A no-nonsense hardware-accelerated image viewer

Oculante's vision is to be a fast, unobtrusive, portable image viewer with a wide range of supported image formats while also offering image analysis and basic editing tools.

• Free of charge, bloat-free, ad-free, privacy-respecting open source application
• Fast opening of images, fast startup
• Available for Windows, Mac, Linux, FreeBSD, and NetBSD
• Supports a wide range of image formats
• Caches images for faster reloading
• Can display unassociated channels correctly (If your image uses alpha and color channels to encode data in a special way)
• Lets you pick pixels to see their location and color values.
• Offers basic nondestructive editing such as cropping, resizing, painting, rotating, blur, and more!
• SIMD-accelerated image editing

With configurable caching, Oculante can quickly step through image sequences:

Get information about pixel values and position, with precise picking:

You can use the File Manager built into Oculante to do basic tasks such as accessing recent images or stepping through a virtual list of files so you can compare easily. There is also a dedicated compare option to flip between images, remembering zoom level and position.

Images may contain color information that is masked by the alpha channel. Although it is present you will not see it since usually RGB values are multiplied with the A channel when displayed. Oculante allows you to inspect all channels individually and see color data without transparency applied.

Get started with Oculante by downloading the executable relevant to your platform from the releases page. The download size is kept small (currently around 25MB) by linking dependencies statically by default. Packages for ARM Linux are also built, please feel free to open an issue if you want your operating system of choice supported!

For those looking to manage Oculante through a package manager, please see the options below.

cargo install oculante

• Arch Linux

pacman -S oculante

• NixOS

environment.systemPackages = [
    pkgs.oculante
];

• openSUSE

zypper install oculante

• Flatpak

flatpak install flathub io.github.woelper.Oculante

• FreeBSD

pkg install oculante

• NetBSD

pkgin install oculante

• Scoop

scoop install extras/oculante

Linux (Debian):

sudo apt-get install libxcb-shape0-dev libxcb-xfixes0-dev libgtk-3-dev libasound2-dev nasm cmake

Windows: Install Nasm from https://www.nasm.us/pub/nasm/releasebuilds/2.15.05/win64/

Mac: brew install nasm

Oculante only gets updated when it improves something for you. You'll still see new releases about every month or two! To stay up to date you can use the update button in settings, or download the new releases executable! Updates are also managed through your package manager if you installed through one.

Uninstalling Oculante is a quick process, just delete the executable and delete the data folder. You can find the data folder in the relevant location for your operating system below.

• Windows: ~/AppData/Local/.oculante
• Mac: ~/Library/Application Support/oculante
• Linux & BSD: ~/.local/share/oculante

• bmp
• gif (animation support and correct timing)
• hdr, tonemapped
• ico
• icns (via rust-icns)
• jpeg
• jpeg2000 (via jpeg2k, feature "j2k", on by default)
• png
• pnm
• tga
• jxl (JPEG XL, via jxl-oxide)
• avif
• tiff (via tiff with additional float/half support)
• webp (via libwebp-sys - image had very limited format support)
• farbfeld
• DDS (DXT1-5, via dds-rs)
• psd (via psd)
• svg (via resvg)
• exr (via exr-rs), tonemapped
• RAW (via quickraw - nef, cr2, dng, mos, erf, raf, arw, 3fr, ari, srf, sr2, braw, r3d, nrw, raw). Since raw is a complex field without true standards, not all camera models are supported.
• ppm
• HEIC/HEIF (via libheif-rs). Enabled on Windows builds, but optional dependency on MacOS and Linux - available behind heif flag.
• qoi
• kra (currently only available on the krita_support branch)

• Linux
• Mac
• Windows
• FreeBSD
• NetBSD

• Image info (i) (pixel position, color info)
• Threaded image loading
• Fit image to view
• Window can be configured to be always on top - helpful to keep image as reference
• Low cpu usage
• Non-destructive painting and operator stack - edit very large images interactively by scaling them down first, then deleting the downscale operator once you want to export.
• Metafile support: Edit stack can be saved into a metafile which will be auto-loaded and applied when loading the original.
• Pretty fast startup / loading time
• Configurable image caching (Select how many images to keep in memory)
• Display unassociated / unpremultiplied alpha (u)
• Lossless JPEG editing: Crop, rotate, mirror without recompressing data
• Light/Dark theme and follow system theme mode
• Network listen mode: Start with oculante -l port and oculante will switch to receive mode. You can then pipe raw image data to that port, for example using nc localhost 8888 < image.jpg. Image types will be auto-detected. If you pipe image sequences, these will be played at about 30 fps so you can pipe videos to it. This can be useful to visualize images from a headless system.
• EXIF support: Load metadata if present
• Load files from stdin: pipe your data with cat image | oculante -s

Viewing EXIF data

Extracting a signature

• Tests and benchmarks
• Read EXIF for image rotation
• Investigate PVR / ETC support
• Brighness/gamma adjust for HDR
• Redesigning the User Interface

Test / benchmark / screenshot pictures:

https://unsplash.com/@mohsen_karimi

https://unsplash.com/@frstvisuals

https://unsplash.com/@eberhardgross

Oculante does in no way collect or send anonymous or non-anonynmous user data or statistics. Oculante is and will remain free and open source. There will never be ads. There are only two instances where oculante interacts with the network, and both never happen without being triggered by the user:

• Updating the application (must be triggered manually from settings)
• Listening for incoming images on a custom port (must be set on command line)

In addition, Oculante saves some settings locally, for example:

• UI accent color
• Keybindings
• Vsync preferences
• Keep view offset/scale
• Whether the directory index bar is displayed
• Recent files

This project is MIT licensed, but some parts such as the LUTs in res/LUT are under the GPL license. As a result, we're making our entire source code public. If you would like to use Oculante without publishing your source code, please remove any GPL-licensed components and their references.