From Sentinel-2 to 1-m Imagery: Real-World ×10 Cross-Sensor Super-Resolution via Visual Autoregressive Modeling
Authors: Tailai Chen, Yuluxin Fu, Jie Deng, Shu Luo, Yanan Wu, Danfeng Hong
Organizations: College of Water Resources and Intelligence Engineering, China Agricultural University, Beijing 100083, China · College of Information and Electrical Engineering, China Agricultural University, Beijing 100083, China · Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China · University of Chinese Academy of Sciences, Beijing 100049, China · Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China · Beijing Key Laboratory of Precision Forestry, Beijing Forestry University, Beijing 100091, China · School of Automation, Southeast University, Nanjing 210096, China
Reconstructing 1-m imagery from Sentinel-2 combines two difficulties. The input and the reference are observed by different satellites, which differ in spatial resolution, spectral response, radiometry, acquisition time, and local geometry, so no synthetic degradation operator links them. The required magnification of ten in each spatial dimension also far exceeds the factors of two to four at which remote sensing super-resolution is usually developed. We study this real-world ×10 problem using YREB-SR, which pairs 2022 Sentinel-2 RGB composites with 2022 Jilin-1 RGB references resampled to a 1-m grid over the Yangtze River Economic Belt. The benchmark contains 11,559 geographically matched scene pairs, with 6,409, 2,135, and 3,015 assigned to training, validation, and testing, respectively. We develop CrossVAR, a visual autoregressive model that predicts the 1-m latent as a nine-scale hierarchy conditioned on the Sentinel-2 input and estimates the remaining quantization residual with a diffusion refiner run without injected noise. Complete 1600 × 1600 scenes are reconstructed in overlapping windows that start on the Sentinel-2 pixel grid, as every training patch does, and every window is decoded at the size on which the decoder was trained before the windows are blended with Gaussian weights. On all 3,015 test scenes, CrossVAR achieves 27.60 dB PSNR, 0.7725 SSIM, 0.1451 LPIPS, and 7.15 FID, the best value of each metric among the compared methods. These results establish a strong autoregressive baseline for large-scale cross-sensor reconstruction. To facilitate reproducibility, the source code and implementation are publicly available at https://github.com/SHANOAL/RSSR.
Figures & tables
Fig. 1: PSNR and model time per complete 1600×1600 test scene of YREB-SR. Marker area grows with the number of parameters.
Fig. 2: Spatial distribution of the 11,559 cross-sensor scene pairs in YREB-SR across the Yangtze River Economic Belt. Colors indicate the training, validation, and test subsets, while blue lines represent the Yangtze River network.
Attribute
Setting
Cross-sensor image pairs
Sensor pair
Sentinel-2 RGB → 1-m RGB reference
Spectral channels
B4–B3–B2 → R–G–B
Nominal GSD
10 m → 1 m ( ×10 )
Full-scene grids
160×160→1600×1600 pixels
Training grids
40×40→400×400 pixels
TABLE I: Summary of the YREB-SR Benchmark
Fig. 3: Overview of CrossVAR. Panels 1 to 3 reconstruct one window. The condition encoder maps the Sentinel-2 window, resized to the output grid, to one condition token per latent position, and the next-scale transformer predicts nine code maps from 1×1 to 25×25 . Deterministic residual refinement (DRR) estimates the residual of the codes without injected noise, and the frozen VQ decoder outputs the 1-m window. Aligned window decoding (AWD) in panel 4 starts every window of a complete scene on the input pixel grid, reconstructs it through panels 1 to 3, and blends the decoded windows with Gaussian weights.
Method
Batch
Steps
EDSR-baseline
16
150k
SwinIR
8
150k
TTST
4
150k
Real-ESRGAN+
4
150k
TABLE II: Training Budgets of the Retrained Baselines
Method
Representation
PSNR (dB) ↑
SSIM ↑
LPIPS ↓
FID ↓
Reconstruction and continuous-representation methods
Bicubic
Interpolation
14.5051
0.4626
0.9534
215.9498
EDSR-baseline [ 10 ]
CNN
24.0986
0.6596
0.6831
68.2941
SwinIR [ 11 ]
Transformer
24.5078
0.6706
0.6371
58.0257
TTST [ 12 ]
RS transformer
24.7157
0.6739
0.6201
48.9027
Thera [ 19 ]
Neural field
25.2978
0.6855
0.5679
37.8334
TABLE III: Full-Scene ×10 Reconstruction on YREB-SR. All Reported Scores Use the Same 3,015 Test Pairs. Best and Second-Best Results Are Bold and Underlined.
