Convert a Color Image into Grascale

First create a new C# Windows Form Application, Add two picture boxes and a button. (I am using default names of the controls.) 

Set an image for the first Picture Box (pictureBox1) 

Add the following code to the button click event. 





Bitmap bitmap1 = new Bitmap(pictureBox1.Image); 


int width1 = bitmap1.Width;
int height1 = bitmap1.Height;


Bitmap bitmap2 = new Bitmap(width1, height1);


for (int i = 0; i < width1; i++)


{


    for (int j = 0; j < height1; j++)
    {
Color color1 = bitmap1.GetPixel(i, j);


byte R = color1.R;
byte G = color1.G;
byte B = color1.B;


int common = (R + G + B) / 3;
color1 = Color.FromArgb(common, common, common);
bitmap2.SetPixel(i, j, color1);


    }


}


pictureBox2.Image = bitmap2;