/// <summary>
/// Performs the Jfif data extraction, adding found values to the specified
/// instance of
/// <see cref="Com.Drew.Metadata.Metadata"/>
/// .
/// </summary>
public virtual void Extract(RandomAccessReader reader, Com.Drew.Metadata.Metadata metadata)
{
JfifDirectory directory = metadata.GetOrCreateDirectory<JfifDirectory>();
try
{
// For JFIF, the tag number is also the offset into the segment
int ver = reader.GetUInt16(JfifDirectory.TagVersion);
directory.SetInt(JfifDirectory.TagVersion, ver);
int units = reader.GetUInt8(JfifDirectory.TagUnits);
directory.SetInt(JfifDirectory.TagUnits, units);
int height = reader.GetUInt16(JfifDirectory.TagResx);
directory.SetInt(JfifDirectory.TagResx, height);
int width = reader.GetUInt16(JfifDirectory.TagResy);
directory.SetInt(JfifDirectory.TagResy, width);
}
catch (IOException me)
{
directory.AddError(me.Message);
}
}
public virtual void TestGetUInt16_OutOfBounds()
{
try
{
RandomAccessReader reader = CreateReader(new sbyte[2]);
reader.GetUInt16(1);
NUnit.Framework.Assert.Fail("Exception expected");
}
catch (IOException ex)
{
Sharpen.Tests.AreEqual("Attempt to read from beyond end of underlying data source (requested index: 1, requested count: 2, max index: 1)", ex.Message);
}
}
public virtual void Extract(RandomAccessReader reader, Com.Drew.Metadata.Metadata metadata)
{
PsdHeaderDirectory directory = metadata.GetOrCreateDirectory<PsdHeaderDirectory>();
try
{
int signature = reader.GetInt32(0);
if (signature != unchecked((int)(0x38425053)))
{
directory.AddError("Invalid PSD file signature");
return;
}
int version = reader.GetUInt16(4);
if (version != 1 && version != 2)
{
directory.AddError("Invalid PSD file version (must be 1 or 2)");
return;
}
// 6 reserved bytes are skipped here. They should be zero.
int channelCount = reader.GetUInt16(12);
directory.SetInt(PsdHeaderDirectory.TagChannelCount, channelCount);
// even though this is probably an unsigned int, the max height in practice is 300,000
int imageHeight = reader.GetInt32(14);
directory.SetInt(PsdHeaderDirectory.TagImageHeight, imageHeight);
// even though this is probably an unsigned int, the max width in practice is 300,000
int imageWidth = reader.GetInt32(18);
directory.SetInt(PsdHeaderDirectory.TagImageWidth, imageWidth);
int bitsPerChannel = reader.GetUInt16(22);
directory.SetInt(PsdHeaderDirectory.TagBitsPerChannel, bitsPerChannel);
int colorMode = reader.GetUInt16(24);
directory.SetInt(PsdHeaderDirectory.TagColorMode, colorMode);
}
catch (IOException)
{
directory.AddError("Unable to read PSD header");
}
}
public virtual void TestGetUInt16()
{
sbyte[] buffer = new sbyte[] { unchecked ((int)(0x00)), unchecked ((int)(0x01)), unchecked ((sbyte)unchecked ((int)(0x7F))), unchecked ((sbyte)unchecked ((int)(0xFF))) };
RandomAccessReader reader = CreateReader(buffer);
Sharpen.Tests.AreEqual(unchecked ((int)(0x0001)), reader.GetUInt16(0));
Sharpen.Tests.AreEqual(unchecked ((int)(0x017F)), reader.GetUInt16(1));
Sharpen.Tests.AreEqual(unchecked ((int)(0x7FFF)), reader.GetUInt16(2));
reader.SetMotorolaByteOrder(false);
Sharpen.Tests.AreEqual(unchecked ((int)(0x0100)), reader.GetUInt16(0));
Sharpen.Tests.AreEqual(unchecked ((int)(0x7F01)), reader.GetUInt16(1));
Sharpen.Tests.AreEqual(unchecked ((int)(0xFF7F)), reader.GetUInt16(2));
}
/// <summary>Processes a TIFF data sequence.</summary>
/// <param name="reader">
/// the
/// <see cref="Com.Drew.Lang.RandomAccessReader"/>
/// from which the data should be read
/// </param>
/// <param name="handler">
/// the
/// <see cref="TiffHandler"/>
/// that will coordinate processing and accept read values
/// </param>
/// <param name="tiffHeaderOffset">the offset within <code>reader</code> at which the TIFF header starts</param>
/// <exception cref="TiffProcessingException">
/// if an error occurred during the processing of TIFF data that could not be
/// ignored or recovered from
/// </exception>
/// <exception cref="System.IO.IOException">an error occurred while accessing the required data</exception>
/// <exception cref="Com.Drew.Imaging.Tiff.TiffProcessingException"/>
public virtual void ProcessTiff(RandomAccessReader reader, TiffHandler handler, int tiffHeaderOffset)
{
// This must be either "MM" or "II".
