/// <summary>
/// Extracts the content from the image
/// </summary>
/// <param name="img">the image from which to extract</param>
/// <param name="planes">the planes to embed in</param>
/// <param name="bitDepth">the bit depth of the embedding</param>
/// <returns>the embedded content, null if a problem occurs</returns>
public static EmbeddingContent Extract(Bitmap img, EmbeddingPlane planes, int bitDepth)
{
// short circuit
if ((img == null) || (bitDepth < 1) || (bitDepth > 8))
{
return(null);
}
// var declatation
EmbeddingContent retVal = null;
try
{
// get the header to determine what to extract
EmbeddingHeader eh = new EmbeddingHeader(img, planes, bitDepth);
// read the bytes
int totalBytesToExtract = eh.ToString().Length + eh.SizeOfContent;
retVal = new EmbeddingContent(SteganographyMethods.ExtractBytes(img, planes, bitDepth, totalBytesToExtract));
}
catch
{
retVal = null;
}
return(retVal);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="content">the file to embed</param>
public EmbeddingContent(FileInfo content)
{
// short circuit
if ((content == null) || (content.Exists == false))
{
throw new SteganographyException("Incorrect parameters for EmbeddingContent");
}
this.Header = new EmbeddingHeader(ContentType.File, Convert.ToInt32(content.Length), content.Name);
this.HeaderAndContent = EmbeddingContent.MergeHeaderAndContent(this.Header, File.ReadAllBytes(content.FullName));
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="typeOfContent">the type of content</param>
/// <param name="filename">the filename (if the content is file)</param>
/// <param name="content">byte array of content</param>
public EmbeddingContent(ContentType typeOfContent, String filename, byte[] content)
{
// short circuit
if ((content == null) || (content.Length < 1))
{
throw new SteganographyException("Incorrect parameters for EmbeddingContent");
}
this.Header = new EmbeddingHeader(typeOfContent, content.Length, filename);
this.HeaderAndContent = EmbeddingContent.MergeHeaderAndContent(this.Header, content);
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="content">the text content</param>
public EmbeddingContent(String content)
{
// short circuit
content = content.Trim();
if (content.Length < 1)
{
throw new SteganographyException("Incorrect parameters for EmbeddingContent");
}
this.Header = new EmbeddingHeader(ContentType.Text, content.Length, String.Empty);
this.HeaderAndContent = EmbeddingContent.MergeHeaderAndContent(this.Header, Encoding.ASCII.GetBytes(content));
}
/// Extracts the content from the image
/// </summary>
/// <param name="imageFile">the image file from which to extract</param>
/// <param name="planes">the planes to embed in</param>
/// <param name="bitDepth">the bit depth of the embedding</param>
/// <returns>the embedded content, null if a problem occurs</returns>
public static EmbeddingContent Extract(String imageFile, EmbeddingPlane planes, int bitDepth)
{
// var init
EmbeddingContent retVal = null;
// wrap call
try
{
using (Bitmap img = new Bitmap(imageFile))
{
retVal = SteganographyMethods.Extract(img, planes, bitDepth);
}
}
catch
{
retVal = null;
}
return(retVal);;
}
/// <summary>
/// Embeds content in the image
/// </summary>
/// <param name="imageFile">the image file in which to embed</param>
/// <param name="planes">the planes to embed in</param>
/// <param name="bitDepth">the bit depth of the embedding</param>
/// <param name="content">the content to embed</param>
/// <returns>the image with the data embedded if successful, otherwise null</returns>
public static Bitmap Embed(String imageFile, EmbeddingPlane planes, int bitDepth, EmbeddingContent content)
{
// var init
Bitmap retVal = null;
// wrap call
try
{
retVal = new Bitmap(imageFile);
if (SteganographyMethods.Embed(retVal, planes, bitDepth, content) == false)
{
throw new SteganographyException(String.Empty);
}
}
catch
{
if (retVal != null)
{
retVal.Dispose();
}
retVal = null;
}
return(retVal);
}
/// <summary>
/// Embeds content in the image
/// </summary>
/// <param name="img">the image in which to embed</param>
/// <param name="planes">the planes to embed in</param>
/// <param name="bitDepth">the bit depth of the embedding</param>
/// <param name="content">the content to embed</param>
/// <returns>true if successful</returns>
public static Boolean Embed(Bitmap img, EmbeddingPlane planes, int bitDepth, EmbeddingContent content)
{
// short circuit
if ((img == null) || (bitDepth < 1) || (bitDepth > 8) || (content == null) || (content.HeaderAndContent.Length > SteganographyMethods.MaxBytesInImage(img, planes, bitDepth)))
{
return(false);
}
// var init
Boolean retVal = true;
int currentByteIndex = 0;
byte currentBitIndex = 1;
try
{
// loop through the x and y pixels of the image, as well as the correct bit depths
for (int x = 0; x < img.Width; x++)
{
for (int y = 0; y < img.Height; y++)
{
for (byte embedBit = 1; embedBit <= bitDepth; embedBit++)
{
// embed in R
if ((planes == EmbeddingPlane.R) || (planes == EmbeddingPlane.RGB))
{
Color rgb = img.GetPixel(x, y);
byte r = SteganographyMethods.SetBitValueInByte(rgb.R, embedBit, SteganographyMethods.GetBitValueFromByte(content.HeaderAndContent[currentByteIndex], currentBitIndex));
img.SetPixel(x, y, Color.FromArgb(r, rgb.G, rgb.B));
// enumerate bit/byte counter
currentBitIndex++;
if (currentBitIndex > 8)
{
currentBitIndex = 1;
currentByteIndex++;
}
if (currentByteIndex >= content.HeaderAndContent.Length)
{
x = img.Width;
y = img.Height;
break;
}
}
// embed in G
if ((planes == EmbeddingPlane.G) || (planes == EmbeddingPlane.RGB))
{
Color rgb = img.GetPixel(x, y);
byte g = SteganographyMethods.SetBitValueInByte(rgb.G, embedBit, SteganographyMethods.GetBitValueFromByte(content.HeaderAndContent[currentByteIndex], currentBitIndex));
img.SetPixel(x, y, Color.FromArgb(rgb.R, g, rgb.B));
// enumerate bit/byte counter
currentBitIndex++;
if (currentBitIndex > 8)
{
currentBitIndex = 1;
currentByteIndex++;
}
if (currentByteIndex >= content.HeaderAndContent.Length)
{
x = img.Width;
y = img.Height;
break;
}
}
// embed in B
if ((planes == EmbeddingPlane.B) || (planes == EmbeddingPlane.RGB))
{
Color rgb = img.GetPixel(x, y);
byte b = SteganographyMethods.SetBitValueInByte(rgb.B, embedBit, SteganographyMethods.GetBitValueFromByte(content.HeaderAndContent[currentByteIndex], currentBitIndex));
img.SetPixel(x, y, Color.FromArgb(rgb.R, rgb.G, b));
// enumerate bit/byte counter
currentBitIndex++;
if (currentBitIndex > 8)
{
currentBitIndex = 1;
currentByteIndex++;
}
if (currentByteIndex >= content.HeaderAndContent.Length)
{
x = img.Width;
y = img.Height;
break;
}
}
}
}
}
}
catch
{
retVal = false;
}
return(retVal);
}
