Guided depth super-resolution (GDSR) typically extracts RGB guidance features through convolutional hierarchies, inheriting their fine-to-coarse bias. Thus, low-level spatial cues surface in early layers, leaving the deeper layers to suppress those that do not correspond to true depth boundaries, which risks artifacts and blurred edges. The same fine-to-coarse bias persists in semantics-based methods that consume low-level tokens early and global tokens late. We present WAVE, which introduces a multi-level discrete wavelet transform (ML-DWT) as an explicit and interpretable feature-control mechanism, enabling a coarse-to-fine reconstruction by consuming sub-bands and semantic tokens in reverse of their generation order. WAVE further exploits these sub-bands to treat high- and low-frequency content separately, isolating the misleading RGB color and texture cues before any feature is learned so that their admission can be controlled explicitly, offering an intuitive alternative to the suppression learned implicitly by an opaque network. WAVE separates structure and detail reconstruction into dedicated modules that: i) model interactions within and across wavelet sub-bands, depth features, and semantic priors, ii) apply semantic gating to the high-frequency bands, and iii) fuse modalities through an invertible coupling mechanism that prevents collapse onto a single modality. Extensive experiments across multiple benchmarks demonstrate that WAVE matches or outperforms existing methods, with the largest gains at high upsampling factors, where low-resolution depth contains the least structure.
Figures & tables
Fig. 1: Coarse-to-fine spatial guidance in GDSR. a. WAVE uses ML-DWT and consumes the sub-bands in reverse of their generation order, i.e., coarsest first, restoring global structure before finer details. b. A conventional CNN-encoder for spatial feature extraction extracts RGB features directly, surfacing fine local cues in the earliest feature maps and recovering global structure only in deeper layers, where these early high-frequency cues must be suppressed later. c. Full-scene and d. zoomed comparisons show WAVE producing crisp and non-bleeding boundaries, with sharper contours and clean surfaces.
Fig. 2: Overview of the WAVE architecture and the coarse-to-fine HUMMA reconstruction blocks pipeline. a. ML-DWT decomposes the RGB guide into a fine-to-coarse sub-band pyramid, DINOv3 produces semantic tokens adapted by SToRA, and the Depth Preprocessor encodes the low-resolution depth. b. Four HUMMA blocks progressively reconstruct and upsample the depth feature maps using the coarse-to-fine sub-bands and semantic tokens, and the Final Fusion Block applies a global correction guided by semantic boundaries.
Fig. 3: Overview of the HUMMA block. a. Detail branch processes the high-frequency sub-bands along edge and texture paths, each modulated by the SToRA token via semantic gating. The two feature maps are merged to produce a detail map. b. Structure branch relates the low-frequency depth features, LL approximation, and SToRA tokens through learnable projections. The IRN-style coupling bijectively mixes the modalities, discouraging collapse onto either. c. The Reconstruction block aligns and residually adds the details to the structure map, followed by back-projection for 2× upsampling to produce the next refined depth feature map.
Method
RGB-D-D
NYU_v2
M-bury
Lu
Average
DJFR
6.48
14.12
8.57
9.94
9.78
CUNet
7.75
15.95
9.23
10.97
10.98
DKN
5.97
12.46
7.76
8.98
8.79
FDSR
5.08
14.19
7.26
8.62
8.79
DCTNet
5.99
13.33
8.22
9.28
9.21
SGNet
5.15
11.24
6.79
7.23
7.60
TABLE I: 32× results under the NYU_v2 training protocol, evaluated on RGB-D-D, NYU_v2, Middlebury, and Lu. Baseline numbers are taken from [ 23 ] . Best in bold , second-best underlined .
