Slice image into grid, by width of number

crop.sh

#!/usr/bin/env bash

# Crop image using the CSS method top-right-bottom-left
# Uses get_tmp_hash.py

declare -i e_c=1 img_w=0 img_h=0 i=0 x=0 c_t=0 c_r=0 c_b=0 c_l=0 arglen=0 form_w=0 form_h=0 form_x=0 form_y=0 gui_input=0
declare -a args=() im_cmd=()
declare img mime_type jpeg_re='jpe?g' jpeg_quality tmp_file num_re='^[0-9]+$' output_name

parse_gui_args(){
	eval "${*}" || exit 1
	handle_num "$c_t"
	handle_num "$c_b"
	handle_num "$c_l"
	handle_num "$c_r"
	if (( c_t == 0 && c_b == 0 && c_l == 0 && c_r == 0)) ; then
		exit 1
	fi
	return 0
}

handle_num(){
	local num="${*}"
	if [[ ! "$num" =~ $num_re ]] ; then
		echo "invalid format: $num" 1>&2
		exit 2
	fi
	return 0
}

while getopts ":t:r:b:l:a:o:g" options ; do
	case "$options" in
		a)	handle_num "$OPTARG"; c_t=$OPTARG; c_b=$OPTARG; c_l=$OPTARG; c_r=$OPTARG;;
		t)	handle_num "$OPTARG"; c_t=$OPTARG;;
		r)	handle_num "$OPTARG"; c_r=$OPTARG;;
		b)	handle_num "$OPTARG"; c_b=$OPTARG;;
		l)	handle_num "$OPTARG"; c_l=$OPTARG;;
		o)	output_name="${OPTARG##**/}";;
		g)	gui_input=1;;
		*)  exit 1;;
	esac
done
args+=( "${@:OPTIND}" )
arglen=${#args[@]}

if ((gui_input == 1)) ; then
	if ! parse_gui_args "$(
		rofi -p '' -mesg 'Crop cli arguments (eval):' -lines 9 -dmenu -i -width 50% -location 6 -disable-history \
			<<< 'c_t=0; c_b=0; c_l=0; c_r=0;'
	)"; then
		exit 1
	fi
fi

for (( ; x < arglen; x++ )); do
	img="$(realpath "${args[x]}")"
	if [[ $? -ne 0 || ! -f "$img" || ! -r "$img" ]] ; then
		echo "file is invalid: $img"  1>&2
		e_c=2
		continue
	fi
	mime_type="$(file -b --mime-type "$img")"
	if [[ ! "$mime_type" =~ ^image/ ]] ; then
		echo "file is not an image: ${args[x]}" 1>&2
		file -b --mime-type "$img" 1>&2
		continue
	fi
	echo "$(basename "$img"): $mime_type" 1>&2
	i=0
	for n in $(identify -format "%w %h" "$img") ; do
		i=$((i+1))
		if ((i==1)) ; then
			img_w=$n
		elif ((i==2)) ; then
			img_h=$n
		fi
	done
	e_c=$?
	if (( e_c != 0 || (img_w+img_h) == 0 )); then
		echo ERROR 1>&2
		e_c=1
		continue
	fi
	echo -e "Width:\t${img_w}px" 1>&2
	echo -e "Height:\t${img_h}px" 1>&2
	# default values - diff. for every argument (image)
	form_w=$img_w
	form_h=$img_h
	form_x=0
	form_y=0
	if ((c_t > 0)) ; then
		form_h=$((form_h - c_t))
		form_y=$c_t
	fi
	if ((c_l > 0)) ; then
		form_w=$((form_w - c_l))
		form_x=$c_l
	fi
	if ((c_r > 0)) ; then
		form_w=$((form_w - c_r))
	fi
	if ((c_b > 0)) ; then
		form_h=$((form_h - c_b))
	fi
	if [[ "$mime_type" =~ $jpeg_re ]] ; then
		jpeg_quality="$(identify -format '%Q' "$img" || echo -n 100)"
		if [[ ! "$jpeg_quality" =~ $num_re ]] || ((jpeg_quality < 1 || jpeg_quality > 100)) ; then
			jpeg_quality=100
		fi
		im_cmd=( convert "$img" -quality $jpeg_quality )
	else
		im_cmd=( convert "$img" )
	fi
	tmp_file="$(dirname "$img" || echo -n /tmp)/$(get_tmp_hash.py 10)"
	im_cmd+=(
		'-crop'
		"${form_w}x${form_h}+${form_x}+${form_y}"
		"$tmp_file"
	)
	echo -n "Cropping (${form_w}x${form_h}+${form_x}+${form_y}) ... " 1>&2
	"${im_cmd[@]}" 1>&2
	if [[ $? -ne 0 || ! -f "$tmp_file" || ! -s "$tmp_file" ]] ; then
		[[ $e_c -eq 0 ]] && e_c=1
		echo "CROP COMMAND FAILED" 1>&2
		nfy -i e crop.sh "CROP COMMAND FAILED"
		[[ -f "$tmp_file" ]] && rm -f "$tmp_file" 1>&2
		continue
	else
		touch -c -m --reference="$img" "$tmp_file"
		echo OK 1>&2
	fi
	if [[ -z "$output_name" ]] ; then
		output_name="crop-${form_w}x${form_h}+${form_x}+${form_y}-$(basename "$img")"
	fi
	mv --backup=numbered "$tmp_file" "$(dirname "$img")/$output_name" 1>&2
	if [[ $? -ne 0 || ! -f "$img" || ! -s "$img" ]] ; then
		[[ $e_c -eq 0 ]] && e_c=1
		echo "ERROR"
		continue
	fi
	echo "Cropped: $(identify -format "%G" "$img")" 1>&2
	echo 1>&2
done
exit "$e_c"