short byteOrderIdentifier = reader.GetInt16(tiffHeaderOffset);
if (byteOrderIdentifier == unchecked((int)(0x4d4d)))
{
// "MM"
reader.SetMotorolaByteOrder(true);
}
else
{
if (byteOrderIdentifier == unchecked((int)(0x4949)))
{
// "II"
reader.SetMotorolaByteOrder(false);
}
else
{
throw new TiffProcessingException("Unclear distinction between Motorola/Intel byte ordering: " + byteOrderIdentifier);
}
}
// Check the next two values for correctness.
int tiffMarker = reader.GetUInt16(2 + tiffHeaderOffset);
handler.SetTiffMarker(tiffMarker);
int firstIfdOffset = reader.GetInt32(4 + tiffHeaderOffset) + tiffHeaderOffset;
// David Ekholm sent a digital camera image that has this problem
// TODO getLength should be avoided as it causes RandomAccessStreamReader to read to the end of the stream
if (firstIfdOffset >= reader.GetLength() - 1)
{
handler.Warn("First IFD offset is beyond the end of the TIFF data segment -- trying default offset");
// First directory normally starts immediately after the offset bytes, so try that
firstIfdOffset = tiffHeaderOffset + 2 + 2 + 4;
}
ICollection<int> processedIfdOffsets = new HashSet<int>();
ProcessIfd(handler, reader, processedIfdOffsets, firstIfdOffset, tiffHeaderOffset);
handler.Completed(reader, tiffHeaderOffset);
}
public virtual void Extract(RandomAccessReader reader, Com.Drew.Metadata.Metadata metadata)
{
PhotoshopDirectory directory = metadata.GetOrCreateDirectory<PhotoshopDirectory>();
int pos;
try
{
pos = reader.GetString(0, 13).Equals("Photoshop 3.0") ? 14 : 0;
}
catch (IOException)
{
directory.AddError("Unable to read header");
return;
}
long length;
try
{
length = reader.GetLength();
}
catch (IOException e)
{
directory.AddError("Unable to read Photoshop data: " + e.Message);
return;
}
while (pos < length)
{
try
{
// 4 bytes for the signature. Should always be "8BIM".
//String signature = new String(data, pos, 4);
pos += 4;
// 2 bytes for the resource identifier (tag type).
int tagType = reader.GetUInt16(pos);
// segment type
pos += 2;
// A variable number of bytes holding a pascal string (two leading bytes for length).
int descriptionLength = reader.GetUInt16(pos);
pos += 2;
// Some basic bounds checking
if (descriptionLength < 0 || descriptionLength + pos > length)
{
return;
}
//String description = new String(data, pos, descriptionLength);
pos += descriptionLength;
// The number of bytes is padded with a trailing zero, if needed, to make the size even.
if (pos % 2 != 0)
{
pos++;
}
// 4 bytes for the size of the resource data that follows.
int byteCount = reader.GetInt32(pos);
pos += 4;
// The resource data.
sbyte[] tagBytes = reader.GetBytes(pos, byteCount);
pos += byteCount;
// The number of bytes is padded with a trailing zero, if needed, to make the size even.
