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Restore Old Images with Transformers

In this example, we will demonstrate how to use the SwinIR library and fal-serverless to restore images. SwinIR is an image restoration library that uses a Swin Transformer to restore images. The Swin Transformer is a type of neural network architecture that is designed for processing images. The Swin Transformer is similar to the popular Vision Transformer (ViT) architecture, but it uses a hierarchical structure that allows it to process images more efficiently. SwinIR uses a pre-trained Swin Transformer to restore images.

Step 1: Install fal-serverless and authenticate

pip install fal-serverless
fal-serverless auth login

More info on authentication.

Step 2: Import fal_serverless and define requirements

In a new python file,, import fal_serverless and define a requirements list:

from fal_serverless import isolated, cached

requirements = [

Step 3: Define cached functions

Next, we define two functions that will be cached using the @cached decorator.

def download_model():
import os
model_path = "/data/models/swinir/003_realSR_BSRGAN_DFO_s64w8_SwinIR-M_x4_GAN.pth"
if not os.path.exists(model_path):
print("Downloading SwinIR model.")
url = ""
os.system(f"mkdir -p /data/models/swinir && cd /data/models/swinir && wget {url}")

def clone_repo():
import os
repo_path = "/data/repos/swinir"
if not os.path.exists(repo_path):
print("Cloning SwinIR repository")
os.system("git clone --depth=1 /data/repos/swinir")

The download_model function downloads the SwinIR model if it is not already present in the /data/models/swinir directory. The clone_repo function clones the SwinIR repository from GitHub if it is not already present in the /data/repos/swinir directory.

Step 4: Define the isolated function

Next, we define the run function that will be executed using fal-serverless.

@isolated(requirements=requirements, machine_type="GPU", keep_alive=1800)
def run(data):
import os
import sys
import io
import uuid
from PIL import Image

# Setup

imagedir = str(uuid.uuid4())
os.system(f'mkdir -p {imagedir}')
if os.path.exists("results/swinir_real_sr_x4"):
os.system('rm -rf results/swinir_real_sr_x4/*')
imagename = str(uuid.uuid4())
img =
if img.mode in ("RGBA", "P"):
img = img.convert("RGB")
basewidth = 256
wpercent = (basewidth/float(img.size[0]))
hsize = int((float(img.size[1])*float(wpercent)))
img = img.resize((basewidth,hsize), Image.ANTIALIAS)"{imagedir}/0.jpg", "JPEG")
command = (
f"python --task real_sr --folder_lq {imagedir} --scale 4 "
"--model_path /data/models/swinir/003_realSR_BSRGAN_DFO_s64w8_SwinIR-M_x4_GAN.pth"
os.system(f"rm -rf {imagedir}")
with open('results/swinir_real_sr_x4/0_SwinIR.png', "rb") as f:
result_data =
return result_data

In this function, we first call the clone_repo and download_model functions to ensure that we have the SwinIR repository and model downloaded. We then create a directory for the input image and save the image as a JPEG file. We then execute the SwinIR command to restore the image. Finally, we read the restored image and return it in bytes.

Step 5: Restore an image

Finally, we try to restore an image:

with open("test_image.png", "rb") as f:
data =
result = run(data)

with open("result.png", "wb") as f:

Here, we're openning test_image.png and passing its bytes to the isolated run function. We then save the result in result.png.


This example demonstrates how to use the SwinIR model for image restoration by using fal-serverless. This type of image restoration process can be performed in an isolated and scalable manner, while using minimal local resources.