/// <exception cref="PngProcessingException"/>
/// <exception cref="System.IO.IOException"/>
private static IEnumerable <Directory> ProcessChunk([NotNull] PngChunk chunk)
{
var chunkType = chunk.ChunkType;
var bytes = chunk.Bytes;
if (chunkType == PngChunkType.IHDR)
{
var header = new PngHeader(bytes);
var directory = new PngDirectory(PngChunkType.IHDR);
directory.Set(PngDirectory.TagImageWidth, header.ImageWidth);
directory.Set(PngDirectory.TagImageHeight, header.ImageHeight);
directory.Set(PngDirectory.TagBitsPerSample, header.BitsPerSample);
directory.Set(PngDirectory.TagColorType, header.ColorType.NumericValue);
directory.Set(PngDirectory.TagCompressionType, header.CompressionType);
directory.Set(PngDirectory.TagFilterMethod, header.FilterMethod);
directory.Set(PngDirectory.TagInterlaceMethod, header.InterlaceMethod);
yield return(directory);
}
else if (chunkType == PngChunkType.PLTE)
{
var directory = new PngDirectory(PngChunkType.PLTE);
directory.Set(PngDirectory.TagPaletteSize, bytes.Length / 3);
yield return(directory);
}
else if (chunkType == PngChunkType.tRNS)
{
var directory = new PngDirectory(PngChunkType.tRNS);
directory.Set(PngDirectory.TagPaletteHasTransparency, 1);
yield return(directory);
}
else if (chunkType == PngChunkType.sRGB)
{
int srgbRenderingIntent = unchecked ((sbyte)bytes[0]);
var directory = new PngDirectory(PngChunkType.sRGB);
directory.Set(PngDirectory.TagSrgbRenderingIntent, srgbRenderingIntent);
yield return(directory);
}
else if (chunkType == PngChunkType.cHRM)
{
var chromaticities = new PngChromaticities(bytes);
var directory = new PngChromaticitiesDirectory();
directory.Set(PngChromaticitiesDirectory.TagWhitePointX, chromaticities.WhitePointX);
directory.Set(PngChromaticitiesDirectory.TagWhitePointY, chromaticities.WhitePointY);
directory.Set(PngChromaticitiesDirectory.TagRedX, chromaticities.RedX);
directory.Set(PngChromaticitiesDirectory.TagRedY, chromaticities.RedY);
directory.Set(PngChromaticitiesDirectory.TagGreenX, chromaticities.GreenX);
directory.Set(PngChromaticitiesDirectory.TagGreenY, chromaticities.GreenY);
directory.Set(PngChromaticitiesDirectory.TagBlueX, chromaticities.BlueX);
directory.Set(PngChromaticitiesDirectory.TagBlueY, chromaticities.BlueY);
yield return(directory);
}
else if (chunkType == PngChunkType.gAMA)
{
var gammaInt = ByteConvert.ToInt32BigEndian(bytes);
var directory = new PngDirectory(PngChunkType.gAMA);
directory.Set(PngDirectory.TagGamma, gammaInt / 100000.0);
yield return(directory);
}
else if (chunkType == PngChunkType.iCCP)
{
var reader = new SequentialByteArrayReader(bytes);
var profileName = reader.GetNullTerminatedString(maxLengthBytes: 79);
var directory = new PngDirectory(PngChunkType.iCCP);
directory.Set(PngDirectory.TagIccProfileName, profileName);
var compressionMethod = reader.GetSByte();
if (compressionMethod == 0)
{
// Only compression method allowed by the spec is zero: deflate
// This assumes 1-byte-per-char, which it is by spec.
