Fig. 4.

The causal effect of altering units within a GAN generator. (A) When successively larger sets of units are removed from a GAN trained to generate outdoor church scenes, the tree area of the generated images is reduced. Removing 20 tree units removes more than half the generated tree pixels from the output. (B) Qualitative results: Removing tree units affects trees while leaving other objects intact. Building parts that were previously occluded by trees are rendered as if revealing the objects that were behind the trees. (C) Doors can be added to buildings by activating 20 door units. The location, shape, size, and style of the rendered door depend on the location of the activated units. The same activation levels produce different doors or no door at all (case 4) depending on locations. (D) Similar context dependence can be seen quantitatively: doors can be added in reasonable locations, such as at the location of a window, but not in abnormal locations, such as on a tree or in the sky.