// original: may be is null if mode is xor
public T_Data Decrypt(Bitmap original)
{
ImageOrigimal = original;
WriteReadData.SetSettingsMode();
if (GetConfPixel(WriteReadDataIdPosition) != WriteReadData.GetID())
{
return(DataReader.ToObject(System.Text.Encoding.UTF8.GetBytes("There is no hidden data in image!")));
//throw new ArgumentException("Parameter is not correct", "WriteReadData");
}
var CompressionId = GetConfPixel(DataCompressionIdPosition);
var EncryptId1 = GetConfPixel(Encrypt1IdPosition);
var EncryptId2 = GetConfPixel(Encrypt2IdPosition);
byte[] countDataList = new byte[4];
for (int i = 0; i < 4; ++i)
{
var r = i * 2;
var bigPath = GetConfPixel(r);
var littlePath = GetConfPixel(r + 1);
bigPath = (byte)(bigPath << 4);
countDataList[3 - i] = (byte)(bigPath | littlePath); // index from end becouse big endian format
}
var dataLengthBits = BitConverter.ToInt32(countDataList, 0);
var dataLengthBytes = dataLengthBits / 8;
countDataList = new byte[dataLengthBytes * 2];
WriteReadData.SetDataMode();
int x = 0, y = 1;
for (int i = 0; i < countDataList.Length;)
{
if (x >= ImageModifying.Width)
{
y++; x = 0;
}
var pixelEnc = ImageModifying.GetPixel(x, y);
var pixelOrg = original == null ? new Color() : original.GetPixel(x, y);
var d = WriteReadData.ReadData(pixelEnc, pixelOrg);
if (i < countDataList.Length)
{
countDataList[i++] = d[0];
}
if (i < countDataList.Length)
{
countDataList[i++] = d[1];
}
if (i < countDataList.Length)
{
countDataList[i++] = d[2];
}
++x;
}
var data = _byteOperations.JoinBytes(countDataList);
if (EncryptId2 > 0)
{
var enc = this.Encrypts.Where(r => r.GetID() == EncryptId2).FirstOrDefault();
if (enc != null)
{
data = enc.Decrypt(data);
}
}
if (EncryptId1 > 0)
{
var enc = this.Encrypts.Where(r => r.GetID() == EncryptId1).FirstOrDefault();
if (enc != null)
{
data = enc.Decrypt(data);
}
}
if (CompressionId > 0)
{
var compr = this.Compressions.Where(r => r.GetID() == CompressionId).FirstOrDefault();
if (compr != null)
{
data = compr.Recovery(data);
}
}
return(DataReader.ToObject(data));
}
private byte GetConfPixel(int x)
{
return(WriteReadData.ReadData(
ImageModifying.GetPixel(x, 0), ImageOrigimal == null ? new Color() : ImageOrigimal.GetPixel(x, 0))[0]);
}