if (pos % 2 != 0)
{
pos++;
}
directory.SetByteArray(tagType, tagBytes);
// TODO allow rebasing the reader with a new zero-point, rather than copying data here
if (tagType == PhotoshopDirectory.TagIptc)
{
new IptcReader().Extract(new SequentialByteArrayReader(tagBytes), metadata, tagBytes.Length);
}
if (tagType >= unchecked((int)(0x0fa0)) && tagType <= unchecked((int)(0x1387)))
{
PhotoshopDirectory._tagNameMap.Put(tagType, Sharpen.Extensions.StringFormat("Plug-in %d Data", tagType - unchecked((int)(0x0fa0)) + 1));
}
}
catch (IOException ex)
{
directory.AddError(ex.Message);
return;
}
}
}
private static void ProcessTag(Com.Drew.Metadata.Directory directory, int tagType, int tagValueOffset, int componentCount, int formatCode, RandomAccessReader reader)
{
switch (formatCode)
{
case FmtUndefined:
{
// Directory simply stores raw values
// The display side uses a Descriptor class per directory to turn the raw values into 'pretty' descriptions
// this includes exif user comments
directory.SetByteArray(tagType, reader.GetBytes(tagValueOffset, componentCount));
break;
}
case FmtString:
{
string @string = reader.GetNullTerminatedString(tagValueOffset, componentCount);
directory.SetString(tagType, @string);
break;
}
case FmtSrational:
{
if (componentCount == 1)
{
directory.SetRational(tagType, new Rational(reader.GetInt32(tagValueOffset), reader.GetInt32(tagValueOffset + 4)));
}
else
{
if (componentCount > 1)
{
Rational[] rationals = new Rational[componentCount];
for (int i = 0; i < componentCount; i++)
{
rationals[i] = new Rational(reader.GetInt32(tagValueOffset + (8 * i)), reader.GetInt32(tagValueOffset + 4 + (8 * i)));
}
directory.SetRationalArray(tagType, rationals);
}
}
break;
}
case FmtUrational:
{
if (componentCount == 1)
{
directory.SetRational(tagType, new Rational(reader.GetUInt32(tagValueOffset), reader.GetUInt32(tagValueOffset + 4)));
}
else
{
if (componentCount > 1)
{
Rational[] rationals = new Rational[componentCount];
for (int i = 0; i < componentCount; i++)
{
rationals[i] = new Rational(reader.GetUInt32(tagValueOffset + (8 * i)), reader.GetUInt32(tagValueOffset + 4 + (8 * i)));
}
directory.SetRationalArray(tagType, rationals);
}
}
break;
}
case FmtSingle:
{
if (componentCount == 1)
{
directory.SetFloat(tagType, reader.GetFloat32(tagValueOffset));
}
else
{
float[] floats = new float[componentCount];
for (int i = 0; i < componentCount; i++)
{
floats[i] = reader.GetFloat32(tagValueOffset + (i * 4));
}
directory.SetFloatArray(tagType, floats);
}
break;
}
case FmtDouble:
{
if (componentCount == 1)
{
directory.SetDouble(tagType, reader.GetDouble64(tagValueOffset));
}
else
{
double[] doubles = new double[componentCount];
for (int i = 0; i < componentCount; i++)
{
doubles[i] = reader.GetDouble64(tagValueOffset + (i * 4));
}
directory.SetDoubleArray(tagType, doubles);
}
break;
}
case FmtSbyte:
{
//
// Note that all integral types are stored as int32 internally (the largest supported by TIFF)
//
if (componentCount == 1)
{
directory.SetInt(tagType, reader.GetInt8(tagValueOffset));
}
else
{
int[] bytes = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
bytes[i] = reader.GetInt8(tagValueOffset + i);
}
directory.SetIntArray(tagType, bytes);
}
break;
}
case FmtByte:
{
if (componentCount == 1)
{
directory.SetInt(tagType, reader.GetUInt8(tagValueOffset));
}
else
{
int[] bytes = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
bytes[i] = reader.GetUInt8(tagValueOffset + i);
}
directory.SetIntArray(tagType, bytes);
}
break;
}
case FmtUshort:
{
if (componentCount == 1)
{
int i = reader.GetUInt16(tagValueOffset);
directory.SetInt(tagType, i);
}
else
{
int[] ints = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
ints[i] = reader.GetUInt16(tagValueOffset + (i * 2));
}
directory.SetIntArray(tagType, ints);
}
break;
}
case FmtSshort:
{
if (componentCount == 1)
{
int i = reader.GetInt16(tagValueOffset);
directory.SetInt(tagType, i);
}
else
{
int[] ints = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
ints[i] = reader.GetInt16(tagValueOffset + (i * 2));
}
directory.SetIntArray(tagType, ints);
}
break;
}
case FmtSlong:
case FmtUlong:
{
// NOTE 'long' in this case means 32 bit, not 64
if (componentCount == 1)
{
int i = reader.GetInt32(tagValueOffset);
directory.SetInt(tagType, i);
}
else
{
int[] ints = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
ints[i] = reader.GetInt32(tagValueOffset + (i * 4));
}
directory.SetIntArray(tagType, ints);
}
break;
}
default:
{
directory.AddError("Unknown format code " + formatCode + " for tag " + tagType);
break;
}
}
}
private static void ProcessKodakMakernote(KodakMakernoteDirectory directory, int tagValueOffset, RandomAccessReader reader)
{
// Kodak's makernote is not in IFD format. It has values at fixed offsets.
