1 /* 2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 /** 27 * The main package of the Java Image I/O API. 28 * <p> 29 * Many common image I/O operations may be performed using the static methods of 30 * the {@code ImageIO} class. 31 * <p> 32 * This package contains the basic classes and interfaces for describing the 33 * contents of image files, including metadata and thumbnails 34 * ({@code IIOImage}); for controlling the image reading process 35 * ({@code ImageReader}, {@code ImageReadParam}, and {@code ImageTypeSpecifier}) 36 * and image writing process ({@code ImageWriter} and {@code ImageWriteParam}); 37 * for performing transcoding between formats ({@code ImageTranscoder}), and for 38 * reporting errors ({@code IIOException}). 39 * <p> 40 * All implementations of javax.imageio provide the following standard image 41 * format plug-ins: 42 * 43 * <table class="striped"> 44 * <caption>Standard image format plug-ins</caption> 45 * <thead> 46 * <tr> 47 * <th scope="col">Image format 48 * <th scope="col">Reading 49 * <th scope="col">Writing 50 * <th scope="col">Notes 51 * <th scope="col">Metadata 52 * </thead> 53 * <tbody> 54 * <!-- BMP plugin --> 55 * <tr> 56 * <th scope="row"> 57 * <a href="https://msdn.microsoft.com/en-us/library/dd183391.aspx">BMP</a> 58 * <td>yes 59 * <td>yes 60 * <td>none 61 * <td><a href='metadata/doc-files/bmp_metadata.html'>BMP 62 * metadata format</a> 63 * <!-- GIF plugin --> 64 * <tr> 65 * <th scope="row"> 66 * <a href="http://www.w3.org/Graphics/GIF/spec-gif89a.txt">GIF</a> 67 * <td>yes 68 * <td>yes 69 * <td><a href="#gif_plugin_notes">GIF plug-in notes</a> 70 * <td><a href='metadata/doc-files/gif_metadata.html'>GIF 71 * metadata format</a> 72 * <!-- JPEG plugin --> 73 * <tr> 74 * <th scope="row"><a href="http://www.jpeg.org">JPEG</a> 75 * <td>yes 76 * <td>yes 77 * <td>none 78 * <td><a href='metadata/doc-files/jpeg_metadata.html'> 79 * JPEG metadata format</a> 80 * <!-- PNG plugin --> 81 * <tr> 82 * <th scope="row"><a href="http://www.libpng.org/pub/png/spec/">PNG</a> 83 * <td>yes 84 * <td>yes 85 * <td>none 86 * <td><a href='metadata/doc-files/png_metadata.html'>PNG 87 * metadata format</a> 88 * <!-- TIFF plugin --> 89 * <tr> 90 * <th scope="row"> 91 * <a href="https://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf"> 92 * TIFF</a> 93 * <td>yes 94 * <td>yes 95 * <td> 96 * <a href='metadata/doc-files/tiff_metadata.html#Reading'>TIFF plug-in 97 * notes</a> 98 * <td> 99 * <a href='metadata/doc-files/tiff_metadata.html#StreamMetadata'>TIFF 100 * metadata format</a> 101 * <!-- WBMP plugin --> 102 * <tr> 103 * <th scope="row"> 104 * <a href="http://www.wapforum.org/what/technical/SPEC-WAESpec-19990524.pdf"> 105 * WBMP</a> 106 * <td>yes 107 * <td>yes 108 * <td>none 109 * <td><a href='metadata/doc-files/wbmp_metadata.html'> 110 * WBMP metadata format</a> 111 * </tbody> 112 * </table> 113 * 114 * <h2> Standard Plug-in Notes</h2> 115 * 116 * <h3><a id="gif_plugin_notes">Standard plug-in for GIF image format</a></h3> 117 * ImageIO provides {@code ImageReader} and {@code ImageWriter}plug-ins for the 118 * <a href="http://www.w3.org/Graphics/GIF/spec-gif89a.txt"> Graphics 119 * Interchange Format (GIF)</a> image format. These are the "standard" GIF 120 * plug-ins, meaning those that are included in the JRE, as distinct from those 121 * included in standard extensions, or 3rd party plug-ins. The following notes 122 * and metadata specification apply to the standard plug-ins. 123 * 124 * <h3>Writing GIF images</h3> 125 * The GIF image writer plug-in guarantees lossless writing for images which 126 * meet the following requirements: 127 * <ul> 128 * <li>the number of bands is 1;</li> 129 * <li>the number of bits per sample is not greater than 8;</li> 130 * <li>the size of a color component is not greater than 8;</li> 131 * </ul> 132 * <p> 133 * By default the GIF writer plug-in creates version "89a" images. This can be 134 * changed to "87a" by explicitly setting the version in the stream metadata 135 * (see 136 * <a href="metadata/doc-files/gif_metadata.html#gif_stream_metadata_format"> 137 * GIF Stream Metadata Format Specification</a>). 