getTables() {
+ return tables;
+ }
+
+ /**
+ * Evaluates whether all the tables in this {@link HuffmanTablesDirectory}
+ * are "typical" Huffman tables.
+ *
+ * "Typical" has a special meaning in this context as the JPEG standard
+ * (ISO/IEC 10918 or ITU-T T.81) defines 4 Huffman tables that has been
+ * developed from the average statistics of a large set of images with 8-bit
+ * precision. Using these instead of calculating the optimal Huffman tables
+ * for a given image is faster, and is preferred by many hardware encoders
+ * and some hardware decoders.
+ *
+ * Even though the JPEG standard doesn't define these as "standard tables"
+ * and requires a decoder to be able to read any valid Huffman tables, some
+ * are in reality limited decoding images using these "typical" tables.
+ * Standards like DCF (Design rule for Camera File system) and DLNA (Digital
+ * Living Network Alliance) actually requires any compliant JPEG to use only
+ * the "typical" Huffman tables.
+ *
+ * This is also related to the term "optimized" JPEG. An "optimized" JPEG is
+ * a JPEG that doesn't use the "typical" Huffman tables.
+ *
+ * @return Whether or not all the tables in this
+ * {@link HuffmanTablesDirectory} are the predefined "typical"
+ * Huffman tables.
+ */
+ public boolean isTypical() {
+ if (tables.size() == 0) {
+ return false;
+ }
+ for (HuffmanTable table : tables) {
+ if (!table.isTypical()) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * The opposite of {@link #isTypical()}.
+ *
+ * @return Whether or not the tables in this {@link HuffmanTablesDirectory}
+ * are "optimized" - which means that at least one of them aren't
+ * one of the "typical" Huffman tables.
+ */
+ public boolean isOptimized() {
+ return !isTypical();
+ }
+
+ /**
+ * An instance of this class holds a JPEG Huffman table.
+ */
+ public static class HuffmanTable {
+ private final int tableLength;
+ private final HuffmanTableClass tableClass;
+ private final int tableDestinationId;
+ private final byte[] lengthBytes;
+ private final byte[] valueBytes;
+
+ public HuffmanTable (
+ @NotNull HuffmanTableClass
+ tableClass,
+ int tableDestinationId,
+ @NotNull byte[] lBytes,
+ @NotNull byte[] vBytes
+ ) {
+ this.tableClass = tableClass;
+ this.tableDestinationId = tableDestinationId;
+ this.lengthBytes = lBytes;
+ this.valueBytes = vBytes;
+ this.tableLength = vBytes.length + 17;
+ }
+
+ /**
+ * @return The table length in bytes.
+ */
+ public int getTableLength() {
+ return tableLength;
+ }
+
+
+ /**
+ * @return The {@link HuffmanTableClass} of this table.
+ */
+ public HuffmanTableClass getTableClass() {
+ return tableClass;
+ }
+
+
+ /**
+ * @return the the destination identifier for this table.
+ */
+ public int getTableDestinationId() {
+ return tableDestinationId;
+ }
+
+
+ /**
+ * @return A byte array with the L values for this table.
+ */
+ public byte[] getLengthBytes() {
+ if (lengthBytes == null)
+ return null;
+ byte[] result = new byte[lengthBytes.length];
+ System.arraycopy(lengthBytes, 0, result, 0, lengthBytes.length);
+ return result;
+ }
+
+
+ /**
+ * @return A byte array with the V values for this table.
+ */
+ public byte[] getValueBytes() {
+ if (valueBytes == null)
+ return null;
+ byte[] result = new byte[valueBytes.length];
+ System.arraycopy(valueBytes, 0, result, 0, valueBytes.length);
+ return result;
+ }
+
+ /**
+ * Evaluates whether this table is a "typical" Huffman table.
+ *
+ * "Typical" has a special meaning in this context as the JPEG standard
+ * (ISO/IEC 10918 or ITU-T T.81) defines 4 Huffman tables that has been
+ * developed from the average statistics of a large set of images with
+ * 8-bit precision. Using these instead of calculating the optimal
+ * Huffman tables for a given image is faster, and is preferred by many
+ * hardware encoders and some hardware decoders.