int dataOffset = tagValueOffset + 8;
try
{
directory.SetString(KodakMakernoteDirectory.TagKodakModel, reader.GetString(dataOffset, 8));
directory.SetInt(KodakMakernoteDirectory.TagQuality, reader.GetUInt8(dataOffset + 9));
directory.SetInt(KodakMakernoteDirectory.TagBurstMode, reader.GetUInt8(dataOffset + 10));
directory.SetInt(KodakMakernoteDirectory.TagImageWidth, reader.GetUInt16(dataOffset + 12));
directory.SetInt(KodakMakernoteDirectory.TagImageHeight, reader.GetUInt16(dataOffset + 14));
directory.SetInt(KodakMakernoteDirectory.TagYearCreated, reader.GetUInt16(dataOffset + 16));
directory.SetByteArray(KodakMakernoteDirectory.TagMonthDayCreated, reader.GetBytes(dataOffset + 18, 2));
directory.SetByteArray(KodakMakernoteDirectory.TagTimeCreated, reader.GetBytes(dataOffset + 20, 4));
directory.SetInt(KodakMakernoteDirectory.TagBurstMode2, reader.GetUInt16(dataOffset + 24));
directory.SetInt(KodakMakernoteDirectory.TagShutterMode, reader.GetUInt8(dataOffset + 27));
directory.SetInt(KodakMakernoteDirectory.TagMeteringMode, reader.GetUInt8(dataOffset + 28));
directory.SetInt(KodakMakernoteDirectory.TagSequenceNumber, reader.GetUInt8(dataOffset + 29));
directory.SetInt(KodakMakernoteDirectory.TagFNumber, reader.GetUInt16(dataOffset + 30));
directory.SetLong(KodakMakernoteDirectory.TagExposureTime, reader.GetUInt32(dataOffset + 32));
directory.SetInt(KodakMakernoteDirectory.TagExposureCompensation, reader.GetInt16(dataOffset + 36));
directory.SetInt(KodakMakernoteDirectory.TagFocusMode, reader.GetUInt8(dataOffset + 56));
directory.SetInt(KodakMakernoteDirectory.TagWhiteBalance, reader.GetUInt8(dataOffset + 64));
directory.SetInt(KodakMakernoteDirectory.TagFlashMode, reader.GetUInt8(dataOffset + 92));
directory.SetInt(KodakMakernoteDirectory.TagFlashFired, reader.GetUInt8(dataOffset + 93));
directory.SetInt(KodakMakernoteDirectory.TagIsoSetting, reader.GetUInt16(dataOffset + 94));
directory.SetInt(KodakMakernoteDirectory.TagIso, reader.GetUInt16(dataOffset + 96));
directory.SetInt(KodakMakernoteDirectory.TagTotalZoom, reader.GetUInt16(dataOffset + 98));
directory.SetInt(KodakMakernoteDirectory.TagDateTimeStamp, reader.GetUInt16(dataOffset + 100));
directory.SetInt(KodakMakernoteDirectory.TagColorMode, reader.GetUInt16(dataOffset + 102));
directory.SetInt(KodakMakernoteDirectory.TagDigitalZoom, reader.GetUInt16(dataOffset + 104));
directory.SetInt(KodakMakernoteDirectory.TagSharpness, reader.GetInt8(dataOffset + 107));
}
catch (IOException ex)
{
directory.AddError("Error processing Kodak makernote data: " + ex.Message);
}
}
private static void ProcessIFD(Com.Drew.Metadata.Directory directory, ICollection<int> processedIfdOffsets, int ifdOffset, int tiffHeaderOffset, Com.Drew.Metadata.Metadata metadata, RandomAccessReader reader)
{
// check for directories we've already visited to avoid stack overflows when recursive/cyclic directory structures exist
if (processedIfdOffsets.Contains(Sharpen.Extensions.ValueOf(ifdOffset)))
{
return;
}
// remember that we've visited this directory so that we don't visit it again later
processedIfdOffsets.Add(ifdOffset);
if (ifdOffset >= reader.GetLength() || ifdOffset < 0)
{
directory.AddError("Ignored IFD marked to start outside data segment");
return;
}
// First two bytes in the IFD are the number of tags in this directory
int dirTagCount = reader.GetUInt16(ifdOffset);
int dirLength = (2 + (12 * dirTagCount) + 4);
if (dirLength + ifdOffset > reader.GetLength())
{
directory.AddError("Illegally sized IFD");
return;
}
// Handle each tag in this directory
for (int tagNumber = 0; tagNumber < dirTagCount; tagNumber++)
{
int tagOffset = CalculateTagOffset(ifdOffset, tagNumber);
// 2 bytes for the tag type
int tagType = reader.GetUInt16(tagOffset);
// 2 bytes for the format code
int formatCode = reader.GetUInt16(tagOffset + 2);
if (formatCode < 1 || formatCode > MaxFormatCode)
{
// This error suggests that we are processing at an incorrect index and will generate
// rubbish until we go out of bounds (which may be a while). Exit now.
directory.AddError("Invalid TIFF tag format code: " + formatCode);
return;
}
// 4 bytes dictate the number of components in this tag's data
int componentCount = reader.GetInt32(tagOffset + 4);
if (componentCount < 0)
{
directory.AddError("Negative TIFF tag component count");
continue;
}
// each component may have more than one byte... calculate the total number of bytes
int byteCount = componentCount * BytesPerFormat[formatCode];
int tagValueOffset;
if (byteCount > 4)
{
// If it's bigger than 4 bytes, the dir entry contains an offset.