var bytesLeft = bytes.Length - profileName.Length - 2;
var compressedProfile = reader.GetBytes(bytesLeft);
using (var inflaterStream = new InflaterInputStream(new MemoryStream(compressedProfile)))
yield return(new IccReader().Extract(new IndexedCapturingReader(inflaterStream)));
}
else
{
directory.AddError("Invalid compression method value");
}
yield return(directory);
}
else if (chunkType == PngChunkType.bKGD)
{
var directory = new PngDirectory(PngChunkType.bKGD);
directory.Set(PngDirectory.TagBackgroundColor, bytes);
yield return(directory);
}
else if (chunkType == PngChunkType.tEXt)
{
var reader = new SequentialByteArrayReader(bytes);
var keyword = reader.GetNullTerminatedString(maxLengthBytes: 79);
var bytesLeft = bytes.Length - keyword.Length - 1;
var value = reader.GetNullTerminatedString(bytesLeft);
var textPairs = new List <KeyValuePair> {
new KeyValuePair(keyword, value)
};
var directory = new PngDirectory(PngChunkType.iTXt);
directory.Set(PngDirectory.TagTextualData, textPairs);
yield return(directory);
}
else if (chunkType == PngChunkType.iTXt)
{
var reader = new SequentialByteArrayReader(bytes);
var keyword = reader.GetNullTerminatedString(maxLengthBytes: 79);
var compressionFlag = reader.GetSByte();
var compressionMethod = reader.GetSByte();
var languageTag = reader.GetNullTerminatedString(bytes.Length);
var translatedKeyword = reader.GetNullTerminatedString(bytes.Length);
var bytesLeft = bytes.Length - keyword.Length - 1 - 1 - 1 - languageTag.Length - 1 - translatedKeyword.Length - 1;
string text = null;
if (compressionFlag == 0)
{
text = reader.GetNullTerminatedString(bytesLeft);
}
else if (compressionFlag == 1)
{
if (compressionMethod == 0)
{
using (var inflaterStream = new DeflateStream(new MemoryStream(bytes, bytes.Length - bytesLeft, bytesLeft), CompressionMode.Decompress))
text = new StreamReader(inflaterStream).ReadToEnd();
}
else
{
var directory = new PngDirectory(PngChunkType.iTXt);
directory.AddError("Invalid compression method value");
yield return(directory);
}
}
else
{
var directory = new PngDirectory(PngChunkType.iTXt);
directory.AddError("Invalid compression flag value");
yield return(directory);
}
if (text != null)
{
if (keyword == "XML:com.adobe.xmp")
{
// NOTE in testing images, the XMP has parsed successfully, but we are not extracting tags from it as necessary
yield return(new XmpReader().Extract(text));
}
else
{
var textPairs = new List <KeyValuePair> {
new KeyValuePair(keyword, text)
};
var directory = new PngDirectory(PngChunkType.iTXt);
directory.Set(PngDirectory.TagTextualData, textPairs);
yield return(directory);
}
}
}
else if (chunkType == PngChunkType.tIME)
{
var reader = new SequentialByteArrayReader(bytes);
var year = reader.GetUInt16();
var month = reader.GetByte();
int day = reader.GetByte();
int hour = reader.GetByte();
int minute = reader.GetByte();
int second = reader.GetByte();
var directory = new PngDirectory(PngChunkType.tIME);
try
{
var time = new DateTime(year, month, day, hour, minute, second, DateTimeKind.Utc);
directory.Set(PngDirectory.TagLastModificationTime, time);
}
catch (ArgumentOutOfRangeException e)
{
directory.AddError("Error constructing DateTime: " + e.Message);
}
yield return(directory);
}
else if (chunkType == PngChunkType.pHYs)
{
var reader = new SequentialByteArrayReader(bytes);
var pixelsPerUnitX = reader.GetInt32();
var pixelsPerUnitY = reader.GetInt32();
var unitSpecifier = reader.GetSByte();
var directory = new PngDirectory(PngChunkType.pHYs);
directory.Set(PngDirectory.TagPixelsPerUnitX, pixelsPerUnitX);
directory.Set(PngDirectory.TagPixelsPerUnitY, pixelsPerUnitY);
