opencl/snn-mean.cl

   1 static inline float colordiff (float4 pixA,
   2                                float4 pixB)
   3 {
   4   float4 pix = pixA - pixB;
   5   pix *= pix;
   6   return pix.x + pix.y + pix.z;
   7 }
   8
   9 __kernel void snn_mean (__global const   float4 *src_buf,
  10                                          int src_width,
  11                                          int src_height,
  12                         __global         float4 *dst_buf,
  13                                          int radius,
  14                                          int pairs)
  15 {
  16   int gidx   = get_global_id(0);
  17   int gidy   = get_global_id(1);
  18   int offset = gidy * get_global_size(0) + gidx;
  19
  20   const float4 center_pix  =
  21       *(src_buf + ((radius + gidx) + (gidy + radius) * src_width));
  22         float4 accumulated = 0;
  23
  24   int count = 0;
  25   if (pairs == 2)
  26     {
  27       for (int i = -radius; i <= 0; i++)
  28         {
  29           for (int j = -radius; j <= 0 ; j++)
  30             {
  31               float4 selected_pix = center_pix;
  32               float  best_diff    = 1000.0f;
  33
  34               if (i != 0 && j != 0)
  35                 {
  36                   int xs[4] =
  37                     {
  38                       gidx + j + radius, gidx - j + radius,
  39                       gidx - j + radius, gidx + j + radius
  40                     };
  41                   int ys[4] =
  42                     {
  43                       gidy + i + radius, gidy - i + radius,
  44                       gidy + i + radius, gidy - i + radius
  45                     };
  46
  47                   for (int k = 0; k < 4; k++)
  48                     {
  49                       if (xs[k] >= 0 && xs[k] < src_width &&
  50                           ys[k] >= 0 && ys[k] < src_height)
  51                         {
  52                           const float4 tpix =
  53                               *(src_buf + (xs[k] + ys[k] * src_width));
  54                                 float  diff = colordiff (tpix, center_pix);
  55                           if (diff < best_diff)
  56                             {
  57                               best_diff    = diff;
  58                               selected_pix = tpix;
  59                             }
  60                         }
  61                     }
  62                 }
  63               accumulated += selected_pix;
  64               ++count;
  65               if (i == 0 && j == 0)
  66                 break;
  67             }
  68         }
  69       dst_buf[offset] = accumulated / (float4)(count);
  70       return;
  71     }
  72   else if (pairs == 1)
  73     {
  74       for (int i = -radius; i <= 0; i++)
  75         {
  76           for (int j = -radius; j <= radius; j++)
  77             {
  78               float4 selected_pix = center_pix;
  79               float  best_diff    = 1000.0f;
  80
  81               /* skip computations for the center pixel */
  82               if (i != 0 && j != 0)
  83                 {
  84                   int xs[4] =
  85                     {
  86                       gidx + j + radius, gidx - j + radius,
  87                       gidx - j + radius, gidx + j + radius
  88                     };
  89                   int ys[4] =
  90                     {
  91                       gidy + i + radius, gidy - i + radius,
  92                       gidy + i + radius, gidy - i + radius
  93                     };
  94
  95                   for (int k = 0; k < 2; k++)
  96                     {
  97                       if (xs[k] >= 0 && xs[k] < src_width &&
  98                           ys[k] >= 0 && ys[k] < src_height)
  99                         {
 100                           const float4 tpix =
 101                               *(src_buf + (xs[k] + ys[k] * src_width));
 102                                 float  diff = colordiff (tpix, center_pix);
 103                           if (diff < best_diff)
 104                             {
 105                               best_diff    = diff;
 106                               selected_pix = tpix;
 107                             }
 108                         }
 109                     }
 110                 }
 111               accumulated += selected_pix;
 112               ++count;
 113               if (i == 0 && j == 0)
 114                  break;
 115             }
 116         }
 117       dst_buf[offset] = accumulated / (float4)(count);
 118       return;
 119     }
 120   return;
 121 }