The main idea of the model is to integrate the FourierUnit into the GatedCNN pipeline in order to strengthen the model’s global perception with minimal computational overhead.

The FourierUnit adds feature processing in the frequency domain, expanding the effective receptive field, while the GatedCNN provides efficient local modeling and control of information flow through a gating mechanism. Their combination allows merging global context and computational efficiency within a compact SISR architecture.

TODO:

Fix trt inference

Showcase:

show pics

gdrive

Model structure:

figsr

GDB FU

Main blocks and their changes relative to the originals:

GatedCNN — borrowed from the MambaOut repository with the following changes:
- Linear replaced with Conv to avoid unnecessary permute operations;
- one of the linear layers replaced with a Conv 3×3, which improves quality without a significant increase in computational cost;
- LayerNorm replaced with RMSNorm for speed and greater stability;
- DConv replaced with InceptionConv.
InceptionConv — a modified version of the block from InceptionNeXt:
- DConv replaced with standard convolutions;
- kernel sizes increased following the findings of PLKSR;
- the shortcut replaced with FourierUnit, which improves convergence because a residual connection is already present inside GatedCNN.
FourierUnit — a modified version of the block from SFHformer:
- BatchNorm replaced with RMSNorm, which works better with the small batch sizes typical for SISR;
- structural changes made for correct export to ONNX;
- post-normalization added, since without it training instability and NaN values were observed in the context of GatedCNN.

Metrics:

Metrics were computed using PyIQA, except for those starting with “bs”, which were calculated using BasicSR.

Esrgan DF2K:

Dataset	SSIM-Y	PSNR-Y	TOPIQ	bs_ssim_y	bs_psnr_y
BHI100	0.7150	22.84	0.5694	0.7279	24.1636
psisrd_val125	0.7881	27.01	0.6043	0.8034	28.3273
set14	0.7730	27.67	0.6905	0.7915	28.9969
urban100	0.8025	25.71	0.6701	0.8152	27.0282

FIGSR BHI:

Dataset	SSIM-Y	PSNR-Y	TOPIQ	bs_ssim_y	bs_psnr_y
BHI100	0.7196	22.83	0.5723	0.7327	24.1549
psisrd_val125	0.7911	26.97	0.6095	0.8065	28.2946
set14	0.7769	27.70	0.7036	0.7952	29.0221
urban100	0.8056	25.80	0.6725	0.8185	27.1170

Performance 3060 12gb:

Model	input_size	params ↓	avg_inference ↓	fps ↑	memory_use ↓
ESRGAN	1024x1024	~16.6m	~2.8s	0.3483220866736526	8.29GB
FIGSR	1024x1024	~4.4m	~1.64s	0.6081749253740837	2.26GB

Training

To train, choose one of the frameworks and place the model file in the archs folder:

NeoSR — figsr_arch.py → neosr/archs/figsr_arch.py. Config
- Uncomment lines 14–17, 694 and 705.
- Comment out line 703.
traiNNer-redux — figsr_arch.py → traiNNer/archs/figsr_arch.py. Config
- Uncomment lines 11 and 694.
BasicSR — figsr_arch.py → basicsr/archs/figsr_arch.py. Config
- Uncomment lines 19 and 694.

Inference:

Resselt install

shell

uv venv  --python=3.12
source .venv/bin/activate
uv pip install "resselt==1.3.1" "pepeline==1.2.3"

main.py

python main.py --input_dir urban/x4 --output_dir urban/x4_scale --weights 4x_FIGSR.safetensors

Contacts:

discord

enhancr-dev/figsr

Fourier Inception Gated Super Resolution