/// <summary>
/// Decrypts a text from a BitmapImage
/// </summary>
/// <param name="picture">The picture in which a text will be searched for</param>
/// <param name="usage">How many bits will be used in each channel</param>
/// <param name="seed">The seed used in the generator for the order of pixels</param>
/// <returns>Text found in the picture</returns>
public static string Decrypt(BitmapImage picture, ChannelUsage usage, int seed)
{
using (var decrypter = new Decrypter(new Picture(picture.ToByteArray(), seed, picture.PixelHeight, picture.PixelWidth)))
{
var text = decrypter.ReadText(usage);
return((text == "") ? "No text found." : text);
}
}
public static string Decrypt(Bitmap encryptedPicture, ChannelUsage usage, int seed)
{
using (encryptedPicture)
using (var decrypter = new Decrypter(new Picture(encryptedPicture, seed)))
{
var text = decrypter.ReadText(usage);
return((text == "") ? "No text found." : text);
}
}
public void TestEncrypt()
{
const string text = "Sample text to hide";
var image = ColoredBitmap.CreateBitmap(100, 100);
var usage = new ChannelUsage(2);
var picture = Interface.Encrypt(image, usage, 0, text);
var decrypter = new Decrypter(new Picture(picture));
var resText = decrypter.ReadText(usage);
Assert.AreEqual(text, resText);
}
public void TestNoAlpha()
{
const string text = "Sample Text written with 2 bits per channel, but not using the alpha channel";
var usage = new ChannelUsage(2, 2, 2);
var encrypter = new Encrypter(new Picture(new Bitmap(20, 20)));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
var res = decrypter.ReadText(usage);
Assert.AreEqual(text, res);
}
public void TestChnUsage()
{
const string text = "Sample Text written with 3 bits per channel which gives the possibility to store more text";
var usage = new ChannelUsage(3);
var encrypter = new Encrypter(new Picture(new Bitmap(20, 20)));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
var res = decrypter.ReadText(usage);
Assert.AreEqual(text, res);
}
public void TestLong()
{
const string text = "Pretty long text just to test if everything is working properly!";
var usage = new ChannelUsage(2);
var encrypter = new Encrypter(new Picture(ColoredBitmap.CreateBitmap(20, 20, Color.Aqua), 0));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
var res = decrypter.ReadText(usage);
Assert.AreEqual(text, res);
}
public void TestShort()
{
const string text = "Sample Text to hide";
var usage = new ChannelUsage(2);
var encrypter = new Encrypter(new Picture(ColoredBitmap.CreateBitmap(10, 10, Color.Aqua), 0));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
var res = decrypter.ReadText(usage);
Assert.AreEqual(text, res);
}
public void TestDifferentChnUsage()
{
const string text = "Sample Text written with different bits used per channel, but not using the alpha channel";
var usage = new ChannelUsage(2, 3, 0, 1);
var encrypter = new Encrypter(new Picture(100, 100));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
var res = decrypter.ReadText(usage);
Assert.AreEqual(text, res);
}
public void TestWrongSeed()
{
const int seed = 26;
const string text = "This won't work because we use another seed for decrypting our image";
var usage = new ChannelUsage(2);
var encrypter = new Encrypter(new Picture(new Bitmap(20, 20), seed));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(new Picture(picture.GetImage(), 0));
var res = decrypter.ReadText(usage);
Assert.AreNotEqual(text, res);
}
public void TestSeed()
{
const int seed = 23;
const string text = "Sample Text to hide";
var usage = new ChannelUsage(2);
var encrypter = new Encrypter(new Picture(new Bitmap(20, 20), seed));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
var res = decrypter.ReadText(usage);
Assert.AreEqual(text, res);
}
public void TestWrongChnUsage()
{
const string text = "Sample Text written with 2 bits per channel, but not using the alpha channel while encrypting but using it when decrypting";
var usage = new ChannelUsage(2, 3, 3, 2);
var encrypter = new Encrypter(new Picture(100, 100));
encrypter.InsertText(text, usage);
var picture = encrypter.GetPictureData();
var decrypter = new Decrypter(picture);
usage = new ChannelUsage(3, 2, 2, 3);
var res = decrypter.ReadText(usage);
Assert.AreNotEqual(text, res);
}
public void TestSingleCharTagless()
{
const string text = "s";
var image = ColoredBitmap.CreateBitmap(1, 1);
var usage = new ChannelUsage(2);
var encrypter = new Encrypter(new Picture(image));
encrypter.InsertText(text, usage, false);
var resImage = encrypter.GetPictureData().GetImage();
encrypter.Dispose();
var decrypter = new Decrypter(new Picture(resImage));
var resText = decrypter.ReadText(usage, false);
Assert.AreEqual(text, resText);
}
