STARFlow2: Bridging Language Models and Normalizing Flows for Unified Multimodal Generation
On the map: Efficient LLM inference and serving → Visual token pruning in multimodal models
Abstract (arXiv)
Deep generative models have advanced rapidly across text and vision, motivating unified multimodal systems that can understand, reason over, and generate interleaved text-image sequences. Most existing approaches combine autoregressive language modeling with diffusion-based image generators, inheriting a structural mismatch between causal text generation and iterative visual denoising. We observe that autoregressive normalizing flows are autoregressive Transformers--sharing the same causal mask, KV-cache mechanism, and left-to-right structure as LLMs--making them the most natural paradigm for true unified multimodal generation. We present STARFlow2, built on the Pretzel architecture that vertically interleaves a pretrained VLM stream with a TarFlow stream via residual skip connections, both operating under the same causal mask. Combined with a deep-shallow flow design and a unified FAE latent space, STARFlow2 enables cache-friendly interleaved generation where both text and visual outputs directly enter the KV-cache without re-encoding. Experiments demonstrate strong performance across image generation and multimodal understanding benchmarks, validating autoregressive flows as a viable foundation for unified multimodal modeling.
Key facts. Cited by 2 papers in the map (data through 7 Oct 2026). Placed in Visual token pruning in multimodal models, one of 12 directions in Efficient LLM inference and serving. Builds on 63 of its 66 references that are in the map. First posted on arXiv 8 May 2026.
Builds on
63 of 66 references.
References · 63
- 2020Denoising Diffusion Probabilistic Modelscited by 20,851
- 2021High-Resolution Image Synthesis with Latent Diffusion Modelscited by 18,694
- 2023GPT-4 Technical Reportcited by 18,132
- 2023DINOv2: Learning Robust Visual Features without Supervisioncited by 7,764
- 2022Scalable Diffusion Models with Transformerscited by 5,931
- 2022Flow Matching for Generative Modelingcited by 5,426
- 2025Qwen2.5-VL Technical Reportcited by 5,418
- 2017Neural Discrete Representation Learningcited by 4,650
- 2023Improved Baselines with Visual Instruction Tuningcited by 4,362
- 2024Scaling Rectified Flow Transformers for High-Resolution Image Synthesiscited by 4,094
- 2017FiLM: Visual Reasoning with a General Conditioning Layercited by 2,286
- 2015Variational Inference with Normalizing Flowscited by 2,161
38 more
- 2023MMBench: Is Your Multi-modal Model an All-around Player?cited by 2,105
- 2023MMMU: A Massive Multi-discipline Multimodal Understanding and Reasoning Benchmark for Expert AGIcited by 2,044
- 2016Density estimation using Real NVPcited by 2,029
- 2023MME: A Comprehensive Evaluation Benchmark for Multimodal Large Language Modelscited by 1,624
- 2018Glow: Generative Flow with Invertible 1x1 Convolutionscited by 1,539
- 2021Conceptual 12M: Pushing Web-Scale Image-Text Pre-Training To Recognize Long-Tail Visual Conceptscited by 1,209
- 2014NICE: Non-linear Independent Components Estimationcited by 1,052
- 2025Qwen-Image Technical Reportcited by 973
- 2025FLUX.1 Kontext: Flow Matching for In-Context Image Generation and Editing in Latent Spacecited by 960
- 2023GenEval: An Object-Focused Framework for Evaluating Text-to-Image Alignmentcited by 946
- 2023SEED-Bench: Benchmarking Multimodal LLMs with Generative Comprehensioncited by 929
- 2025Emerging Properties in Unified Multimodal Pretrainingcited by 855
- 2024Cambrian-1: A Fully Open, Vision-Centric Exploration of Multimodal LLMscited by 822
- 2016A Diagram Is Worth A Dozen Imagescited by 793
- 2025Janus-Pro: Unified Multimodal Understanding and Generation with Data and Model Scalingcited by 787
- 2024Emu3: Next-Token Prediction is All You Needcited by 761
- 2024Show-o: One Single Transformer to Unify Multimodal Understanding and Generationcited by 734
- 2017Masked Autoregressive Flow for Density Estimationcited by 680
- 2016Improving Variational Inference with Inverse Autoregressive Flowcited by 636
- 2023Language Model Beats Diffusion -- Tokenizer is Key to Visual Generationcited by 633
- 2024Transfusion: Predict the Next Token and Diffuse Images with One Multi-Modal Modelcited by 468
- 2024ELLA: Equip Diffusion Models with LLM for Enhanced Semantic Alignmentcited by 455
- 2025BLIP3-o: A Family of Fully Open Unified Multimodal Models-Architecture, Training and Datasetcited by 363
- 2024Visual Sketchpad: Sketching as a Visual Chain of Thought for Multimodal Language Modelscited by 260
- 2019Flow++: Improving Flow-Based Generative Models with Variational Dequantization and Architecture Designcited by 258
- 2025Show-o2: Improved Native Unified Multimodal Modelscited by 242
- 2025Transfer between Modalities with MetaQueriescited by 231
- 2024MetaMorph: Multimodal Understanding and Generation via Instruction Tuningcited by 205
- 2023JourneyDB: A Benchmark for Generative Image Understandingcited by 203
- 2024TokenFlow: Unified Image Tokenizer for Multimodal Understanding and Generationcited by 200
- 2024Open-MAGVIT2: An Open-Source Project Toward Democratizing Auto-regressive Visual Generationcited by 153
- 2024Mixture-of-Transformers: A Sparse and Scalable Architecture for Multi-Modal Foundation Modelscited by 151
- 2024OmniEdit: Building Image Editing Generalist Models Through Specialist Supervisioncited by 145
- 2024LMFusion: Adapting Pretrained Language Models for Multimodal Generationcited by 120
- 2025Mogao: An Omni Foundation Model for Interleaved Multi-Modal Generationcited by 108
- 2024SEED-Data-Edit Technical Report: A Hybrid Dataset for Instructional Image Editingcited by 97
- 2024Normalizing Flows are Capable Generative Modelscited by 89
- 2025Zebra-CoT: A Dataset for Interleaved Vision Language Reasoningcited by 78
50 most cited of 63 All 63 (JSON)
Built on by
Citing papers per year: 2026: 2.
2 papers.
Similar, not cited
Close in wording, no citation either way
- 2026Multimodal Flow: Unified Flow Modeling of Language and Vision in Embedding Spaces
- 2025Muddit: Liberating Generation Beyond Text-to-Image with a Unified Discrete Diffusion Model
- 2024JanusFlow: Harmonizing Autoregression and Rectified Flow for Unified Multimodal Understanding and Generation
- 2024JetFormer: An Autoregressive Generative Model of Raw Images and Text
- 2026Unified Text-Image Generation with Weakness-Targeted Post-Training
- 2025Growing Visual Generative Capacity for Pre-Trained MLLMs
- 2026TextLDM: Language Modeling with Continuous Latent Diffusion
- 2024ANOLE: An Open, Autoregressive, Native Large Multimodal Models for Interleaved Image-Text Generation