public byte[] GetWaterMarkedBytes(string waterMark)
{
InseredWaterMarkIndexes.Clear();
var waterMarkedBytes = new byte[originalBytes.Length];
originalBytes.CopyTo(waterMarkedBytes, 0);
var waterMarkBits = WaterMark.FromString(waterMark);
OriginalWaterMarkBits = waterMarkBits;
var waterMarkBitIndex = 0;
if (mode == Mode.Direct)
{
for (var index = HeaderSize + 4; index + Shift < waterMarkedBytes.Length; index += Shift)
{
var startIndex = index;
var endIndex = index + Shift;
var maxAmplitudeIndex = FindMaxAmplitudeIndex(waterMarkedBytes, startIndex, endIndex);
InseredWaterMarkIndexes.Add(maxAmplitudeIndex);
SetMark(waterMarkedBytes, waterMarkBits[waterMarkBitIndex], maxAmplitudeIndex);
waterMarkBitIndex = waterMarkBitIndex < waterMarkBits.Length - 1
? waterMarkBitIndex + 1
: 0;
}
}
else if (mode == Mode.Quasi)
{
var quasi = new QuasiStationary(waterMarkedBytes.Skip(HeaderSize).Take(waterMarkedBytes.Length - HeaderSize).ToArray(), Shift, QuasiEpsilon);
var quasiIndexes = quasi.Split();
for (var i = 0; i < quasiIndexes.Count; i++)
{
var startIndex = quasiIndexes[i] * Shift;
var endIndex = (i + 1) < quasiIndexes.Count
? quasiIndexes[i + 1] * Shift - 1 // Start index of next quasi area * segment length - 1
: waterMarkedBytes.Length - 1; // End of signal
var maxAmplitudeIndex = FindMaxAmplitudeIndex(waterMarkedBytes, startIndex, endIndex);
InseredWaterMarkIndexes.Add(maxAmplitudeIndex);
SetMark(waterMarkedBytes, waterMarkBits[waterMarkBitIndex], maxAmplitudeIndex);
waterMarkBitIndex = waterMarkBitIndex < waterMarkBits.Length - 1
? waterMarkBitIndex + 1
: 0;
}
}
else
{
throw new NotImplementedException();
}
return(waterMarkedBytes);
}
public byte[] ExtractWaterMark(byte[] waterMarkedBytes)
{
ExtractedWaterMarkIndexes.Clear();
var unwaterMarkedBytes = new byte[waterMarkedBytes.Length];
waterMarkedBytes.CopyTo(unwaterMarkedBytes, 0);
var waterMarkBits = new List <byte>();
if (mode == Mode.Direct)
{
for (var index = HeaderSize + 4; index + Shift < unwaterMarkedBytes.Length; index += Shift)
{
var startIndex = index;
var endIndex = index + Shift;
var maxAmplitudeIndex = FindMaxAmplitudeIndex(unwaterMarkedBytes, startIndex, endIndex);
ExtractedWaterMarkIndexes.Add(maxAmplitudeIndex);
waterMarkBits.Add(GetMark(unwaterMarkedBytes, maxAmplitudeIndex));
}
}
else if (mode == Mode.Quasi)
{
var quasi = new QuasiStationary(waterMarkedBytes.Skip(HeaderSize).Take(waterMarkedBytes.Length - HeaderSize).ToArray(), Shift, QuasiEpsilon);
var quasiIndexes = quasi.Split();
for (var i = 0; i < quasiIndexes.Count; i++)
{
var startIndex = quasiIndexes[i] * Shift;
var endIndex = (i + 1) < quasiIndexes.Count
? quasiIndexes[i + 1] * Shift - 1 // Start index of next quasi area * segment length - 1
: waterMarkedBytes.Length - 1; // End of signal
var maxAmplitudeIndex = FindMaxAmplitudeIndex(waterMarkedBytes, startIndex, endIndex);
ExtractedWaterMarkIndexes.Add(maxAmplitudeIndex);
waterMarkBits.Add(GetMark(unwaterMarkedBytes, maxAmplitudeIndex));
}
}
else
{
throw new NotImplementedException();
}
ExtractedWaterMarkBits = waterMarkBits.ToArray();
return(unwaterMarkedBytes);
}
