/// <exception cref="Com.Drew.Imaging.Png.PngProcessingException"/>
public PngHeader(sbyte[] bytes)
{
if (bytes.Length != 13)
{
throw new PngProcessingException("PNG header chunk must have 13 data bytes");
}
SequentialReader reader = new SequentialByteArrayReader(bytes);
try
{
_imageWidth = reader.GetInt32();
_imageHeight = reader.GetInt32();
_bitsPerSample = reader.GetInt8();
sbyte colorTypeNumber = reader.GetInt8();
PngColorType colorType = PngColorType.FromNumericValue(colorTypeNumber);
if (colorType == null)
{
throw new PngProcessingException("Unexpected PNG color type: " + colorTypeNumber);
}
_colorType = colorType;
_compressionType = reader.GetInt8();
_filterMethod = reader.GetInt8();
_interlaceMethod = reader.GetInt8();
}
catch (IOException e)
{
// Should never happen
throw new PngProcessingException(e);
}
}
/// <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);
}
}
}
}
}
}
}
}
}
}
}
}
}
}
