ICPR 2026

CURE Controllable Unified Image Restoration
for Complex Degradations

Control what to restore and how much.

Hanyang University · Corresponding author

Identity Full restoration
Snow-degraded input with low restoration intensity
w = 0.2
Partially restored image at ratio 0.4
w = 0.4
Partially restored image at ratio 0.6
w = 0.6
Mostly restored image at ratio 0.8
w = 0.8
Strongly restored image at ratio 0.9
w = 0.9

Continuous control over restoration intensity — without changing the network architecture.

In brief

A restoration model that listens precisely.

Composite degradations are intertwined: removing one corruption can alter another, and processing order can change the result. CURE learns disentangled and adjustable representations so a single model can preserve the input, remove selected degradations, and continuously control restoration strength.

Read the full abstract

The presence of composite degradations poses a significant challenge, since the underlying corruption factors exhibit complex and interdependent interactions. Even when the degradation types are known, accurately restoring the image remains difficult due to the intertwined nature of their effects and the need for selective control during the recovery process. To address this, we introduce CURE, a unified framework that enables controllable restoration in complex degradation settings by learning disentangled and adjustable representations. CURE is driven by four complementary objectives. First, an identity embedding is incorporated, along with a reconstruction constraint, to ensure that the model can reproduce the input image when restoration is unnecessary. Second, the ratio control mechanism blends the identity embedding with degradation-specific embeddings using user-regulated mixing ratios, allowing continuous control over restoration intensity. Third, an intermediate loss supervises stepwise outputs, each encouraged to tackle only a single degradation factor within a composite mixture. Finally, a permutation-invariant loss produces consistent restoration quality regardless of the order in which multiple degradations are addressed.

01

Preserve

An identity embedding explicitly tells the model when no restoration is needed.

02

Control

A ratio-controlled embedding continuously adjusts how strongly a degradation is removed.

03

Disentangle

Intermediate supervision isolates individual corruptions inside complex mixtures.

04

Reorder

Permutation-invariant learning keeps outputs consistent across restoration sequences.

01 Intensity control

Dial restoration up or down.

Move the slider to inspect the exact ratio-controlled outputs shown in the paper.

Snow restoration result at intensity ratio 0.5
Snow example
Restoration ratio w = 0.5
Live paper result

Partial restoration

The model removes part of the target degradation while retaining a controlled amount.

The interactive range uses the eight outputs visualized in Figure 3(a). In the formulation, w = 0 is identity and w = 1 is full restoration.
02 Selective restoration

Remove one. Preserve the rest.

CURE isolates a requested corruption instead of blindly clearing the entire image.

Low + Snow Remove Low-light Preserve Snow

Selective low-light enhancement should retain the snow component.

Composite input
Input image affected by low light and snow
OneRestore
OneRestore selective restoration result
CURE
CURE selective restoration result
Target
Ground-truth target retaining snow
03 Order invariance

Same goal. Either order.

Sequential restoration should not depend on which degradation is removed first.

0.02 dB average gap between restoration orders
Input · Low + Snow
Input image degraded by low light and snow
Delow Desnow
CURE result after low-light enhancement followed by desnowing
vs.
Desnow Delow
CURE result after desnowing followed by low-light enhancement
Ground truth
Clean ground-truth image

CURE produces closely aligned outputs across both processing orders.

04 Method

Controllability learned through four objectives.

CURE changes the training strategy, not the underlying restoration architecture.

CURE overview showing embedding generation, identity loss, and the overall training pipeline
Overview of CURE. Degradation and identity embeddings guide disentangled, controllable restoration.

Identity embedding

Constrains the model to reproduce the input when restoration is unnecessary.

Ratio-control loss

Interpolates identity and degradation embeddings for continuous intensity control.

Intermediate loss

Supervises partial outputs so each step removes only the requested degradation.

Permutation-invariant loss

Aligns outputs from reversed restoration sequences for consistent behavior.

05 Results

Qualitative comparisons on CCDD-11.

Figure 2 compares CURE with Restormer, NAFNet, PromptIR, and OneRestore across four complex degradation settings.

Figure 2 qualitative comparison on CCDD-11 showing input, Restormer, NAFNet, PromptIR, OneRestore, CURE, and ground truth outputs
Figure 2. Qualitative comparisons on the CCDD-11 dataset. From top to bottom: snow, low + haze + snow, rain, and low + haze + rain.
Key quantitative results

CURE with the OneRestore backbone on CCDD-11.

28.28 dB

Average PSNR on CCDD-11

93.44 %

Selective restoration accuracy

5.98 M

Parameters

0.02 dB

Average gap between restoration orders

06 Supplementary evidence

Every control, under a closer lens.

Explore twelve supplementary figures by experiment family. Open any figure for a full-resolution inspection.

Supplementary Figure 5. Identity operation on snow.

When snow is meant to remain, the identity embedding preserves the degraded input instead of over-restoring it.

Figures 5–16 from the paper supplementary material, grouped and loaded by experiment family.

07 Dataset

CCDD-11

CDD-11 was originally introduced with OneRestore. CCDD-11 follows its composite-degradation synthesis pipeline, then adds supervision pairs for removing each degradation factor individually. For example, a Low + Haze input is paired with a Haze-only target when removing Low and a Low-only target when removing Haze. It also provides a half-restored target at approximately 50% restoration strength for every degradation—enabling both selective restoration and continuous intensity control rather than only full recovery.

Download CCDD-11 on Hugging Face
Original composite pipeline CDD-11 by OneRestore
Add factor-level and half-restoration targets
Composite input
Low-light + Haze
Remove Low-light Haze remains
Remove Haze Low-light remains
Half restoration ≈ 50% restored target
CCDD-11 · supervision for selective and strength-controlled restoration
Citation

If CURE helps your research, please cite:

@inproceedings{kim2026cure,
  title     = {CURE: Controllable Unified Image Restoration for Complex Degradations},
  author    = {Kim, Boseong and Cho, Donghyeon},
  booktitle = {International Conference on Pattern Recognition (ICPR)},
  year      = {2026}
}