Bloom.Edit.JpegWarningDialog.GetIsGrey C# (CSharp) Method

        private static bool GetIsGrey(Bitmap bmp, int lineNumber)
        {
            const int thresholdForGrey = 20;
            if (lineNumber >= bmp.Height)
                return false; //guard against math errors by the caller
            for(int x = 0; x < bmp.Width; x++)
            {
                var pixelColor = bmp.GetPixel(x, lineNumber);
                var rgbDelta = Math.Abs(pixelColor.R - pixelColor.G) + Math.Abs(pixelColor.G - pixelColor.B) + Math.Abs(pixelColor.B - pixelColor.R);
                if (rgbDelta > thresholdForGrey)
                    return false;
            }
            return true;
        }