rhoThetaToImageMaxMinLine(const double rho,double theta,number& x1, number& y1,number& x2,number& y2) {

  const double  x_orig_mid = rho * std::cos(theta + M_PI);
  const double  y_orig_mid = rho * std::sin(theta + M_PI);

  int x = (this->width  / 2)+(x_orig_mid);
  int y = (this->height / 2)+(y_orig_mid);

  int top,right,bottom,left = 0;

  top    = x + ceil(y           * std::tan( theta ) );
  right  = y + ceil(int(this->width  - x)   * std::tan( theta - (M_PI / 2) ));
  bottom = x - floor(int(this->height - y)  * std::tan( theta - M_PI ));
  left   = y - floor(x          * std::tan( theta - ((M_PI) + (M_PI / 2)) ) );



  this->height--;
  this->width--;//why is this necessary??

  if ( top >= 0 && top <= this->width ) {
    x1 = top;
    y1 = 0;

    if ( right >= 0 && right <= this->height ) {
     x2 = this->width;
     y2 = right;
    } else {
      if ( bottom < 0 ) {
    x2 = 0;
    y2 = left;
      } else {
        x2 = bottom;
        y2 = this->height;
      }
    }
    #ifdef DEBUGON
    std::cout << "top" << std::endl;
    #endif
  }

  if ( right >= 0 && right <= this->height ) { //three quaters
    x1 = this->width;
    y1 = right;

    if ( bottom >= 0 && bottom <= this->width ) {
      x2 = bottom;
      y2 = this->height;
    } else {
      if ( left < 0 ) {
    x2 = top;
    y2 = 0;
      } else {
        x2 = 0;
        y2 = left;// + 1;//This gives pixel perfect lines as a result from rouding.
      }
    }
    #ifdef DEBUGON
    std::cout << "right" << std::endl;
    #endif
  }

  if ( bottom >= 0 && bottom <= this->width ) {
    x1 = bottom;
    y1 = this->height;

    if ( left >= 0 && left <= this->height ) {
      x2 = 0;
      y2 = left;
    } else {
      if ( top > this->width ) {
        x2 = this->width;
    y2 = right ; //+1 else a but arises at rho:245 theta:3.67683 x1:568 y1:767 x2:1023 y2:4294967295
      } else {
    x2 = top;
    y2 = 0;
      }
    }
    #ifdef DEBUGON
    std::cout << "bottom" << std::endl;
    #endif
  }

  if ( left >= 0 && left <= this->height ) {
    x1 = 0;
    y1 = left;// - 1;//This gives pixel perfect lines as a result from rouding errors.

    if ( top >= 0 && top <= this->width ) {
      x2 = top;
      y2 = 0;
    } else {
      if ( right > this->height ) {
    x2 = bottom;
    y2 = this->height;
      } else {
        x2 = this->width;
        y2 = right;
      }
    }
    #ifdef DEBUGON
    std::cout << "left" << std::endl;
    #endif
  }

  if (x2 > this->height ) {
   x2  = this->height - 1;
  }

  this->height++;
  this->width++;

}