Baseline
Δ PSNR (dB)
Δ SSIM
Δ LPIPS
Better (%)
EDSR-baseline
+3.50
+0.113
− 0.538
100
SwinIR
+3.09
+0.102
− 0.492
100
TTST
+2.89
+0.099
− 0.475
100
Thera
+2.30
+0.087
− 0.423
100
Real-ESRGAN+
+5.64
+0.155
− 0.182
100
Satlas-SR
+4.30
+0.140
− 0.070
100
TABLE IV: Scene-Wise Comparison of CrossVAR with the Retrained Baselines on the 3,015 Test Scenes. Differences Are CrossVAR Minus Baseline, and the Last Column Gives the Share of Scenes on Which CrossVAR Is Better in All Three Metrics.
Fig. 4: Scene-wise analysis on the 3,015 test scenes. (a) Radially averaged power spectrum of the reconstructions relative to the Jilin-1 reference. The dotted line marks the Nyquist frequency of the Sentinel-2 input. (b) Mean PSNR in quartiles of the mean gradient magnitude of the reference. (c) PSNR gain of CrossVAR over Thera at the scene centers.
Method
Parameters (M)
Precision
Model time
I/O-inclusive
Peak memory
Bicubic
–
CPU
26.44
127.91
–
EDSR-baseline
1.39
FP32
2.92
384.07
124
SwinIR
11.99
FP32
106.41
440.12
499
TTST
21.76
FP32
189.63
503.57
1,632
Thera
5.85
FP32
303.50
717.46
4,534
Real-ESRGAN+
20.32
FP32
44.96
446.78
2,283
TABLE V: Full-Scene Efficiency. Times Are Milliseconds per Scene and Memory Is Peak MiB.
Fig. 5: Coarse-to-fine reconstruction. (a) Four test windows decoded after the 13×13 , 18×18 , and 25×25 code maps and after deterministic residual refinement, with PSNR against the Jilin-1 reference. (b) Mean PSNR after every scale on 427 validation scenes, with the interquartile range shaded.
Fig. 6: Complete-scene and local-detail comparisons on four test scenes. Seven learned methods are shown between the Sentinel-2 input and the Jilin-1 reference, and red and blue boxes mark the enlarged regions. Only the Sentinel-2 input is contrast-stretched for display.
Fig. 7: PSNR change of single windows on 427 validation scenes when the window start is moved away from the Sentinel-2 pixel grid. The outlined cell is the aligned start.
DRR
AWD
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
25.93
0.6960
0.1796
10.29
✓
26.27
0.7076
0.1695
9.81
✓
27.01
0.7509
0.1539
6.38
✓
✓
27.60
0.7725
0.1451
7.15
TABLE VI: Ablation of Deterministic Residual Refinement (DRR) and Aligned Window Decoding (AWD) on the 3,015 Test Scenes
Windows
Fusion
Decoding
PSNR ↑
SSIM ↑
LPIPS ↓
FID ↓
On grid
None
Scene
26.39
0.7406
0.1804
10.98
Off grid
Latent
Scene
26.27
0.7076
0.1695
9.81
Off grid
Latent
Window
26.51
0.7145
0.1595
8.94
Off grid
RGB
Window
26.45
0.7131
0.1558
7.96
On grid
Latent
Scene
27.26
0.7645
0.1609
9.08
On grid
Latent
Window
27.58
0.7708
0.1506
8.21
TABLE VII: Complete-Scene Assembly Rules with τ=0 on the 3,015 Test Scenes
Department of Agricultural and Biological Engineering, Mississippi State University · North Mississippi Research and Extension Center, Mississippi State University
University of Idaho, Moscow, Idaho, USA · NCEAS, UC Santa Barbara, Santa Barbara, California, USA · Fujian Agriculture and Forestry University, Fuzhou, China