Open Image Viewer

Open Image Viewer (OIViewer) is a hardware-accelerated C++26 image viewer for Windows and Linux, built for accurate display, fast browsing, and keyboard-driven use.

Simplicity and performance guide its design. OIViewer embraces modern operating systems, graphics APIs, and C++ features, adopting technologies that are generally available on its CI servers.

Website · Downloads · A word from the author

Features

• Fast browsing with read-ahead loading, sorting, and slideshows.
• Zoom, pan, fullscreen, automatic scrolling, and high-DPI support.
• Animated GIF, APNG, and WebP playback, plus subimage navigation.
• Texel grids, pixel values, image properties, and EXIF metadata.
• Gamma, exposure, saturation, grayscale, transparency, and filtering controls.
• Selection, cropping, rotation, flipping, clipboard support, and saving.
• Direct3D 11, Vulkan, and OpenGL backends with automatic GPU selection.
• Configurable keyboard shortcuts and commands; press F1 for active bindings.

Image formats

• Common images: JPEG (JPG/JPEG/JIF/JPE), PNG/APNG, GIF, WebP, TIFF (TIF/TIFF), and Windows/OS/2 BMP.
• Documents, textures, and icons: Photoshop PSD/PSB, DirectDraw Surface DDS, Windows icons (ICO/ICON), and cursors (CUR).
• Other raster formats: JPEG XR (JXR/WDP/HDP), Kodak Photo CD (PCD), ZSoft Paintbrush (PCX), portable graymaps (PGM/PGMRAW) and pixmaps (PPM/PPMRAW) in ASCII or binary form, Targa (TGA/TARGA), Sun Raster (RAS), Amiga IFF/LBM, SGI (SGI/RGB/RGBA/BW), Macintosh PICT (PICT/PCT/PIC), Dr. Halo (CUT), and X11 Pixmap (XPM).
• Camera RAW: the RAW codec lists 3FR, ARW, BAY, BMQ, CAP, CINE, CR2, CRW, CS1, DC2, DCR, DRF, DSC, DNG, ERF, FFF, IA, IIQ, K25, KC2, KDC, MDC, MEF, MOS, MRW, NEF, NRW, ORF, PEF, PTX, PXN, QTK, RAF, RAW, RDC, RW2, RWL, RWZ, SR2, SRF, SRW, STI, and X3F. The bundled LibRaw version also implements Canon CR3 decoding. Compatibility depends on the camera model and encoding.
• Save: JPEG (JPG/JPEG) and PNG.

Getting started

Download a package from GitHub Releases, extract it, and launch OIViewer. Press Ctrl+O or pass an image or folder on the command line.

Scroll to zoom, right-drag to pan, Alt+left-drag to select, and Shift+scroll to browse images. Alt+scroll switches subimages; middle-click toggles automatic scrolling.

Common shortcuts

These are the shipped defaults; press F1 for the full list of active bindings.

Shortcut	Action
Ctrl+O	Open an image
Left / Right or Page Up / Page Down	Previous / next image in the folder
Home / End	First / last image in the folder
Space	Start or stop the slideshow
Alt+Enter	Toggle fullscreen
Numpad * / Numpad /	Original size / fit to window
G	Toggle the texel grid
Grave (`)	Toggle image information
Ctrl+C / Ctrl+V	Copy the selected area / paste an image
C	Crop to the selected area
H / V	Flip horizontally / vertically
Ctrl+S	Save an image
Ctrl+F1 / Ctrl+F2 / Ctrl+F3	Sort by name / modification date / extension

Command line

OIViewer "path/to/image-or-folder"
OIViewer --renderer Vulkan "photo.jpg"
OIViewer --help

With no graphics options, Windows prefers D3D11, then Vulkan, and Linux prefers Vulkan, then GL. These are also the renderers included in default builds. Windows can include OpenGL as a final choice.

Configuration

Edit the files in Resources/Configuration beside the executable, then restart OIViewer:

• Settings.json: viewing and browsing settings.
• KeyBindings.json: keyboard shortcuts.
• Commands.json: command definitions.

Automatic reloading of externally modified images is supported on Windows only.

Runtime requirements

64-bit Windows or Linux x86_64, with a driver supporting Direct3D 11, Vulkan 1.1+, or OpenGL 3.0+, as included in the build.

• Windows: 7 SP1, 8, 8.1, 10, or 11. Windows 11 24H2 or newer is recommended.
• Linux: official binaries require glibc 2.39+ and a Wayland desktop.

Windows 7 SP1 also requires the platform update, D3DCompiler_47, and Universal C runtime.

Build from source

Use Git, CMake 3.24+, Ninja, and a C++26-capable toolchain. Clang/clang-cl 21 or newer is recommended.

git clone --recursive https://github.com/OpenImageViewer/OpenImageViewer.git
cd OpenImageViewer

For an existing checkout, initialize dependencies with git submodule update --init --recursive.

Windows

Install the Windows SDK and use an x64 Visual Studio developer shell:

cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release `
    -DCMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl
cmake --build build --parallel

MSVC with Visual Studio 2026 or newer is also supported. For its generator, omit the Ninja and Clang options and build with cmake --build build --config Release in a separate build directory.

CMake can download Vulkan build tools; install 7-Zip for extraction or provide an existing Vulkan SDK.

Linux

Install development packages for GTK 3, Wayland, X11, OpenGL/EGL, and Vulkan, plus pkg-config and Wayland protocol tools.

cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++
cmake --build build --parallel

Output is in build/bin, or build/bin/Release with a Visual Studio generator. See the CI workflows for dependency setup.

Build options

Pass -DNAME=ON or -DNAME=OFF to CMake:

Option	Purpose
OIV_BUILD_TESTS	Build test binaries; default ON
OIV_BUILD_RENDERER_D3D11	Direct3D 11; Windows only
OIV_BUILD_RENDERER_VK	Vulkan
OIV_BUILD_RENDERER_GL	OpenGL

Default renderers are listed above; keep at least one enabled. Codec switches are documented in ImageCodec's CMake configuration.

Packaging

Run ./publish.ps1 (pwsh ./publish.ps1 on Linux) to create a .7z package. It uses Ninja and RelWithDebInfo, builds in publish, and requires 7-Zip. Add -EnablePackage $false to build without an archive.

License

OIViewer is distributed under the OpenImageViewer License, which permits sharing and modification with attribution for noncommercial use.