We propose MorphSIG, a training-free framework that reformulates subject-driven image generation (SIG) as pseudo-video feature transport. MorphSIG contains two core modules: Progressive Decoupled Anchoring, which uses frequency-domain decoupling and structural scrambling during early denoising to break structural locking and enable a gradual transition from free composition to identity alignment; and Pseudo-flow Guided Feature Transport, which constructs a latent-space pseudo-flow field to mimic Image-to-Video temporal coherence and transport subject semantics precisely. To address stylistic homogeneity and the lack of ground truth in existing benchmarks, we further introduce a benchmark with diverse stylized subjects. Extensive experiments show that MorphSIG significantly improves pose diversity and subject fidelity over baselines without additional training. Overall, MorphSIG bridges static generation and dynamic propagation, providing a cost-effective paradigm for high-fidelity subject consistency.
Figures & tables
Figure 1: Qualitative comparison between MorphSIG and the baseline.
Figure 2: Comparison of different SIG paradigms. SC (Subject Consistency), and Cost (computational complexity).
Figure 3: Overview of the proposed framework. MorphSIG consists of two modules: Progressive Decoupled Anchoring (PDA) and Warping Feature Transport (WFT). PDA suppresses structural shortcut copying by decoupling and progressively restoring reference anchors during denoising, enabling flexible composition. WFT estimates pseudo-flow to warp and transport reference features into the generation space, improving identity consistency under large pose and geometry variations.
Figure 4: Analysis of High-frequency Shortcut in T&I2I and Temporal Feature Transport in I2V.
Figure 5: Synergistic Analysis of Spectral Decoupling and Structural Permutation.
Figure 6: Feature Energy Analysis.
Methods
Venue
CSD ↑
CIDS ↑
PA ↑
AES ↑
CP ↓
INC ↑
Cross
Self
Cross
Self
Scene
Shot
CI
IA
Avg.
DreamO Mou et al. (2025)
SIGGA’25
0.489
0.584
0.542
0.643
2.99
2.21
1.72
1.65
2.14
5.31
0.533
9.21
DiptychP Shin et al. (2025)
CVPR’25
0.394
0.462
0.417
0.536
2.73
2.04
1.61
1.50
1.97
4.60
0.524
13.18
XVerse Chen et al. (2025a)
NIPS’25
0.229
0.461
0.342
0.531
2.96
2.37
1.89
1.73
2.23
4.92
0.519
13.67
UNO Wu et al. (2025d)
ICCV’25
0.513
0.576
0.528
0.632
3.08
2.52
2.07
1.91
2.39
4.94
0.542
8.27
OmniGen2 Wu et al. (2025a)
arXiv’25
0.446
0.546
0.460
0.587
3.12
2.46
1.80
1.64
2.27
5.19
0.531
9.87
Table 1: Quantitative Results of Various SIG Methods on ViStoryBench Zhuang et al. (2025) . CI: Character Interaction, IA: Individual Action; The first , second , and third values are highlighted.
Methods
Venue
DreamSim ↓
PA ↑
CLIP-T ↑
CLIP-I ↑
CDS ↑
AES ↑
VRAM ↓
GT
Ref
Scene
CI
IA
Avg.
DreamO Mou et al. (2025)
SIGGA’25
0.273
0.596
3.04
2.43
2.07
2.51
0.361
0.834
0.373
6.00
9.09
DiptychP Shin et al. (2025)
CVPR’25
0.459
0.651
2.72
2.16
2.45
2.44
0.332
0.696
0.339
5.24
30.01
XVerse Chen et al. (2025a)
NIPS’25
0.339
0.660
2.95
2.53
2.12
2.53
0.358
0.767
0.366
6.09
37.39
UNO Wu et al. (2025d)
ICCV’25
0.315
0.604
3.21
2.59
2.28
2.69
0.345
0.802
0.366
5.64
35.09
OmniGen2 Wu et al. (2025a)
arXiv’25
0.287
0.607
3.28
2.67
2.41
2.78
0.363
0.822
0.380
5.47
9.92
Table 2: Quantitative Results of Various SIG Methods on SIGBench. VRAM: Using GPU memory during inference. The first , second , and third values are highlighted.
Figure 7: Qualitative Comparison on ViStoryBench Across Diverse Characters and Styles.
Figure 8: Qualitative Comparison on Multi-Character Story Generation in ViStoryBench.
Figure 9: Qualitative Comparison on SIGBench with Ground Truth.
