One-step and few-step text-to-image generation must accurately render the details specified in the prompt despite limited opportunities for refinement. Distribution matching distillation (DMD) uses score differences to bring the generated distribution closer to a reference distribution. Following prior work, we estimate this difference with internal velocity branches, avoiding a separate fake-score network. We ask whether an explicit moment constraint improves this learned score supervision. A decomposition of the reverse-KL field into a Gaussian moment component and a non-Gaussian residual identifies statistics that can be constrained explicitly. We introduce Intrinsic Distribution Matching (IDM), which retains the full DMD correction and matches feature means and per-coordinate standard deviations using the generator's exponential-moving-average (EMA) copy, requiring no external feature encoder. Experiments use full-parameter and low-rank adaptation (LoRA) tuning on Z-Image-Turbo 6B and Qwen-Image 20B. At two network evaluations, IDM reaches 94.25% and 90.20% on Chinese and English LongText-Bench, the highest scores among the compared methods at this budget. Controlled ablations show gains from the added moment loss, while generator EMA features perform competitively with an external DINOv2 encoder across the five reported metrics. Code is available at https://github.com/inclusionAI/IDM.
Figures & tables
Figure 1: Overview of IDM for one-step generation. Multi-step sampling refines samples iteratively, whereas one-step generation learns a direct noise-to-data map. IDM combines an internal DMD loss with a feature-moment loss in the generator’s EMA feature space. The right panel illustrates idealized alignment with single-evaluation inference.
Figure 2: IDM (Z-Image), 2 NFE. Text rendering and portrait generation.
Figure 3: Reverse-KL Field Decomposition. The full field gKL=sθ−sr ( left ) is the sum of a Gaussian moment component ( middle ) and a non-Gaussian residual component ( right ). Solid contours show pi and dashed contours its moment-matched Gaussian qi , for i∈{r,θ} . Equal means and covariances eliminate the Gaussian component but can leave a nonzero residual. All fields use the same evaluation points and arrow scale.
Figure 4: Intrinsic losses of IDM . Top, DMD loss: re-noise the predicted clean sample and use the internal velocity difference to construct detached velocity and endpoint targets for Lscore in Eq. 12 . Bottom, feature-moment loss: match means and per-coordinate standard deviations of EMA features hi:=ϕθˉ(xi,c) using current model features and detached model/reference queues Qθ,Qr in Eq. 13 . Base objective omitted.
Methods
NFEs
Throughput
Latency
Params
FID ↓
CLIP ↑
GenEval ↑
(samples/s)
(s)
(B)
Few-Step Generative Models
SDXL-LCM Luo et al. (2023)
2
2.89
0.40
0.9
18.11
27.51
0.44
PixArt-LCM Chen et al. (2024c)
2
3.52
0.31
0.6
10.33
27.24
0.42
SD3.5-Turbo ( Esser et al., 2024 ) ‡
2
1.61
0.68
8.0
51.47
25.59
0.53
PCM Wang et al. (2024a) †
2
2.62
0.56
0.9
14.70
27.66
0.55
SDXL-DMD2 Yin et al. (2024a) †
2
2.89
0.40
0.9
7.61
28.87
0.58
Table 1: System-level comparison of efficiency and quality. Speeds are on a single A100 ( BF16 ). Throughput is samples/s (batch=10); latency is seconds (batch=1). GenEval measures compositional prompt following; FID/CLIP complement the efficiency comparison. LongText results appear in Table 5 . † indicates that distinct models are required for different NFEs. ‡ marks a noncanonical operating point or a secondary comparison source. § indicates that the LoRA weights are merged into the base weights before timing. Params: backbone size in billions; LoRA entries additionally give rank r and trainable parameters in parentheses. Blue/red backbone counts indicate full/LoRA tuning, respectively.
Model
Single
Two
Counting
Colors
Position
Attribute
Overall ↑
Object
Object
Binding
Show-o ( Xie et al., 2024 )
0.95
0.52
0.49
0.82
0.11
0.28
0.53
Emu3-Gen ( Wang et al., 2024b )
0.98
0.71
0.34
0.81
0.17
0.21
0.54
PixArt- α ( Chen et al., 2024d )
0.98
0.50
0.44
0.80
0.08
0.07
0.48
SD3 Medium ( Esser et al., 2024 )
0.98
0.74
0.63
0.67
0.34
0.36
0.62
FLUX.1 [Dev] ( BlackForest, 2024 )
0.98
0.81
0.74
0.79
0.22
0.45
0.66
Table 2: Quantitative evaluation on GenEval. Per-category and overall scores at the NFE shown in each model label; unlabeled published baselines use their reported default sampling budget. Z-Image is the base model ( ∼ 100 NFE), whereas Z-Image-Turbo is the 8-NFE distilled model.