directory.Set(PngDirectory.TagUnitSpecifier, unitSpecifier);
yield return(directory);
}
else if (chunkType.Equals(PngChunkType.sBIT))
{
var directory = new PngDirectory(PngChunkType.sBIT);
directory.Set(PngDirectory.TagSignificantBits, bytes);
yield return(directory);
}
}
/// <exception cref="Com.Drew.Imaging.Png.PngProcessingException"/>
/// <exception cref="System.IO.IOException"/>
private static void ProcessChunk([NotNull] Com.Drew.Metadata.Metadata metadata, [NotNull] PngChunk chunk)
{
PngChunkType chunkType = chunk.GetChunkType();
sbyte[] bytes = chunk.GetBytes();
if (chunkType.Equals(PngChunkType.Ihdr))
{
PngHeader header = new PngHeader(bytes);
PngDirectory directory = new PngDirectory(PngChunkType.Ihdr);
directory.SetInt(PngDirectory.TagImageWidth, header.GetImageWidth());
directory.SetInt(PngDirectory.TagImageHeight, header.GetImageHeight());
directory.SetInt(PngDirectory.TagBitsPerSample, header.GetBitsPerSample());
directory.SetInt(PngDirectory.TagColorType, header.GetColorType().GetNumericValue());
directory.SetInt(PngDirectory.TagCompressionType, header.GetCompressionType());
directory.SetInt(PngDirectory.TagFilterMethod, header.GetFilterMethod());
directory.SetInt(PngDirectory.TagInterlaceMethod, header.GetInterlaceMethod());
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.Plte))
{
PngDirectory directory = new PngDirectory(PngChunkType.Plte);
directory.SetInt(PngDirectory.TagPaletteSize, bytes.Length / 3);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.tRNS))
{
PngDirectory directory = new PngDirectory(PngChunkType.tRNS);
directory.SetInt(PngDirectory.TagPaletteHasTransparency, 1);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.sRGB))
{
int srgbRenderingIntent = new SequentialByteArrayReader(bytes).GetInt8();
PngDirectory directory = new PngDirectory(PngChunkType.sRGB);
directory.SetInt(PngDirectory.TagSrgbRenderingIntent, srgbRenderingIntent);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.cHRM))
{
PngChromaticities chromaticities = new PngChromaticities(bytes);
PngChromaticitiesDirectory directory = new PngChromaticitiesDirectory();
directory.SetInt(PngChromaticitiesDirectory.TagWhitePointX, chromaticities.GetWhitePointX());
directory.SetInt(PngChromaticitiesDirectory.TagWhitePointX, chromaticities.GetWhitePointX());
directory.SetInt(PngChromaticitiesDirectory.TagRedX, chromaticities.GetRedX());
directory.SetInt(PngChromaticitiesDirectory.TagRedY, chromaticities.GetRedY());
directory.SetInt(PngChromaticitiesDirectory.TagGreenX, chromaticities.GetGreenX());
directory.SetInt(PngChromaticitiesDirectory.TagGreenY, chromaticities.GetGreenY());
directory.SetInt(PngChromaticitiesDirectory.TagBlueX, chromaticities.GetBlueX());
directory.SetInt(PngChromaticitiesDirectory.TagBlueY, chromaticities.GetBlueY());
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.gAMA))
{
int gammaInt = new SequentialByteArrayReader(bytes).GetInt32();
PngDirectory directory = new PngDirectory(PngChunkType.gAMA);
directory.SetDouble(PngDirectory.TagGamma, gammaInt / 100000.0);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.iCCP))
{
SequentialReader reader = new SequentialByteArrayReader(bytes);
string profileName = reader.GetNullTerminatedString(79);
PngDirectory directory = new PngDirectory(PngChunkType.iCCP);
directory.SetString(PngDirectory.TagIccProfileName, profileName);
sbyte compressionMethod = reader.GetInt8();
if (compressionMethod == 0)
{
// Only compression method allowed by the spec is zero: deflate
// This assumes 1-byte-per-char, which it is by spec.
