Schema comprehension fails for type System.Drawing.Bitmap

[abgoswam]

Several of the image transforms in ML.NET produce intermediate columns of type System.Drawing.Bitmap

machinelearning/docs/samples/Microsoft.ML.Samples/Dynamic/Transforms/ImageAnalytics/ConvertToGrayScale.cs

Lines 39 to 42 in e5cbca7

	var pipeline = mlContext.Transforms.LoadImages("ImageObject", imagesFolder, "ImagePath")
	.Append(mlContext.Transforms.ConvertToGrayscale("Grayscale", "ImageObject"));
	var transformedData = pipeline.Fit(data).Transform(data);

If we try to use schema comprehension to map some intermediate data (e.g. transformedData) to an IEnumerable, we hit an exception when dealing with a column of type System.Drawing.Bitmap

Error: Unhandled Exception: System.ArgumentOutOfRangeException: Could not determine an IDataView type for member ImageObject

@Ivanidzo4ka