  We present a learned image compression system based on GANs, operating at
extremely low bitrates. Our proposed framework combines an encoder,
decoder/generator and a multi-scale discriminator, which we train jointly for a
generative learned compression objective. The model synthesizes details it
cannot afford to store, obtaining visually pleasing results at bitrates where
previous methods fail and show strong artifacts. Furthermore, if a semantic
label map of the original image is available, our method can fully synthesize
unimportant regions in the decoded image such as streets and trees from the
label map, proportionally reducing the storage cost. A user study confirms that
for low bitrates, our approach is preferred to state-of-the-art methods, even
when they use more than double the bits.