int bytesLeft = bytes.Length - profileName.Length - 2;
sbyte[] compressedProfile = reader.GetBytes(bytesLeft);
InflaterInputStream inflateStream = new InflaterInputStream(new ByteArrayInputStream(compressedProfile));
new IccReader().Extract(new RandomAccessStreamReader(inflateStream), metadata);
inflateStream.Close();
}
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.bKGD))
{
PngDirectory directory = new PngDirectory(PngChunkType.bKGD);
directory.SetByteArray(PngDirectory.TagBackgroundColor, bytes);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.tEXt))
{
SequentialReader reader = new SequentialByteArrayReader(bytes);
string keyword = reader.GetNullTerminatedString(79);
int bytesLeft = bytes.Length - keyword.Length - 1;
string value = reader.GetNullTerminatedString(bytesLeft);
IList <KeyValuePair> textPairs = new AList <KeyValuePair>();
textPairs.Add(new KeyValuePair(keyword, value));
PngDirectory directory = new PngDirectory(PngChunkType.iTXt);
directory.SetObject(PngDirectory.TagTextualData, textPairs);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.iTXt))
{
SequentialReader reader = new SequentialByteArrayReader(bytes);
string keyword = reader.GetNullTerminatedString(79);
sbyte compressionFlag = reader.GetInt8();
sbyte compressionMethod = reader.GetInt8();
string languageTag = reader.GetNullTerminatedString(bytes.Length);
string translatedKeyword = reader.GetNullTerminatedString(bytes.Length);
int bytesLeft = bytes.Length - keyword.Length - 1 - 1 - 1 - languageTag.Length - 1 - translatedKeyword.Length - 1;
string text = null;
if (compressionFlag == 0)
{
text = reader.GetNullTerminatedString(bytesLeft);
}
else
{
if (compressionFlag == 1)
{
if (compressionMethod == 0)
{
text = StringUtil.FromStream(new InflaterInputStream(new ByteArrayInputStream(bytes, bytes.Length - bytesLeft, bytesLeft)));
}
else
{
PngDirectory directory = new PngDirectory(PngChunkType.iTXt);
directory.AddError("Invalid compression method value");
metadata.AddDirectory(directory);
}
}
else
{
PngDirectory directory = new PngDirectory(PngChunkType.iTXt);
directory.AddError("Invalid compression flag value");
metadata.AddDirectory(directory);
}
}
if (text != null)
{
if (keyword.Equals("XML:com.adobe.xmp"))
{
// NOTE in testing images, the XMP has parsed successfully, but we are not extracting tags from it as necessary
new XmpReader().Extract(text, metadata);
}
else
{
IList <KeyValuePair> textPairs = new AList <KeyValuePair>();
textPairs.Add(new KeyValuePair(keyword, text));
PngDirectory directory = new PngDirectory(PngChunkType.iTXt);
directory.SetObject(PngDirectory.TagTextualData, textPairs);
metadata.AddDirectory(directory);
}
}
}
else
{
if (chunkType.Equals(PngChunkType.tIME))
{
SequentialByteArrayReader reader = new SequentialByteArrayReader(bytes);
int year = reader.GetUInt16();
int month = reader.GetUInt8() - 1;
int day = reader.GetUInt8();
int hour = reader.GetUInt8();
int minute = reader.GetUInt8();
int second = reader.GetUInt8();
Sharpen.Calendar calendar = Sharpen.Calendar.GetInstance(Sharpen.Extensions.GetTimeZone("UTC"));
//noinspection MagicConstant
calendar.Set(year, month, day, hour, minute, second);
PngDirectory directory = new PngDirectory(PngChunkType.tIME);
directory.SetDate(PngDirectory.TagLastModificationTime, calendar.GetTime());
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.pHYs))
{
SequentialByteArrayReader reader = new SequentialByteArrayReader(bytes);
int pixelsPerUnitX = reader.GetInt32();
int pixelsPerUnitY = reader.GetInt32();
sbyte unitSpecifier = reader.GetInt8();
PngDirectory directory = new PngDirectory(PngChunkType.pHYs);
directory.SetInt(PngDirectory.TagPixelsPerUnitX, pixelsPerUnitX);
directory.SetInt(PngDirectory.TagPixelsPerUnitY, pixelsPerUnitY);
directory.SetInt(PngDirectory.TagUnitSpecifier, unitSpecifier);
metadata.AddDirectory(directory);
}
else
{
if (chunkType.Equals(PngChunkType.sBIT))
{
PngDirectory directory = new PngDirectory(PngChunkType.sBIT);
directory.SetByteArray(PngDirectory.TagSignificantBits, bytes);
metadata.AddDirectory(directory);
}
}
}
}
}
}
}
}
}
}
}
}
}
}