// dirEntryOffset must be passed, as some makernote implementations (e.g. Fujifilm) incorrectly use an
// offset relative to the start of the makernote itself, not the TIFF segment.
int offsetVal = reader.GetInt32(tagOffset + 8);
if (offsetVal + byteCount > reader.GetLength())
{
// Bogus pointer offset and / or byteCount value
directory.AddError("Illegal TIFF tag pointer offset");
continue;
}
tagValueOffset = tiffHeaderOffset + offsetVal;
}
else
{
// 4 bytes or less and value is in the dir entry itself
tagValueOffset = tagOffset + 8;
}
if (tagValueOffset < 0 || tagValueOffset > reader.GetLength())
{
directory.AddError("Illegal TIFF tag pointer offset");
continue;
}
// Check that this tag isn't going to allocate outside the bounds of the data array.
// This addresses an uncommon OutOfMemoryError.
if (byteCount < 0 || tagValueOffset + byteCount > reader.GetLength())
{
directory.AddError("Illegal number of bytes for TIFF tag data: " + byteCount);
continue;
}
//
// Special handling for certain known tags that point to or contain other chunks of data to be processed
//
if (tagType == ExifIFD0Directory.TagExifSubIfdOffset && directory is ExifIFD0Directory)
{
if (byteCount != 4)
{
directory.AddError("Exif SubIFD Offset tag should have a component count of four (bytes) for the offset.");
}
else
{
int subDirOffset = tiffHeaderOffset + reader.GetInt32(tagValueOffset);
ProcessIFD(metadata.GetOrCreateDirectory<ExifSubIFDDirectory>(), processedIfdOffsets, subDirOffset, tiffHeaderOffset, metadata, reader);
}
}
else
{
if (tagType == ExifSubIFDDirectory.TagInteropOffset && directory is ExifSubIFDDirectory)
{
if (byteCount != 4)
{
directory.AddError("Exif Interop Offset tag should have a component count of four (bytes) for the offset.");
}
else
{
int subDirOffset = tiffHeaderOffset + reader.GetInt32(tagValueOffset);
ProcessIFD(metadata.GetOrCreateDirectory<ExifInteropDirectory>(), processedIfdOffsets, subDirOffset, tiffHeaderOffset, metadata, reader);
}
}
else
{
if (tagType == ExifIFD0Directory.TagGpsInfoOffset && directory is ExifIFD0Directory)
{
if (byteCount != 4)
{
directory.AddError("Exif GPS Info Offset tag should have a component count of four (bytes) for the offset.");
}
else
{
int subDirOffset = tiffHeaderOffset + reader.GetInt32(tagValueOffset);
ProcessIFD(metadata.GetOrCreateDirectory<GpsDirectory>(), processedIfdOffsets, subDirOffset, tiffHeaderOffset, metadata, reader);
}
}
else
{
if (tagType == ExifSubIFDDirectory.TagMakernote && directory is ExifSubIFDDirectory)
{
// The makernote tag contains the encoded makernote data directly.
// Pass the offset to this tag's value. Manufacturer/Model-specific logic will be used to
// determine the correct offset for further processing.
ProcessMakernote(tagValueOffset, processedIfdOffsets, tiffHeaderOffset, metadata, reader);
}
else
{
ProcessTag(directory, tagType, tagValueOffset, componentCount, formatCode, reader);
}
}
}
}
}
// at the end of each IFD is an optional link to the next IFD
int finalTagOffset = CalculateTagOffset(ifdOffset, dirTagCount);
int nextDirectoryOffset = reader.GetInt32(finalTagOffset);
if (nextDirectoryOffset != 0)
{
nextDirectoryOffset += tiffHeaderOffset;
if (nextDirectoryOffset >= reader.GetLength())
{
// Last 4 bytes of IFD reference another IFD with an address that is out of bounds
// Note this could have been caused by jhead 1.3 cropping too much
return;
}
else
{
if (nextDirectoryOffset < ifdOffset)
{
// Last 4 bytes of IFD reference another IFD with an address that is before the start of this directory
return;
}
}
// TODO in Exif, the only known 'follower' IFD is the thumbnail one, however this may not be the case
ExifThumbnailDirectory nextDirectory = metadata.GetOrCreateDirectory<ExifThumbnailDirectory>();
ProcessIFD(nextDirectory, processedIfdOffsets, nextDirectoryOffset, tiffHeaderOffset, metadata, reader);
}
}
private static void ExtractTiff(RandomAccessReader reader, Com.Drew.Metadata.Metadata metadata, Com.Drew.Metadata.Directory firstDirectory, int tiffHeaderOffset)
{
// this should be either "MM" or "II"
string byteOrderIdentifier = reader.GetString(tiffHeaderOffset, 2);
if ("MM".Equals(byteOrderIdentifier))
{
reader.SetMotorolaByteOrder(true);
}
else
{
if ("II".Equals(byteOrderIdentifier))
{
reader.SetMotorolaByteOrder(false);
}
else
{
firstDirectory.AddError("Unclear distinction between Motorola/Intel byte ordering: " + byteOrderIdentifier);
return;
}
}
// Check the next two values for correctness.
