/* * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * The main package of the Java Image I/O API. *

* Many common image I/O operations may be performed using the static methods of * the {@code ImageIO} class. *

* This package contains the basic classes and interfaces for describing the * contents of image files, including metadata and thumbnails * ({@code IIOImage}); for controlling the image reading process * ({@code ImageReader}, {@code ImageReadParam}, and {@code ImageTypeSpecifier}) * and image writing process ({@code ImageWriter} and {@code ImageWriteParam}); * for performing transcoding between formats ({@code ImageTranscoder}), and for * reporting errors ({@code IIOException}). *

* All implementations of javax.imageio provide the following standard image * format plug-ins: * * * * * * * * * * * * * * * *
Standard image format plug-ins
Image format * Reading * Writing * Notes * Metadata *
* BMP * yes * yes * none * BMP * metadata format * *
* GIF * yes * yes * GIF plug-in notes * GIF * metadata format * *
JPEG * yes * yes * none * * JPEG metadata format * *
PNG * yes * yes * none * PNG * metadata format * *
* * TIFF * yes * yes * * TIFF plug-in * notes * * TIFF * metadata format * *
* * WBMP * yes * yes * none * * WBMP metadata format *
* *

Standard Plug-in Notes

* *

Standard plug-in for GIF image format

* ImageIO provides {@code ImageReader} and {@code ImageWriter}plug-ins for the * Graphics * Interchange Format (GIF) image format. These are the "standard" GIF * plug-ins, meaning those that are included in the JRE, as distinct from those * included in standard extensions, or 3rd party plug-ins. The following notes * and metadata specification apply to the standard plug-ins. * *

Writing GIF images

* The GIF image writer plug-in guarantees lossless writing for images which * meet the following requirements: * *

* By default the GIF writer plug-in creates version "89a" images. This can be * changed to "87a" by explicitly setting the version in the stream metadata * (see * * GIF Stream Metadata Format Specification). * * *

* The GIF writer plug-in supports the creation of animated GIF images through * the standard sequence writing methods defined in the {@code ImageWriter} * class. * * * * *

* A global color table is written to the output stream if one of the following * conditions is met: *

*

* In the first case the global color table in the stream metadata is used, in * the second the local color table in the image metadata is used, and in the * third a global color table is created from the ColorModel or SampleModel of * the (first) image. *

* A local color table is written to the output stream only if image metadata * containing a LocalColorTable element is supplied to the writer, or no image * metadata is supplied to the writer and the local color table which would be * generated from the image itself is not equal to the global color table. *

* A Graphic Control Extension block is written to the output stream only if * image metadata containing a GraphicControlExtension element is supplied to * the writer, or no image metadata is supplied and the local color table * generated from the image requires a transparent index. Application, Plain * Text, and Comment Extension blocks are written only if they are supplied to * the writer via image metadata. * * *

* The writing of interlaced images can be controlled by the progressive mode of * the provided {@code ImageWriteParam} instance. If progressive mode is * {@code MODE_DISABLED} then a non-interlaced image will be written. If * progressive mode is {@code MODE_DEFAULT} then an interlaced image will be * written. If progressive mode is {@code MODE_COPY_FROM_METADATA}, then the * metadata setting is used (if it is provided, otherwise an interlaced image * will be written). *

* The GIF image writer plug-in supports setting output stream metadata from * metadata supplied to the writer in either the native GIF stream metadata * format * * javax_imageio_gif_stream_1.0 or the standard metadata format * javax_imageio_1.0, * and setting output image metadata from metadata supplied to the writer in * either the native GIF image metadata format * * javax_imageio_gif_image_1.0 or the standard metadata format * javax_imageio_1.0. * The mapping of standard metadata format to the GIF native stream and image * metadata formats is given in the tables * here. * * @since 1.4 */ package javax.imageio;