Dimensionality of model responses to parametrically-altered versions of the images in the natural movie.

A: Images were generated by gradually decreasing contrast of the original images. B: Images were generated by adding a random offset to the phases of the original images, which transformed the natural images to pink noise. Each random offset was drawn from a uniform distribution over the specified range. C: Images were generated by raising the power spectrum of the same pink noise images generated in B to a fractional exponent. This gradually transformed the pink noise images to white noise.