public static void Encode(Bitmap bitmap, string text)
{
var bytes = new BitArray(Encoding.UTF8.GetBytes($"{text}\u0000"));
var counter = 0;
var decorator = new BitmapIndexDecorator(bitmap, c => c.R);
foreach (bool b in bytes)
{
var color = decorator[counter];
var red = (int)color.R;
if (red % 2 == 0 && b)
{
red += 1;
}
else if (red % 2 == 1 && !b)
{
red -= 1;
}
decorator[counter] = Color.FromArgb(color.A, red, color.G, color.B);
counter++;
}
}
public static void SetWatermark(Bitmap bitmap)
{
var bytes = new BitArray(Encoding.UTF8.GetBytes(Watermaker));
var counter = 0;
var decorator = new BitmapIndexDecorator(bitmap, c => c.B);
foreach (bool b in bytes)
{
var color = decorator[counter];
var blue = (int)color.B;
if (blue % 2 == 0 && b)
{
blue += 1;
}
else if (blue % 2 == 1 && !b)
{
blue -= 1;
}
decorator[counter] = Color.FromArgb(color.A, color.R, color.G, blue);
counter++;
}
}
public static string Decode(Bitmap bitmap)
{
var bytes = new BitmapIndexDecorator(bitmap, c => c.R)
.TakeWhile(b => b != 0)
.ToArray();
return(Encoding.UTF8.GetString(bytes.ToArray()));
}
public static bool CheckWatermark(Bitmap bitmap)
{
var bytes = new BitmapIndexDecorator(bitmap, c => c.B)
.Take(Encoding.UTF8.GetBytes(Watermaker).Length)
.ToArray();
return(Encoding.UTF8.GetString(bytes).Equals(Watermaker));
}
