I wondered what was new about this particular implementation (since I've seen several others, notably the one this code is partially based on, from Justin Johns

I wondered what was new about this particular implementation (since I've seen several others, notably the one this code is partially based on, from Justin Johnson). From the paper: "Our contribution is to constrain the transformation from the input to the output to be locally affine in colorspace, and to express this constraint as a custom CNN layer through which we can backpropagate. We show that this approach successfully suppresses distortion and yields satisfying photorealistic style transfers in a broad variety of scenarios, including transfer of the time of day, weather, season, and artistic edits" I was skeptical at first (even posted then deleted a sort of negative comment), but now that I read this, I see the value. The images are much more crisp and distortion free.