Prism: A Framework for Decoupling and Assessing the Capabilities of VLMs

TL;DR

Prism is a modular framework that separates perception and reasoning in vision-language models, enabling detailed assessment and improving efficiency in vision-language tasks by combining perception-focused VLMs with large language models.

Contribution

Prism introduces a novel two-stage approach to disentangle perception and reasoning in VLMs, allowing systematic evaluation and enhancing performance with reduced costs.

Findings

Prism achieves comparable performance to larger VLMs on MMStar benchmark.

Using GPT-3.5 and a 2B VLM, Prism reduces training and operational expenses.

The framework enables detailed analysis of perception and reasoning capabilities.

Abstract

Vision Language Models (VLMs) demonstrate remarkable proficiency in addressing a wide array of visual questions, which requires strong perception and reasoning faculties. Assessing these two competencies independently is crucial for model refinement, despite the inherent difficulty due to the intertwined nature of seeing and reasoning in existing VLMs. To tackle this issue, we present Prism, an innovative framework designed to disentangle the perception and reasoning processes involved in visual question solving. Prism comprises two distinct stages: a perception stage that utilizes a VLM to extract and articulate visual information in textual form, and a reasoning stage that formulates responses based on the extracted visual information using a Large Language Model (LLM). This modular design enables the systematic comparison and assessment of both proprietary and open-source VLM for their perception and reasoning strengths. Our analytical framework provides several valuable insights, underscoring Prism's potential as a cost-effective solution for vision-language tasks. By combining a streamlined VLM focused on perception with a powerful LLM tailored for reasoning, Prism achieves superior results in general vision-language tasks while substantially cutting down on training and operational expenses. Quantitative evaluations show that Prism, when configured with a vanilla 2B LLaVA and freely accessible GPT-3.5, delivers performance on par with VLMs $10 \times$ larger on the rigorous multimodal benchmark MMStar. The project is released at: https://github.com/SparksJoe/Prism.