An interesting and early (1992) demonstration of deep nets learning latent structure in the visual domain was presented by Usui et al. They presented a deep autoencoder with the spectral values of color chips and show that the hidden layer representation corresponds to the Munsell color space where each dimension corresponds to a psychological&#x2F;intuitive color attribute. Pretty amazing. Even cooler that they showed this in 1992.<p>10.1364&#x2F;JOSAA.9.000516
Shiro Usui, Shigeki Nakauchi, and Masae Nakano, &quot;Reconstruction of Munsell color space by a five-layer neural network,&quot; J. Opt. Soc. Am. A 9, 516-520 (1992)