title: Getting the brightness of a Grayscale pixel
body: <p>Basically I am trying to find the brightness of all pixels in a bitmap image. The images I am using are 24 bit bitmap images and I am not allow to use function GetBrightness().
  I am getting the RGB value of the pixels, I am wondering if the RGB value is also the brightness of the pixel or can anyone recommend a method of getting the pixel brightness of a grayscale pixel?</p>
  
  <p>Thanks</p>