System.Drawing.Color.FromArgb C# (CSharp) Method

        public static Color FromArgb(int argb) => new Color(argb & 0xffffffff, StateARGBValueValid, null, 0);

        private void btn_equalization_Click(object sender, RoutedEventArgs e)
        {
            if (_primeBitmap == null)
            {
                MessageBox.Show("请选择图片");
                return;
            }
            var numPixel = new int[256];

            for (var i = 0; i < _primeBitmap.Height; i++)
            {
                for (var j = 0; j < _primeBitmap.Width; j++)
                {
                    int x = _primeBitmap.GetPixel(j, i).R;
                    numPixel[x]++;
                }
            }
            for (var i = 0; i < 256; i++)
            {
                Console.WriteLine(numPixel[i]);
            }
            var probPixel = new double[256];

            for (var i = 0; i < 256; i++)
            {
                probPixel[i] = numPixel[i] / (_primeBitmap.Height * _primeBitmap.Width * 1.0);
            }
            var cumuPixel = new double[256];

            for (var i = 0; i < 256; i++)
            {
                if (i == 0)
                {
                    cumuPixel[i] = probPixel[i];
                }
                else
                {
                    cumuPixel[i] = cumuPixel[i - 1] + probPixel[i];
                }
            }
            for (var i = 0; i < 256; i++)
            {
                cumuPixel[i] = cumuPixel[i] * 256 + 0.5;
                Console.WriteLine(@"pixel is :" + cumuPixel[i]);
            }
            for (var i = 0; i < _primeBitmap.Height; i++)
            {
                for (var j = 0; j < _primeBitmap.Width; j++)
                {
                    int x     = _primeBitmap.GetPixel(j, i).R;
                    var value = (int)cumuPixel[x];
                    if (value > 255)
                    {
                        value = 255;
                    }
                    var color = Color.FromArgb(value, value, value);
                    _primeBitmap.SetPixel(j, i, color);
                }
            }
            //for (int i = 0; i < prime_bitmap.Height; i++)
            //{
            //    for (int j = 0; j < prime_bitmap.Width; j++)
            //    {
            //        System.Drawing.Color color = prime_bitmap.GetPixel(j, i);
            //        MessageBox.Show(color.ToString());
            //    }
            //}
            show_pic();
        }