OpenVision 2: A Family of Generative Pretrained Visual Encoders for
  Multimodal Learning
Authors: name: Yanqing Liu; name: Xianhang Li; name: Letian Zhang; name: Zirui Wang; name: Zeyu Zheng; name: Yuyin Zhou; name: Cihang Xie
Published: 2025-09-01 17:38:21

Abstract: This paper provides a simplification on OpenVision's architecture and loss
design for enhancing its training efficiency. Following the prior
vision-language pretraining works CapPa and AIMv2, as well as modern multimodal
designs like LLaVA, our changes are straightforward: we remove the text encoder
(and therefore the contrastive loss), retaining only the captioning loss as a
purely generative training signal. We name this new version OpenVision 2. The
initial results are promising: despite this simplification, OpenVision 2
competitively matches the original model's performance on a broad set of
multimodal benchmarks while substantially cutting both training time and memory
consumption. For example, with ViT-L/14, it reduces training time by about 1.5x
(from 83h to 57h), and memory usage by about 1.8x (from 24.5GB to 13.8GB,
equivalently allowing the maximum batch size to grow from 2k to 8k). This
superior training efficiency also allows us to scale far beyond the largest
vision encoder used in OpenVision, reaching more than 1 billion parameters. We
hold a strong belief that this lightweight, generative-only paradigm is
compelling for future vision encoder development in multimodal foundation
models.