Modify and convert all images from folders to one PDF

magic-scoodle-pdf.sh

#!/usr/bin/env sh

EXTENSION=".png"
OUTPUT_EXTENSION=".jpg"

function resize_image {
    local FILE=$1
    local OUTPUT_FILE=${FILE/$EXTENSION/}
    # Recto
    convert "$FILE" -quality 90 -crop 1278x1920+400+90 +repage -resize 2480x3508\! "$OUTPUT_FILE"_recto"$OUTPUT_EXTENSION"
    # Verso
    convert "$FILE" -quality 90 -crop 1278x1920+1681+90 +repage -resize 2480x3508\! "$OUTPUT_FILE"_verso"$OUTPUT_EXTENSION"
}

JOBS=0
MAX_JOBS=35

BEGINNING_TIME=`date +%s`
for dir in */
do
    directory=${dir::-1}

    echo "[INFO] Starting $directory..."
    START_TIME=`date +%s`
    cd "$directory"
    for file in *.png
    do
        ((JOBS=JOBS%MAX_JOBS)); ((JOBS++==0)) && wait
        [ -f "$file" ] && resize_image "$file" &
    done
    wait
    END_TIME=`date +%s`
    echo "[INFO] Finished in $(($END_TIME-$START_TIME)) seconds."

    echo "[INFO] Convert all images to one PDF..."
    START_TIME=`date +%s`
    # Don't use convert because it slows!
    img2pdf --pagesize A4 -o "$directory".pdf *.jpg
    mv "$directory".pdf pdfToTrim.pdf
    pdftk pdfToTrim.pdf cat 2-end output "$directory".pdf
    rm pdfToTrim.pdf
    END_TIME=`date +%s`
    echo "[INFO] PDF generated in $(($END_TIME-$START_TIME)) seconds."

    cd ..
done
FINISHING_TIME=`date +%s`
echo "[INFO] FINISHED in $(($FINISHING_TIME-$BEGINNING_TIME)) seconds."