ViewSkater

ViewSkater is a fast, cross-platform image viewer written in Rust & Iced. It aims to alleviate the challenges of exploring and comparing numerous images. Linux, macOS and Windows are currently supported.

Note: This (iced) version is in maintenance mode. Active development is moving to the egui version, which offers better performance and a simpler codebase.

Features

• GPU-based image rendering powered by wgpu
• Dynamic image caching on CPU or GPU memory
• Continuous image rendering via key presses and the slider UI
• Dual pane view for side-by-side image comparison
• Supports image formats supported by the image crate (JPG, PNG, GIF, BMP, TIFF, WebP, QOI, TGA, etc.)
• JPEG 2000 support (optional feature): View JP2, J2K, and J2C files
• Supports viewing images inside ZIP, RAR, and 7z (LZMA2 codec) files
• Renders images up to 8192×8192 px (larger images are resized to fit)
• COCO annotation support (optional feature): Display bounding boxes and segmentation masks with dual rendering modes (polygon/pixel)
• Selection feature (optional feature): Select and export subsets of images from large datasets

Installation

Download the pre-built binaries from the releases page, or build it locally:

cargo run

To see debug logs while running, set the RUST_LOG environment variable:

RUST_LOG=viewskater=debug cargo run

To build a full release binary for packaging or distribution:

cargo build --release

Building with optional features:

# Build with COCO annotation support
cargo build --release --features coco

# Build with selection feature
cargo build --release --features selection

# Build with JPEG 2000 support
cargo build --release --features jp2

# Build with multiple features
cargo build --release --features coco,selection,jp2

See docs/bundling.md for full packaging instructions.

Linux icon setup

On GNOME 46+ (Ubuntu 24.04+), the taskbar icon requires installing a .desktop file and icon:

mkdir -p ~/.local/share/icons/hicolor/256x256/apps
cp assets/icon_256.png ~/.local/share/icons/hicolor/256x256/apps/viewskater.png
gtk-update-icon-cache -f ~/.local/share/icons/hicolor/
cp resources/linux/viewskater.desktop ~/.local/share/applications/

Edit the Exec= line in the installed .desktop file to point to your binary:

sed -i "s|Exec=.*|Exec=/path/to/viewskater %f|" \
    ~/.local/share/applications/viewskater.desktop

For the AppImage, use the AppImage path instead:

sed -i "s|Exec=.*|Exec=/path/to/ViewSkater.AppImage %f|" \
    ~/.local/share/applications/viewskater.desktop

Usage

Drag and drop an image or a directory of images onto a pane, and navigate through the images using the A / D keys or the slider UI. Use the mouse wheel to zoom in/out of an image.

In dual-pane mode (Ctrl + 2), the slider syncs images in both panes by default. You can switch to per-pane sliders by selecting the "Controls -> Controls -> Toggle Slider" menu item or pressing the Space bar.

COCO Annotations (when built with --features coco): Drag and drop a COCO-format JSON annotation file onto the app. The app will automatically search for the image directory in common locations:

• Same directory as the JSON file
• images/, img/, val2017/, or train2017/ subdirectories
• Single subdirectory if only one exists in the JSON's parent directory

If the image directory is not found automatically, a folder picker will prompt you to select the image directory manually.

Image Selection (when built with --features selection): Mark images for dataset curation while browsing. Press S to mark an image as selected (green badge), X to exclude it (red badge), or U to clear the mark. Export your selections to JSON using Cmd+E (macOS) or Ctrl+E (Windows/Linux). Selection states are automatically saved and persist across sessions.

Shortcuts

Action	macOS Shortcut	Windows/Linux Shortcut
Show previous / next image	Left / Right or A / D	Left / Right or A / D
Continuous scroll ("skate" mode)	Shift + Left / Right or Shift + A / D	Shift + Left / Right or Shift + A / D
Jump to first / last image	Cmd + Left / Right	Ctrl + Left / Right
Toggle UI (slider + footer)	Tab	Tab
Toggle single / dual slider	Space	Space
Select Pane 1 / 2 (Dual slider)	1 / 2	1 / 2
Open folder in Pane 1 / 2	Alt + 1 / 2	Alt + 1 / 2
Open file in Pane 1 / 2	Shift + Alt + 1 / 2	Shift + Alt + 1 / 2
Open file (Single pane)	Cmd + O	Ctrl + O
Open folder (Single pane)	Cmd + Shift + O	Ctrl + Shift + O
Toggle single / dual pane mode	Cmd + 1 / 2	Ctrl + 1 / 2
Toggle fullscreen mode	F11	F11
Close all panes	Cmd + W	Ctrl + W
Exit	Cmd + Q	Ctrl + Q

Documentation

• Bundling & Packaging - Build for Linux, macOS, Windows
• Replay Mode - Automated benchmarking with CLI options

Resources

• Website
• egui version

Acknowledgments

ViewSkater's slider UI was inspired by the open-source project emulsion.

License

ViewSkater is licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.