get_tmp_hash.py

#!/usr/bin/env python3
"""Random hash"""

import sys
import random

def get_rand_hash(n):
    """Random N character string"""
    chars = ["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f","g","h","i",
        "j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","A","B","C",
        "D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W",
        "X","Y","Z"]
    s = ""
    i = 0
    while i < n:
        s += random.choice(chars)
        i += 1

    return s

print(get_rand_hash(int(sys.argv[1])))

slice_img.sh

#!/usr/bin/env bash

# This script uses crop.sh
# $ ./splice_img.sh -W 2 -H 2 %F // splits images into a 2x2 grid
# $ ./splice_img.sh -w 2 -w 2 %F // splits images of @10x10px into a grid of 25 imgs @2x2px

declare -i n=1 arglen=0
declare -i imgw=0 imgh=0 w=0 h=0 t=0 r=0 b=0 l=0 x=0 y=0 loopx=0 loopy=0 W=0 H=0
declare img img_ext format padw
declare -a args=()

while getopts ":w:h:W:H:" options ; do
	case "$options" in
		w)	w=$OPTARG;; # Specify exact width per slice
		h)	h=$OPTARG;; # Specify exact height per slice
		W)	W=$OPTARG;; # Specify rows to split into
		H)	H=$OPTARG;; # Specify cols to split into
		*)	exit 1;;
	esac
done
args+=("${@:OPTIND}")
arglen=${#args[@]}

for (( i = 0; i < arglen; i++ )); do
	img="${args[i]}"
	if [[ ! -f "$img" ]] ; then continue; fi
	format="$(identify -format '%w'$'\t''%h' "$img")" || exit 5
	imgw=$(cut -f1 <<< "$format")
	imgh=$(cut -f2 <<< "$format")
	if ((W > 0 && H > 0)) ; then
		w=$(awk -v imgw="$imgw" -v W="$W" 'BEGIN{printf "%i\n", (imgw / W) + 1}')
		h=$(awk -v imgh="$imgh" -v H="$H" 'BEGIN{printf "%i\n", (imgh / H) + 1}')
	fi
	loopx=$(awk -v imgw="$imgw" -v w="$w" 'BEGIN{printf "%i\n", (imgw / w) + 1}')
	loopy=$(awk -v imgh="$imgh" -v h="$h" 'BEGIN{printf "%i\n", (imgh / h) + 1}')
	if ((w <= 0 || h <= 0)) ; then
		echo "No target dimensions specified" 1>&2
		exit 4
	fi
	padw=$(( loopx * loopy ))
	padw="${#padw}"
	for ((y = 0; y < loopy; y++)); do
		for ((x=0; x < loopx; x++)); do
			l=$((x * w))
			r=$((imgw - ((x+1) * w) ))
			if ((r < 0)) ; then r=0; fi
			t=$((y * h))
			b=$((imgh - ((y+1) * h) ))
			if ((b < 0)) ; then b=0; fi
			# echo "x=${x}, y=${y} t=${t} r=${r} b=${b} l=${l}"
			img_ext=".$(file --brief --extension "$img")" || exit 6
			# echo "$img_ext"
			crop.sh -o "$(
				dirname "$img"
			)/$(
				basename "$img" "$img_ext"
			)-slice-$(printf '%0*d\n' "$padw" $n)${img_ext}" -t "$t" -r "$r" -b "$b" -l "$l" "$img" || exit 4
			n=$((n+1))
		done
	done
done