private double Grayscale(Color c)
        {
            return (double)(c.R + c.G + c.B / 3;
        }



        private void button14_Click(object sender, EventArgs e)
        {
            int template_size = workImageCorelatie.Width * workImageCorelatie.Height;
            double sum = 0;
            double sqrsum = 0;
            workImage.Lock();
            workImageCorelatie.Lock();
            for (int i = 0; i < workImageCorelatie.Width; i++)
            {
                for (int j = 0; j < workImageCorelatie.Height; j++)
                {
                    double template = Grayscale(workImageCorelatie.GetPixel(i, j));
                    sum += template;
                    sqrsum += template * template;
                }
            }
            double mean_template = sum / template_size;
            double var2template = sqrsum - (sum * sum) / template_size;
            double var2image = 0;
            double prodsum = 0;
            double[,] corr_coeff = new double[workImage.Width, workImage.Height];
            for (int i = 0; i < workImage.Width - workImageCorelatie.Width; i++)
            {
                for (int j = 0; j < workImage.Height - workImageCorelatie.Height; j++)
                {
                    sum = 0;
                    sqrsum = 0;
                    prodsum = 0;
                    for (int k = 0; k < workImageCorelatie.Width; k++)
                        for (int m = 0; m < workImageCorelatie.Height; m++)
                        {
                            double img = Grayscale(workImage.GetPixel(i + k, j + m));
                            double template = Grayscale(workImageCorelatie.GetPixel(k, m));
                            sum += img;
                            sqrsum += img * img;
                            prodsum += img * template;
                        }
                    var2image = sqrsum - (sum * sum) / template_size;
                    corr_coeff[i, j] = ((prodsum - (mean_template * sum)) / Math.Sqrt(var2image * var2template));
                }
            }
            //cauti maximul in matrice
            double max = Double.NegativeInfinity;
            int imax = 0, jmax = 0;
            for (int i = 0; i < workImage.Width - workImageCorelatie.Width; i++)
                for (int j = 0; j < workImage.Height - workImageCorelatie.Height; j++)
                    if (max < corr_coeff[i, j])
                    {
                        max = corr_coeff[i, j];
                        imax = i;
                        jmax = j;
                    }

            // desenezi liniile de pe poza mare
            for (int i = 0; i < workImageCorelatie.Width; i++)
            {
                workImage.SetPixel(imax + i, jmax, Color.Blue);
                workImage.SetPixel(imax + i, jmax + workImageCorelatie.Height, Color.Blue);
            }
            for (int j = 0; j < workImageCorelatie.Height; j++)
            {
                workImage.SetPixel( imax, jmax + j, Color.Blue);
                workImage.SetPixel( imax + workImageCorelatie.Width, jmax + j, Color.Blue);
            }
            panelDestination.BackgroundImage = null;
            panelDestination.BackgroundImage = workImage.GetBitMap();
            workImage.Unlock();
            workImageCorelatie.Unlock();

        }

        private void button15_Click(object sender, EventArgs e)
        {
            openFileDialog.ShowDialog();
            sSourceFileNameCorelatie = openFileDialog.FileName;
            imageCorelatie = new Bitmap(sSourceFileNameCorelatie);
            workImageCorelatie = new FastImage(imageCorelatie);
            panelDestination.BackgroundImage = workImageCorelatie.GetBitMap();
        }