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/* * ImageInfo.java * * Version 1.9 * * A Java class to determine image width, height and color depth for * a number of image file formats. * * Written by Marco Schmidt * * Contributed to the Public Domain. */ package com.jeecms.common.image; import java.io.DataInput; import java.io.FileInputStream; import java.io.InputStream; import java.io.IOException; import java.net.URL; import java.util.Vector; /** * Get file format, image resolution, number of bits per pixel and optionally * number of images, comments and physical resolution from * JPEG, GIF, BMP, PCX, PNG, IFF, RAS, PBM, PGM, PPM and PSD files * (or input streams). * <p> * Use the class like this: * <pre> * ImageInfo ii = new ImageInfo(); * ii.setInput(in); // in can be InputStream or RandomAccessFile * ii.setDetermineImageNumber(true); // default is false * ii.setCollectComments(true); // default is false * if (!ii.check()) { * System.err.println("Not a supported image file format."); * return; * } * System.out.println(ii.getFormatName() + ", " + ii.getMimeType() + * ", " + ii.getWidth() + " x " + ii.getHeight() + " pixels, " + * ii.getBitsPerPixel() + " bits per pixel, " + ii.getNumberOfImages() + * " image(s), " + ii.getNumberOfComments() + " comment(s)."); * // there are other properties, check out the API documentation * </pre> * You can also use this class as a command line program. * Call it with a number of image file names and URLs as parameters: * <pre> * java ImageInfo *.jpg *.png *.gif http://somesite.tld/image.jpg * </pre> * or call it without parameters and pipe data to it: * <pre> * java ImageInfo &lt; image.jpg * </pre> * <p> * Known limitations: * <ul> * <li>When the determination of the number of images is turned off, GIF bits * per pixel are only read from the global header. * For some GIFs, local palettes change this to a typically larger * value. To be certain to get the correct color depth, call * setDetermineImageNumber(true) before calling check(). * The complete scan over the GIF file will take additional time.</li> * <li>Transparency information is not included in the bits per pixel count. * Actually, it was my decision not to include those bits, so it's a feature! ;-)</li> * </ul> * <p> * Requirements: * <ul> * <li>Java 1.1 or higher</li> * </ul> * <p> * The latest version can be found at <a href="http://schmidt.devlib.org/image-info/">http://schmidt.devlib.org/image-info/</a>. * <p> * Written by Marco Schmidt. * <p> * This class is contributed to the Public Domain. * Use it at your own risk. * <p> * <a name="history">History</a>: * <ul> * <li><strong>2001-08-24</strong> Initial version.</li> * <li><strong>2001-10-13</strong> Added support for the file formats BMP and PCX.</li> * <li><strong>2001-10-16</strong> Fixed bug in read(int[], int, int) that returned * <li><strong>2002-01-22</strong> Added support for file formats Amiga IFF and Sun Raster (RAS).</li> * <li><strong>2002-01-24</strong> Added support for file formats Portable Bitmap / Graymap / Pixmap (PBM, PGM, PPM) and Adobe Photoshop (PSD). * Added new method getMimeType() to return the MIME type associated with a particular file format.</li> * <li><strong>2002-03-15</strong> Added support to recognize number of images in file. Only works with GIF. * Use {@link #setDetermineImageNumber} with <code>true</code> as argument to identify animated GIFs * ({@link #getNumberOfImages()} will return a value larger than <code>1</code>).</li> * <li><strong>2002-04-10</strong> Fixed a bug in the feature 'determine number of images in animated GIF' introduced with version 1.1. * Thanks to Marcelo P. Lima for sending in the bug report. * Released as 1.1.1.</li> * <li><strong>2002-04-18</strong> Added {@link #setCollectComments(boolean)}. * That new method lets the user specify whether textual comments are to be * stored in an internal list when encountered in an input image file / stream. * Added two methods to return the physical width and height of the image in dpi: * {@link #getPhysicalWidthDpi()} and {@link #getPhysicalHeightDpi()}. * If the physical resolution could not be retrieved, these methods return <code>-1</code>. * </li> * <li><strong>2002-04-23</strong> Added support for the new properties physical resolution and * comments for some formats. Released as 1.2.</li> * <li><strong>2002-06-17</strong> Added support for SWF, sent in by Michael Aird. * Changed checkJpeg() so that other APP markers than APP0 will not lead to a failure anymore. * Released as 1.3.</li> * <li><strong>2003-07-28</strong> Bug fix - skip method now takes return values into consideration. * Less bytes than necessary may have been skipped, leading to flaws in the retrieved information in some cases. * Thanks to Bernard Bernstein for pointing that out. * Released as 1.4.</li> * <li><strong>2004-02-29</strong> Added support for recognizing progressive JPEG and * interlaced PNG and GIF. A new method {@link #isProgressive()} returns whether ImageInfo * has found that the storage type is progressive (or interlaced). * Thanks to Joe Germuska for suggesting the feature. * Bug fix: BMP physical resolution is now correctly determined. * Released as 1.5.</li> * <li><strong>2004-11-30</strong> Bug fix: recognizing progressive GIFs * (interlaced in GIF terminology) did not work (thanks to Franz Jeitler for * pointing this out). Now it should work, but only if the number of images is determined. * This is because information on interlacing is stored in a local image header. * In theory, different images could be stored interlaced and non-interlaced in one * file. However, I think that's unlikely. Right now, the last image in the GIF file * that is examined by ImageInfo is used for the "progressive" status.</li> * <li><strong>2005-01-02</strong> Some code clean up (unused methods and variables * commented out, missing javadoc comments, etc.). Thanks to George Sexton for a long list. * Removed usage of Boolean.toString because * it's a Java 1.4+ feature (thanks to Gregor Dupont). * Changed delimiter character in compact output from semicolon to tabulator * (for better integration with cut(1) and other Unix tools). * Added some points to the <a href="http://schmidt.devlib.org/image-info/index.html#knownissues">'Known * issues' section of the website</a>. * Released as 1.6.</li> * <li><strong>2005-07-26</strong> Removed code to identify Flash (SWF) files. * Has repeatedly led to problems and support requests, and I don't know the * format and don't have the time and interest to fix it myself. * I repeatedly included fixes by others which didn't work for some people. * I give up on SWF. Please do not contact me about it anymore. * Set package of ImageInfo class to org.devlib.schmidt.imageinfo (a package * was repeatedly requested by some users). * Released as 1.7.</li> * <li><strong>2006-02-23</strong> Removed Flash helper methods which weren't used elsewhere. * Updated skip method which tries "read" whenever "skip(Bytes)" returns a result of 0. * The old method didn't work with certain input stream types on truncated data streams. * Thanks to Martin Leidig for reporting this and sending in code. * Released as 1.8.</li> * </li> * <li><strong>2006-11-13</strong> Removed check that made ImageInfo report JPEG APPx * markers smaller than 14 bytes as files in unknown format. Such JPEGs seem to be * generated by Google's Picasa application. First reported with fix by * Karl von Randow. Released as 1.9.</li> * </ul> * @author Marco Schmidt */ @SuppressWarnings("unchecked") public class ImageInfo { /** * Return value of {@link #getFormat()} for JPEG streams. * ImageInfo can extract physical resolution and comments * from JPEGs (only from APP0 headers). * Only one image can be stored in a file. * It is determ