how to read a swizzled / tiled texture as used in some consoles? here some C# snipped of mine

int[,] Image = new int[width, height];
int m = 16;
int n = 16;
for (int y = 0; y < height / n; y++)
 for (int x = 0; x < width / m; x++)
  for (int j = 0; j < n; j++)  
   for (int i = 0; i < m; i++)                                 
    Image[x * m + i, y * n + j] = ReadRGBInt(source);

greetz WV