Method
RGB-D-D
TOFDSR
NYU_v2
M-bury
Lu
Average
8×
16×
8×
16×
8×
16×
8×
16×
8×
16×
8×
16×
DJF
2.58
4.46
5.59
8.19
5.56
9.82
3.09
5.50
3.58
6.53
4.08
6.90
DJFR
2.61
4.36
5.11
8.06
5.20
9.50
2.82
5.16
3.24
6.46
3.80
6.71
CUNet
2.35
3.81
5.14
7.36
5.50
8.63
2.86
4.72
2.85
5.63
3.74
6.03
FDKN
2.25
3.71
4.40
7.16
4.93
7.97
2.51
4.42
2.67
5.48
3.35
5.75
DKN
2.33
3.70
4.54
7.24
4.88
7.70
2.43
4.17
2.88
5.44
3.41
5.65
TABLE II: Hypersim training protocol at 8× and 16× , evaluated on RGB-D-D, TOFDSR, NYU_v2, Middlebury, and Lu. Baselines taken from [ 4 ] . Best in bold , second-best underlined
Method
RGB-D-D
DIML
NYU_v2
M-bury
Lu
8×
16×
8×
16×
8×
16×
8×
16×
8×
16×
DJFR
5.57
7.99
2.34
4.13
4.94
9.18
3.19
5.57
3.57
6.77
JIIF
1.79
2.87
1.86
3.22
2.76
5.27
1.82
3.31
1.73
4.16
DKN
1.96
3.42
1.86
3.22
3.26
6.51
2.12
4.24
2.16
5.11
FDSR
1.82
3.06
1.71
2.87
3.18
5.86
2.08
4.39
2.19
5.00
DCTNet
1.74
3.05
1.71
3.73
3.16
5.84
2.05
4.19
1.85
4.39
TABLE III: NYU_v2 training protocol at 8× and 16× , evaluated on RGB-D-D, DIML, NYU_v2, Middlebury, and Lu. At these scales, the benchmark is largely saturated, where the leading methods fall within roughly 0.1–0.2cm RMSE. Baselines taken from [ 5 , 23 ] . Best in bold , second-best underlined .
Method
Trainable (M)
Frozen (M)
FLOPs (G)
Memory (GB)
DCTNet
0.48
–
5.73
1.36
DADA
31.03
–
212.58
4.96
DuCos
34.38
–
2927.49
9.02
SPFNet
31.10
–
3259.42
2.23
SGNet
85.94
–
9715.16
1.97
C2PD
65.05
–
414.75
1.27
TABLE IV: Model complexity at 16× for single-batch inference, measured on one NVIDIA RTX 4090. Trainable and frozen parameters in millions (M), FLOPs in Giga-operations (G), peak GPU memory in GB. WAVE’s frozen DINOv3 backbone is not updated during training.
Fig. 4: Qualitative comparison at 8 × on TOFDSR (top) and RGB-D-D (bottom). WAVE recovers thin structures and object openings with sharper, non-bleeding boundaries, closest to the ground truth (GT).
Fig. 5: Qualitative comparison at 16 × on TOFDSR (top) and RGB-D-D (bottom). WAVE recovers sharper object boundaries and cleaner surfaces with fewer texture-copying artifacts, closest to the ground truth (GT).
Fig. 6: Qualitative comparison at 32 × on NYU_v2, RGB-D-D, TOFDSR, and DIML. We compare against C2PD, the only competing method with publicly available 32 × weights. WAVE preserves object openings, produces straighter boundaries, and avoids the false discontinuities and background artifacts visible in C2PD, remaining closest to GT.
Fig. 7: Texture copying at 32 × on TOFDSR. The grid pattern on the background cloth has no depth counterpart. C2PD transfers it into the depth map, whereas WAVE suppresses it while retaining the object boundaries.
Fig. 8: Robustness to RGB–depth misalignment at 16 × . RMSE (cm, lower is better) on DIML, NYU_v2, TOFDSR, and RGB-D-D as the RGB guide is translated by 1–8 pixels while the low-resolution depth and ground truth remain fixed.
Variant
Ablated component
TOFDSR
WAVE
-
4.57
WAVE-a
Fine-to-coarse schedule
4.79
WAVE-b
No cross-modal invertible coupling
4.63
WAVE-c
No wavelet spatial bands (semantics only)
4.73
WAVE-d
No high-frequency details injection
4.65
WAVE-e
No semantics refinement in structure branch
4.69
TABLE V: Ablations at 16× under the NYU_v2 protocol. We report the RMSE in centimeters (lower is better), with the overall increase highlighting the significance of each component. Results are reported for the TOFDSR dataset, serving as an out-of-distribution test.
Encoder
RGB-D-D
DIML
NYU_v2
M-bury
Lu
Frozen Parameters (M)
DINOv3
2.39
2.50
4.60
2.82
3.20
21.6
SAM-2
2.43
2.47
4.55
2.87
3.32
26.9
ResNet-50
2.44
2.50
4.63
2.82
3.40
23.5
TABLE VI: Semantic encoder substitution under the NYU_v2 training protocol at 16× , evaluated on RGB-D-D, DIML, NYU_v2, Middlebury, and Lu (RMSE in cm, lower is better). Each encoder is kept frozen, and its layer-wise features are consumed in the same coarse-to-fine schedule. Best in bold , second-best underlined . The last column lists frozen encoder parameters in millions (M).