+ *
+ * Even though the JPEG standard doesn't define these as
+ * "standard tables" and requires a decoder to be able to read any valid
+ * Huffman tables, some are in reality limited decoding images using
+ * these "typical" tables. Standards like DCF (Design rule for Camera
+ * File system) and DLNA (Digital Living Network Alliance) actually
+ * requires any compliant JPEG to use only the "typical" Huffman tables.
+ *
+ * This is also related to the term "optimized" JPEG. An "optimized"
+ * JPEG is a JPEG that doesn't use the "typical" Huffman tables.
+ *
+ * @return Whether or not this table is one of the predefined "typical"
+ * Huffman tables.
+ */
+ public boolean isTypical() {
+ if (tableClass == HuffmanTableClass.DC) {
+ return
+ Arrays.equals(lengthBytes, TYPICAL_LUMINANCE_DC_LENGTHS) &&
+ Arrays.equals(valueBytes, TYPICAL_LUMINANCE_DC_VALUES) ||
+ Arrays.equals(lengthBytes, TYPICAL_CHROMINANCE_DC_LENGTHS) &&
+ Arrays.equals(valueBytes, TYPICAL_CHROMINANCE_DC_VALUES);
+ } else if (tableClass == HuffmanTableClass.AC) {
+ return
+ Arrays.equals(lengthBytes, TYPICAL_LUMINANCE_AC_LENGTHS) &&
+ Arrays.equals(valueBytes, TYPICAL_LUMINANCE_AC_VALUES) ||
+ Arrays.equals(lengthBytes, TYPICAL_CHROMINANCE_AC_LENGTHS) &&
+ Arrays.equals(valueBytes, TYPICAL_CHROMINANCE_AC_VALUES);
+ }
+ return false;
+ }
+
+ /**
+ * The opposite of {@link #isTypical()}.
+ *
+ * @return Whether or not this table is "optimized" - which means that
+ * it isn't one of the "typical" Huffman tables.
+ */
+ public boolean isOptimized() {
+ return !isTypical();
+ }
+
+ public enum HuffmanTableClass {
+ DC,
+ AC,
+ UNKNOWN;
+
+ public static HuffmanTableClass typeOf(int value) {
+ switch (value) {
+ case 0: return DC;
+ case 1 : return AC;
+ default: return UNKNOWN;
+ }
+ }
+ }
+ }
+}
Index: trunk/src/com/drew/metadata/jpeg/JpegCommentDescriptor.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegCommentDescriptor.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegCommentDescriptor.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -30,4 +30,5 @@
* @author Drew Noakes https://drewnoakes.com
*/
+@SuppressWarnings("WeakerAccess")
public class JpegCommentDescriptor extends TagDescriptor
{
Index: trunk/src/com/drew/metadata/jpeg/JpegCommentDirectory.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegCommentDirectory.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegCommentDirectory.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -31,4 +31,5 @@
* @author Drew Noakes https://drewnoakes.com
*/
+@SuppressWarnings("WeakerAccess")
public class JpegCommentDirectory extends Directory
{
Index: trunk/src/com/drew/metadata/jpeg/JpegCommentReader.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegCommentReader.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegCommentReader.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -25,4 +25,5 @@
import com.drew.lang.annotations.NotNull;
import com.drew.metadata.Metadata;
+import com.drew.metadata.StringValue;
import java.util.Collections;
@@ -49,5 +50,5 @@
// The entire contents of the directory are the comment
- directory.setString(JpegCommentDirectory.TAG_COMMENT, new String(segmentBytes));
+ directory.setStringValue(JpegCommentDirectory.TAG_COMMENT, new StringValue(segmentBytes, null));
}
}
Index: trunk/src/com/drew/metadata/jpeg/JpegComponent.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegComponent.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegComponent.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -89,3 +89,14 @@
return _samplingFactorByte & 0x0F;
}
+
+ @NotNull
+ @Override
+ public String toString() {
+ return String.format(
+ "Quantization table %d, Sampling factors %d horiz/%d vert",
+ _quantizationTableNumber,
+ getHorizontalSamplingFactor(),
