/// <summary>
/// Decrypts the image hidden
/// </summary>
/// <returns>the image without the encrypted image below</returns>
public MyImage Decrypt()
{
byte[] zero = { 0, 0, 0, 0 };
Pixel[,] img = new Pixel[image.GetLength(0), image.GetLength(1)];
MyImage result = new MyImage(img);
for (int i = 0; i < image.GetLength(0); i++)
{
for (int j = 0; j < image.GetLength(1); j++)
{
byte[] rBits = ByteToBit(image[i, j].R);
byte[] gBits = ByteToBit(image[i, j].G);
byte[] bBits = ByteToBit(image[i, j].B);
byte[] rBits2 = ByteToBit(image[i, j].R);
byte[] gBits2 = ByteToBit(image[i, j].G);
byte[] bBits2 = ByteToBit(image[i, j].B);
//insert creation of new image
Insert(rBits, SubArray(rBits, 0, 4), 4);
Insert(gBits, SubArray(gBits, 0, 4), 4);
Insert(bBits, SubArray(bBits, 0, 4), 4);
Clean(rBits, 0, 4);
Clean(gBits, 0, 4);
Clean(bBits, 0, 4);
Clean(rBits2, 0, 4);
Clean(gBits2, 0, 4);
Clean(bBits2, 0, 4);
image[i, j].R = BitToByte(rBits);
image[i, j].G = BitToByte(gBits);
image[i, j].B = BitToByte(bBits);
img[i, j] = new Pixel(BitToByte(rBits2), BitToByte(gBits2), BitToByte(bBits2));
}
}
return(result);
}
/* Cryptography */
/// <summary>
/// Hide the image into another image
/// </summary>
/// <param name="img">image to hide our image</param>
public void Encrypt(MyImage img)
{
int i = 0, j = 0;
while (image.GetLength(0) >= img.image.GetLength(0) || image.GetLength(1) >= img.image.GetLength(1))
{
img.IncreaseSize();
}
img.CropFromMiddle(image.GetLength(0), image.GetLength(1));
for (i = 0; i < image.GetLength(0); i++)
{
for (j = 0; j < image.GetLength(1); j++)
{
byte[] rBits1 = ByteToBit(image[i, j].R);
byte[] rBits2 = ByteToBit(img.image[i, j].R);
byte[] gBits1 = ByteToBit(image[i, j].G);
byte[] gBits2 = ByteToBit(img.image[i, j].G);
byte[] bBits1 = ByteToBit(image[i, j].B);
byte[] bBits2 = ByteToBit(img.image[i, j].B);
Insert(rBits2, SubArray(rBits1, 4, 4), 0);
Insert(gBits2, SubArray(gBits1, 4, 4), 0);
Insert(bBits2, SubArray(bBits1, 4, 4), 0);
image[i, j].R = BitToByte(rBits2);
image[i, j].G = BitToByte(gBits2);
image[i, j].B = BitToByte(bBits2);
}
}
}
static void Main(string[] args)
{
MyImage img = new MyImage("taxi.bmp");
img.RedFilter();
img.Save("taxi.bmp");
Console.ReadKey();
}
/// <summary>
/// Creates an histogram based on the image
/// </summary>
/// <param name="filename">specify the folder and filename</param>
/// <returns>
/// returns a string with the filename
/// itcan vary because of existing file in the folder
/// </returns>
public string Histogram(string filename)
{
imageType = "BM";
offsetSize = 54;
int[,] histogram = this.histogram;
int max = 0;
foreach (int n in histogram)
{
if (n > max)
{
max = n;
}
}
float ratio = 100f / (float)max;
Pixel[,] imageTemp = new Pixel[100, 256];
for (int i = 0; i < imageTemp.GetLength(1); i++)
{
for (int j = 0; j < imageTemp.GetLength(0); j++)
{
imageTemp[imageTemp.GetLength(0) - j - 1, imageTemp.GetLength(1) - i - 1] = Pixel.Black;
if (histogram[0, i] * ratio >= j)
{
imageTemp[imageTemp.GetLength(0) - j - 1, imageTemp.GetLength(1) - i - 1].AddRed();
}
if (histogram[1, i] * ratio >= j)
{
imageTemp[imageTemp.GetLength(0) - j - 1, imageTemp.GetLength(1) - i - 1].AddGreen();
}
if (histogram[2, i] * ratio >= j)
{
imageTemp[imageTemp.GetLength(0) - j - 1, imageTemp.GetLength(1) - i - 1].AddBlue();
}
}
}
MyImage histo = new MyImage(imageTemp);
string[] split = filename.Split('\\');
filename = "";
for (int i = 0; i < split.Length - 1; i++)
{
filename += split[i] + '\\';
}
