refactor: optimize PDF image splitting script

refactor: optimize PDF image splitting script

- simplify path and filename handling
- safely quote file paths
- improve temporary directory management
- remove redundant shell pipelines
- simplify image batching
- add error handling and progress output
- document usage and processing steps

pdf tools/pdf_edit.sh

@@ -0,0 +1,102 @@
+#!/bin/bash
+
+# Convert a PDF into processed JPG images and split them into
+# multiple PDF files, with a maximum of 100 images per output PDF.
+
+set -e
+
+if [ "$#" -ne 1 ]; then
+    echo "Usage: $0 <pdf-file>"
+    exit 1
+fi
+
+pdf_file="$1"
+
+if [ ! -f "$pdf_file" ]; then
+    echo "Error: '$pdf_file' does not exist."
+    exit 1
+fi
+
+echo "Using $pdf_file"
+
+# Resolve the input directory and filename.
+pdf_dir="$(cd "$(dirname "$pdf_file")" && pwd)"
+pdf_name="$(basename "$pdf_file")"
+base_name="${pdf_name%.*}"
+
+buffer_dir="$pdf_dir/.BUFFERFOLDER"
+
+# Recreate the temporary working directory.
+rm -rf "$buffer_dir"
+mkdir -p "$buffer_dir"
+
+cp "$pdf_file" "$buffer_dir/$pdf_name"
+
+cd "$buffer_dir"
+
+echo "Extracting images..."
+
+# Extract PDF images as PNG.
+pdfimages -png "$pdf_name" "$base_name"
+
+count=0
+
+shopt -s nullglob
+
+for img in *.png; do
+    jpg="${img%.png}.jpg"
+
+    echo "Processing $jpg"
+
+    # PNG -> JPG
+    convert "$img" "$jpg"
+    rm "$img"
+
+    # Normalize image dimensions.
+    convert "$jpg" -resize 2550x3300! "$jpg"
+
+    # Use different crop dimensions for images containing "000".
+    if [[ "$jpg" == *000* ]]; then
+        convert "$jpg" -crop 2206x3200+200+50 "$jpg"
+    else
+        convert "$jpg" -crop 2106x3200+200+50 "$jpg"
+    fi
+
+    # Remove white background.
+    convert "$jpg" -fuzz 20% -transparent White "$jpg"
+
+    # Center image on a white 2550x3300 canvas.
+    convert "$jpg" \
+        -resize 2550x3300 \
+        -gravity center \
+        -background White \
+        -extent 2550x3300 \
+        "$jpg"
+
+    # Group images into batches of 100.
+    split_var=$((count / 100))
+    split_dir="split_${split_var}"
+
+    mkdir -p "$split_dir"
+    mv "$jpg" "$split_dir/"
+
+    ((count++)) || true
+done
+
+# Convert each group of images into a PDF.
+for split_dir in split_*; do
+    [ -d "$split_dir" ] || continue
+
+    split_number="${split_dir#split_}"
+
+    echo "Converting Part $split_number"
+
+    convert "$split_dir"/*.jpg \
+        "$pdf_dir/${base_name}_split_${split_number}.pdf"
+done
+
+# Remove temporary files.
+cd "$pdf_dir"
+rm -rf "$buffer_dir"
+
+echo "Done."

quiethost/pdf_edit.sh

@@ -1,54 +0,0 @@
-#!/bin/bash
-pdf_file="$1"
-if [ $# -ne 1 ]; then
-	echo "Filename Missing"
-	exit
-fi
-if [ -f ${pdf_file} ]; then 
-	echo "Using ${pdf_file}"
-else
-	echo "${pdf_file} doesnt exist!"
-	exit
-fi
-NAME="$(echo ${pdf_file} | rev | cut -f1 -d'/' | rev)"
-if [ "$(echo ${pdf_file} | grep -o '/')" != "" ]; then 
-	path="$(echo ${pdf_file} | rev | cut -f2- -d'/' | rev)"
-else 
-	path="$(pwd)"
-fi
-cd ${path}
-if [ -d .BUFFERFOLDER ]; then
-	rm -dr .BUFFERFOLDER
-fi
-mkdir .BUFFERFOLDER
-cp ${NAME} .BUFFERFOLDER/
-NAME="$(echo ${NAME} | rev | cut -f2- -d'.' | rev)"
-cd .BUFFERFOLDER
-pdfimages -png ${NAME}.pdf ${NAME}
-count=0
-for img in *.png; do
-		convert ${img} "$(echo ${img} | sed 's/png/jpg/g')"
-		rm ${img}
-		img="$(echo ${img} | sed 's/png/jpg/g')"
-	       	echo ${img}
-		convert ${img} -resize 2550x3300! ${img}
-		if [ "$(echo ${img} | grep "000")" != "" ]; then
-			convert ${img} -crop 2206x3200+200+50 ${img}
-		else
-			convert ${img} -crop 2106x3200+200+50 ${img}
-		fi
-		convert ${img} -fuzz 20%% -transparent White ${img}
-		convert ${img} -resize 2550x3300 -gravity center -background White -extent 2550x3300 ${img}
-		split_var=$((count / 100))
-		if [ ! -d "split_${split_var}" ]; then
-			mkdir split_${split_var}
-		fi
-		mv ${img} split_${split_var}/
-		((count++))
-done
-for ((i=0;i<$(ls | grep split_ | wc -l);i++)); do
-	echo "Convert Part $i"
-	convert split_$i/*.jpg ../${NAME}_split_${i}.pdf
-done
-cd ../
-rm -dr .BUFFERFOLDER