Method
DreamO
DiptychP
XVerse
UNO
OmniGen2
Scone
UMO
MOSAIC
FLUX.2-4B
Ours
Percent (%) ↑
2.79
1.41
0.62
10.19
3.03
12.84
15.95
4.48
22.75
26.31
Table 3: Human preference comparison among different methods.
CIDS ↑
INC ↑
PA ↑
AES ↑
w/o PDA
0.614
13.41
2.37
5.30
w/o SP
0.556
13.64
2.72
5.33
w/o SD
0.618
13.57
2.39
5.36
High-pass only
0.485
12.81
1.92
5.05
Full PDA
0.629
13.88
2.58
5.39
Table 4: The ablation study of PDA.
CIDS ↑
INC ↑
PA ↑
AES ↑
w/o WFT
0.541
13.47
2.64
5.25
w/o MNN
0.578
13.32
2.47
5.18
w/o HF-WTA
0.601
13.65
2.52
5.14
w/o LF-SLERP
0.584
13.30
2.34
5.19
ADD
0.561
12.93
2.16
5.05
Full WFT
0.629
13.88
2.58
5.39
Table 5: The ablation study of WFT.
Figure 10: Qualitative Comparison of Ablation Study.
Figure 11: Ablation analysis. (a) Effect of neighborhood size K in Local Consensus. (b, c) Sensitivity of PDA and WFT scheduling ranges.
Method
DreamO
DiptychP
XVerse
UNO
OmniGen2
Scone
UMO
MOSAIC
FLUX.2-4B
Ours
Training-free
×
✓
×
×
×
×
×
×
–
✓
Latency (s)
76.9
169.4
126.2
82.6
171.7
98.5
84.3
154.7
115.6
130.1
VRAM (GB)
9.09
30.01
37.39
35.09
9.92
30.43
33.78
35.79
12.21
13.44
Table 6: Comparison of computational cost on a single NVIDIA A100 GPU.
We present FlowFixer, a refinement framework for subject-driven generation (SDG) that restores fine details lost during generation caused by changes in scale and perspective of a subject. FlowFixer proposes direct image-to-image translation from visual references, avoiding ambiguities in language prompts. To enable image-to-image training, we introduce a one-step denoising scheme to generate self-supervised training data, which automatically removes high-frequency details while preserving global structure, effectively simulating real-world SDG errors. We further propose a keypoint matching-based metric to properly assess fidelity in details beyond semantic similarities usually measured by CLIP or DINO. Experimental results demonstrate that FlowFixer outperforms state-of-the-art SDG methods in both qualitative and quantitative evaluations, setting a new benchmark for high-fidelity subject-driven generation.
Subject-driven text-to-image generation still struggles to preserve high-frequency identity details such as logos, patterns, and text. Existing methods typically operate directly in RGB space, which often leads to detail degradation under substantial edits. We propose a two-stage framework that decouples structure from appearance by first predicting a Canny map and then rendering the final image conditioned on both the source appearance and the predicted structure. To improve text handling, we further introduce a fully automatic pipeline that constructs a 100k-pair text-aware dataset with cross-view textual consistency. Experiments, including GPT-4.1-based evaluation and a knowledge distillation study, show clear gains over selected baselines and suggest that intermediate structural prediction is an effective route for high-fidelity subject-driven generation. Our dataset and code will be made publicly available.
Hanzhong Guo, Yizhou Yu
School of Computing and Data Science, The University of Hong Kong
Subject-driven image generation has shown great success in creating personalized content, but its capabilities are largely confined to single subjects in common poses. Current approaches face a fundamental conflict when handling multiple subjects with complex, distinct actions: preserving individual identities while enforcing precise pose structures. This challenge often leads to identity fusion and pose distortion, as appearance and structure signals become entangled within the model's architecture. To resolve this conflict, we introduce ASTRA(Adaptive Synthesis through Targeted Retrieval Augmentation), a novel framework that architecturally disentangles subject appearance from pose structure within a unified Diffusion Transformer. ASTRA achieves this through a dual-pronged strategy. It first employs a Retrieval-Augmented Pose (RAG-Pose) pipeline to provide a clean, explicit structural prior from a curated database. Then, its core generative model learns to process these dual visual conditions using our Enhanced Universal Rotary Position Embedding (EURoPE), an asymmetric encoding mechanism that decouples identity tokens from spatial locations while binding pose tokens to the canvas. Concurrently, a Disentangled Semantic Modulation (DSM) adapter offloads the identity preservation task into the text conditioning stream. Extensive experiments demonstrate that our integrated approach achieves superior disentanglement. On our designed COCO-based complex pose benchmark, ASTRA achieves a new state-of-the-art in pose adherence, while maintaining high identity fidelity and text alignment in DreamBench.