private Dictionary <int, string> GetAllowablePixelTypes() { var pixelTypesVector = _twain32.GetPixelTypes(); if (pixelTypesVector == null) { return(null); } var allowablePixelTypes = new Dictionary <int, string>(); foreach (var pixelType in pixelTypesVector.Items) { var key = (int)(TwPixelType)pixelType; var value = (GlobalDictionaries.PixelTypes.ContainsKey((TwPixelType)pixelType) ? GlobalDictionaries.PixelTypes[(TwPixelType)pixelType] : pixelType.ToString()); allowablePixelTypes.Add(key, value); } return(allowablePixelTypes); }