/// <summary>
/// Converts a list of locations back to their hex characters.
/// </summary>
/// <param name="locations">List of locations read from file.</param>
/// <returns>A string of hex characters.</returns>
public string decode(IEnumerable <Location> locations)
{
var sb = new StringBuilder();
foreach (var loc in locations)
{
var x = Convert.ToInt32(loc.getX());
var y = Convert.ToInt32(loc.getY());
var hashLocation = Convert.ToInt32(loc.getHashLocation());
if (x >= imageWidth || y >= imageHeight || hashLocation >= 128)
{
Console.Error.WriteLine("[ERROR]: Decode file has invalid sizes.");
Environment.Exit(91);
}
var key = x + "-" + y;
PixelInformation px;
try
{
px = pixelMap[key];
}
catch (KeyNotFoundException)
{
px = new PixelInformation(this, x, y);
pixelMap.Add(key, px);
}
sb.Append(px.getLetter(hashLocation));
}
return(sb.ToString());
}
/// <summary>
/// Adds more pixels from the original image file.
/// </summary>
/// <param name="amount">Amount of pixels to add from parent image.</param>
public void addPixels(int amount)
{
if (pixelMap.Count + 1 + amount > getImageSize())
{
Console.Error.WriteLine(
"[ERROR]: This image is not large enough to hide the data, please start again with a bigger image.");
Environment.Exit(97);
}
using (var provider = new RNGCryptoServiceProvider())
{
for (var i = 0; i < amount; i++)
{
var data = new byte[100];
var invalid = true;
do
{
//X
provider.GetBytes(data);
var value = BitConverter.ToUInt64(data, 0);
var x = (int)(value % Convert.ToUInt64(imageWidth));
//Y
provider.GetBytes(data);
value = BitConverter.ToUInt64(data, 0);
var y = (int)(value % Convert.ToUInt64(imageHeight));
var key = x + "-" + y;
try
{
var px = new PixelInformation(this, x, y);
pixelMap.Add(key, px);
}
//If it's duplicated we need a different one
catch (ArgumentException)
{
continue;
}
invalid = false;
} while (invalid);
}
updateHexCharacters();
}
}
