public void Encode(SteganoContainer container, SteganoMessage steganoMessage, int key, int P)
{
if (steganoMessage.Size + 32 > container.Blocks.Count)
{
throw new Exception("Размер контейнера слишком мал, сэмпай!");
}
//Применили дкп ко всем блокам 8х8
foreach (var block in container.BlueComponent)
{
EncodeCoefficient.Add(DKP.Dkp(block));
}
Random rnd = new Random(key);
bool[] data = new bool[container.BlueComponent.Count - 32];
for (int i = 0; i < steganoMessage.DataBinaryString.Length; i++)
{
data[i] = true;
}
var distribution = Shuffle(data, rnd);
var steganoMessageLength = GetBinaryStringFromUInt32(steganoMessage.Size);
// put data about message length in blocks
for (int counter = 0; counter < 32; counter++)
{
EncodeCoefficient[counter] = DKP.CoefficientChange(EncodeCoefficient[counter],
steganoMessageLength[counter], u1, v1, u2, v2, P);
}
int marker = 32;
for (int i = 32; i < container.BlueComponent.Count; i++)
{
if (marker == steganoMessage.DataBinaryString.Length + 32)
{
break;
}
if (distribution[i - 32] == true)
{
EncodeCoefficient[i] = DKP.CoefficientChange(EncodeCoefficient[i], steganoMessage.DataBinaryString[marker - 32], u1, v1, u2, v2, P);
marker += 1;
}
else
{
continue;
}
}
foreach (var block in EncodeCoefficient)
{
EncodeCoefficientForWrite.Add(DKP.Odkp(block));
}
// change BlueComponent in container
for (var counter = 0; counter < container.BlueComponent.Count; counter++)
{
byte[,] buf = new byte[8, 8];
for (uint i = 0; i < 8; i++)
{
for (uint k = 0; k < 8; k++)
{
if (EncodeCoefficientForWrite[counter][i, k] < 0)
{
buf[i, k] = 0;
}
else if (EncodeCoefficientForWrite[counter][i, k] > 255)
{
buf[i, k] = 255;
}
else
{
buf[i, k] = (byte)Math.Round(EncodeCoefficientForWrite[counter][i, k]);
}
}
}
container.BlueComponent[counter] = buf;
}
}
public void Decode(SteganoContainer container, SteganoMessage steganoMessage, int key)
{
// Применили ДКП к блокам 8х8
foreach (var block in container.BlueComponent)
{
DecodeCoefficient.Add(DKP.Dkp(block));
}
double Abs1;
double Abs2;
string bits = ""; //временная переменная для записи сообщения
double[,] dkp_8x8; // временная переменная для одной матрицы 8на8
var steganoMessageLength = "";
for (int counter = 0; counter < 32; counter++)
{
dkp_8x8 = DecodeCoefficient[counter];
Abs1 = Math.Abs(dkp_8x8[u1, v1]);
Abs2 = Math.Abs(dkp_8x8[u2, v2]);
if (Abs1 > Abs2)
{
steganoMessageLength += "0";
}
if (Abs1 < Abs2)
{
steganoMessageLength += "1";
}
}
var steganoMessageLengthUInt32 = GetUInt32FromBinaryString(steganoMessageLength);
if (steganoMessageLengthUInt32 + 32 > container.Blocks.Count)
{
throw new Exception("Контейнер поврежден, сэмпай!");
}
Random rnd = new Random(key);
bool[] data = new bool[container.BlueComponent.Count - 32];
for (int i = 0; i < steganoMessageLengthUInt32; i++)
{
data[i] = true;
}
var distribution = Shuffle(data, rnd);
for (int k = 32; k < container.Blocks.Count; k++)
{
if (distribution[k - 32] == true)
{
dkp_8x8 = DecodeCoefficient[k];
Abs1 = Math.Abs(dkp_8x8[u1, v1]);
Abs2 = Math.Abs(dkp_8x8[u2, v2]);
if (Abs1 > Abs2)
{
bits += "0";
}
if (Abs1 < Abs2)
{
bits += "1";
}
}
else
{
continue;
}
}
steganoMessage.DataBinaryString = bits;
}
