10, 10, 10... I hope?
Processing 2, 448-25=423 bytes

int x,y,w,b,v,c,m;color g;PImage i;void setup(){i=loadImage("f.png");w=i.width;size(w,w);g=#00ff00;image(i,0,0);b=v=x=y=c=m=0;loadPixels();while(y*w+x&lt;w*w){if(pixels[y*w+x]==g){f(y,x);if(v&gt;=0)c+=v;else m++;}v=-1;x++;if(x==w){x=0;y++;}}println(c+" "+m);}void f(int k,int l){pixels[k*w+l]=color(0);if(pixels[(k+1)*w+l]==g)f(k+1,l);if(pixels[k*w+l+1]==g)f(k,l+1);if(pixels[k*w+l-1]==g)f(k,l-1);k-=w/2;l-=w/2;b=10-(int)(sqrt(k*k+l*l)/(w/20));if(b&gt;v)v=b;}


Reads in an image file f loops through the pixels until it finds green then flood fills the circle determining the point that is closest to the center. Then adds that score to a total.  if the score is negative, it is added to a miss counter.

The program will output 2 numbers, the first is the score and the second is the number of misses.

  int x,y,w,b,v,c,m;
  color g;
  PImage i;
void setup()
{
  i=loadImage("f.png");
  w=i.width;
  size(w,w);
  g=#00ff00;
  image(i,0,0);
  b=v=x=y=c=m=0;  
  loadPixels();
  while(y*w+x&lt;w*w)
  {
    if(pixels[y*w+x]==g)
    {
      f(y,x);
      if(v&gt;=0)c+=v;
      else m++;
    }
    v=-1;
    x++;
    if(x==w){x=0;y++;}
  }
  print(c+" "+m);
}

void f(int k,int l)
{
  pixels[k*w+l]=color(0);
 if(pixels[(k+1)*w+l]==g)f(k+1,l);
 if(pixels[k*w+l+1]==g)f(k,l+1);
 if(pixels[k*w+l-1]==g)f(k,l-1); 
 k-=w/2;
 l-=w/2;
 b=10-(int)(sqrt(k*k+l*l)/(w/20));
 if(b&gt;v)v=b;
}


you can get processing here