Works with test command but aspect ratio of produced images seem off

apply_image.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+cd fourcell
+source env/bin/activate
+cd ..
+
+python ./fourcell/apply_image.py "${@}"

fourcell.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+#set -e
+
 if [[ "${1}" == "" ]]; then
 	echo "Please provide a calibration JSON"
 fi
@@ -9,15 +11,79 @@ if [[ "${2}" == "" ]]; then
 	exit 2
 fi
 
-
+if [ -f "${2}" ]; then
-if [ -f "${1}" ]; then
+	echo "Exporting frames from ${2}..."
 	OUTPUT=$(mktemp -d)
-	ffmpeg -y -re -i "${1}" \
+	ffmpeg -y -re -i "${2}" \
 		-q:v 1 -qmin 1 -qmax 1 \
 		"${OUTPUT}/frame_%06d.tif"
 else
-	OUTPUT="${1}"
+	if [ -d "${2}" ]; then
+		OUTPUT="${2}"
+	else
+		echo "Argument ${2} is neither video nor directory"
+		exit 43
+	fi
 fi
 
+tiff_name () {
+	filename=$(basename "${1}")
+	filename="${filename%.*}"
+	echo "${filename}.tif"
+}
 
+echo "Using frames in ${OUTPUT}..."
 
+W=$(cat "${1}" | jq -r ".width")
+H=$(cat "${1}" | jq -r ".height")
+DPI=$(echo "${W}/8.5" | bc)
+FRAMES=$(mktemp)
+
+echo "DPI: $DPI"
+
+ls -1 "${OUTPUT}"*.{jpg,jpeg,JPG,JPG,png,PNG,gif,GIF,tif,tiff,TIF,TIFF} > "${FRAMES}" 2> /dev/null
+FC=$(wc -l < "${FRAMES}")
+PAGES=$(echo "(${FC}/4)+1" | bc)
+
+TMP=$(mktemp -d)
+
+for ((i=0;i<${PAGES};++i)); do
+	f1=$(sed -n "$(((i*4)+1))p" < "${FRAMES}")
+	f2=$(sed -n "$(((i*4)+2))p" < "${FRAMES}")
+	f3=$(sed -n "$(((i*4)+3))p" < "${FRAMES}")
+	f4=$(sed -n "$(((i*4)+4))p" < "${FRAMES}")
+	args=""
+	if [[ "${f1}" != "" ]]; then
+		name=$(tiff_name "${f1}")
+		dest="${TMP}/${name}"
+		bash white_fourcell.sh $DPI "${f1}" "${dest}"
+		args="${args} ${dest}"
+	else 
+		continue 
+	fi
+	if [[ "${f2}" != "" ]]; then
+		name=$(tiff_name "${f2}")
+		dest="${TMP}/${name}"
+		bash white_fourcell.sh $DPI "${f2}" "${dest}"
+		args="${args} ${dest}"
+	fi
+	if [[ "${f3}" != "" ]]; then
+		name=$(tiff_name "${f3}")
+		dest="${TMP}/${name}"
+		bash white_fourcell.sh $DPI "${f3}" "${dest}"
+		args="${args} ${dest}"
+	fi
+	if [[ "${f4}" != "" ]]; then
+		name=$(tiff_name "${f4}")
+		dest="${TMP}/${name}"
+		bash white_fourcell.sh $DPI "${f4}" "${dest}"
+		args="${args} ${dest}"
+	fi
+	bash apply_image.sh ~/Desktop/page_$i.tiff "${1}" ${args}
+done
+
+# x determine dpi
+# convert frame to white_fourcell
+
+rm "${FRAMES}"
+rm -rf "${TMP}"