static Quantum ApplyFunction(Quantum pixel,const MagickFunction function,
  const size_t number_parameters,const double *parameters,
  ExceptionInfo *exception)
{
  MagickRealType
    result;

  register ssize_t
    i;

  (void) exception;
  result=0.0;
  switch (function)
  {
    case PolynomialFunction:
    {
      /*
       * Polynomial
       * Parameters:   polynomial constants,  highest to lowest order
       *   For example:      c0*x^3 + c1*x^2 + c2*x  + c3
       */
      result=0.0;
      for (i=0; i < (ssize_t) number_parameters; i++)
        result=result*QuantumScale*pixel + parameters[i];
      result*=QuantumRange;
      break;
    }
    case SinusoidFunction:
    {
      /* Sinusoid Function
       * Parameters:   Freq, Phase, Ampl, bias
       */
      double  freq,phase,ampl,bias;
      freq  = ( number_parameters >= 1 ) ? parameters[0] : 1.0;
      phase = ( number_parameters >= 2 ) ? parameters[1] : 0.0;
      ampl  = ( number_parameters >= 3 ) ? parameters[2] : 0.5;
      bias  = ( number_parameters >= 4 ) ? parameters[3] : 0.5;
      result=(MagickRealType) (QuantumRange*(ampl*sin((double) (2.0*MagickPI*
        (freq*QuantumScale*pixel + phase/360.0) )) + bias ) );
      break;
    }
    case ArcsinFunction:
    {
      /* Arcsin Function  (peged at range limits for invalid results)
       * Parameters:   Width, Center, Range, Bias
       */
      double  width,range,center,bias;
      width  = ( number_parameters >= 1 ) ? parameters[0] : 1.0;
      center = ( number_parameters >= 2 ) ? parameters[1] : 0.5;
      range  = ( number_parameters >= 3 ) ? parameters[2] : 1.0;
      bias   = ( number_parameters >= 4 ) ? parameters[3] : 0.5;
      result = 2.0/width*(QuantumScale*pixel - center);
      if ( result <= -1.0 )
        result = bias - range/2.0;
      else if ( result >= 1.0 )
        result = bias + range/2.0;
      else
        result=(MagickRealType) (range/MagickPI*asin((double) result)+bias);
      result *= QuantumRange;
      break;
    }
    case ArctanFunction:
    {
      /* Arctan Function
       * Parameters:   Slope, Center, Range, Bias
       */
      double  slope,range,center,bias;
      slope  = ( number_parameters >= 1 ) ? parameters[0] : 1.0;
      center = ( number_parameters >= 2 ) ? parameters[1] : 0.5;
      range  = ( number_parameters >= 3 ) ? parameters[2] : 1.0;
      bias   = ( number_parameters >= 4 ) ? parameters[3] : 0.5;
      result=(MagickRealType) (MagickPI*slope*(QuantumScale*pixel-center));
      result=(MagickRealType) (QuantumRange*(range/MagickPI*atan((double)
                  result) + bias ) );
      break;
    }
    case UndefinedFunction:
      break;
  }
  return(ClampToQuantum(result));
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.