int tiffMarker = reader.GetUInt16(2 + tiffHeaderOffset);
int standardTiffMarker = unchecked((int)(0x002A));
int olympusRawTiffMarker = unchecked((int)(0x4F52));
// for ORF files
int panasonicRawTiffMarker = unchecked((int)(0x0055));
// for RW2 files
if (tiffMarker != standardTiffMarker && tiffMarker != olympusRawTiffMarker && tiffMarker != panasonicRawTiffMarker)
{
firstDirectory.AddError("Unexpected TIFF marker after byte order identifier: 0x" + Sharpen.Extensions.ToHexString(tiffMarker));
return;
}
int firstIfdOffset = reader.GetInt32(4 + tiffHeaderOffset) + tiffHeaderOffset;
// David Ekholm sent a digital camera image that has this problem
// TODO getLength should be avoided as it causes RandomAccessStreamReader to read to the end of the stream
if (firstIfdOffset >= reader.GetLength() - 1)
{
firstDirectory.AddError("First Exif directory offset is beyond end of Exif data segment");
// First directory normally starts 14 bytes in -- try it here and catch another error in the worst case
firstIfdOffset = 14;
}
ICollection<int> processedIfdOffsets = new HashSet<int>();
ProcessIFD(firstDirectory, processedIfdOffsets, firstIfdOffset, tiffHeaderOffset, metadata, reader);
// after the extraction process, if we have the correct tags, we may be able to store thumbnail information
ExifThumbnailDirectory thumbnailDirectory = metadata.GetDirectory<ExifThumbnailDirectory>();
if (thumbnailDirectory != null && thumbnailDirectory.ContainsTag(ExifThumbnailDirectory.TagThumbnailCompression))
{
int? offset = thumbnailDirectory.GetInteger(ExifThumbnailDirectory.TagThumbnailOffset);
int? length = thumbnailDirectory.GetInteger(ExifThumbnailDirectory.TagThumbnailLength);
if (offset != null && length != null)
{
try
{
sbyte[] thumbnailData = reader.GetBytes(tiffHeaderOffset + offset.Value, length.Value);
thumbnailDirectory.SetThumbnailData(thumbnailData);
}
catch (IOException ex)
{
firstDirectory.AddError("Invalid thumbnail data specification: " + ex.Message);
}
}
}
}
/// <exception cref="System.IO.IOException"/>
private static void ProcessTag(TiffHandler handler, int tagId, int tagValueOffset, int componentCount, int formatCode, RandomAccessReader reader)
{
switch (formatCode)
{
case TiffDataFormat.CodeUndefined:
{
// this includes exif user comments
handler.SetByteArray(tagId, reader.GetBytes(tagValueOffset, componentCount));
break;
}
case TiffDataFormat.CodeString:
{
handler.SetString(tagId, reader.GetNullTerminatedString(tagValueOffset, componentCount));
break;
}
case TiffDataFormat.CodeRationalS:
{
if (componentCount == 1)
{
handler.SetRational(tagId, new Rational(reader.GetInt32(tagValueOffset), reader.GetInt32(tagValueOffset + 4)));
}
else
{
if (componentCount > 1)
{
Rational[] array = new Rational[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = new Rational(reader.GetInt32(tagValueOffset + (8 * i)), reader.GetInt32(tagValueOffset + 4 + (8 * i)));
}
handler.SetRationalArray(tagId, array);
}
}
break;
}
case TiffDataFormat.CodeRationalU:
{
if (componentCount == 1)
{
handler.SetRational(tagId, new Rational(reader.GetUInt32(tagValueOffset), reader.GetUInt32(tagValueOffset + 4)));
}
else
{
if (componentCount > 1)
{
Rational[] array = new Rational[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = new Rational(reader.GetUInt32(tagValueOffset + (8 * i)), reader.GetUInt32(tagValueOffset + 4 + (8 * i)));
}
handler.SetRationalArray(tagId, array);
}
}
break;
}
case TiffDataFormat.CodeSingle:
{
if (componentCount == 1)
{
handler.SetFloat(tagId, reader.GetFloat32(tagValueOffset));
}
else
{
float[] array = new float[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetFloat32(tagValueOffset + (i * 4));
}
handler.SetFloatArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeDouble:
{
if (componentCount == 1)
{
handler.SetDouble(tagId, reader.GetDouble64(tagValueOffset));
}
else
{
double[] array = new double[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetDouble64(tagValueOffset + (i * 4));
}
handler.SetDoubleArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeInt8S:
{
if (componentCount == 1)
{
handler.SetInt8s(tagId, reader.GetInt8(tagValueOffset));
}
else
{
sbyte[] array = new sbyte[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetInt8(tagValueOffset + i);
}
handler.SetInt8sArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeInt8U:
