AForge.Imaging.Image.IsGrayscale C# (CSharp) Method

        public static bool IsGrayscale( Bitmap image )
        {
            bool ret = false;

            // check pixel format
            if ( image.PixelFormat == PixelFormat.Format8bppIndexed )
            {
                ret = true;
                // check palette
                ColorPalette cp = image.Palette;
                Color c;
                // init palette
                for ( int i = 0; i < 256; i++ )
                {
                    c = cp.Entries[i];
                    if ( ( c.R != i ) || ( c.G != i ) || ( c.B != i ) )
                    {
                        ret = false;
                        break;
                    }
                }
            }
            return ret;
        }