Not only that, but it then becomes a 'slippery slope', where do you draw the line at what manipulation is possible. Here they've draw a pretty clear line that t

Not only that, but it then becomes a 'slippery slope', where do you draw the line at what manipulation is possible. Here they've draw a pretty clear line that the 'content' of the image cannot be changed but that coloring and associated items can be tweaked to more accurately represent the scene. [Lets avoid picking apart the generalization I made above, yes color is 'content' but I think the meaning is fairly clear here]