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Apache Commons Imaging (previously Sanselan) is a pure-Java image library.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.commons.imaging.formats.jpeg.segments;
import static org.apache.commons.imaging.common.BinaryFunctions.read2Bytes;
import static org.apache.commons.imaging.common.BinaryFunctions.readByte;
import static org.apache.commons.imaging.common.BinaryFunctions.readBytes;
import static org.apache.commons.imaging.common.BinaryFunctions.skipBytes;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.imaging.ImageReadException;
import org.apache.commons.imaging.formats.jpeg.JpegConstants;
public class JfifSegment extends Segment {
public final int jfifMajorVersion;
public final int jfifMinorVersion;
public final int densityUnits;
public final int xDensity;
public final int yDensity;
public final int xThumbnail;
public final int yThumbnail;
public final int thumbnailSize;
@Override
public String getDescription() {
return "JFIF (" + getSegmentType() + ")";
}
public JfifSegment(final int marker, final byte[] segmentData)
throws ImageReadException, IOException {
this(marker, segmentData.length, new ByteArrayInputStream(segmentData));
}
public JfifSegment(final int marker, final int markerLength, final InputStream is)
throws ImageReadException, IOException {
super(marker, markerLength);
final byte[] signature = readBytes(is, JpegConstants.JFIF0_SIGNATURE.size());
if (!JpegConstants.JFIF0_SIGNATURE.equals(signature)
&& !JpegConstants.JFIF0_SIGNATURE_ALTERNATIVE.equals(signature)) {
throw new ImageReadException(
"Not a Valid JPEG File: missing JFIF string");
}
jfifMajorVersion = readByte("JFIF_major_version", is,
"Not a Valid JPEG File");
jfifMinorVersion = readByte("JFIF_minor_version", is,
"Not a Valid JPEG File");
densityUnits = readByte("density_units", is, "Not a Valid JPEG File");
xDensity = read2Bytes("x_density", is, "Not a Valid JPEG File", getByteOrder());
yDensity = read2Bytes("y_density", is, "Not a Valid JPEG File", getByteOrder());
xThumbnail = readByte("x_thumbnail", is, "Not a Valid JPEG File");
yThumbnail = readByte("y_thumbnail", is, "Not a Valid JPEG File");
thumbnailSize = xThumbnail * yThumbnail;
if (thumbnailSize > 0) {
skipBytes(is, thumbnailSize,
"Not a Valid JPEG File: missing thumbnail");
}
}
}