The pursuit of fair and equitable AI in human-centric tasks is critically hindered by the inherent biases and privacy risks of real-world datasets, which offer imbalanced representations of identity and often contain sensitive personal information. Consequently, state-of-the-art generative models trained on this skewed data exhibit unfair performance, particularly in identity-preserving generation. In this work we propose a pipeline for controllable generation of dataset with diverse faces for generative models training and finetuning. We achieve this by expanding foundational Arc2Face diffusion model with a flow matching generative model in the manifold of identity embeddings. We demonstrate that such approach achieves both goals of generative fidelity and label diversity not present in real human-centric datasets. As a result we collect and further contextualize a highly balanced identity-centric dataset of humans named SynthFaces. By design, our released images and identities are synthetic, reducing direct reliance on real personal images; we empirically check identity separation with a nearest-neighbor non-leakage metric. We purpose it for training and tuning of fair models for various downstream tasks, and showcase its usability in finetuning an existing adapter-based method for personalized generation.
Figures & tables
Type
Dataset
Captions
Balanced labels
ID-grouped
Private
HQ
Raw Images
VGG-Face, WebFace
no
partially
yes
no
partially
HQ Captioned
Cosmic, DeepFashion
yes
no
no
no
yes
Face Recognition
DCFace, HyperFace
no
no
yes
partially
no
SynthFaces (ours)
yes
yes
yes
yes
yes
Table 1: High level comparison of dataset types, in columns Caption denotes that images are paired with prompts, Balanced labels that dataset is balanced over selected demographic labels, ID-grouped that multiple images per person are provided and HQ suggests that images are high resolution and visually high quality
Figure 1: Distribution of labels across different categories in some of conventional datasets with humans. Dashed lines denotes mean value across labels, color highlights values above mean
Figure 3: Left - Conditional identity flow between uniform points on sphere and ArcFace embeddings used for training, constrained to tangent hyperplanes, right - inference scheme together with Arc2Face at stage 2, trained ID-flow samples identity embedding with given control signals and Arc2Face samples image
Category
Method
FID-i ↓
FID-e ↓
Prec. ↑
Rec. ↑
F1 ↑
ID-NL ↑
Naive
uniform
96.53
0.277
0.011
0.95
0.02
–
*interpolation
30.59
0.035
0.765
0.622
0.68
0.43
*PCA
51.18
0.048
0.29
0.88
0.44
0.76
Model
StyleGAN
45.8
0.111
0.711
0.173
0.28
–
Arc2Face
37.3
0.118
0.701
0.185
0.29
–
SDXL-Photomaker
73.9
0.207
0.73
0.01
0.02
–
Table 2: Baseline comparison of Stages 1 and 2. Lower FID is better and higher Precision/Recall/F1/ID-NL scores are better. ID-NL (ID-NonLeak) measures average nearest-neighbor separation from real training identities.
Figure 4: Distribution of different label categories data generation by ID-Flow. Compared to conventional datasets, our method offers significant data balance for all major characteristics of persons
Method
KL
FFHQ
0.449
SHHQ
0.533
EasyPortait
0.508
CosmicHQ-1.0
0.576
HyperFace-10k
0.49
PCA
0.75
Table 3: Label diversity
Figure 5: Diverse samples from ID-Flow. Dataset was sampled with uniform label controls, ensuring greatest variance of identity representations
Figure 6: Data filtering pipeline from Stage 2 to contextualization - in order to minimize amount of corrupted images with faces we 1) remove images in long tails of statistics 2) detect images with artifacts via vision-language model 3) threshold pairwise similarity, ensuring variability of identities in all categories, resulting in the end with approximately 150,000 final images
F1
Precision
Recall
FID e
FID i
KL-age
KL-race
KL-gender
Before
0.496
0.425
0.596
0.163
65.59
0.000108
0.000042
0.000001
After
0.444
0.359
0.580
0.127
57.66
0.121146
0.006530
0.003619
Table 4: Comparison of metrics before and after filtering Stage 2 images. F1/Precision/Recall/FID and KL divergence same as in previous tables, KL is split for separate categories analysis. Note that metrics are computed with skewed test set of face images
Method
Label KL ↓
ID-div. ↑
Flux.2 T2I, unconditional
0.891
0.257
Flux.2 T2I, balanced prompts
0.101
0.201
ID-Flow (ours)
0.037
0.751
Table 5: Text-conditioned Flux.2 sampling versus ID-Flow ( N=1000 each). Label KL is the mean KL divergence from a uniform distribution over age, race, and gender; ID-div. is mean nearest-neighbor cosine distance.
