woelper/oculante

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

Flipbook

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

Inspection

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

File Management

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.

Correct color channel display:

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.

Installation

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

cargo install oculante

Linux

Arch Linux

pacman -S oculante

NixOS

environment.systemPackages = [
    pkgs.oculante
];

openSUSE

zypper install oculante

Flatpak

flatpak install flathub io.github.woelper.Oculante

BSD

FreeBSD

pkg install oculante

NetBSD

pkgin install oculante

Windows

Scoop

scoop install extras/oculante

Build Dependencies

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

Updates

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

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

Features

Image format support

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 (Krita files)

Platform support

Linux
Mac
Windows
FreeBSD
NetBSD

Misc features

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

Misc examples:

Viewing EXIF data

Extracting a signature

Roadmap

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

Attribution

Test / benchmark / screenshot pictures:

https://unsplash.com/@mohsen_karimi

https://unsplash.com/@frstvisuals

https://unsplash.com/@eberhardgross

Privacy pledge

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

License

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.

Extras

Cargo Features

turbo (on by default), the turbojpeg library will not be used to open jpeg images. You won't need Nasm to be installed.
file_open will enable/disable a OS-native file open dialog. This pulls in additional dependencies and is enabled by default. Disabling it will enable a custom file dialog. This will probably the default in the future.
notan/glsl-to-spirv (default) uses the spirv shader compiler
notan/shaderc uses shaderc as a shader compiler. Longer build time.
update (default) enable app updating.

Default Shortcuts

Shortcuts:

mouse wheel = zoom

left mouse,middle mouse = pan

ctrl + mouse wheel = prev/next image in folder

Right mouse pick color from image (in paint mode)

T = AlwaysOnTop

F = Fullscreen

I = InfoMode

E = EditMode

Right = NextImage

Home = FirstImage

End = LastImage

Left = PreviousImage

R = RedChannel

G = GreenChannel

B = BlueChannel

A = AlphaChannel

U = RGBChannel

C = RGBAChannel

V = ResetView

Minus = ZoomOut

Equals = ZoomIn

Key1 = ZoomActualSize

Key2 = ZoomDouble

Key3 = ZoomThree

Key4 = ZoomFour

Key5 = ZoomFive

LShift + C = CompareNext

LShift + Left = PanLeft

LShift + Right = PanRight

LShift + Up = PanUp

LShift + Down = PanDown

Delete = DeleteFile

LShift + Delete = ClearImage

RBracket = LosslessRotateRight

LBracket = LosslessRotateLeft

LControl + C = Copy

LControl + V = Paste

LControl + O = Browse

Q = Quit

Z = ZenMode

woelper / oculante