filename += "histogram-" + split.Last();
return(histo.Save(filename));
}
/// <summary>
/// Decode a QRCode
/// </summary>
/// <param name="img">image containing the QRCode</param>
private QRCode(MyImage img)
{
// Copy image on this object
image = new Pixel[img.image.GetLength(0), img.image.GetLength(1)];
for (int i = 0; i < image.GetLength(0); i++)
{
for (int j = 0; j < image.GetLength(1); j++)
{
image[i, j] = new Pixel(img.image[i, j]);
}
}
/* https://www.researchgate.net/publication/221337868_Fast_QR_Code_Detection_in_Arbitrarily_Acquired_Images */
//Assume image is flat on the surface
//Find the size of a finder and the size of a code to determine the version
//and the size of a bit to be accurate while reading
// plus save the start index of QRCode;
// Different size horizontal and vertical (if image is warped
int sizeOfFinderHorizontal = 0;
int sizeOfCodeHorizontal = 0;
int sizeOfFinderVertical = 0;
int sizeOfCodeVertical = 0;
bool b = true;
int line = 0;
int column = 0;
int startLine = 0;
int startColumn = 0;
//Searching
while (b)
{
column = 0;
while (column < image.GetLength(1) && !image[line, column].isCloseToBlack)
{
column++;
}
startColumn = column;
startLine = line;
// For horizontal size
while (column < image.GetLength(1) && image[startLine, column].isCloseToBlack)
{
b = false;
sizeOfFinderHorizontal++;
column++;
}
// For Vertical size
while (!b && line < image.GetLength(0) && image[line, startColumn].isCloseToBlack)
{
sizeOfFinderVertical++;
line++;
}
if (!b)
{
// Horizontal size
for (int j = image.GetLength(1) - 1; j >= 0 && sizeOfCodeHorizontal == 0; j--)
{
if (image[startLine, j].isCloseToBlack)
{
sizeOfCodeHorizontal = j - startColumn;
}
}
// Vertical Size
for (int j = image.GetLength(0) - 1; j >= 0 && sizeOfCodeVertical == 0; j--)
{
if (image[j, startColumn].isCloseToBlack)
{
sizeOfCodeVertical = j - startLine;
}
}
}
line++;
}
//Compute the size of a bit (finder is 7 pixels wide)
int bitSizeHorizontal = sizeOfFinderHorizontal / 7;
int bitSizeVertical = sizeOfFinderVertical / 7;
int approxSize = sizeOfCodeHorizontal / bitSizeHorizontal;
//Determine the version of QR based on the size
if (approxSize < 23)
{
type = 1;
}
else
{
type = 2;
}
//Now read the QRCode but first Draw the Canvas
DrawCanvas();
//Read DAta
string messageBits = ReadData(bitSizeHorizontal, bitSizeVertical, startLine, startColumn);
// Get rid of the last seven bits if type 2
if (type == 2)
{
messageBits = messageBits.Substring(0, 352);
}
Console.WriteLine(messageBits);
// Get The Error count
int eccCount = 7 * 8;
if (type == 2)
{
eccCount = 10 * 8;
}
//Split error bits and message bits
string errorBits = messageBits.Substring(messageBits.Length - eccCount, eccCount);
messageBits = messageBits.Substring(0, messageBits.Length - eccCount);
// Decode with Reed Solomon Algorithm
byte[] messageBytes = BitsToByte(messageBits);
byte[] errorBytes = BitsToByte(errorBits);
byte[] finalMessage = ReedSolomonAlgorithm.Decode(messageBytes, errorBytes, ErrorCorrectionCodeType.QRCode);
messageBits = ByteToBit(finalMessage);
// Assume the image is alphanumeric and get rid of the length
messageBits = messageBits.Substring(4, messageBits.Length - 4);
Decode_Message(messageBits);
}
/// <summary>
/// Decode a QRCode
/// </summary>
/// <param name="img">the image containing the QRCode</param>
/// <returns>the message contatained in the QRCode</returns>
public static string Decode(MyImage img)
{
QRCode init = new QRCode(img);
return(init.message);
}