FaceSize
IR
CLIP
Cosmic-HQ
0.22
-0.69
31.20
FluxSynID [ 10 ]
0.61
1.54
34.07
SynthFaces
0.29
1.38
33.04
Table 6: Comparison of HQ dataset metrics with SynthFaces - our dataset offers superior quality over Cosmic-HQ, while allowing richer contextualization without overly large faces
Figure 7: SynthFaces dataset sample examples - after filtration and caption matching identities are contextualized with Flux-based methods, resulting in total 150,000 high-quality contextualized images with approximately 10 images per identity
Figure 8: Face similarity measured across different categories of IpAdapter-FaceID before and after tuning on data generated by ID-flow.
FairBench
Context
Method
ID
CLIP-T
ID
CLIP-T
SD-1.5 + FaceID
68.63
32.91
28.81
53.56
SD-1.5 + FaceID (+ tuned)
71.31
33.27
28.49
51.56
Table 7: Effect of tuning pipelines with our dataset, reporting average metric values
Table 9: Maximum racial SER at FPR = 0.1% on standard FR benchmarks ( ↓ fairer, 1.0 = perfect parity). Bold = best. ⋆ = SynthFaces-500K is fairest.
Domain
Model
Avg acc ↑
Δ↓
HQ
Baseline
0.551
0.183
HQ
SynthFaces-HQ (ours)
0.700
0.151
non-HQ
Baseline
0.645
0.176
non-HQ
Vec2Face
0.559
0.263
non-HQ
SynthFaces-nonHQ (ours)
0.797
0.138
Table 10: Domain-aligned VQA results Avg acc = mean over gender/race/age ( ↑ ); Δ↓ fairer. Bold = best per domain.
Appendix figures & tables13 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 9: Left - high level architecture of the ID-flow model, with conceptual parts corresponding to encoder/decoder architecture, Right - architecture of Modulated ResBlock , which consists of parts inspired by DiT architectures, but without attention mechanisms, orange color highlights trainable parameters
block_num
hidden_dim
c_embed dim
attention
activation
optimizer
schedule
2, 4, 6
128, 256, 512
128, 256, 512,
yes, no
LeakyRelu Sigmoid SoftSign GeLu
SGD, Adam, AdamW
const, linear warmup
Appendix
Table 12: Ablated parameters of model
Figure 10: Trade-off of inference quality of the model embedding samples between fidelity and variability of the samples. We change guidance scale values in range from 1.0 to 8.0
Figure 11: Examples removed by image-statistics filtering. Low entropy corresponds to heavily stylized samples; low saturation identifies grayscale images, while high saturation exposes unnatural colors and lighting artifacts.
Figure 12: Distribution of similarities within data before and after filtering w.r.t. label of data. Each section correspond to distribution with certain race label attached - effect of filtering eliminates tails present for certain labels
Baseline
ID-diversity
Real train data
0.305
HyperFace
0.306
ID-flow samples (before filtering)
0.355
ID-flow samples (after filtering)
0.295
Appendix
Table 13: Embedding diversity measured as mean cosine distance to closest neighbor within data. After filtering Stage 2 faces match in quality filtered label data that was used for training and HyperFace baseline
Figure 13: VLM-filtering output examples of stage 2 - VLM is prompted to visually analyze face in the image, its alignment with labels, detect any artifacts and reason about them
Figure 14: Comparison of various models and checkpoints of Flux-2 and Qwen-IE for contextualization stage. It can be seen that only Flux-2 [dev]- turbo achieves both preservation and fidelity. Images generated with same prompt ”Realistic image of man from image 1, in glasses reading book at home”
Figure 15: Face similarity metric unfairness for different age categories in identity preserving generation - measured preservation across labels is far from balanced
Figure 16: Finetuning results for Photomaker - FairBench benchmark shows average improvement of quality, while also balancing performance between categories
Figure 17: More samples from SynthFaces dataset, including non-square resolution images cropped around faces. Each column corresponds to images of the same synthetic identity.
LFW
CFP-FP
AgeDB-30
CALFW
CPLFW
Mean
Model
Acc
AUC
Acc
AUC
Acc
AUC
Acc
AUC
Acc
AUC
Acc
AUC
SynthFaces-500K
0.913
0.971
0.727
0.803
0.713
0.791
0.791
0.867
0.679
0.741
0.764
0.835
Vec2Face
0.993
0.999
0.913
0.969
0.945
0.984
0.946
0.973
0.877
0.927
0.935
0.970
HyperFace
0.983
0.998
0.880
0.945
0.855
0.931
0.879
0.944
0.825
0.891
0.884
0.942
Appendix
Table 15: Global accuracy and AUC on standard FR benchmarks ( ↑ better). SynthFaces-500K’s lower accuracy reflects its earlier training stage.
