/*
* Copyright 2002-2012 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* More information about this project is available at:
*
* http://drewnoakes.com/code/exif/
* http://code.google.com/p/metadata-extractor/
*/
package com.drew.imaging.jpeg;
import com.drew.lang.ByteArrayReader;
import com.drew.lang.annotations.NotNull;
import com.drew.metadata.Metadata;
import com.drew.metadata.adobe.AdobeJpegReader;
import com.drew.metadata.exif.ExifReader;
import com.drew.metadata.icc.IccReader;
import com.drew.metadata.iptc.IptcReader;
import com.drew.metadata.jfif.JfifReader;
import com.drew.metadata.jpeg.JpegCommentReader;
import com.drew.metadata.jpeg.JpegDirectory;
import com.drew.metadata.jpeg.JpegReader;
import com.drew.metadata.photoshop.PhotoshopReader;
import com.drew.metadata.xmp.XmpReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
/**
* Obtains all available metadata from Jpeg formatted files.
*
* @author Drew Noakes http://drewnoakes.com
*/
public class JpegMetadataReader
{
// TODO investigate supporting javax.imageio
// public static Metadata readMetadata(IIOMetadata metadata) throws JpegProcessingException {}
// public static Metadata readMetadata(ImageInputStream in) throws JpegProcessingException{}
// public static Metadata readMetadata(IIOImage image) throws JpegProcessingException{}
// public static Metadata readMetadata(ImageReader reader) throws JpegProcessingException{}
@NotNull
public static Metadata readMetadata(@NotNull InputStream inputStream) throws JpegProcessingException
{
return readMetadata(inputStream, true);
}
@NotNull
public static Metadata readMetadata(@NotNull InputStream inputStream, final boolean waitForBytes) throws JpegProcessingException
{
JpegSegmentReader segmentReader = new JpegSegmentReader(inputStream, waitForBytes);
return extractMetadataFromJpegSegmentReader(segmentReader.getSegmentData());
}
@NotNull
public static Metadata readMetadata(@NotNull File file) throws JpegProcessingException, IOException
{
JpegSegmentReader segmentReader = new JpegSegmentReader(file);
return extractMetadataFromJpegSegmentReader(segmentReader.getSegmentData());
}
@NotNull
public static Metadata extractMetadataFromJpegSegmentReader(@NotNull JpegSegmentData segmentReader)
{
final Metadata metadata = new Metadata();
// Loop through looking for all SOFn segments. When we find one, we know what type of compression
// was used for the JPEG, and we can process the JPEG metadata in the segment too.
for (byte i = 0; i < 16; i++) {
// There are no SOF4 or SOF12 segments, so don't bother
if (i == 4 || i == 12)
continue;
// Should never have more than one SOFn for a given 'n'.
byte[] jpegSegment = segmentReader.getSegment((byte)(JpegSegmentReader.SEGMENT_SOF0 + i));
if (jpegSegment == null)
continue;
JpegDirectory directory = metadata.getOrCreateDirectory(JpegDirectory.class);
directory.setInt(JpegDirectory.TAG_JPEG_COMPRESSION_TYPE, i);
new JpegReader().extract(new ByteArrayReader(jpegSegment), metadata);
break;
}
// There should never be more than one COM segment.
byte[] comSegment = segmentReader.getSegment(JpegSegmentReader.SEGMENT_COM);
if (comSegment != null)
new JpegCommentReader().extract(new ByteArrayReader(comSegment), metadata);
// Loop through all APP0 segments, looking for a JFIF segment.
for (byte[] app0Segment : segmentReader.getSegments(JpegSegmentReader.SEGMENT_APP0)) {
if (app0Segment.length > 3 && new String(app0Segment, 0, 4).equals("JFIF"))
new JfifReader().extract(new ByteArrayReader(app0Segment), metadata);
}
// Loop through all APP1 segments, checking the leading bytes to identify the format of each.
for (byte[] app1Segment : segmentReader.getSegments(JpegSegmentReader.SEGMENT_APP1)) {
if (app1Segment.length > 3 && "EXIF".equalsIgnoreCase(new String(app1Segment, 0, 4)))
new ExifReader().extract(new ByteArrayReader(app1Segment), metadata);
if (app1Segment.length > 27 && "http://ns.adobe.com/xap/1.0/".equalsIgnoreCase(new String(app1Segment, 0, 28)))
new XmpReader().extract(new ByteArrayReader(app1Segment), metadata);
}
// Loop through all APP2 segments, looking for something we can process.
for (byte[] app2Segment : segmentReader.getSegments(JpegSegmentReader.SEGMENT_APP2)) {
if (app2Segment.length > 10 && new String(app2Segment, 0, 11).equalsIgnoreCase("ICC_PROFILE")) {
byte[] icc = new byte[app2Segment.length-14];
System.arraycopy(app2Segment, 14, icc, 0, app2Segment.length-14);
new IccReader().extract(new ByteArrayReader(icc), metadata);
}
}
// Loop through all APPD segments, checking the leading bytes to identify the format of each.
for (byte[] appdSegment : segmentReader.getSegments(JpegSegmentReader.SEGMENT_APPD)) {
if (appdSegment.length > 12 && "Photoshop 3.0".compareTo(new String(appdSegment, 0, 13))==0) {
new PhotoshopReader().extract(new ByteArrayReader(appdSegment), metadata);
} else {
// TODO might be able to check for a leading 0x1c02 for IPTC data...
new IptcReader().extract(new ByteArrayReader(appdSegment), metadata);
}
}
// Loop through all APPE segments, checking the leading bytes to identify the format of each.
for (byte[] appeSegment : segmentReader.getSegments(JpegSegmentReader.SEGMENT_APPE)) {
if (appeSegment.length == 12 && "Adobe".compareTo(new String(appeSegment, 0, 5))==0) {
new AdobeJpegReader().extract(new ByteArrayReader(appeSegment), metadata);
}
}
return metadata;
}
private JpegMetadataReader() throws Exception
{
throw new Exception("Not intended for instantiation");
}
}