{
if (componentCount == 1)
{
handler.SetInt8u(tagId, reader.GetUInt8(tagValueOffset));
}
else
{
short[] array = new short[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetUInt8(tagValueOffset + i);
}
handler.SetInt8uArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeInt16S:
{
if (componentCount == 1)
{
handler.SetInt16s(tagId, (int)reader.GetInt16(tagValueOffset));
}
else
{
short[] array = new short[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetInt16(tagValueOffset + (i * 2));
}
handler.SetInt16sArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeInt16U:
{
if (componentCount == 1)
{
handler.SetInt16u(tagId, reader.GetUInt16(tagValueOffset));
}
else
{
int[] array = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetUInt16(tagValueOffset + (i * 2));
}
handler.SetInt16uArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeInt32S:
{
// NOTE 'long' in this case means 32 bit, not 64
if (componentCount == 1)
{
handler.SetInt32s(tagId, reader.GetInt32(tagValueOffset));
}
else
{
int[] array = new int[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetInt32(tagValueOffset + (i * 4));
}
handler.SetInt32sArray(tagId, array);
}
break;
}
case TiffDataFormat.CodeInt32U:
{
// NOTE 'long' in this case means 32 bit, not 64
if (componentCount == 1)
{
handler.SetInt32u(tagId, reader.GetUInt32(tagValueOffset));
}
else
{
long[] array = new long[componentCount];
for (int i = 0; i < componentCount; i++)
{
array[i] = reader.GetUInt32(tagValueOffset + (i * 4));
}
handler.SetInt32uArray(tagId, array);
}
break;
}
default:
{
handler.Error(Sharpen.Extensions.StringFormat("Unknown format code %d for tag %d", formatCode, tagId));
break;
}
}
}
/// <summary>Processes a TIFF IFD.</summary>
/// <remarks>
/// Processes a TIFF IFD.
/// <p/>
/// IFD Header:
/// <ul>
/// <li><b>2 bytes</b> number of tags</li>
/// </ul>
/// Tag structure:
/// <ul>
/// <li><b>2 bytes</b> tag type</li>
/// <li><b>2 bytes</b> format code (values 1 to 12, inclusive)</li>
/// <li><b>4 bytes</b> component count</li>
/// <li><b>4 bytes</b> inline value, or offset pointer if too large to fit in four bytes</li>
/// </ul>
/// </remarks>
/// <param name="handler">
/// the
/// <see cref="TiffHandler"/>
/// that will coordinate processing and accept read values
/// </param>
/// <param name="reader">
/// the
/// <see cref="Com.Drew.Lang.RandomAccessReader"/>
/// from which the data should be read
/// </param>
/// <param name="processedIfdOffsets">the set of visited IFD offsets, to avoid revisiting the same IFD in an endless loop</param>
/// <param name="ifdOffset">the offset within <code>reader</code> at which the IFD data starts</param>
/// <param name="tiffHeaderOffset">the offset within <code>reader</code> at which the TIFF header starts</param>
/// <exception cref="System.IO.IOException">an error occurred while accessing the required data</exception>
public static void ProcessIfd(TiffHandler handler, RandomAccessReader reader, ICollection<int> processedIfdOffsets, int ifdOffset, int tiffHeaderOffset)
{
try
{
// check for directories we've already visited to avoid stack overflows when recursive/cyclic directory structures exist
if (processedIfdOffsets.Contains(Sharpen.Extensions.ValueOf(ifdOffset)))
{
return;
}
// remember that we've visited this directory so that we don't visit it again later
processedIfdOffsets.Add(ifdOffset);
if (ifdOffset >= reader.GetLength() || ifdOffset < 0)
{
handler.Error("Ignored IFD marked to start outside data segment");
return;
}
// First two bytes in the IFD are the number of tags in this directory
int dirTagCount = reader.GetUInt16(ifdOffset);
int dirLength = (2 + (12 * dirTagCount) + 4);
if (dirLength + ifdOffset > reader.GetLength())
{
handler.Error("Illegally sized IFD");
return;
}
//
// Handle each tag in this directory
//
for (int tagNumber = 0; tagNumber < dirTagCount; tagNumber++)
{
int tagOffset = CalculateTagOffset(ifdOffset, tagNumber);
// 2 bytes for the tag id
int tagId = reader.GetUInt16(tagOffset);
// 2 bytes for the format code
int formatCode = reader.GetUInt16(tagOffset + 2);
TiffDataFormat format = TiffDataFormat.FromTiffFormatCode(formatCode);
if (format == null)
{
// This error suggests that we are processing at an incorrect index and will generate
// rubbish until we go out of bounds (which may be a while). Exit now.
