static byte[] GzDecompress(byte[] input)
{
ZlibDecoder decoder = ZlibCodecFactory.NewZlibDecoder(ZlibWrapper.Gzip);
var channel = new EmbeddedChannel(decoder);
Assert.True(channel.WriteInbound(Unpooled.CopiedBuffer(input)));
Assert.True(channel.Finish()); // close the channel to indicate end-of-data
int outputSize = 0;
IByteBuffer o;
var inbound = new List <IByteBuffer>();
while ((o = channel.ReadInbound <IByteBuffer>()) != null)
{
inbound.Add(o);
outputSize += o.ReadableBytes;
}
var output = new byte[outputSize];
int readCount = 0;
foreach (IByteBuffer b in inbound)
{
int readableBytes = b.ReadableBytes;
b.ReadBytes(output, readCount, readableBytes);
b.Release();
readCount += readableBytes;
}
Assert.True(channel.InboundMessages.Count == 0 && channel.OutboundMessages.Count == 0);
return(output);
}
public Image Read(byte[] bytes)
{
var reader = new BinaryReader(bytes);
if (reader.GetUint8() != 137)
{
return(null);
}
if (reader.GetUint8() != 80)
{
return(null);
}
if (reader.GetUint8() != 78)
{
return(null);
}
if (reader.GetUint8() != 71)
{
return(null);
}
if (reader.GetUint8() != 13)
{
return(null);
}
if (reader.GetUint8() != 10)
{
return(null);
}
if (reader.GetUint8() != 26)
{
return(null);
}
if (reader.GetUint8() != 10)
{
return(null);
}
Image re = null;
while (reader.Tell() < bytes.Length)
{
var len = reader.GetUint32();
var name = reader.GetString(4);
var pos = reader.Tell();
bool done = false;
switch (name)
{
case "IHDR":
re = new Image((int)reader.GetUint32(), (int)reader.GetUint32());
var bitdepth = reader.GetUint8();
var colortype = reader.GetUint8();
var compression = reader.GetUint8();
var filtermethod = reader.GetUint8();
var interlace = reader.GetUint8();
break;
case "PLTE":
break;
case "IDAT":
var buf = new List <byte>();
reader.GetUint8();
reader.GetUint8();
for (int i = 2; i < len; i++)
{
buf.Add(reader.GetUint8());
}
var data = ZlibDecoder.Inflate(buf);
var d = new BinaryReader(data.ToArray());
var totalScanlines = data.Count / (re.Width + 1) / 4;
var prevScanline = new List <byte>();
for (int y = 0; y < totalScanlines; y++)
{
var filter = d.GetUint8();
var dat = new List <byte>();
for (int x = 0; x < re.Width * 4; x++)
{
dat.Add(d.GetUint8());
}
var scanline = new List <byte>();
if (filter == 1)
{
scanline.Add(dat[0]);
for (var index = 1; index < dat.Count; index++)
{
scanline.Add((byte)((scanline[index - 4 > 0 ? index - 4 : 0] + dat[index - 1]) % 256));
//scanline.Add((byte) (255));
}
}
else if (filter == 2)
{
for (var index = 0; index < dat.Count; index++)
{
scanline.Add((byte)((prevScanline[index] + dat[index]) % 256));
//scanline.Add((byte) (255));
}
}
else
{
}
var line = new BinaryReader(scanline.ToArray());
prevScanline.Clear();
prevScanline.AddRange(scanline);
for (int x = 0; x < re.Width; x++)
{
var a = line.GetUint8();
var r = line.GetUint8();
var g = line.GetUint8();
var b = line.GetUint8();
// if (b == 55 || r == 55 || g == 55) Debugger.Break();
var c = new Color(r, g, b, 255);
re.SetPixel(x, y, c);
}
/* //re.SetPixel(x, y, d.GetUint32());
*
* var b = UnSub(d, x, decoded);
* var g = UnSub(d, x, decoded);
* var r = UnSub(d, x, decoded);
* var a = UnSub(d, x, decoded);
*
* var c = new Color(r, g, b);
*
* if (c.ToHex() == 0) c = new Color(prev);
*
* prev = c.ToHex();
*
*
* //if(b == 55 || r == 55 || g == 55) Debugger.Break();
*
* re.SetPixel(x, y, c);*/
}
break;
case "IEND":
done = true;
break;
}
if (done)
{
break;
}
reader.Seek((int)(pos + len));
var crc = reader.GetUint32();
}
return(re);
}
