[forgotusername6]

I'm pretty sure you could also layer the cat noise evenly over the image without significantly damaging the woman. The DCT puts all the importantly information top left, but there is nothing stopping you adding a step to distribute that information across the whole image, or using another transform that didn't have the same concentration effect

[topherclay]

Well sure, but whatever extra step you use to encode you will also need as an extra step to decode.