How to capture screenshot from the Linux terminal

Linux distributions normally include a default screen capture program tailored to their specific desktop environment. For example, KDE uses Spectacle and GNOME utilizes Shutter. These programs are designed to work seamlessly with their respective desktop environments and offer convenient keyboard shortcuts for quick access.

For users operating within a command-line interface, such as an SSH session, a command-line tool is required to capture a screenshot. While dedicated tools like Scrot are available, ImageMagick's import tool is a more versatile option. ImageMagick is a powerful and flexible command-line image processing toolkit.

1. Open your preferred terminal application..
2. Install imagemagick for your Linux distribution.

   $ sudo apt update && sudo apt install --assume-yes imagemagick # Ubuntu and Debian

3. Use ImageMagick's import tool to capture a screenshot from the terminal.

   $ import -window root -pause 3 Screenshot-$(date --iso-8601=seconds).png

   Capture options:

   • -window root: capture the entire screen
   • -pause 3: add a 3 seconds delay before creating screen shot, perhaps to close unnecessary application etc.
   • Screenshot-$(date –iso-8601=seconds).png: target file name to save the screenshot to, using date command to produce a timestamped filename.

   More options for import:

   $ import --help
   Version: ImageMagick 7.0.8-53 Q16 x86_64 2019-07-09 https://imagemagick.org
   Copyright: © 1999-2019 ImageMagick Studio LLC
   License: https://imagemagick.org/script/license.php
   Features: Cipher DPC HDRI Modules OpenMP(3.1)
   Delegates (built-in): bzlib freetype heic jng jp2 jpeg lcms ltdl lzma openexr png tiff webp xml zlib
   Usage: import [options ...] [ file ]
   
   Image Settings:
     -adjoin              join images into a single multi-image file
     -border              include window border in the output image
     -channel type        apply option to select image channels
     -colorspace type     alternate image colorspace
     -comment string      annotate image with comment
     -compress type       type of pixel compression when writing the image
     -define format:option
                          define one or more image format options
     -density geometry    horizontal and vertical density of the image
     -depth value         image depth
     -descend             obtain image by descending window hierarchy
     -display server      X server to contact
     -dispose method      layer disposal method
     -dither method       apply error diffusion to image
     -delay value         display the next image after pausing
     -encipher filename   convert plain pixels to cipher pixels
     -endian type         endianness (MSB or LSB) of the image
     -encoding type       text encoding type
     -filter type         use this filter when resizing an image
     -format "string"     output formatted image characteristics
     -frame               include window manager frame
     -gravity direction   which direction to gravitate towards
     -identify            identify the format and characteristics of the image
     -interlace type      None, Line, Plane, or Partition
     -interpolate method  pixel color interpolation method
     -label string        assign a label to an image
     -limit type value    Area, Disk, Map, or Memory resource limit
     -monitor             monitor progress
     -page geometry       size and location of an image canvas
     -pause seconds       seconds delay between snapshots
     -pointsize value     font point size
     -quality value       JPEG/MIFF/PNG compression level
     -quiet               suppress all warning messages
     -regard-warnings     pay attention to warning messages
     -repage geometry     size and location of an image canvas
     -respect-parentheses settings remain in effect until parenthesis boundary
     -sampling-factor geometry
                          horizontal and vertical sampling factor
     -scene value         image scene number
     -screen              select image from root window
     -seed value          seed a new sequence of pseudo-random numbers
     -set property value  set an image property
     -silent              operate silently, i.e. don't ring any bells
     -snaps value         number of screen snapshots
     -support factor      resize support: > 1.0 is blurry, < 1.0 is sharp
     -synchronize         synchronize image to storage device
     -taint               declare the image as modified
     -transparent-color color
                          transparent color
     -treedepth value     color tree depth
     -verbose             print detailed information about the image
     -virtual-pixel method
                          Constant, Edge, Mirror, or Tile
     -window id           select window with this id or name
                          root selects whole screen
   
   Image Operators:
     -annotate geometry text
                          annotate the image with text
     -colors value        preferred number of colors in the image
     -crop geometry       preferred size and location of the cropped image
     -encipher filename   convert plain pixels to cipher pixels
     -geometry geometry   preferred size or location of the image
     -help                print program options
     -monochrome          transform image to black and white
     -negate              replace every pixel with its complementary color
     -quantize colorspace reduce colors in this colorspace
     -resize geometry     resize the image
     -rotate degrees      apply Paeth rotation to the image
     -strip               strip image of all profiles and comments
     -thumbnail geometry  create a thumbnail of the image
     -transparent color   make this color transparent within the image
     -trim                trim image edges
     -type type           image type
   
   Miscellaneous Options:
     -debug events        display copious debugging information
     -help                print program options
     -list type           print a list of supported option arguments
     -log format          format of debugging information
     -version             print version information
   
   By default, 'file' is written in the MIFF image format.  To
   specify a particular image format, precede the filename with an image
   format name and a colon (i.e. ps:image) or specify the image type as
   the filename suffix (i.e. image.ps).  Specify 'file' as '-' for
   standard input or output.

4. Verify the output file to ensure the screenshot was captured correctly.

   $ file Screenshot-*.png
   Screenshot-2019-07-22T13:59:02+08:00.png: PNG image data, 800 x 610, 8-bit/color RGB, non-interlaced

5. Use other ImageMagick tools to further process the saved screenshot (optional).