public Bitmap Encode(Bitmap inputImage, IInputMessage inputMessage)
{
Bitmap image = new Bitmap(inputImage);
const int lastBit = 0;
// index of current bit of inputMessage
int bitIndex = 0;
string messageWithHeader = inputMessage.GetMessageWithHeader();
int messageLength = messageWithHeader.Length;
for (int i = 0; i < image.Height; i++)
{
for (int j = 0; j < image.Width; j++)
{
Color pixel = image.GetPixel(j, i);
int R = pixel.R;
int G = pixel.G;
int B = pixel.B;
// pass through every channel
for (int n = 0; n < 3; n++)
{
if (bitIndex == messageLength)
{
Color newPixel = Color.FromArgb(R, G, B);
image.SetPixel(j, i, newPixel);
return(image);
}
switch (n)
{
case 0:
{
R ^= (-messageWithHeader[bitIndex] ^ R) & (1 << lastBit);
bitIndex++;
break;
}
case 1:
{
G ^= (-messageWithHeader[bitIndex] ^ G) & (1 << lastBit);
bitIndex++;
break;
}
case 2:
{
B ^= (-messageWithHeader[bitIndex] ^ B) & (1 << lastBit);
bitIndex++;
Color newPixel = Color.FromArgb(R, G, B);
image.SetPixel(j, i, newPixel);
break;
}
}
}
}
}
return(image);
}
public Bitmap Encode(Bitmap inputImage, IInputMessage inputMessage)
{
Bitmap image = new Bitmap(inputImage);
Dictionary <int, int> histogram = calculateHistogram(image);
Tuple <int, int, int, int> myTuple = findMinAndMax(histogram);
int min = myTuple.Item1;
int max = myTuple.Item2;
int minIndex = myTuple.Item3;
int maxIndex = myTuple.Item4;
/* Console.WriteLine("Max value is: " + max + " for index: " + maxIndex);
* Console.WriteLine("Min value is: " + min + " for index: " + minIndex);*/
string messageWithHeader = inputMessage.GetMessageWithHeader();
if (maxIndex < minIndex)
{
shiftHistogramRight(image, minIndex, maxIndex);
encodeMessageRight(image, messageWithHeader, minIndex, maxIndex);
}
else if (maxIndex > minIndex)
{
shiftHistogramLeft(image, minIndex, maxIndex);
encodeMessageLeft(image, messageWithHeader, minIndex, maxIndex);
}
return(image);
}