   iu::LinearDeviceMemory_8u_C1 row_mins(num_row_sums);
   iu::LinearDeviceMemory_8u_C1 row_maxs(num_row_sums);
 
-#if 0
+#if 1
   cuMinMaxXKernel_8u_C1 <<< dimGridX, dimBlock >>> (
       row_mins.data(), row_maxs.data(), roi.x, roi.y, roi.width, roi.height);
 #else

 float cur_sum = 0.0f;

 // compute sum of each column
 if ((x+xoff)<width)
 {
   for(int y = yoff; y < height; ++y)
   {

   for(int y = 1; y < height; ++y)
   {
     yy = y+yoff+0.5f;
     val = tex2D(tex1_8u_C1__, xx, yy);
     if(val < cur_min) cur_min = val;
     if(val > cur_max) cur_max = val;
   }