Model
Cultural
Time
Space
Biology
Physics
Chemistry
Overall ↑
SD v1.5 ( Rombach et al., 2022 )
0.34
0.35
0.32
0.28
0.29
0.21
0.32
SDXL ( Podell et al., 2023 )
0.43
0.48
0.47
0.44
0.45
0.27
0.43
SD3.5-Large ( Esser et al., 2024 ) ‡
0.44
0.50
0.58
0.44
0.52
0.31
0.46
PixArt- α ( Chen et al., 2024d )
0.45
0.50
0.48
0.49
0.56
0.34
0.47
Playground-v2.5 ( Li et al., 2024a )
0.49
0.58
0.55
0.43
0.48
0.33
0.49
FLUX.1 [Dev] ( BlackForest, 2024 )
0.48
0.58
0.62
0.42
0.51
0.35
0.50
Table 3: Quantitative evaluation on WISE ( Niu et al., 2025 ) . Per-domain and overall world-knowledge grounding scores.
Table 5: Overall ablation results across benchmarks (2 NFE). Scores are percentages. Row \raisebox{-0.05ex}{\tiny1}⃝ is the full configuration and the shared control; rows \raisebox{-0.05ex}{\tiny2}⃝ – \raisebox{-0.05ex}{\tiny11}⃝ vary the losses, DMD regression weights, or feature map. The v -only and x -only controls retain Lpop . APEX ( Liu et al., 2026a ) is the published Z-Image reference from its comparison with TwinFlow; rows \raisebox{-0.05ex}{\tiny12}⃝ – \raisebox{-0.05ex}{\tiny16}⃝ are from Liu et al. (2026b) , with row \raisebox{-0.05ex}{\tiny16}⃝ evaluated at 8 NFE.
Figure 5: Reference methods and IDM loss configurations. The two prompts are evaluated at 1 and 2 NFE. The v+x control omits Lpop , while full IDM includes EMA feature-moment matching. APEX is an external reference trained on a smaller collection; the IDM loss ablations share the same training setting.
Idx
Model
NFE
Overall
Two obj.
Color attr.
Position
Counting
Colors
Single obj.
Distribution Matching Loss Ablation
\raisebox{-0.05ex}{\tiny2}⃝
00 w/o Lscore (DMD loss)
2
76.90
90.40
64.50
49.25
70.31
87.23
99.69
\raisebox{-0.05ex}{\tiny3}⃝
00 w/o Lpop (feature-moment loss)
2
77.46
90.91
65.25
50.75
70.94
87.23
99.69
\raisebox{-0.05ex}{\tiny4}⃝
00 w/o Lscore and Lpop
2
76.24
90.15
63.75
49.25
68.44
86.17
99.69
DMD Regression Ablation
\raisebox{-0.05ex}{\tiny5}⃝
00 v -loss only
2
76.64
90.40
64.00
50.00
69.06
86.70
99.69
Table 6: Detailed GenEval ablation results. Scores are percentages; Overall is the mean of the six category scores. Configurations, row groups, and sources follow Table 5 .
Idx
Model
NFE
Overall
Attribute
Global
Relation
Other
Entity
Distribution Matching Loss Ablation
\raisebox{-0.05ex}{\tiny2}⃝
00 w/o Lscore (DMD loss)
2
86.15
89.33
80.23
94.32
89.54
92.58
\raisebox{-0.05ex}{\tiny3}⃝
00 w/o Lpop (feature-moment loss)
2
86.54
89.54
79.94
94.48
89.41
92.88
\raisebox{-0.05ex}{\tiny4}⃝
00 w/o Lscore and Lpop
2
85.68
89.07
80.01
94.12
89.37
92.23
DMD Regression Ablation
\raisebox{-0.05ex}{\tiny5}⃝
00 v -loss only
2
85.93
89.21
79.45
94.22
89.05
92.42
Table 7: Detailed DPG-Bench ablation results. Scores are percentages. Overall follows the standard prompt-level aggregation over the benchmark question hierarchy, rather than the mean of the five category columns. Configurations, row groups, and sources follow Table 5 .
Idx
Model
NFE
Overall
Alignment
Text
Diversity
Style
Reasoning
Distribution Matching Loss Ablation
\raisebox{-0.05ex}{\tiny2}⃝
00 w/o Lscore (DMD loss)
2
52.58
86.13
97.09
12.74
38.04
28.90
\raisebox{-0.05ex}{\tiny3}⃝
00 w/o Lpop (feature-moment loss)
2
52.87
86.31
97.73
12.81
38.16
29.34
\raisebox{-0.05ex}{\tiny4}⃝
00 w/o Lscore and Lpop
2
52.25
85.94
96.37
12.67
37.90
28.37
DMD Regression Ablation
\raisebox{-0.05ex}{\tiny5}⃝
00 v -loss only
2
52.43
86.04
96.76
12.71
37.97
28.67
Table 8: Detailed OneIG ablation results. Scores are percentages; Overall is the mean of the five category scores. Configurations, row groups, and sources follow Table 5 .
Figure 6: Sampling-budget comparison on Z-Image. Final outputs from Z-Image-Turbo, DMD2, TwinFlow, APEX, and IDM at the indicated NFE budgets, grouped by two prompts. Each column represents a sampling budget, not an intermediate state of one trajectory.
Figure 7: IDM (Z-Image), 2 NFE. Additional samples across styles and content. Every panel uses the same model and sampling budget; the grid is a gallery of outputs rather than a method or NFE comparison.
Text-to-image generation creates images from natural-language prompts using generative models, with research focused on fidelity, control, efficiency, and safety.