Free tools Windows power users keep installed
One-click scans. No signup required.
FBCNN is an open-source PyTorch project for removing JPEG compression artifacts in color and grayscale images. Its distinguishing feature is a user-adjustable quality factor: you can favor stronger artifact reduction or preserve more fine detail. The official repository documents separate testing paths for ordinary JPEGs, double-compressed images, and real-world color images, but its scripts alone are not a complete Linux installation guide.
What is FBCNN?
FBCNN stands for flexible blind convolutional neural network. It is designed to restore JPEG images without requiring you to know the compression quality factor beforehand. The project describes a two-part approach: predict a quality factor from the image, then use that factor to guide reconstruction. As the authors put it, “FBCNN decouples the quality factor from the JPEG image via a decoupler module and then embeds the predicted quality factor into the subsequent reconstructor module through a quality factor attention block for flexible control.”
The project’s official implementation is written in PyTorch and is released under the Apache 2.0 license. See the official FBCNN repository for its code and documentation.
How do I remove JPEG artifacts in Linux with FBCNN?
Use the official PyTorch repository’s testing script that matches your image type. The repository documents these commands:
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
| Use case | Documented command |
|---|---|
| Grayscale JPEG | python main_test_fbcnn_gray.py |
| Grayscale double-JPEG degradation model | python main_test_fbcnn_gray_doublejpeg.py |
| Color JPEG | python main_test_fbcnn_color.py |
| Real-world color JPEG | python main_test_fbcnn_color_real.py |
These are repository-documented test entry points, not a complete setup recipe. The README does not establish current Linux distribution support, required dependencies, minimum memory, or GPU requirements. Check the repository’s current instructions and configure its input and output paths before running a script; do not assume a command will work unchanged in every environment.
The repository also documents python main_train_fbcnn.py for training. Training is a separate task from applying the model to images.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Can FBCNN restore a JPEG compressed more than once?
Yes, the project includes a double-JPEG testing path, and its authors describe two approaches for difficult double-compression cases: FBCNN-D, which automatically corrects the dominant quality factor, and FBCNN-A, which uses training augmentation based on a double-JPEG degradation model.
Double compression can be especially difficult when the two JPEG passes use misaligned 8×8 block grids. Cropping an image and saving it again as JPEG is one way that misalignment can arise. The README notes that FBCNN may predict the later compression’s quality factor even when artifacts from the earlier, lower factor dominate; manual factor adjustment is one remedy described by the project. Its discussion of failures in other blind methods is the authors’ account of the methods they address, not a guarantee about every restoration tool.
Recommended Free Tools
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Can I control how much detail FBCNN preserves?
Yes. The predicted quality factor can be adjusted to change the balance between removing visible compression artifacts and retaining fine detail. A stronger cleanup preference can suppress artifacts more aggressively, while a detail-preserving preference can leave more compression traces. There is no universally best setting: inspect the output at the image size where it will be used, especially around edges and textures.
Does FBCNN work on color and grayscale images?
The official repository provides distinct scripts for grayscale and color inputs, plus a real-world color-image path. Those script names show that the project supports testing these cases; they do not establish that every image will improve or that results will be equally good across content and compression histories.
Rank #4
- Dual Converters, Infinite Potential:Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
What do published FBCNN figures tell you?
The Open Model Zoo documentation reports 71.922 MParams and 1420.78235 GFLOPs for its FBCNN model documentation. It reports 34.34 dB PSNR and 0.99 SSIM on LIVE_1 for both the original and converted models. These are figures in that model-documentation and dataset context, not expected results for an arbitrary input image or a measure of speed on a particular Linux computer. The underlying paper, “Towards Flexible Blind JPEG Artifacts Removal,” by Jiaxi Jiang, Kai Zhang, and Radu Timofte, appeared at ICCV 2021, pages 4997–5006.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is FBCNN a good fit for your Linux workflow?
- Consider it if you want a research-backed, open-source JPEG restoration model with color and grayscale paths and a control for the artifact-removal/detail trade-off.
- Check the setup first if you need a ready-to-run desktop application, a guaranteed distribution-specific install, batch-processing instructions, or known hardware requirements; the cited project documentation does not establish those details.
- Evaluate your own images if the source has been cropped and recompressed, since double-JPEG alignment and which compression factor dominates can affect the restoration problem.
The project links a Gradio demo through Hugging Face Spaces as a convenience, but hosted demo availability can change and does not replace a verified local Linux workflow. The official project code and instructions are at GitHub; model figures are documented by the Open Model Zoo FBCNN page.
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.

