NewTOAPIA.Drawing.image_filter_kaiser.bessel_i0 C# (CSharp) Method

        private double bessel_i0(double x)
        {
            int i;
            double sum, y, t;

            sum = 1.0;
            y = x * x / 4.0;
            t = y;

            for (i = 2; t > epsilon; i++)
            {
                sum += t;
                t *= (double)y / (i * i);
            }
            return sum;
        }
    };