Deepdream and neural style transfer are from around the same time period and used deep neural nets. The precursor to them was computer vision stuff on visualization like https://
arxiv.org/pdf/1112.6209 & https://
arxiv.org/abs/1312.6034 GANs were also predated by VAEs. VAEs might have been the
Evolution of Deep Learning: From Visualization to GANs and VAEs
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