138 * 139 * <!-- animated images --> 140 * <p> 141 * The GIF writer plug-in supports the creation of animated GIF images through 142 * the standard sequence writing methods defined in the {@code ImageWriter} 143 * class. 144 * 145 * <!-- TODO: add example here --> 146 * 147 * <!-- color tables --> 148 * <p> 149 * A global color table is written to the output stream if one of the following 150 * conditions is met: 151 * <ul> 152 * <li>stream metadata containing a GlobalColorTable element is supplied; 153 * </li> 154 * <li>a sequence is being written and image metadata containing a 155 * LocalColorTable element is supplied for the first image in the sequence; 156 * </li> 157 * <li>image metadata is not supplied or does not contain a LocalColorTable 158 * element.</li> 159 * </ul> 160 * <p> 161 * In the first case the global color table in the stream metadata is used, in 162 * the second the local color table in the image metadata is used, and in the 163 * third a global color table is created from the ColorModel or SampleModel of 164 * the (first) image. 165 * <p> 166 * A local color table is written to the output stream only if image metadata 167 * containing a LocalColorTable element is supplied to the writer, or no image 168 * metadata is supplied to the writer and the local color table which would be 169 * generated from the image itself is not equal to the global color table. 170 * <p> 171 * A Graphic Control Extension block is written to the output stream only if 172 * image metadata containing a GraphicControlExtension element is supplied to 173 * the writer, or no image metadata is supplied and the local color table 174 * generated from the image requires a transparent index. Application, Plain 175 * Text, and Comment Extension blocks are written only if they are supplied to 176 * the writer via image metadata. 177 * 178 * <!-- writing interlaced images --> 179 * <p> 180 * The writing of interlaced images can be controlled by the progressive mode of 181 * the provided {@code ImageWriteParam} instance. If progressive mode is 182 * {@code MODE_DISABLED} then a non-interlaced image will be written. If 183 * progressive mode is {@code MODE_DEFAULT} then an interlaced image will be 184 * written. If progressive mode is {@code MODE_COPY_FROM_METADATA}, then the 185 * metadata setting is used (if it is provided, otherwise an interlaced image 186 * will be written). 187 * <p> 188 * The GIF image writer plug-in supports setting output stream metadata from 189 * metadata supplied to the writer in either the native GIF stream metadata 190 * format 191 * <a href="metadata/doc-files/gif_metadata.html#gif_stream_metadata_format"> 192 * javax_imageio_gif_stream_1.0</a> or the standard metadata format 193 * <a href="metadata/doc-files/standard_metadata.html">javax_imageio_1.0</a>, 194 * and setting output image metadata from metadata supplied to the writer in 195 * either the native GIF image metadata format 196 * <a href="metadata/doc-files/gif_metadata.html#gif_image_metadata_format"> 197 * javax_imageio_gif_image_1.0</a> or the standard metadata format 198 * <a href="metadata/doc-files/standard_metadata.html">javax_imageio_1.0</a>. 199 * The mapping of standard metadata format to the GIF native stream and image 200 * metadata formats is given in the tables 201 * <a href="metadata/doc-files/gif_metadata.html#mapping">here</a>. 202 * 203 * @since 1.4 204 */ 205 package javax.imageio;