Efficient image compression relies on modeling both local and global redundancy. Most state-of-the-art (SOTA) learned image compression (LIC) methods are based on CNNs or Transformers, which are inherently rigid. Standard CNN kernels and window-based attention mechanisms impose fixed receptive fields and static connectivity patterns, which potentially couple non-redundant pixels simply due to their proximity in Euclidean space. This rigidity limits the model's ability to adaptively capture spatially varying redundancy across the image, particularly at the global level. To overcome these limitations, we propose a content-adaptive image compression framework based on Graph Neural Networks (GNNs). Specifically, our approach constructs dual-scale graphs that enable flexible, data-driven receptive fields. Furthermore, we introduce adaptive connectivity by dynamically adjusting the number of neighbors for each node based on local content complexity. These innovations empower our Graph-based Learned Image Compression (GLIC) model to effectively model diverse redundancy patterns across images, leading to more efficient and adaptive compression. Experiments demonstrate that GLIC achieves state-of-the-art performance, achieving BD-rate reductions of 19.29%, 21.69%, and 18.71% relative to VTM-9.1 on Kodak, Tecnick, and CLIC, respectively. Code will be released at https://github.com/UnoC-727/GLIC.
Figures & tables
Figure 2: Overview of our method. (a) Architecture of the proposed GLIC codec. Channel widths are C1,C2,C3,C4 , and the numbers of non-linear transform blocks are L1,L2,L3 . (b) Graph-based Feature Aggregation Block used as advanced non-linear transforms. (c) Lightweight Conv Block for early feature extraction and reduced complexity.
Method
Candidates
Selection & Degree
Receptive Field
Complexity
Canonical operators
Dynamic CNN
k×k window
keep-all; degree =k2
bounded by window
O(1)+O(Nk2)
Deformable CNN
offset-enlarged k×k window
keep-all; degree =k2
offset-enlarged local window
O(Nk)+O(Nk)
Window Attention
L×L window
keep-all; degree =L2
bounded by window
O(1)+O(NL2)
Transformer (global)
all nodes
keep-all; degree =N
full
O(1)+O(N2)
GNN-based LIC
Table 1: Connectivity-oriented comparison. Notation: N denotes the total number of nodes/pixels; k the side length of the convolution kernel; L the side length of the attention/GNN window; and K the average neighborhood size (connectivity and in-degrees for GNNs). Computational cost is reported as construction + aggregation . “Construction” counts candidate search and similarity calculation.
Figure 3
Figure 5: PSNR and MS-SSIM R-D curves on the Kodak Dataset.
Method
Complexity
BD‑rate (%) ↓
Params (M)
FLOPs (T)
Enc‑Lat. (s)
Dec‑Lat. (s)
Peak‑Mem. (G)
Kodak
Tecnick
CLIC
VTM‑9.1 [ 7 ]
-
-
-
-
-
0.00
0.00
0.00
ELIC (CVPR’22) [ 26 ]
33.29
1.74
0.583
0.335
1.50
-5.95
-7.68
-1.20
MLIC++ (ICML’23W) [ 29 ]
116.48
2.64
0.508
0.547
2.08
-15.14
-17.23
-14.41
TCM-L (CVPR’23) [ 47 ]
75.89
3.74
0.647
0.542
7.73
-13.42
-10.93
-9.10
FTIC (ICLR’24) [ 38 ]
69.78
2.38
> 10
> 10
4.90
-14.83
-14.39
-10.70
Table 2: Quantitative Comparisons of leading LIC methods. BD‑rates are evaluated against VTM‑9.1. FLOPs, peak memory and decoding time are measured on 2K‑resolution images.
Figure 6: (Top) Averaged Effective Receptive Fields of state-of-the-art LIC models across the 24 Kodak images. (Bottom) Single-image Effective Receptive Field for Kodak image 23, demonstrating the adaptivity of our GLIC model. More results are in the supplementary.
Figure 7: Spatial redundancy versus RMS-G scores. Image023 from the Kodak dataset (left) and the RMS-G maps for the second- and third-stage graphs in GLIC (right). Brighter regions have higher RMS-G scores, indicating lower spatial redundancy and larger in-degrees.
Figure 8: Visual Comparisons with other methods. More results are in the supplementary.
Variant
Kodak
CLIC
Tecnick
w/o Global (Local only)
-16.98
-15.71
-18.89
w/o Local (Global only)
-15.62
-15.02
-17.51
Reverse (Local+Global)
-18.77
-18.21
-20.79
Global+Local (Ours)
-19.29
-18.71
-21.69
Table 3: Ablations on dual-scale graph flexibility.
Scoring Strategy
Channel Pooling
Kodak
CLIC
Tecnick
None
None
-16.97
-16.21
-18.21
Local Entropy
RMS
-17.05
-17.01
-18.97
Rescaling Residual
RMS
-17.67
-17.03
-19.68
Rescaling Residual
Mean
-18.23
-17.82
-20.39
Sobel Gradient
Mean
-18.02
-17.42
-20.62
Sobel Gradient
RMS
-19.29
-18.71
-21.69
Table 4: Ablations on complexity scoring and channel pooling.
Department of Electronic Engineering, Tsinghua University · Department of Automation, Tsinghua University · State Key Laboratory of Space Network and Communications +1