I'm trying to implement the Connected Components Labeling in C++ with Qt but i'm struggling in implementing the equivalence table and having some problems to understand how to work with it.
Here is what i've done so far :

Qt Code: 
  1. for (int x = 0; x < image.width(); ++x) {
  2.     for (int y = 0; y < image.height(); ++y) {
  3.  
  4.         color = image.pixel(x,y);
  5.  
  6.         if(color.red() == 0)
  7.             imageLabeled.setPixel(x,y, qRgb(0,0,0));
  8.  
  9.         else{
  10.             color1 = imageLabeled.pixel(x, y-1);
  11.             color2 = imageLabeled.pixel(x-1, y);
  12.  
  13.             if(color1.red() == 0 && color2.red() == 0)
  14.             {
  15.                 imageLabeled.setPixel(x,y, qRgb(label, label, label));
  16.                 label+=1;
  17.  
  18.             }else if(color1.red() == 0 && color2.red() != 0)
  19.                 imageLabeled.setPixel(x,y,color2.rgb());
  20.  
  21.  
  22.             else if(color1.red() != 0 && color2.red() == 0)
  23.                 imageLabeled.setPixel(x,y, color1.rgb());
  24.  
  25.             else if(color1.red() != 0 && color2.red() != 0)
  26.             {
  27.                 if(color1.red() < color2.red())
  28.                     imageLabeled.setPixel(x,y, color1.rgb());
  29.                 else
  30.                     imageLabeled.setPixel(x,y, color2.rgb());
  31.             }
  32.  
  33.         }
  34.  
  35.     }
  36. }
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In this block of instructions i'm just searching for pixels to be labeled. There is no equivalence table or so.

Thanks you for your help !
Cheers !