TIRMamba: A Thermal-Prior-Modulated State-Space Network for Sub-Million-Parameter Infrared Image Super-Resolution
Organizations: Department of Electrical Engineering, National Chung Hsing University, Taichung 402202, Taiwan · College of Computing and Informatics, Providence University, Taichung 433303, Taiwan
Abstract
Infrared image super-resolution is currently led by Mamba-based networks with 26 to 37 million parameters, which are difficult to deploy on the airborne and handheld platforms where thermal imaging is most needed. This paper presents TIRMamba, a network with 896K to 910K parameters for single-channel thermal imagery. A Thermal Prior Highway computes gradient, local-contrast and spectral cues once at the input and, through one adapter per residual group, modulates a weight-tied bidirectional state-space trunk and gates its dual-scale detail branch; a tri-path reconstruction adds the learned residual to a bicubic radiometric baseline. Because the standard benchmark provides only 265 infrared training images and evaluates fusion products on full images, we train with a replay strategy: grayscale DIV2K pre-training followed by fine-tuning on 64-pixel patches drawn with equal probability from the infrared and natural corpora. At scale factor 4, TIRMamba matches the strongest protocol-trained methods on both official test sets with 29 to 40 times fewer parameters and 2.8 to 9.4 times lower latency; at scale factor 2 it gives the highest SSIM on both. A variant with prior-conditioned selectivity, TIRMamba-Rad, corrects a 3 dB raw-thermal failure of an intermediate size-invariant design and gives the best results at scale factor 4 on raw-thermal, unmanned-aerial-vehicle and independent-sensor test sets. Code and trained models will be released at https://github.com/julian135707/TIRMamba upon acceptance.
Figures & tables
| Method | #Params (K) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| results-A | results-C | results-A | results-C | ||||||
| PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | ||
| Bicubic | – | 37.6846 | 0.9270 | 38.6222 | 0.9391 | 33.2435 | 0.8313 | 33.8318 | 0.8504 |
| PSRGAN [ 16 ] | 2,414 | 39.2146 | 0.9429 | 40.0543 | 0.9539 | 34.4595 | 0.8540 | 35.1023 | 0.8715 |
| SwinIR [ 27 ] | 11,752 | 38.6899 | 0.9374 | 39.5215 | 0.9492 | 34.4321 | 0.8537 | 35.0329 | 0.8710 |
| ShuffleMixer-T [ 9 ] | 108 | 39.0465 | 0.9414 | 39.8766 | 0.9527 | 34.5440 | 0.8550 | 35.1640 | 0.8723 |
| Method | #Params (K) / | ( ) | ( ) | ||||
| FLOPs (G) | Time (ms) | Mem. (MB) | FLOPs (G) | Time (ms) | Mem. (MB) | ||
| ShuffleMixer-T [ 9 ] | 108 / 113 | 2.6 | 8.2 | 28 | 0.8 | 7.9 | 26 |
| PSRGAN ‡ [ 16 ] | 313 / 350 | 12.9 | 6.1 | 93 | 9.6 | 4.6 | 79 |
| CATANet [ 11 ] | 477 / 535 | 11.5 | 63.5 | 843 | 4.3 | 31.0 | 250 |
| ATD-light [ 12 ] | 753 / 769 | 19.3 | 132.2 | 349 | 5.5 | 63.9 | 108 |
| MambaIR [ 4 ] | 20,422 / 20,570 | 401.7 | 354.1 | 955 | 103.4 | 92.0 | 353 |
| Method | M3FD-heldout (raw thermal) | HIT-UAV (zero-shot aerial) | LLVIP (independent sensor) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | PSNR | SSIM | |
| Bicubic | 46.2755 | 0.9919 | 36.7248 | 0.9450 | 44.3950 | 0.9868 | 36.4883 | 0.9381 | 45.3021 | 0.9935 | 36.2073 | 0.9651 |
| PSRGAN ‡ [ 16 ] | 45.8364 | 0.9861 | 36.5073 | 0.9370 | 43.6266 | 0.9786 | 36.5489 | 0.9265 | 44.3612 | 0.9860 | 34.5795 | 0.9456 |
| IRSRMamba ∗ [ 7 ] | 50.9925 | 0.9960 | 41.2956 | 0.9718 | 47.0329 | 0.9915 | 39.5859 | 0.9591 | 49.5494 | 0.9957 | 40.9524 | 0.9822 |
| GPSMamba ∗ [ 8 ] | 50.9514 | 0.9960 | 41.0734 | 0.9711 | 47.0719 | 0.9915 | 39.6305 | 0.9598 | 49.7891 | 0.9958 | 41.0220 | 0.9831 |
| Training strategy | results-A | results-C |
|---|---|---|
| Zero-shot (DIV2K only, no adaptation) | 39.0305/0.9441 | 40.2767/ 0.9549 |
| From scratch (M3FD only, 500k) | 39.0587/0.9420 | 39.9128/0.9530 |
| Fine-tune on M3FD only, patch 16 | 39.2115/0.9431 | 40.0940/0.9540 |
| Fine-tune on M3FD only, patch 64 (transfer) | 39.3078 /0.9440 | 40.2298/0.9548 |
| Matched-corpus control (Sec. V-A ) | ||
| 265 natural images | 39.1337/0.9442 | 40.2585/ 0.9549 |
| Variant | #Par. (K) | results-A | results-C | / |
|---|---|---|---|---|
| Full model | 912.9 | 38.646/0.9436 | 39.388/0.9544 | 0.122/0.124 |
| raster scan (no serpentine) | 912.9 | 38.014/0.9423 | 37.824/0.9522 | 0.426/1.639 |
| w/o detail branch (DDB) | 894.5 | 35.574/0.9066 | 36.910/0.9371 | 0.201/0.478 |
| untied bi-SSM | 1132.1 | 37.277/0.9431 | 38.042/0.9538 | 0.497/0.551 |
| loss (no FFT term) | 912.9 | 38.820/0.9433 | 39.774/0.9542 | 0.057/0.026 |
| w/o Spectral Prior Branch | 889.1 | 39.208/0.9436 | 40.174/0.9544 | 0.009/0.002 |