Java 图像处理类库：Apache Commons Imaging

Apache Commons Imaging 之前是著名的 Apache Commons Sanselan ，用于读写各种图像格式的 Java 类库，包括快速解析图片的基本信息（size, color space, ICC profile等）和元数据。尽管慢点但非常好的可移植性。比起 ImageIO/JAI/Toolkit 更容易使用，支持更多的格式，提供简单访问元数据的方法。javadoc

读取图像EXIF信息的示例代码：

001 package org.apache.commons.imaging.examples;
002
003 import java.io.BufferedOutputStream;
004 import java.io.File;
005 import java.io.FileOutputStream;
006 import java.io.IOException;
007 import java.io.OutputStream;
008
009 import org.apache.commons.imaging.ImageReadException;
010 import org.apache.commons.imaging.ImageWriteException;
011 import org.apache.commons.imaging.Imaging;
012 import org.apache.commons.imaging.common.IImageMetadata;
013 import org.apache.commons.imaging.common.RationalNumber;
014 import org.apache.commons.imaging.formats.jpeg.JpegImageMetadata;
015 import org.apache.commons.imaging.formats.jpeg.exif.ExifRewriter;
016 import org.apache.commons.imaging.formats.tiff.TiffImageMetadata;
017 import org.apache.commons.imaging.formats.tiff.constants.ExifTagConstants;
018 import org.apache.commons.imaging.formats.tiff.write.TiffOutputDirectory;
019 import org.apache.commons.imaging.formats.tiff.write.TiffOutputSet;
020 import org.apache.commons.imaging.util.IoUtils;
021
022 public class WriteExifMetadataExample {
023     public void removeExifMetadata(final File jpegImageFile, final File dst)
024             throws IOException, ImageReadException, ImageWriteException {
025         OutputStream os = null;
026         try {
027             os = new FileOutputStream(dst);
028             os = new BufferedOutputStream(os);
029
030             new ExifRewriter().removeExifMetadata(jpegImageFile, os);
031         } finally {
032             if (os != null) {
033                 try {
034                     os.close();
035                 } catch (final IOException e) {
036
037                 }
038             }
039         }
040     }
041
042     /**
043      * This example illustrates how to add/update EXIF metadata in a JPEG file.
044      *
045      * @param jpegImageFile
046      *            A source image file.
047      * @param dst
048      *            The output file.
049      * @throws IOException
050      * @throws ImageReadException
051      * @throws ImageWriteException
052      */
053     public void changeExifMetadata(final File jpegImageFile, final File dst)
054             throws IOException, ImageReadException, ImageWriteException {
055         OutputStream os = null;
056         try {
057             TiffOutputSet outputSet = null;
058
059             // note that metadata might be null if no metadata is found.
060             final IImageMetadata metadata = Imaging.getMetadata(jpegImageFile);
061             final JpegImageMetadata jpegMetadata = (JpegImageMetadata) metadata;
062             if (null != jpegMetadata) {
063                 // note that exif might be null if no Exif metadata is found.
064                 final TiffImageMetadata exif = jpegMetadata.getExif();
065
066                 if (null != exif) {
067                     // TiffImageMetadata class is immutable (read-only).
068                     // TiffOutputSet class represents the Exif data to write.
069                     //
070                     // Usually, we want to update existing Exif metadata by
071                     // changing
072                     // the values of a few fields, or adding a field.
073                     // In these cases, it is easiest to use getOutputSet() to
074                     // start with a "copy" of the fields read from the image.
075                     outputSet = exif.getOutputSet();
076                 }
077             }
078
079             // if file does not contain any exif metadata, we create an empty
080             // set of exif metadata. Otherwise, we keep all of the other
081             // existing tags.
082             if (null == outputSet) {
083                 outputSet = new TiffOutputSet();
084             }
085
086             {
087                 // Example of how to add a field/tag to the output set.
088                 //
089                 // Note that you should first remove the field/tag if it already
090                 // exists in this directory, or you may end up with duplicate
091                 // tags. See above.
092                 //
093                 // Certain fields/tags are expected in certain Exif directories;
094                 // Others can occur in more than one directory (and often have a
095                 // different meaning in different directories).
096                 //
097                 // TagInfo constants often contain a description of what
098                 // directories are associated with a given tag.
099                 //
100                 // see
101                 // org.apache.commons.sanselan.formats.tiff.constants.AllTagConstants
102                 //
103                 final TiffOutputDirectory exifDirectory = outputSet
104                         .getOrCreateExifDirectory();
105                 // make sure to remove old value if present (this method will
106                 // not fail if the tag does not exist).
107                 exifDirectory
108                         .removeField(ExifTagConstants.EXIF_TAG_APERTURE_VALUE);
109                 exifDirectory.add(ExifTagConstants.EXIF_TAG_APERTURE_VALUE,
110                         RationalNumber.factoryMethod(3, 10));
111             }
112
113             {
114                 // Example of how to add/update GPS info to output set.
115
116                 // New York City
117                 final double longitude = -74.0; // 74 degrees W (in Degrees East)
118                 final double latitude = 40 + 43 / 60.0; // 40 degrees N (in Degrees
119                 // North)
120
121                 outputSet.setGPSInDegrees(longitude, latitude);
122             }
123
124             // printTagValue(jpegMetadata, TiffConstants.TIFF_TAG_DATE_TIME);
125
126             os = new FileOutputStream(dst);
127             os = new BufferedOutputStream(os);
128
129             new ExifRewriter().updateExifMetadataLossless(jpegImageFile, os,
130                     outputSet);
131
132             os.close();
133             os = null;
134         } finally {
135             if (os != null) {
136                 try {
137                     os.close();
138                 } catch (final IOException e) {
139
140                 }
141             }
142         }
143     }
144
145     /**
146      * This example illustrates how to remove a tag (if present) from EXIF
147      * metadata in a JPEG file.
148      *
149      * In this case, we remove the "aperture" tag from the EXIF metadata if
150      * present.
151      *
152      * @param jpegImageFile
153      *            A source image file.
154      * @param dst
155      *            The output file.
156      * @throws IOException
157      * @throws ImageReadException
158      * @throws ImageWriteException
159      */
160     public void removeExifTag(final File jpegImageFile, final File dst) throwsIOException,
161             ImageReadException, ImageWriteException {
162         OutputStream os = null;
163         try {
164             TiffOutputSet outputSet = null;
165
166             // note that metadata might be null if no metadata is found.
167             final IImageMetadata metadata = Imaging.getMetadata(jpegImageFile);
168             final JpegImageMetadata jpegMetadata = (JpegImageMetadata) metadata;
169             if (null != jpegMetadata) {
170                 // note that exif might be null if no Exif metadata is found.
171                 final TiffImageMetadata exif = jpegMetadata.getExif();
172
173                 if (null != exif) {
174                     // TiffImageMetadata class is immutable (read-only).
175                     // TiffOutputSet class represents the Exif data to write.
176                     //
177                     // Usually, we want to update existing Exif metadata by
178                     // changing
179                     // the values of a few fields, or adding a field.
180                     // In these cases, it is easiest to use getOutputSet() to
181                     // start with a "copy" of the fields read from the image.
182                     outputSet = exif.getOutputSet();
183                 }
184             }
185
186             if (null == outputSet) {
187                 // file does not contain any exif metadata. We don't need to
188                 // update the file; just copy it.
189                 IoUtils.copyFileNio(jpegImageFile, dst);
190                 return;
191             }