDeviceGray.INSTANCE; case ColorSpace.TYPE_CMYK: return PDDeviceCMYK.INSTANCE; default: throw new UnsupportedOperationException("color space not implemented: " + awtColorSpace.getType()); } } // returns the color channels of an image private static BufferedImage getColorImage(BufferedImage image) { if (!image.getColorModel().hasAlpha()) { return image; } if (image.getColorModel().getColorSpace().getType() != ColorSpace.TYPE_RGB) { throw new UnsupportedOperationException("only RGB color spaces are implemented"); } // create an RGB image without alpha //BEWARE: the previous solution in the history // g.setComposite(AlphaComposite.Src) and g.drawImage() // didn't work properly for TYPE_4BYTE_ABGR. // alpha values of 0 result in a black dest pixel!!! BufferedImage rgbImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_3BYTE_BGR); return new ColorConvertOp(null).filter(image, rgbImage); } }