handler.Error("Invalid TIFF tag format code: " + formatCode);
return;
}
// 4 bytes dictate the number of components in this tag's data
int componentCount = reader.GetInt32(tagOffset + 4);
if (componentCount < 0)
{
handler.Error("Negative TIFF tag component count");
continue;
}
int byteCount = componentCount * format.GetComponentSizeBytes();
int tagValueOffset;
if (byteCount > 4)
{
// If it's bigger than 4 bytes, the dir entry contains an offset.
int offsetVal = reader.GetInt32(tagOffset + 8);
if (offsetVal + byteCount > reader.GetLength())
{
// Bogus pointer offset and / or byteCount value
handler.Error("Illegal TIFF tag pointer offset");
continue;
}
tagValueOffset = tiffHeaderOffset + offsetVal;
}
else
{
// 4 bytes or less and value is in the dir entry itself.
tagValueOffset = tagOffset + 8;
}
if (tagValueOffset < 0 || tagValueOffset > reader.GetLength())
{
handler.Error("Illegal TIFF tag pointer offset");
continue;
}
// Check that this tag isn't going to allocate outside the bounds of the data array.
// This addresses an uncommon OutOfMemoryError.
if (byteCount < 0 || tagValueOffset + byteCount > reader.GetLength())
{
handler.Error("Illegal number of bytes for TIFF tag data: " + byteCount);
continue;
}
//
// Special handling for tags that point to other IFDs
//
if (byteCount == 4 && handler.IsTagIfdPointer(tagId))
{
int subDirOffset = tiffHeaderOffset + reader.GetInt32(tagValueOffset);
ProcessIfd(handler, reader, processedIfdOffsets, subDirOffset, tiffHeaderOffset);
}
else
{
if (!handler.CustomProcessTag(tagValueOffset, processedIfdOffsets, tiffHeaderOffset, reader, tagId, byteCount))
{
ProcessTag(handler, tagId, tagValueOffset, componentCount, formatCode, reader);
}
}
}
// at the end of each IFD is an optional link to the next IFD
int finalTagOffset = CalculateTagOffset(ifdOffset, dirTagCount);
int nextIfdOffset = reader.GetInt32(finalTagOffset);
if (nextIfdOffset != 0)
{
nextIfdOffset += tiffHeaderOffset;
if (nextIfdOffset >= reader.GetLength())
{
// Last 4 bytes of IFD reference another IFD with an address that is out of bounds
// Note this could have been caused by jhead 1.3 cropping too much
return;
}
else
{
if (nextIfdOffset < ifdOffset)
{
// TODO is this a valid restriction?
// Last 4 bytes of IFD reference another IFD with an address that is before the start of this directory
return;
}
}
if (handler.HasFollowerIfd())
{
ProcessIfd(handler, reader, processedIfdOffsets, nextIfdOffset, tiffHeaderOffset);
}
}
}
finally
{
handler.EndingIFD();
}
}
/// <exception cref="System.IO.IOException"/>
private void SetDate(IccDirectory directory, int tagType, RandomAccessReader reader)
{
int y = reader.GetUInt16(tagType);
int m = reader.GetUInt16(tagType + 2);
int d = reader.GetUInt16(tagType + 4);
int h = reader.GetUInt16(tagType + 6);
int M = reader.GetUInt16(tagType + 8);
int s = reader.GetUInt16(tagType + 10);
// final Date value = new Date(Date.UTC(y - 1900, m - 1, d, h, M, s));
Sharpen.Calendar calendar = Sharpen.Calendar.GetInstance(Sharpen.Extensions.GetTimeZone("UTC"));
calendar.Set(y, m, d, h, M, s);
DateTime value = calendar.GetTime();
directory.SetDate(tagType, value);
}