GenEval 2: Addressing Benchmark Drift in Text-to-Image Evaluation

TL;DR

This paper investigates the problem of benchmark drift in Text-to-Image evaluation, demonstrates its impact on GenEval, and introduces GenEval 2 with an improved evaluation method, Soft-TIFA, to better align with human judgment and reduce drift.

Contribution

The paper identifies benchmark drift in T2I evaluation, analyzes its effects on GenEval, and proposes GenEval 2 with Soft-TIFA for more robust, human-aligned assessment.

Findings

GenEval has drifted significantly from human judgment over time.

GenEval 2 offers improved coverage and challenge for current models.

Soft-TIFA aligns better with human judgment and reduces drift.

Abstract

Automating Text-to-Image (T2I) model evaluation is challenging; a judge model must be used to score correctness, and test prompts must be selected to be challenging for current T2I models but not the judge. We argue that satisfying these constraints can lead to benchmark drift over time, where the static benchmark judges fail to keep up with newer model capabilities. We show that benchmark drift is a significant problem for GenEval, one of the most popular T2I benchmarks. Although GenEval was well-aligned with human judgment at the time of its release, it has drifted far from human judgment over time -- resulting in an absolute error of as much as 17.7% for current models. This level of drift strongly suggests that GenEval has been saturated for some time, as we verify via a large-scale human study. To help fill this benchmarking gap, we introduce a new benchmark, GenEval 2, with improved coverage of primitive visual concepts and higher degrees of compositionality, which we show is more challenging for current models. We also introduce Soft-TIFA, an evaluation method for GenEval 2 that combines judgments for visual primitives, which we show is more well-aligned with human judgment and argue is less likely to drift from human-alignment over time (as compared to more holistic judges such as VQAScore). Although we hope GenEval 2 will provide a strong benchmark for many years, avoiding benchmark drift is far from guaranteed and our work, more generally, highlights the importance of continual audits and improvement for T2I and related automated model evaluation benchmarks.