🎮 JXR to PNG Converter

Just a note before the rest of the description which was completely written by Google Gemini: this is basically just a GUI with some commodity features i really needed in order to share screenshots i made with NVIDIA Share with my friends on Discord, telegram and so on... The core of the project is - jxr_to_png by ledoge, which actually coded the program. Also thanks to hdrfix by bvibber.

A desktop application that automatically monitors NVIDIA screenshot directories for HDR .jxr files and converts them to high-quality SDR .png format with professional tone mapping.

Built with PyQt5 — features a premium dark-mode UI, system tray integration, multi-language support, and multi-threaded parallel conversion.

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✨ Features

• 🔄 Automatic Monitoring — Watches NVIDIA screenshot folders recursively via Watchdog, converting new .jxr files on the fly.
• 🎨 Professional Tone Mapping — Two-stage pipeline: HDR decode → Hable tone mapping with boosted saturation for vivid, social-media-ready colors.
• 🌐 Multi-Language Support — Available in 10 languages (IT, EN, ES, DE, FR, PT, JA, ZH, KO, RU) with automatic system language detection and in-app language selector.
• 🤫 Customizable Background Mode — Toggle between "Minimize to Tray" or "Close App" on window close.
• ⚡ Parallel Conversion — Multi-threaded processing (3 workers) for blazing fast batch conversions.
• 🛡️ Smart File Detection — Automatically detects and fixes fake .jxr files that are actually mislabeled PNGs (a known NVIDIA bug).
• 🖥️ Premium Dark UI — Glassmorphism-inspired interface with purple/blue accents, smooth animations, and a polished system tray experience.
• 📦 Single Instance Guard — Prevents multiple instances from running simultaneously.
• 🔧 Persistent Configuration — Settings stored in %APPDATA% for seamless operation even when installed in C:\Program Files.

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🌐 Supported Languages

Language	Code	Flag
Italiano	it	🇮🇹
English	en	🇬🇧
Español	es	🇪🇸
Deutsch	de	🇩🇪
Français	fr	🇫🇷
Português	pt	🇧🇷
日本語	ja	🇯🇵
中文	zh	🇨🇳
한국어	ko	🇰🇷
Русский	ru	🇷🇺

The app automatically detects your system language on first launch. You can change the language at any time from the in-app selector — it switches instantly without restart.

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📸 How It Works

The conversion pipeline uses a two-step process to ensure maximum color fidelity:

┌──────────┐      ┌──────────────┐      ┌─────────────┐      ┌──────────┐
│  .jxr    │ ──▶  │ jxr_to_png   │ ──▶  │   hdrfix    │ ──▶  │  .png    │
│  (HDR)   │      │  (decode)    │      │ (tone map)  │      │  (SDR)   │
└──────────┘      └──────────────┘      └─────────────┘      └──────────┘

1. Decode: jxr_to_png.exe decodes the JPEG XR HDR file into a raw HDR PNG.
2. Tone Map: hdrfix.exe applies the Hable filmic tone mapping curve with +20% saturation boost, producing an SDR image that looks vivid even after social media compression (Telegram, WhatsApp, etc.).

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🚀 Installation

Prerequisites

• Python 3.8+
• Windows 10/11

From Source

# Clone the repository
git clone https://github.com/TargetMisser/JXRConverter.git
cd JXRConverter

# Install dependencies
pip install -r requirements.txt

# Run the application
python main.py

Build MSI Installer

You can build an MSI installer natively using cx_Freeze:

pip install cx_Freeze
python setup.py bdist_msi

This will create an standard Windows .msi package in the dist/ directory that handles:

1. Installing the app to C:\Program Files\JXRConverter\
2. Creating all necessary shortcuts
3. Registering uninstallation entries

External Tools Required

You need to place these executables in the project root before building:

Tool	Source	Purpose
jxr_to_png.exe	ledoge/jxr_to_png	Decodes JPEG XR HDR files to PNG
hdrfix.exe	bvibber/hdrfix	Applies tone mapping (HDR → SDR)

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⚙️ Configuration

On first launch, configure:

• Watch Folder: The NVIDIA screenshot directory to monitor (default: C:\Users\<you>\Videos\NVIDIA)
• Tool Path: Path to the folder containing jxr_to_png.exe and hdrfix.exe
• Language: Auto-detected from your system, or pick manually from the dropdown

Settings are persisted in %APPDATA%\JXRConverter\config.json.

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🏗️ Project Structure

JXRConverter/
├── main.py              # Entry point, single-instance guard, High-DPI
├── ui.py                # PyQt5 GUI (dark mode, system tray, config, i18n)
├── converter.py         # Watchdog + ThreadPool conversion engine
├── translations.py      # Multi-language i18n system (10 languages)
├── styles.py            # QSS stylesheet (glassmorphism dark theme)
├── resources.py         # Inline SVG icons for window and tray
├── requirements.txt     # Python dependencies
└── build_and_install.ps1 # Automated build & deploy script

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🙏 Credits & Acknowledgments

External Tools

This project would not be possible without these excellent open-source tools:

• jxr_to_png by ledoge — JPEG XR to PNG decoder with HDR metadata support. Used as the first stage of the conversion pipeline.
• hdrfix by bvibber (Brion Vibber) — HDR to SDR tone mapping tool with multiple algorithms (Hable, ACES, Reinhard). Used as the second stage for professional-grade color conversion.

Libraries

• PyQt5 — Cross-platform GUI framework by Riverbank Computing.
• Watchdog — Filesystem monitoring library.
• PyInstaller — Used for packaging the standalone executable.

Development

• Built with the assistance of Antigravity by Google DeepMind.

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📝 License

This project is licensed under the MIT License — see the LICENSE file for details.

Note: The external tools (jxr_to_png.exe, hdrfix.exe) are not included in this repository and are subject to their own licenses. Please refer to their respective repositories for license information.

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🐛 Known Issues & Notes

• NVIDIA occasionally saves screenshots with a .jxr extension that are actually PNG files internally. The app automatically detects and handles this case.
• The Hable tone mapping with +20% saturation is tuned to counteract the color desaturation that occurs when sharing images on platforms like Telegram and WhatsApp.
• jxr_to_png.exe already uses multi-threading internally (6 threads for decoding), so the app limits parallel workers to 3 to avoid CPU saturation.

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📋 Changelog

v1.4 — Swiss Minimalist UI & MSI Installer

• Redesigned the UI using the solid "Swiss Minimalist" design system.
• Transitioned colors to deep black (#101217) and electric blue (#2B6CEE).
• Replaced the standalone PyInstaller packaging with a clean MSI Windows Installer via cx_Freeze.

v1.3 — UI Redesign (Premium Glassmorphism)

• Complete UI overhaul using The Midnight Luminary design system
• New neon purple and electric blue accent colors
• Fully adopted dark glassmorphism effects for cards and console

v1.2 — Multi-Language Support

• Added internationalization (i18n) with support for 10 languages
• Auto-detects system language on first launch
• In-app language selector with instant switching (no restart needed)
• New styled QComboBox for language selection

v1.1 — Tray Toggle

• Added toggle for minimize-to-tray vs close behavior

v1.0 — Initial Release

• Automatic HDR screenshot monitoring and conversion
• Two-stage conversion pipeline with Hable tone mapping
• Premium dark-mode UI with system tray integration