Modality-Specific Hierarchical Enhancement for RGB-D Camouflaged Object Detection
Organizations: College of Computer and Data Science, Fuzhou University, Fuzhou, China
Abstract
Camouflaged object detection (COD) is challenging due to high target-background similarity, and recent methods address this by complementarily using RGB-D texture and geometry cues. However, RGB-D COD methods still underutilize modality-specific cues, which limits fusion quality. We believe this is because RGB and depth features are fused directly after backbone extraction without modality-specific enhancement. To address this limitation, we propose MHENet, an RGB-D COD framework that performs modality-specific hierarchical enhancement and adaptive fusion of RGB and depth features. Specifically, we introduce a Texture Hierarchical Enhancement Module (THEM) to amplify subtle texture variations by extracting high-frequency information and a Geometry Hierarchical Enhancement Module (GHEM) to enhance geometric structures via learnable gradient extraction, while preserving cross-scale semantic consistency. Finally, an Adaptive Dynamic Fusion Module (ADFM) adaptively fuses the enhanced texture and geometry features with spatially varying weights. Experiments on four benchmarks demonstrate that MHENet surpasses 16 state-of-the-art methods qualitatively and quantitatively. Code is available at https://github.com/afdsgh/MHENet.
Figures & tables
| Methods | Pub.Year | CHAMELEON | CAMO-Test | COD10K-Test | NC4K | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RGB-based COD Methods | |||||||||||||||||
| SINet [ 7 ] | CVPR.20 | 0.872 | 0.936 | 0.806 | 0.034 | 0.745 | 0.804 | 0.644 | 0.092 | 0.776 | 0.864 | 0.631 | 0.043 | 0.808 | 0.871 | 0.723 | 0.058 |
| BGNet [ 9 ] | IJCAI.22 | 0.901 | 0.943 | 0.850 | 0.027 | 0.812 | 0.857 | 0.749 | 0.073 | 0.831 | 0.901 | 0.722 | 0.033 | 0.851 | 0.907 | 0.788 | 0.044 |
| ZoomNet [ 10 ] | CVPR.22 | 0.902 | 0.943 | 0.845 | 0.023 | 0.820 | 0.877 | 0.752 | 0.066 | 0.838 | 0.888 | 0.729 | 0.029 | 0.853 | 0.896 | 0.784 | 0.043 |
| FSPNet [ 25 ] | CVPR.23 | 0.908 | 0.943 | 0.851 | 0.023 | 0.856 | 0.899 | 0.799 | 0.050 | 0.851 | 0.895 | 0.735 | 0.026 | 0.879 | 0.915 | 0.816 | 0.035 |
| NO. | Modules | COD10K-Test | NC4K-Test | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| B. | THEM | GHEM | ADFM | |||||||||
| 1 | 0.873 | 0.925 | 0.786 | 0.022 | 0.893 | 0.930 | 0.842 | 0.032 | ||||
| 2 | 0.883 | 0.934 | 0.806 | 0.020 | 0.895 | 0.932 | 0.849 | 0.031 | ||||
| 3 | 0.885 | 0.938 | 0.813 | 0.020 | 0.898 | 0.937 | 0.856 | 0.030 | ||||
| 4 | 0.887 | 0.938 | 0.813 | 0.020 | 0.900 | 0.937 | 0.855 | 0.030 | ||||
| 5 | 0.889 | 0.942 | 0.817 | 0.019 | 0.902 | 0.939 | 0.859 | 0.029 | ||||
| NO. | Inputs | COD10K-Test | NC4K-Test | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 6 | w/o Semantic Block | 0.885 | 0.939 | 0.816 | 0.020 | 0.898 | 0.935 | 0.856 | 0.030 |
| 7 | w/o Texture Block | 0.886 | 0.940 | 0.814 | 0.020 | 0.899 | 0.937 | 0.855 | 0.030 |
| 8 | w/o Geometry Block | 0.887 | 0.941 | 0.815 | 0.020 | 0.899 | 0.937 | 0.856 | 0.030 |
| 9 | MHENet (Ours) | 0.889 | 0.942 | 0.817 | 0.019 | 0.902 | 0.939 | 0.859 | 0.029 |
| NO. | Inputs | COD10K-Test | NC4K-Test | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 10 | only Depth | 0.844 | 0.902 | 0.740 | 0.028 | 0.869 | 0.912 | 0.807 | 0.039 |
| 11 | only RGB | 0.880 | 0.937 | 0.803 | 0.021 | 0.895 | 0.936 | 0.851 | 0.029 |
| 12 | RGB-D | 0.889 | 0.942 | 0.817 | 0.019 | 0.902 | 0.939 | 0.859 | 0.029 |
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
| Depth Estimation Model | COD10K-Test | NC4K-Test | ||||||
|---|---|---|---|---|---|---|---|---|
| Depth Anything V1 | 0.886 | 0.939 | 0.812 | 0.020 | 0.900 | 0.937 | 0.857 | 0.030 |
| Depth Anything V2 | 0.894 | 0.941 | 0.825 | 0.019 | 0.905 | 0.941 | 0.865 | 0.029 |
| Distill Any Depth | 0.889 | 0.942 | 0.817 | 0.019 | 0.902 | 0.939 | 0.859 | 0.029 |
| Methods/Metrics | SINet | BGNet | FSPNet | RISNet | Ours |
|---|---|---|---|---|---|
| Params (M) | 48.95 | 79.85 | 273.80 | 26.58 | 53.36 |
| FLOPs (G) | 38.76 | 59.45 | 283.31 | 96.57 | 37.97 |
| Speed (FPS) | 46.06 | 39.49 | 26.23 | 24.82 | 23.43 |