001/* ImageTranscoder.java -- Image metadata transcoder.
002   Copyright (C) 2004  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.imageio;
040
041import javax.imageio.metadata.IIOMetadata;
042
043/**
044 * An ImageTranscoder translates IIOMetadata objects provided by an
045 * ImageReader into corresponding IIOMetadata objects that can be
046 * understood by a given ImageWriter.
047 *
048 * Usually an ImageWriter will implement ImageTranscoder directly in
049 * which case the conversion methods will return IIOMetadata objects
050 * appropriate for this ImageWriter.
051 *
052 * Independent transcoders are also allowed; they must have knowledge
053 * of both the source IIOMetadata provided by the reader and the
054 * returned IIOMetadata expected by the writer.
055 *
056 * @author Michael Koch (konqueror@gmx.de)
057 */
058public interface ImageTranscoder
059{
060  /**
061   * Converts IIOMetadata from an input reader format, returning an
062   * IIOMetadata suitable for use by an image writer.
063   *
064   * The ImageTypeSpecifier specifies the destination image type.
065   *
066   * An optional ImageWriteParam argument is available in case the
067   * image writing parameters affect the metadata conversion.
068   *
069   * @param inData the metadata coming from an image reader
070   * @param imageType the output image type of the writer
071   * @param param the image writing parameters or null
072   *
073   * @return the converted metadata that should be used by the image
074   * writer, or null if this ImageTranscoder has no knowledge of the
075   * input metadata
076   *
077   * @exception IllegalArgumentException if either inData or imageType
078   * is null
079   */
080  IIOMetadata convertImageMetadata(IIOMetadata inData,
081                                   ImageTypeSpecifier imageType,
082                                   ImageWriteParam param);
083
084  /**
085   * Converts IIOMetadata from an input stream format, returning an
086   * IIOMetadata suitable for use by an image writer.
087   *
088   * An optional ImageWriteParam argument is available in case the
089   * image writing parameters affect the metadata conversion.
090   *
091   * @param inData the metadata coming from an input image stream
092   * @param param the image writing parameters or null
093   *
094   * @return the converted metadata that should be used by the image
095   * writer, or null if this ImageTranscoder has no knowledge of the
096   * input metadata
097   *
098   * @exception IllegalArgumentException if inData is null
099   */
100  IIOMetadata convertStreamMetadata(IIOMetadata inData,
101                                    ImageWriteParam param);
102}