Single command to screenshot all KDE virtual desktops into one large image.

vd-tops.sh

#!/usr/bin/env bash
# SPDX-License-Identifier: CC-BY-SA-3.0

# Script to take a screenshot of all the desktops and stitch them together into
# single image.

# Only slightly modified from an answer on AskUbuntu
#   https://askubuntu.com/a/951399/1167939
# by user derHugo
#   https://askubuntu.com/users/423684/derhugo
# Licensed under CC BY-SA 3.0

# Slight modifications made by Chindraba
#   https://askubuntu.com/users/1167939/chindraba
#   https://github.com/chindraba-work

# Added the creation of the directory, with a timestamp in the name
# Added the config settings to replace the setting in the montage command
# Doubled up on the motage command to create both the final image in both
# JPEG and PNG formats
# Added an explicit background (transparent in PNG) to accomodate multple
#   monitor setups where the resolutions don't come out even. As in one
#   monitor at 1920x1200 and a second at 1920x1080. That will be saved as
#   an image 3840x1200 even though there is a 1920x120 band missing in the
#   space of one monitor. White, the default was off-putting in too many cases.

desk_size='3840x1200' # the resolution of a single virtual desktop (all monitors as one image)
grid_size='3x2' # the arrangement, columns x rows, of the VDs into the final image
png_bgcolor='rgba(255,255,255,0)' # background color to use on .png final image, transparancy available
jpeg_background='rgb(21,21,21)' # background color to use on .jpg final image, transparancy NOT available


save_dir="capture-$(date --utc +%Y.%m.%d-%H.%M.%S)"
mkdir ~/$save_dir
dnum=$(xdotool get_num_desktops)
desk=0
while [[ "$desk" -lt "$dnum" ]]; do
    xdotool set_desktop $desk;
    sleep 2;
    maim --format png /dev/stdout > ~/$save_dir/desktop$desk.png;
    desk=$((desk+1));
done
pushd ~/$save_dir >/dev/null
montage  desktop*.png  -tile "$grid_size" -background $png_bgcolor -geometry "$desk_size"+1+1 workspaces.png
montage  desktop*.png  -tile "$grid_size" -background $jpeg_background -geometry "$desk_size"+1+1 workspaces.jpg
popd >/dev/null