如何进行图像的乘法（以像素为单位）？

Question

如何进行图像的乘法（以像素为单位）？

Bitmap first = new Bitmap(pictureBox1.Image);
Bitmap second = ProcesarImagen.SetImageOpacity(pictureBox2.Image, 0.5f);
Bitmap result = new Bitmap(Math.Max(first.Width, second.Width), Math.Max(first.Height, second.Height));
Console.WriteLine(first.Width);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.DrawImageUnscaled(second, 0, 0);
pictureBox3.Image = result;