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Image-and-Language Understanding from Pixels Only (arxiv.org)
1 point by mr-ai on Dec 29, 2022 | hide | past | pdf | discuss on HN

In plain words: A single encoder reads both images and text drawn as pictures, trained only to pull matching pairs together instead of using separate image and text towers. It nearly matches those models on image tasks with half the parameters, and handles text, questions, and multilingual search.

Abstract · CLIPPO: Image-and-Language Understanding from Pixels Only

Multimodal models are becoming increasingly effective, in part due to unified components, such as the Transformer architecture. However, multimodal models still often consist of many task- and modality-specific pieces and training procedures. For example, CLIP (Radford et al., 2021) trains independent text and image towers via a contrastive loss. We explore an additional unification: the use of a pure pixel-based model to perform image, text, and multimodal tasks. Our model is trained with contrastive loss alone, so we call it CLIP-Pixels Only (CLIPPO). CLIPPO uses a single encoder that processes both regular images and text rendered as images. CLIPPO performs image-based tasks such as retrieval and zero-shot image classification almost as well as CLIP-style models, with half the number of parameters and no text-specific tower or embedding. When trained jointly via image-text contrastive learning and next-sentence contrastive learning, CLIPPO can perform well on natural language understanding tasks, without any word-level loss (language modelling or masked language modelling), outperforming pixel-based prior work. Surprisingly, CLIPPO can obtain good accuracy in visual question answering, simply by rendering the question and image together. Finally, we exploit the fact that CLIPPO does not require a tokenizer to show that it can achieve strong performance on multilingual multimodal retrieval without modifications.

Michael Tschannen, Basil Mustafa, Neil Houlsby
arXiv:2212.08045 · cs.CV · submitted Dec 15, 2022 · updated Apr 1, 2023
abstract · pdf · html · CVPR 2023. Code and pretrained models are available at https://github.com/google-research/big_vision/blob/main/big_vision/configs/proj/clippo/README.md

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