public static List <Chunk> CompressIDATs(byte[] cipheredBytes)
{
byte[] compressedBytes = ZlibCompression.Compress(cipheredBytes);
List <Chunk> resultIdats = IDATConverter.SplitToIDATs(compressedBytes).Select(idat => (Chunk)idat).ToList();
return(resultIdats);
}
public void ShouldConcatDecompressCompressAndThenSplitImage()
{
string filePath = @"../../../Data/lena.png";
List <Chunk> chunks = PNGFile.Read(filePath);
List <Chunk> parsedChunks = ChunkParser.Parse(chunks);
int firstIdatIndex = parsedChunks.TakeWhile(chunk => !IsIDAT(chunk)).Count();
List <IDAT> idats = parsedChunks.Where(IsIDAT).Select(chunk => (IDAT)chunk).ToList();
byte[] bytes = IDATConverter.ConcatToBytes(idats);
byte[] decompressedBytes = ZlibCompression.Decompress(bytes);
byte[] compressedBytes = ZlibCompression.Compress(decompressedBytes);
List <Chunk> resultIdats = IDATConverter.SplitToIDATs(compressedBytes).Select(idat => (Chunk)idat).ToList();
List <Chunk> resultChunks = parsedChunks.Where(chunk => !IsIDAT(chunk)).ToList();
resultChunks.InsertRange(firstIdatIndex, resultIdats);
PNGFile.Write(@"../../../Data/lenaCompressed.png", resultChunks);
}
public CompiledMetafile(Metafile file)
{
Name = file.Name;
Source = file;
using (var metaFileStream = new MemoryStream())
{
using (var metaFileWriter = new BinaryWriter(metaFileStream, CodePagesEncodingProvider.Instance.GetEncoding(949), true))
{
metaFileWriter.Write((byte)(file.Nodes.Count / 256));
metaFileWriter.Write((byte)(file.Nodes.Count % 256));
foreach (var node in file.Nodes)
{
byte[] nodeBuffer = CodePagesEncodingProvider.Instance.GetEncoding(949).GetBytes(node.Text);
metaFileWriter.Write((byte)nodeBuffer.Length);
metaFileWriter.Write(nodeBuffer);
metaFileWriter.Write((byte)(node.Properties.Count / 256));
metaFileWriter.Write((byte)(node.Properties.Count % 256));
foreach (var property in node.Properties)
{
byte[] propertyBuffer = CodePagesEncodingProvider.Instance.GetEncoding(949).GetBytes(property);
metaFileWriter.Write((byte)(propertyBuffer.Length / 256));
metaFileWriter.Write((byte)(propertyBuffer.Length % 256));
metaFileWriter.Write(propertyBuffer);
}
}
}
Checksum = ~Crc32.Calculate(metaFileStream.ToArray());
metaFileStream.Seek(0, SeekOrigin.Begin);
using (var compressedMetaFileStream = new MemoryStream())
{
ZlibCompression.Compress(metaFileStream, compressedMetaFileStream);
Data = compressedMetaFileStream.ToArray();
}
}
}
private static void CompressAndDecompress(byte[] bytes)
{
byte[] compressed = ZlibCompression.Compress(bytes);
byte[] decompressed = ZlibCompression.Decompress(compressed);
Assert.AreEqual(bytes, decompressed);
}
