Question

I need to copy the pixels from one image to another, but only the black pixels. I have to separate the black pixels out for sending to a printer using the K Panel on the printer ribbon.

Basically I need to make every pixel in the image that isn’t black transparent or white.

What’s the best way to do this?

The only idea I have is something along the lines of:

        var attr = new ImageAttributes();
        attr.SetColorKey(minColor, maxColor);
        using (Graphics g = Graphics.FromImage(backGround))
        {
            var destRect = new Rectangle(0, 0, backGround.Width, backGround.Height);

            g.DrawImage(kPanelImage, destRect, 0, 0, backGround.Width, backGround.Height, GraphicsUnit.Pixel, attr);
        }

Answer 1

Bitmap mySource = new Bitmap("your_image.jpg");

for(int w=0; w<mySource.Width; ++w)
   for(int h=0; h<mySource.Height; ++h)
   {
      Color pixelColor = mySource .GetPixel(w, h);
      if ( pixelColor != Color.Black )
           mySource .SetPixel(w, h, Color.White);
   }