glview

GLView

Lightning-fast image viewer with synchronized split-screen zooming & panning. Designed mainly for algorithm developers who demand pixel-precise and color-accurate output.

Quick Start

pipx install glview
glview --help
glview <your-image-file>

# [LINUX] If there's a failure due to missing libGL.so
sudo apt update
sudo apt install libegl1 mesa-utils libegl1-mesa-dev

# [MACOS] If there's a failure due to missing EXIF libraries
brew install exiv2

Usage

Usage: glview [options] [image.(pgm|ppm|pnm|png|jpg|..)] ...

  options:
    --fullscreen            start in full-screen mode; default = windowed
    --split 1|2|3|4         display images in N separate tiles
    --url <address>         load image from the given web address
    --downsample N          downsample images N-fold to save memory
    --normalize off|max|... exposure normalization mode; default = off
    --filter                use linear filtering; default = nearest
    --idt sRGB|P3|...       input image color space; default = sRGB
    --odt sRGB|P3|...       output device color space; default = sRGB
    --debug 1|2|...|r|g|b   select debug rendering mode; default = 1
    --verbose               print extra traces to the console
    --verbose               print even more traces to the console
    --version               show glview version number & exit
    --help                  show this help message

  keyboard commands:
    mouse wheel             zoom in/out; synchronized if multiple tiles
    + / -                   zoom in/out; synchronized if multiple tiles
    mouse left + move       pan image; synchronized if multiple tiles
    left / right            pan image; synchronized if multiple tiles
    PageUp / PageDown       cycle through images on active tile
    ctrl + left / right     cycle through images on all tiles
    s                       split window into 1/2/3/4 tiles
    1 / 2 / 3 / 4           select active tile for per-tile operations
    p                       in 2-tile layouts, flip the image pair
    h                       reset zoom/pan/exposure to initial state
    f                       toggle fullscreen <-> windowed
    g                       cycle through gamma curves: sRGB/HLG/HDR10
    n                       cycle through exposure normalization modes
    k                       cycle through gamut compression modes
    t                       toggle nearest <-> linear filtering
    e                       adjust exposure within [-2EV, +2EV]
    b                       toggle between HDR/LDR exposure control
    i                       toggle input color space: sRGB/P3/Rec2020
    o                       toggle output color space: sRGB/P3/Rec2020
    r                       [per-image] rotate 90 degrees clockwise
    l                       [per-image] toggle linearization on/off
    m                       [per-tile] toggle mirroring x/y/both/none
    a                       [per-tile] toggle autoexposure on/off
    z                       [per-tile] toggle sharpening on/off
    c                       [per-tile] toggle tonemapping on/off
    x                       [per-tile] print image information (EXIF)
    w                       write a screenshot as both JPG & PFM
    u                       reload currently shown images from disk
    d                       drop the currently shown image(s)
    del                     delete the currently shown image
    space                   toggle debug rendering on/off
    q / esc / ctrl+c        terminate

  supported file types:
    .pnm
    .pgm
    .ppm
    .pfm
    .png
    .jpg
    .jpeg
    .bmp
    .tif
    .tiff
    .insp
    .npy
    .raw
    .exr
    .hdr

  available debug rendering modes (--debug M):
    1 - red => overexposed; blue => out of gamut; magenta => both
    2 - shades of green => out-of-gamut distance
    3 - normalized color: rgb` = rgb / max(rgb)
    4 - red => above diffuse white; magenta => above peak white
    r - show red channel only, set others to zero
    g - show green channel only, set others to zero
    b - show blue channel only, set others to zero
    l - show image as grayscale (perceived brightness)

  glview version 1.19.1.