Model
LFW
CFP-FP
AgeDB-30
CALFW
CPLFW
Mean
SynthFaces-500K (ours)
1.482
1.133
1.117
1.087
1.040
1.172
Vec2Face-HSFace300K
1.536
1.347
1.670
1.196
1.344
1.419
HyperFace-10K-LDM
2.061
1.155
1.686
1.032
1.137
1.414
Appendix
Table 16: Maximum racial SER at FPR = 1% on standard FR benchmarks ( ↓ fairer). ⋆ = SynthFaces-500K is fairest.
Diffusion models have achieved strong results in high-fidelity image synthesis, but their iterative sampling process makes large-scale generation computationally expensive. This limitation is especially relevant when generating synthetic face datasets for face recognition, where a large number of subjects with many samples in different poses, expressions, ages, etc., are required. In this work, we show that identity-conditioned face synthesis can be performed at a substantially lower computational cost by a latent Consistency Model with few iterations, without compromising image quality. For training, we distill knowledge from the foundation Diffusion Model Arc2Face (teacher) by adapting its original text-to-image pipeline to an embedding-to-face setting, replacing textual prompts with ArcFace identity embeddings. Our distilled model (student) generates identity-conditioned face images with an average inference time of 0.4819 seconds per image, compared with 2.102 seconds for Arc2Face, resulting in a 4.36× speed-up. Quantitative results, based on FID scores, show that the distilled model remains competitive with Arc2Face across all evaluation protocols. On 100k generated images, it achieves near-parity on CelebA (13.921 vs. 12.928) and outperforms the teacher on WebFace42M (9.317 vs. 9.802). Further evaluations on Synth-500 and AgeDB show a moderate performance gap for the former but comparable results for the latter. These results indicate that Arc2Face can be accelerated through task-specific latent consistency distillation while preserving high image quality for large-scale synthetic face generation. Our proposal is publicly available at https://github.com/UFPR-IPASP-PR/FaceRec-IdentityConsistency.
Tiago Kienen Chaves, Bernardo Biesseck, David Menotti
Department of Informatics, Federal University of Paraná, Curitiba, Brazil · Federal Institute of Mato Grosso (IFMT), Pontes e Lacerda, MT, Brazil
The shortage of legally compliant data for face recognition training has sparked growing interest in using synthetic data as an alternative. While recent diffusion-based methods enable the generation of photorealistic face images with strong identity adherence and data diversity, their downstream recognition performance still exhibits a significant synthetic-real gap. This paper identifies visual tendency as a previously underexplored limitation, whereby synthetic data exhibit an unrealistic prevalence of visual attributes and thus deviate from the real-data distribution. Visual tendency can be attributed to the generator's conditioning on identity embeddings, through which co-occurring residual visual cues are unintentionally absorbed into learned identity semantics. To discourage the generator from exploiting such visual cues, this paper proposes SteerFace, a simple and efficient training framework that perturbs identity embeddings by steering them toward random orthogonal directions on the embedding hypersphere. The perturbation serves as an identity-preserving regularizer that penalizes the generator's reliance on non-identity components, as supported by theoretical analysis. This paper further introduces an adaptive strategy that learns perturbation strengths with both sample-wise preference and favorable overall statistics. Extensive experiments show that SteerFace effectively mitigates visual tendency, outperforms prior methods in downstream face recognition, and generalizes well across different training datasets and generation pipelines.
Yuxi Mi, Qiuyang Yuan, Jianqing Xu +5
Fudan University Shanghai, China · Youtu Lab, Tencent Shanghai, China · WeChat Pay Lab33, Tencent Shenzhen, China
Identity-preserving image generation becomes increasingly unreliable when a scene must contain many specified people. Beyond retaining each identity, the model must bind every reference to a distinct person and location, while training-time identity losses must establish correspondence among several noisy predicted faces. We introduce WithEveryone, a unified framework for generating group images up to ten reference identities. WithEveryone injects each selected identity as an addressed token, predicts a structured identity--layout plan, and renders the plan as a visual condition. Its key objective, Layout-Grounded ID Loss, uses annotated face regions to supervise the intended identities directly, avoiding unstable embedding-based face matching; ID Representation Forcing additionally trains a prediction for each identity before image synthesis. On an identity-disjoint benchmark, WithEveryone achieves the highest target-context identity similarity, improving face similarity from 0.462 for GPT-Image-2 to 0.499, while reducing copy-paste artifacts from 0.169 to 0.055. It further covers 97.3% of the requested identities with a duplicate rate of only 2.8%. These results show that explicit identity--layout grounding enables identity-preserving generation to scale to larger groups without relying on direct reference-face copying.
Hengyuan Xu, Qixun Wang, Yiji Cheng +5
1Fudan University · 2Hunyuan, Tencent · 3The University of Hong Kong