+ getVerticalSamplingFactor()
+ );
+ }
}
Index: trunk/src/com/drew/metadata/jpeg/JpegDescriptor.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegDescriptor.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegDescriptor.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -33,4 +33,5 @@
* @author Drew Noakes https://drewnoakes.com
*/
+@SuppressWarnings("WeakerAccess")
public class JpegDescriptor extends TagDescriptor
{
@@ -124,7 +125,5 @@
return null;
- return value.getComponentName() + " component: Quantization table " + value.getQuantizationTableNumber()
- + ", Sampling factors " + value.getHorizontalSamplingFactor()
- + " horiz/" + value.getVerticalSamplingFactor() + " vert";
+ return value.getComponentName() + " component: " + value;
}
}
Index: trunk/src/com/drew/metadata/jpeg/JpegDhtReader.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegDhtReader.java (revision 13061)
+++ trunk/src/com/drew/metadata/jpeg/JpegDhtReader.java (revision 13061)
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2002-2017 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:
+ *
+ * https://drewnoakes.com/code/exif/
+ * https://github.com/drewnoakes/metadata-extractor
+ */
+package com.drew.metadata.jpeg;
+
+import com.drew.imaging.jpeg.JpegSegmentMetadataReader;
+import com.drew.imaging.jpeg.JpegSegmentType;
+import com.drew.lang.SequentialByteArrayReader;
+import com.drew.lang.SequentialReader;
+import com.drew.lang.annotations.NotNull;
+import com.drew.metadata.Metadata;
+import com.drew.metadata.jpeg.HuffmanTablesDirectory.HuffmanTable;
+import com.drew.metadata.jpeg.HuffmanTablesDirectory.HuffmanTable.HuffmanTableClass;
+import java.io.IOException;
+import java.util.Collections;
+
+/**
+ * Reader for JPEG Huffman tables, found in the DHT JPEG segment.
+ *
+ * @author Nadahar
+ */
+public class JpegDhtReader implements JpegSegmentMetadataReader
+{
+ @NotNull
+ public Iterable getSegmentTypes()
+ {
+ return Collections.singletonList(JpegSegmentType.DHT);
+ }
+
+ public void readJpegSegments(@NotNull Iterable segments, @NotNull Metadata metadata, @NotNull JpegSegmentType segmentType)
+ {
+ for (byte[] segmentBytes : segments) {
+ extract(new SequentialByteArrayReader(segmentBytes), metadata);
+ }
+ }
+
+ /**
+ * Performs the DHT tables extraction, adding found tables to the specified
+ * instance of {@link Metadata}.
+ */
+ public void extract(@NotNull final SequentialReader reader, @NotNull final Metadata metadata)
+ {
+ HuffmanTablesDirectory directory = metadata.getFirstDirectoryOfType(HuffmanTablesDirectory.class);
+ if (directory == null) {
+ directory = new HuffmanTablesDirectory();
+ metadata.addDirectory(directory);
+ }
+
+ try {
+ while (reader.available() > 0) {
+ byte header = reader.getByte();
+ HuffmanTableClass tableClass = HuffmanTableClass.typeOf((header & 0xF0) >> 4);
+ int tableDestinationId = header & 0xF;
+
+ byte[] lBytes = getBytes(reader, 16);
+ int vCount = 0;
+ for (byte b : lBytes) {
+ vCount += (b & 0xFF);
+ }
+ byte[] vBytes = getBytes(reader, vCount);
+ directory.getTables().add(new HuffmanTable(tableClass, tableDestinationId, lBytes, vBytes));
+ }
+ } catch (IOException me) {
+ directory.addError(me.getMessage());
+ }
+
+ directory.setInt(HuffmanTablesDirectory.TAG_NUMBER_OF_TABLES, directory.getTables().size());
+ }
+
+ private byte[] getBytes(@NotNull final SequentialReader reader, int count) throws IOException {
+ byte[] bytes = new byte[count];
+ for (int i = 0; i < count; i++) {
+ byte b = reader.getByte();
+ if ((b & 0xFF) == 0xFF) {
+ byte stuffing = reader.getByte();
+ if (stuffing != 0x00) {
+ throw new IOException("Marker " + JpegSegmentType.fromByte(stuffing) + " found inside DHT segment");
+ }
+ }
+ bytes[i] = b;
+ }
+ return bytes;
+ }
+}
