public DifferencesExpansionConfiguraitonDialogBox(DifferencesExpansionConfiguration standardDEConfig,
DifferenceExpansionBruteForceConfiguration bruteForceDEConfig,
AlgorithmConfiguration currentConfiguration)
{
InitializeComponent();
if (standardDEConfig != null)
{
this.threshold = standardDEConfig.Threeshold;
tbThreshold.Text = threshold.ToString();
cbEmbeddingDirection.SelectedIndex = (int)standardDEConfig.EmbeddingDirection;
cbR.IsChecked = standardDEConfig.EmbeddingChanels.Contains(EmbeddingChanel.R);
cbG.IsChecked = standardDEConfig.EmbeddingChanels.Contains(EmbeddingChanel.G);
cbB.IsChecked = standardDEConfig.EmbeddingChanels.Contains(EmbeddingChanel.B);
ComboBoxItem standardComboBoxItem = new ComboBoxItem();
standardComboBoxItem.Content = "Standard";
standardComboBoxItem.IsSelected = currentConfiguration is DifferencesExpansionConfiguration;
cbConfigurationType.Items.Add(standardComboBoxItem);
}
if (bruteForceDEConfig != null)
{
cbHorizontal_BF.IsChecked = bruteForceDEConfig.EmbeddingDirections.Contains(Direction.Horizontal);
cbVertical_BF.IsChecked = bruteForceDEConfig.EmbeddingDirections.Contains(Direction.Vertical);
cbR_BF.IsChecked = bruteForceDEConfig.EmbeddingChanels.Contains(EmbeddingChanel.R);
cbG_BF.IsChecked = bruteForceDEConfig.EmbeddingChanels.Contains(EmbeddingChanel.G);
cbB_BF.IsChecked = bruteForceDEConfig.EmbeddingChanels.Contains(EmbeddingChanel.B);
ComboBoxItem bruteForceItem = new ComboBoxItem();
bruteForceItem.Content = "Brute force";
bruteForceItem.IsSelected = currentConfiguration is DifferenceExpansionBruteForceConfiguration;
cbConfigurationType.Items.Add(bruteForceItem);
}
}
public Tuple <Bitmap, string> Decode(Bitmap encodedImage, AlgorithmConfiguration configuration)
{
// Algorithm instances
DifferencesExpansionAlgorithm de = new DifferencesExpansionAlgorithm();
HistogramShiftingAlgorithm hs = new HistogramShiftingAlgorithm();
// Algorithm configs
DifferenceExpansionBruteForceConfiguration deConfig = new DifferenceExpansionBruteForceConfiguration(
new HashSet <EmbeddingChanel>()
{
EmbeddingChanel.R, EmbeddingChanel.G, EmbeddingChanel.B
}, new HashSet <Direction>()
{
Direction.Horizontal, Direction.Vertical
});
HistogramShiftingConfiguration hsConfig = new HistogramShiftingConfiguration(true,
new HashSet <EmbeddingChanel>()
{
EmbeddingChanel.R, EmbeddingChanel.G, EmbeddingChanel.B
});
// Decoding
var deResult = de.BruteforceDecode(encodedImage, deConfig);
if (deResult != null)
{
return(deResult);
}
var hsResult = hs.Decode(encodedImage, hsConfig);
if (hsResult != null)
{
return(hsResult);
}
return(null);
}
public Tuple <Bitmap, string> BruteforceDecode(Bitmap inputImage, DifferenceExpansionBruteForceConfiguration bruteForceConfiguration)
{
Bitmap processedImage = inputImage;
List <string> payloadChunks = new List <string>();
foreach (EmbeddingChanel embeddingChannel in Enum.GetValues(typeof(EmbeddingChanel)))
{
if (bruteForceConfiguration.EmbeddingChanels.Contains(embeddingChannel))
{
// For each RGB channel specified in configuration algorithm tries to perform decoding
Tuple <Bitmap, string> imageAndPayload = TryDecodeImageForChannel(processedImage, embeddingChannel, bruteForceConfiguration);
if (isDecodingSuccessfull(imageAndPayload))
{
// If decoding was successfull then retrived chunk of payload from given channel is saved
// If there was no success next embedding channel is used
processedImage = imageAndPayload.Item1;
payloadChunks.Add(imageAndPayload.Item2);
}
}
}
return(payloadChunks.Count > 0 ? new Tuple <Bitmap, string>(processedImage, String.Join("", payloadChunks)) : null);
}
private void BtnConfigDE_Click(object sender, RoutedEventArgs e)
{
if (isWatermarkingModeSelected())
{
DifferencesExpansionConfiguration config = (DifferencesExpansionConfiguration)standardEncodingDEConfig;
var dialogBox = new ConfigurationDialogBox.DifferencesExpansionConfiguraitonDialogBox(config, null, activeEncodingDEConfig)
{
Owner = this,
};
dialogBox.ShowDialog();
AlgorithmConfiguration newConfig = GetConfigurationBasedOnDialogBoxResult(dialogBox);
if (newConfig != null)
{
standardEncodingDEConfig = newConfig;
activeEncodingDEConfig = standardEncodingDEConfig;
}
}
if (isAnalyzingModeSelected())
{
DifferencesExpansionConfiguration deConfig = (DifferencesExpansionConfiguration)standardDecodingDEConfig;
DifferenceExpansionBruteForceConfiguration deBruteForceConfig = (DifferenceExpansionBruteForceConfiguration)bruteForceDecodingDEConfig;
var dialogBox = new ConfigurationDialogBox.DifferencesExpansionConfiguraitonDialogBox(deConfig, deBruteForceConfig, activeDecodingDEConfig)
{
Owner = this,
};
dialogBox.ShowDialog();
AlgorithmConfiguration newConfig = GetConfigurationBasedOnDialogBoxResult(dialogBox);
if (dialogBox.cbConfigurationType.Text == "Standard" && newConfig != null)
{
standardDecodingDEConfig = newConfig;
activeDecodingDEConfig = standardDecodingDEConfig;
}
else if (dialogBox.cbConfigurationType.Text == "Brute force" && newConfig != null)
{
bruteForceDecodingDEConfig = newConfig;
activeDecodingDEConfig = bruteForceDecodingDEConfig;
}
}
}
public Tuple <Bitmap, string> TryDecodeImageForChannel(Bitmap inputImage, EmbeddingChanel embeddingChanel, DifferenceExpansionBruteForceConfiguration bruteForceConfiguration)
{
foreach (Direction direction in Enum.GetValues(typeof(Direction)))
{
if (bruteForceConfiguration.EmbeddingDirections.Contains(direction))
{
// For given RGB channel algorith tries to decode payload with each embedding direction allowed in configuration
Tuple <Bitmap, string> imageAndPayload = TryDecodeImageForDirectionAndChannel(inputImage, Direction.Horizontal, embeddingChanel);
if (isDecodingSuccessfull(imageAndPayload))
{
// If decoding with given embedding channel and direction was successfull then image and payload chunk is returned
// If there was no success other embedding direction for given channel is used
return(imageAndPayload);
}
}
}
return(null);
}