A Lightweight Framework for Progressive Alignment of Image, Text, Audio, and Video Modalities

核心概念

OneEncoder is a lightweight framework that progressively aligns image, text, audio, and video modalities without relying on vast aligned datasets. It leverages frozen pretrained modality-specific encoders and a compact Universal Projection module to achieve efficient and cost-effective multimodal alignment.

摘要

The paper introduces OneEncoder, a lightweight framework for progressively aligning multiple modalities, including image, text, audio, and video. The key aspects of the method are:

Modality-specific encoders (e.g., ViT for images, BERT for text, Wav2Vec for audio, VideoMAE for video) are used as feature extractors and kept frozen during training.
A lightweight Universal Projection (UP) module is trained in the first step to align image and text modalities using a contrastive loss.
In subsequent steps, the pretrained UP module is frozen, and a compact Alignment Layer (AL) is trained to align new modalities (e.g., audio, video) with the already aligned modalities.
Modality tokens are used to facilitate efficient switching between modalities during the forward pass.

This progressive alignment approach allows OneEncoder to integrate new modalities at a low cost, without the need to retrain the entire framework. Experiments show that OneEncoder outperforms classical methods that train modality-specific encoders simultaneously, especially in scenarios with limited aligned datasets. OneEncoder demonstrates strong performance in various downstream tasks, such as classification, querying, and visual question answering.

統計資料

OneEncoder uses frozen pretrained encoders with a total of 196M parameters.
The Universal Projection (UP) module has 4M trainable parameters.
The Alignment Layer (AL) has 65,792 trainable parameters.

引述

"OneEncoder operates efficiently and cost-effectively, even in scenarios where vast aligned datasets are unavailable, due to its lightweight design."
"Using OneEncoder represents a balanced compromise between alignment performance and complexity, as it minimizes the number of parameters to tune."

從以下內容提煉的關鍵洞見

OneEncoder: A Lightweight Framework for Progressive Alignment of Modalities

by Bilal Faye, ... 於 arxiv.org 09-18-2024

https://arxiv.org/pdf/2409.11059.pdf

深入探究

How can OneEncoder be extended to handle dynamic addition of new modalities without retraining the entire framework?

OneEncoder is designed with a lightweight architecture that allows for the progressive alignment of modalities, which inherently supports the dynamic addition of new modalities without the need for retraining the entire framework. This is achieved through the use of a frozen Universal Projection (UP) module and a compact Alignment Layer (AL).
When a new modality is introduced, the UP module, which has already been trained on existing modalities (e.g., image and text), remains frozen. The AL is then trained specifically for the new modality, aligning it with the already established modalities. This two-step process minimizes the computational cost and time associated with training, as only the parameters of the AL are updated.
Furthermore, the use of modality tokens facilitates efficient switching between modalities, allowing OneEncoder to adapt to new inputs seamlessly. This design not only enhances the framework's flexibility but also ensures that it can maintain high performance even with limited aligned datasets, making it suitable for real-world applications where new modalities may frequently emerge.

What are the potential limitations of the transitive alignment approach used in OneEncoder, and how can they be addressed?

The transitive alignment approach in OneEncoder, while efficient, does have potential limitations. One significant concern is the reliance on the quality of the initial alignment between the first two modalities (e.g., image and text). If this initial alignment is weak or inaccurate, it can propagate errors to subsequent alignments, leading to degraded performance in the overall system.
To address this limitation, it is crucial to ensure that the initial training phase is robust and utilizes high-quality, well-aligned datasets. Additionally, implementing a validation step after each new modality is added can help identify and rectify any misalignments early in the process.
Another limitation is the potential for overfitting when aligning multiple modalities, especially if the datasets for the new modalities are small. To mitigate this, OneEncoder could incorporate regularization techniques or data augmentation strategies during the training of the AL. This would enhance the model's generalization capabilities and ensure that it performs well across diverse tasks and datasets.

How can the OneEncoder framework be adapted to handle multimodal tasks that require generation, such as image captioning or video summarization, in addition to classification and retrieval?

To adapt the OneEncoder framework for multimodal tasks that require generation, such as image captioning or video summarization, modifications can be made to the architecture and training procedures.
Firstly, the framework can be extended to include a generative component, such as a transformer-based decoder, that can take the aligned representations from the UP module and generate textual outputs. For instance, in the case of image captioning, the model can be trained to produce captions based on the visual features extracted from the image encoder and the contextual information from the text encoder.
Secondly, the training process can be adjusted to include a sequence of tasks that involve both alignment and generation. For example, during training, OneEncoder can utilize a combination of contrastive loss for alignment and a language modeling loss for generating coherent text outputs. This dual training approach would ensure that the model learns to align modalities effectively while also being capable of generating meaningful content.
Lastly, incorporating feedback mechanisms, such as reinforcement learning, can enhance the generation quality by allowing the model to learn from its outputs and improve over time. This would be particularly beneficial in tasks like video summarization, where the model can be trained to evaluate the relevance of generated summaries based on user feedback or predefined criteria.
By implementing these adaptations, OneEncoder can effectively handle a broader range of multimodal tasks, expanding its applicability beyond classification and retrieval to include generative tasks that require a deeper understanding of the relationships between different modalities.