Index: trunk/src/com/drew/metadata/jpeg/JpegDirectory.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegDirectory.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegDirectory.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -33,4 +33,5 @@
* @author Darrell Silver http://www.darrellsilver.com and Drew Noakes https://drewnoakes.com
*/
+@SuppressWarnings("WeakerAccess")
public class JpegDirectory extends Directory
{
Index: trunk/src/com/drew/metadata/jpeg/JpegDnlReader.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegDnlReader.java (revision 13061)
+++ trunk/src/com/drew/metadata/jpeg/JpegDnlReader.java (revision 13061)
@@ -0,0 +1,77 @@
+/*
+ * Copyright 2002-2017 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:
+ *
+ * https://drewnoakes.com/code/exif/
+ * https://github.com/drewnoakes/metadata-extractor
+ */
+package com.drew.metadata.jpeg;
+
+import com.drew.imaging.jpeg.JpegSegmentMetadataReader;
+import com.drew.imaging.jpeg.JpegSegmentType;
+import com.drew.lang.SequentialByteArrayReader;
+import com.drew.lang.SequentialReader;
+import com.drew.lang.annotations.NotNull;
+import com.drew.metadata.ErrorDirectory;
+import com.drew.metadata.Metadata;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+
+/**
+ * Decodes JPEG DNL data, adjusting the image height with information missing from the JPEG SOFx segment.
+ *
+ * @author Nadahar
+ */
+public class JpegDnlReader implements JpegSegmentMetadataReader
+{
+ @NotNull
+ public Iterable getSegmentTypes()
+ {
+ return Collections.singletonList(JpegSegmentType.DNL);
+ }
+
+ public void readJpegSegments(@NotNull Iterable segments, @NotNull Metadata metadata, @NotNull JpegSegmentType segmentType)
+ {
+ for (byte[] segmentBytes : segments) {
+ extract(segmentBytes, metadata, segmentType);
+ }
+ }
+
+ public void extract(byte[] segmentBytes, Metadata metadata, JpegSegmentType segmentType)
+ {
+ JpegDirectory directory = metadata.getFirstDirectoryOfType(JpegDirectory.class);
+ if (directory == null) {
+ ErrorDirectory errorDirectory = new ErrorDirectory();
+ metadata.addDirectory(errorDirectory);
+ errorDirectory.addError("DNL segment found without SOFx - illegal JPEG format");
+ return;
+ }
+
+ SequentialReader reader = new SequentialByteArrayReader(segmentBytes);
+
+ try {
+ // Only set height from DNL if it's not already defined
+ Integer i = directory.getInteger(JpegDirectory.TAG_IMAGE_HEIGHT);
+ if (i == null || i == 0) {
+ directory.setInt(JpegDirectory.TAG_IMAGE_HEIGHT, reader.getUInt16());
+ }
+ } catch (IOException ex) {
+ directory.addError(ex.getMessage());
+ }
+ }
+}
Index: trunk/src/com/drew/metadata/jpeg/JpegReader.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/JpegReader.java (revision 10862)
+++ trunk/src/com/drew/metadata/jpeg/JpegReader.java (revision 13061)
@@ -1,4 +1,4 @@
/*
- * Copyright 2002-2016 Drew Noakes
+ * Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -52,5 +52,5 @@
JpegSegmentType.SOF6,
JpegSegmentType.SOF7,
- JpegSegmentType.SOF8,
+// JpegSegmentType.JPG,
JpegSegmentType.SOF9,
JpegSegmentType.SOF10,
Index: trunk/src/com/drew/metadata/jpeg/package-info.java
===================================================================
--- trunk/src/com/drew/metadata/jpeg/package-info.java (revision 13061)
+++ trunk/src/com/drew/metadata/jpeg/package-info.java (revision 13061)
@@ -0,0 +1,4 @@
+/**
+ * Contains classes for the extraction and modelling of JPEG file format metadata.
+ */
+package com.drew.metadata.jpeg;
Index: trunk/src/com/drew/metadata/jpeg/package.html
===================================================================
--- trunk/src/com/drew/metadata/jpeg/package.html (revision 10862)
+++ (revision )
@@ -1,33 +1,0 @@
-
-
-
-
-
-
-
-
-Contains classes for the extraction and modelling of JPEG file format metadata.
-
-
-
-
-