Minimal Image Viewer

The most 🪶 LIGHTWEIGHT image viewer available for Windows

Minimal Image Viewer is an open-source image viewer and editor (now with OCR), prioritizing performance and minimalism. With a compiled size as low as ~20.5kb. It is able to open png photos of over 100mb in seconds (depending on your specs).

💾 Download the latest version here.

For a stripped-down 21kb version, you can try the stable stripped .exe

Key Features

Viewing & Navigation

• Comprehensive Format Support: Leverages Windows Imaging Component (WIC) to support JPEG, PNG, BMP, GIF, TIFF, ICO, WebP, HEIF, AVIF, and many RAW formats (.cr2, .nef, .dng, etc.) with the proper codecs installed.

• Animated Image Support: Plays animated formats (like GIF) by decoding all frames and their metadata-defined delays.

• Asynchronous Pre-loading: Intelligently pre-loads the next and previous images in a directory on background threads for instantaneous browsing.

• Flexible Sorting: Sorts all images in the current directory by Name, Date Modified, or File Size in ascending or descending order.

• Smooth Viewing:

  • Smooth zoom (Ctrl + Mouse Wheel).

  • Pan by clicking and dragging the image.

  • Fit to Window (Ctrl+0 / Double-Click).

  • Actual Size (100%) (Ctrl+*).

• Configurable Interface:

  • Backgrounds: Switch between Grey (default), Black, White, or a transparent checkerboard.

  • Always on Top: Toggle to keep the window on top.

  • Default Zoom: Set the default zoom to "Fit to Window" or "Actual Size (100%)" in Preferences.

OCR

• Whole Image OCR: Press 'q' to OCR the entire image.
• Area OCR: Press 'w' to OCR a selected area.

Editing & Tools

• Non-Destructive Editing: All edits (crop, rotate, flip, grayscale) are previewed in real-time without altering the original file until you explicitly save.

• Visual Crop: Press 'C' to enable crop mode. Click and drag to select a region, then press Enter to apply the crop. The save operation will only save the cropped area.

• High-Quality Resize: Resize images to new dimensions with aspect-ratio locking, using a high-quality Fant interpolation scaler.

• Rotate & Flip: Rotate images in 90° increments or flip them horizontally. All changes are saved correctly.

• Grayscale Filter: Instantly apply or remove a non-destructive grayscale filter.

• Eyedropper Tool: Hold the Alt key to activate an eyedropper. It displays the RGB and Hex value of the pixel under your cursor. Click to copy the Hex value to your clipboard.

• Image Effects: Click to open a box with sliders to adjust the contrast, brightness, and saturation.

Data & File Management

• Detailed Properties Window: Opens a separate window showing extensive file properties and detailed EXIF metadata, including camera, lens, and shot settings (F-stop, ISO, Exposure, etc.).

• OSD Overlay: Press 'I' to toggle an on-screen display (OSD) with key file and image data for quick reference.

• File Operations:

  • Save (Ctrl+S): Overwrites the original file with any applied edits (rotate, flip, crop, grayscale).

  • Save As (Ctrl+Shift+S): Save the edited image to a new file in PNG, JPEG, or BMP format.

  • Delete (Delete): Securely moves the current file to the Recycle Bin.

  • Clipboard: Copy the image file or bitmap to the clipboard (Ctrl+C) and paste an image or file path from the clipboard (Ctrl+V).

  • Drag & Drop: Open an image by dragging it onto the window.

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Why Minimal Image Viewer?

This viewer is built on the philosophy of "do one thing and do it well," offering distinct advantages in resource-constrained or OpSec-sensitive environments.

• 🔒 Secure & Private:

  • Zero Telemetry: The application performs no network activity and contains no tracking or telemetry, ensuring complete privacy.

  • Minimal Attack Surface: Relies only on hardened, native Windows APIs (Direct2D, WIC) and avoids large third-party libraries.

  • Safe File Handling: Uses atomic save operations via temporary files to prevent data corruption and deletes to the Recycle Bin to prevent accidental data loss.

• 🚀 Efficient & Portable:

  • Lightweight: Compiles to a tiny executable (~100 KB) and uses minimal RAM (<10 MB for most images).

  • Portable Settings: Saves all preferences (background color, window size, etc.) to a minimal_image_viewer_settings.ini file in the same directory, making it fully portable and leaving no trace in the Windows Registry.

