/// <summary>
/// Embeds the monochrome image in the source bitmap image by
/// using the least significant bit to alter the color.
/// Precondition: bitmap is not null, bitmap is not larger than source
/// Post-condition: least significant bit in the source image is replaced.
/// </summary>
/// <param name="bitmap">The bitmap.</param>
/// <param name="encrypt">Whether or not to encrypt the image.</param>
/// <exception cref="ArgumentNullException">bitmap</exception>
/// <exception cref="SecretTooLargeException">bitmap is too big to fit</exception>
public void EmbedMonochromeImage(MonochromeBitmap bitmap, bool encrypt)
{
if (bitmap == null)
{
throw new ArgumentNullException(nameof(bitmap));
}
if (bitmap.Width > this.Width || bitmap.Height > this.Height)
{
throw new SecretTooLargeException();
}
for (var x = 0; x < bitmap.Width; x++)
{
for (var y = 0; y < bitmap.Height; y++)
{
var pixelColor = this.GetPixelColor(x, y);
pixelColor.B = pixelColor.B.SetLeastSignificantBit(bitmap.GetPixelColor(x, y).Equals(Colors.White));
this.SetPixelColor(x, y, pixelColor);
}
}
if (encrypt)
{
this.flipEmbeddedImage();
}
this.setUpHeaderForSecretImage(encrypt);
}
private void flipEmbeddedImage()
{
this.EmbedMonochromeImage(MonochromeBitmap.FromEmbeddedSecret(this).GetFlipped(), false);
}