Scale
Dataset
Base RMSE
Zero LL-band RMSE
Δ RMSE
8
DIML
1.62
2.11
0.49
16
DIML
2.50
3.09
0.59
32
DIML
4.63
5.28
0.65
8
NYU_v2
2.50
3.53
1.03
16
NYU_v2
4.60
6.50
1.90
32
NYU_v2
7.90
9.93
2.03
TABLE VII: Dependence of the fused structure on the LL band at 8× , 16× , and 32× under the NYU_v2 protocol. RMSE in centimeters (lower is better) with the LL band intact (Base) and set to zero at inference (Zero LL), and the resulting increase ( Δ ).
Multi-scale feature fusion combines representations at different resolutions or receptive fields to improve perception, prediction, and reconstruction.
Guided depth super-resolution (GDSR) is a multi-modal approach for depth map super-resolution that relies on a low-resolution depth map and a high-resolution RGB image to restore finer structural details. However, the misleading color and texture cues indicating depth discontinuities in RGB images often lead to artifacts and blurred depth boundaries in the generated depth map. Recent methods counter this by drawing priors from large pretrained models, but these priors enter the network as decoded predictions such as relative depth, surface normal, or segmentation maps, coupling restoration quality to the accuracy of the decoded prior and requiring auxiliary objectives. We propose a solution that introduces global contextual semantic priors, generated from pretrained vision transformer token embeddings, injecting them directly into the depth branch. Our Guided Token Attention (GTA) module lets multi-level depth encodings act as queries of cross-attention over semantic tokens drawn from progressively deeper layers of the pretrained visual transformer (ViT), scaled by a zero-initialized gate that admits semantic evidence only to the extent that it reduces reconstruction error. The resulting token-to-depth correspondence is aligned implicitly, through learned attention under a single reconstruction loss, rather than through an explicit alignment or distribution-matching objective. Building on this, we present Neural Attention with Implicit Multi-token Alignment (NAIMA), which, to the best of our knowledge, is the first GDSR framework guided by undecoded semantic tokens. NAIMA remains competitive in-distribution while achieving the strongest cross-dataset generalization.
Tayyab Nasir, Daochang Liu, Ajmal Mian
The University of Western Australia, Perth, Western Australia
Guided depth super-resolution (GDSR) reconstructs HR depth maps from LR inputs with HR RGB guidance. Existing methods either model each modality independently or rely on computationally expensive attention mechanisms with quadratic complexity, hindering the establishment of efficient and semantically interactive joint representations. In this paper, we observe that feature maps from different modalities exhibit semantic-level correlations during feature extraction. This motivates us to develop a more flexible approach enabling dense, semantically-aware deep interactions between modalities. To this end, we propose a novel GDSR framework centered around the Interactive State Space Model. Specifically, we design a cross-modal local scanning mechanism that enables fine-grained semantic interactions between RGB and depth features. Leveraging the Mamba architecture, our framework achieves global modeling with linear complexity. Furthermore, a cross-modal matching transform module is introduced to enhance interactive modeling quality by utilizing representative features from both modalities. Extensive experiments demonstrate competitive performance against state-of-the-art methods.
Chen Wu, Ling Wang, Zhuoran Zheng +4
National University of Defense Technology · The Hong Kong University of Science and Technology (Guangzhou) · Sun Yat-sen University +2
Depth super-resolution (DSR) aims to recover a high-resolution (HR) depth map from its low-resolution (LR) counterpart. With color image guidance, this task is typically formulated as learning the residual between HR and LR in a low-dimensional feature space. However, this additive formulation is insufficient to accurately capture the complex relationship between HR and LR, especially under spatially varying degradations. In this paper, we introduce DegBins, a novel DSR framework that leverages degradation-driven binning to adaptively enhance residual modeling. Specifically, DegBins reformulates the regression-based DSR as a hybrid classification-regression problem, where the residual depth is represented as a linear combination of discrete depth bins weighted by their learned probability distribution, yielding more flexible and expressive representations. Furthermore, DegBins models the degradation relationship between HR and LR in a high-dimensional feature space, enabling adaptive bin range adjustment and probability optimization conditioned on local degradation characteristics. To progressively improve reconstruction quality, DegBins adopts a multi-stage refinement scheme, where each stage performs finer-grained bin partitioning and probability updating based on the former estimation. This coarse-to-fine design facilitates more accurate depth recovery, particularly in regions with severe degradations or complex structural variations. Extensive experiments across five benchmarks demonstrate that DegBins consistently outperforms existing state-of-the-art methods in terms of accuracy, robustness, and generalization.
Zhiqiang Yan, Zhengxue Wang, Jian Yang +1
Department of Computer Science, National University of Singapore · Nanjing University of Science and Technology