  • Hardware Accelerated: Uses Direct2D for all rendering, ensuring smooth, GPU-accelerated scaling, panning, and animations.

Comparison with Alternatives

Feature	Minimal Image Viewer	Windows Photos	IrfanView / XnView
Executable Size	~100 KB	~50 MB+ (UWP)	~3-5 MB+
Telemetry / Network	None	Yes	Optional
Settings	Portable .ini	Registry / UWP	Portable or Registry
Animated GIF Support	Yes	Yes	Yes (with plugins)
Open Source	Yes	No	No

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Installation and Usage

Download the .exe from the Releases page and run it. No installation is required.

To set it as your default viewer, see the Default Viewer Instructions.

Hotkeys

File Operations

• Open Image: Ctrl+O or Drag & Drop

• Save (Overwrite): Ctrl+S

• Save As: Ctrl+Shift+S

• Delete Image: Delete (Moves to Recycle Bin)

• Copy Image: Ctrl+C

• Paste Image: Ctrl+V

• Open File Location: Right-Click → "Open File Location"

• Properties: Right-Click → "Properties..."

Image Navigation

• Next/Previous Image: Right Arrow / Left Arrow

• Pan Image: Click and Drag (when zoomed in)

• Sort By: Right-Click → "Sort By" → (Name/Date/Size)

Viewing

• Zoom In/Out: Ctrl+ / Ctrl- or Mouse Wheel

• Fit to Window: Ctrl+0 or Double-Click

• Actual Size (100%): Ctrl+*

• Toggle Fullscreen: F11

• Exit: Esc

Editing & Tools

• Rotate Clockwise: Up Arrow

• Rotate Counter-Clockwise: Down Arrow

• Flip Horizontal: F

• Toggle Crop Mode: C

• Apply Crop: Enter (while in crop mode)

• Cancel Crop: Esc (while in crop mode)

• Toggle Grayscale: Right-Click → "Edit" → "Grayscale"

• Resize Image: Right-Click → "Edit" → "Resize Image..."

• Toggle OSD: I

• Eyedropper Tool: Hold Alt (Click to copy hex code)

• Preferences: Right-Click → "Preferences..."

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Technical Highlights

• Core Technology: Built with modern C++ and native Win32 APIs. All rendering is hardware-accelerated via Direct2D (ID2D1HwndRenderTarget) and text is rendered with DirectWrite for superior clarity.

• WIC Pipeline: All image I/O and transformations are handled by the Windows Imaging Component (WIC).

  • Loading: IWICBitmapDecoder and IWICFormatConverter are used to load and convert any WIC-supported format to a Direct2D-compatible pixel format (GUID_WICPixelFormat32bppPBGRA).

  • Editing: Edits are applied by chaining WIC components before saving:

    • IWICBitmapFlipRotator (for rotation/flipping)

    • IWICBitmapClipper (for cropping)

    • IWICBitmapScaler (for resizing)

    • IWICFormatConverter (for grayscale)

  • Animation: IWICBitmapDecoder::GetFrameCount() is used to detect multi-frame images. Frame delays are read from the metadata (/grctlext/Delay) and a WM_TIMER event is used to cycle frames.

• Concurrency: Image loading is fully asynchronous on a separate std::thread to keep the UI responsive. A custom WM_APP_IMAGE_LOADED message is posted to the main window thread to safely transfer the decoded image. Directory pre-loading (StartPreloading) uses two additional threads for the next/previous images.

• State Management: Window state and user preferences are persisted in a portable minimal_image_viewer_settings.ini file using GetPrivateProfileIntW and WritePrivateProfileStringW.

Build Process

1. Open MinimalImageViewer-VS.vcxproj in Visual Studio 2022.

2. Set the build configuration to "Release" and "x64".

3. Build the solution.

The project links against the following standard Windows libraries:

user32.lib, gdi32.lib, comdlg32.lib, shlwapi.lib, windowscodecs.lib, ole32.lib, shell32.lib, propsys.lib, oleaut32.lib, d2d1.lib, dwrite.lib, advapi32.lib.

Contributing

Contributions are welcome! This project adheres to a minimalist and security-focused philosophy.

1. Fork the repository.

2. Create a feature branch (git checkout -b feature/YourFeature).

3. Commit your changes (git commit -m "Add YourFeature").

4. Push to the branch (git push origin feature/YourFeature).

5. Open a Pull Request.