Image Comparision on percentage format

        public Double Compare(Image img1_, Image img2_)
        {
            //total number of pixels
            int pixelNb = img1_.Width * img1_.Height;

            Double percent = 100;

            Bitmap resized_img2_ = ResizeBitmap((Bitmap)img2_, img1_.Width, img1_.Height);

            for (int i = 0; i < img1_.Width; i++)
            {
                for (int j = 0; i < img1_.Height; j++)
                {
                    percent -= ColorCompare(((Bitmap)img1_).GetPixel(i, j), ((Bitmap)resized_img2_).GetPixel(i, j))/pixelNb;
                }
            }

            return percent;
        }

        public Bitmap ResizeBitmap(Bitmap b, int nWidth, int nHeight)
        {
            Bitmap result = new Bitmap(nWidth, nHeight);
            using (Graphics g = Graphics.FromImage((Image)result))
                g.DrawImage(b, 0, 0, nWidth, nHeight);
            return result;
        }

        public Double ColorCompare(Color c1, Color c2)
        {
            return Double.Parse((Math.Abs(c1.B - c2.B) + Math.Abs(c1.R - c2.R) + Math.Abs(c1.G - c2.G)).ToString())*100 / (3*255);
        }