CtrlSynth: Controllable Image Text Synthesis for Data-Efficient Multimodal Learning

TL;DR

CtrlSynth introduces a controllable, modular image-text synthesis pipeline that enhances data diversity and robustness in multimodal learning by decomposing and recomposing visual semantics with user-defined policies, leveraging pretrained models.

Contribution

It presents a novel, training-free framework for fine-grained control over synthetic data generation in multimodal tasks, improving model performance across multiple datasets.

Findings

Significantly improves zero-shot classification accuracy.

Enhances image-text retrieval performance.

Boosts compositional reasoning capabilities.

Abstract

Pretraining robust vision or multimodal foundation models (e.g., CLIP) relies on large-scale datasets that may be noisy, potentially misaligned, and have long-tail distributions. Previous works have shown promising results in augmenting datasets by generating synthetic samples. However, they only support domain-specific ad hoc use cases (e.g., either image or text only, but not both), and are limited in data diversity due to a lack of fine-grained control over the synthesis process. In this paper, we design a \emph{controllable} image-text synthesis pipeline, CtrlSynth, for data-efficient and robust multimodal learning. The key idea is to decompose the visual semantics of an image into basic elements, apply user-specified control policies (e.g., remove, add, or replace operations), and recompose them to synthesize images or texts. The decompose and recompose feature in CtrlSynth allows users to control data synthesis in a fine-grained manner by defining customized control policies to manipulate the basic elements. CtrlSynth leverages the capabilities of pretrained foundation models such as large language models or diffusion models to reason and recompose basic elements such that synthetic samples are natural and composed in diverse ways. CtrlSynth is a closed-loop, training-free, and modular framework, making it easy to support different pretrained models. With extensive experiments on 31 datasets spanning different vision and vision-language tasks, we show that CtrlSynth substantially improves zero-shot classification, image-text retrieval, and compositional reasoning performance of CLIP models.