qmk_firmware/users/bbaserdem/keymap-bitmaps/cropBmp

#!/bin/bash

# Copyright 2021 Batuhan Başerdem
# <baserdem.batuhan@gmail.com> @bbaserdem
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Goes through all the files and turns them into strips in their respective folder
if [ -z "${1}" ] ; then
  echo 'No argument; defaulting to script directory.'
  target_dir="$(dirname "${0}")"
elif [ -d "${1}" ] ; then
  echo "Targeting files in '${1}'."
  target_dir="${1}"
else
  echo 'Argument is not directory.'
  exit 1
fi

output_dir="${target_dir}/splitImages"
mkdir -p "${output_dir}"

for this_image in "${target_dir}/"*.bmp ; do
  echo "Found '${this_image}'."
  this_name="$(basename "${this_image%%.bmp}")"
  convert "${this_image}" -crop 'x8' "${output_dir}/${this_name}"_%d.bmp
done