  Inspired by recent advances in multimodal learning and machine translation,
we introduce an encoder-decoder pipeline that learns (a): a multimodal joint
embedding space with images and text and (b): a novel language model for
decoding distributed representations from our space. Our pipeline effectively
unifies joint image-text embedding models with multimodal neural language
models. We introduce the structure-content neural language model that
disentangles the structure of a sentence to its content, conditioned on
representations produced by the encoder. The encoder allows one to rank images
and sentences while the decoder can generate novel descriptions from scratch.
Using LSTM to encode sentences, we match the state-of-the-art performance on
Flickr8K and Flickr30K without using object detections. We also set new best
results when using the 19-layer Oxford convolutional network. Furthermore we
show that with linear encoders, the learned embedding space captures multimodal
regularities in terms of vector space arithmetic e.g. *image of a blue car* -
"blue" + "red" is near images of red cars. Sample captions generated for 800
images are made available for comparison.
