public override BitMatrix sampleGrid(BitMatrix image, int dimension, PerspectiveTransform transform)
 {
     BitMatrix bits = new BitMatrix(dimension);
     float[] points = new float[dimension << 1];
     for (int y = 0; y < dimension; y++)
     {
         int max = points.Length;
         //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
         float iValue = (float) y + 0.5f;
         for (int x = 0; x < max; x += 2)
         {
             //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
             points[x] = (float) (x >> 1) + 0.5f;
             points[x + 1] = iValue;
         }
         transform.transformPoints(points);
         // Quick check to see if points transformed to something inside the image;
         // sufficient to check the endpoints
         checkAndNudgePoints(image, points);
         try
         {
             for (int x = 0; x < max; x += 2)
             {
                 //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
                 if (image.get_Renamed((int) points[x], (int) points[x + 1]))
                 {
                     // Black(-ish) pixel
                     bits.set_Renamed(x >> 1, y);
                 }
             }
         }
         catch (System.IndexOutOfRangeException)
         {
             // This feels wrong, but, sometimes if the finder patterns are misidentified, the resulting
             // transform gets "twisted" such that it maps a straight line of points to a set of points
             // whose endpoints are in bounds, but others are not. There is probably some mathematical
             // way to detect this about the transformation that I don't know yet.
             // This results in an ugly runtime exception despite our clever checks above -- can't have
             // that. We could check each point's coordinates but that feels duplicative. We settle for
             // catching and wrapping ArrayIndexOutOfBoundsException.
             throw ReaderException.Instance;
         }
     }
     return bits;
 }
 // Applies a single threshold to an 8x8 block of pixels.
 private static void threshold8x8Block(sbyte[] luminances, int xoffset, int yoffset, int threshold, int stride, BitMatrix matrix)
 {
     for (int y = 0; y < 8; y++)
     {
         int offset = (yoffset + y) * stride + xoffset;
         for (int x = 0; x < 8; x++)
         {
             int pixel = luminances[offset + x] & 0xff;
             if (pixel < threshold)
             {
                 matrix.set_Renamed(xoffset + x, yoffset + y);
             }
         }
     }
 }