AForge.Math.FourierTransform.DFT2 C# (CSharp) Method

        public static void DFT2(Complex[,] data, Direction direction)
        {
            int n = data.GetLength(0); // rows
            int m = data.GetLength(1); // columns
            double arg, cos, sin;
            var dst = new Complex[System.Math.Max(n, m)];

            // process rows
            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < m; j++)
                {
                    dst[j] = Complex.Zero;

                    arg = -(int) direction*2.0*System.Math.PI*j/m;

                    // sum source elements
                    for (int k = 0; k < m; k++)
                    {
                        cos = System.Math.Cos(k*arg);
                        sin = System.Math.Sin(k*arg);

                        dst[j].Re += (data[i, k].Re*cos - data[i, k].Im*sin);
                        dst[j].Im += (data[i, k].Re*sin + data[i, k].Im*cos);
                    }
                }

                // copy elements
                if (direction == Direction.Forward)
                {
                    // devide also for forward transform
                    for (int j = 0; j < m; j++)
                    {
                        data[i, j].Re = dst[j].Re/m;
                        data[i, j].Im = dst[j].Im/m;
                    }
                }
                else
                {
                    for (int j = 0; j < m; j++)
                    {
                        data[i, j].Re = dst[j].Re;
                        data[i, j].Im = dst[j].Im;
                    }
                }
            }

            // process columns
            for (int j = 0; j < m; j++)
            {
                for (int i = 0; i < n; i++)
                {
                    dst[i] = Complex.Zero;

                    arg = -(int) direction*2.0*System.Math.PI*i/n;

                    // sum source elements
                    for (int k = 0; k < n; k++)
                    {
                        cos = System.Math.Cos(k*arg);
                        sin = System.Math.Sin(k*arg);

                        dst[i].Re += (data[k, j].Re*cos - data[k, j].Im*sin);
                        dst[i].Im += (data[k, j].Re*sin + data[k, j].Im*cos);
                    }
                }

                // copy elements
                if (direction == Direction.Forward)
                {
                    // devide also for forward transform
                    for (int i = 0; i < n; i++)
                    {
                        data[i, j].Re = dst[i].Re/n;
                        data[i, j].Im = dst[i].Im/n;
                    }
                }
                else
                {
                    for (int i = 0; i < n; i++)
                    {
                        data[i, j].Re = dst[i].Re;
                        data[i, j].Im = dst[i].Im;
                    }
                }
            }
        }