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Language Quantized AutoEncoders: Towards Unsupervised Text-Image Alignment (arxiv.org)
3 points by sebg on Feb 21, 2023 | hide | past | pdf | 1 comment on HN

In plain words: An image is broken up and mapped to word tokens from a pretrained language model, then masked and rebuilt so it must be described in words. This links images to text without captioned pairs, letting a language model classify images from a few examples.

Abstract

Recent progress in scaling up large language models has shown impressive capabilities in performing few-shot learning across a wide range of text-based tasks. However, a key limitation is that these language models fundamentally lack visual perception - a crucial attribute needed to extend these models to be able to interact with the real world and solve vision tasks, such as in visual-question answering and robotics. Prior works have largely connected image to text through pretraining and/or fine-tuning on curated image-text datasets, which can be a costly and expensive process. In order to resolve this limitation, we propose a simple yet effective approach called Language-Quantized AutoEncoder (LQAE), a modification of VQ-VAE that learns to align text-image data in an unsupervised manner by leveraging pretrained language models (e.g., BERT, RoBERTa). Our main idea is to encode image as sequences of text tokens by directly quantizing image embeddings using a pretrained language codebook. We then apply random masking followed by a BERT model, and have the decoder reconstruct the original image from BERT predicted text token embeddings. By doing so, LQAE learns to represent similar images with similar clusters of text tokens, thereby aligning these two modalities without the use of aligned text-image pairs. This enables few-shot image classification with large language models (e.g., GPT-3) as well as linear classification of images based on BERT text features. To the best of our knowledge, our work is the first work that uses unaligned images for multimodal tasks by leveraging the power of pretrained language models.

Hao Liu, Wilson Yan, Pieter Abbeel
arXiv:2302.00902 · cs.LG, cs.CL, cs.CV · submitted Feb 2, 2023 · updated Feb 3, 2023
abstract · pdf · html · Fixed typos

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Twitter Thread that led me to the link:

https://twitter.com/0xmaddie_/status/1627777203013398528

Specifically this language:

" if i'm understanding this correctly, you can use a pure text encoder model to find text that lets you reconstruct an image from the text encoding. basically, the latent space of a text model is expressive enough to serve as a compilation target for images "