Generates a "label image" for each JPEG matching INPUT_GLOB, writing them to OUTPUT_DIR.

label-timelapse.sh

#!/bin/bash

# Generates a "label image" for each JPEG matching INPUT_GLOB, writing them to OUTPUT_DIR.
# The labels contain the (possibly adjusted) timestamp of the EXIF tag of the input image.
# As the backgrounds are transparent, they can be overlaid on a timelapse, for example.

# Requires: exiftool imagemagick

INPUT_GLOB="*.JPG"
OUTPUT_DIR="labels"
ADD_SECONDS=0 # Number of seconds to adjust the original date with
LABEL_FORMAT="%H:%M" # See $ man strftime; "%a, %m.%d.%Y %H:%M:%S" -> "Sat, 11.10.2012 16:16:24"
COLOR="white"
FONT="Courier-Bold" # See $ convert -list font
FONT_SIZE="150"
RESOLUTION="3840x2880"
LOCATION="SouthEast" # See $ convert -list gravity

if [ ! -d "$OUTPUT_DIR" ]; then
        echo "ERROR: Please create output directory \"$OUTPUT_DIR\" first"
        exit 1
fi

for FILE_IN in `ls -1 $INPUT_GLOB`; do

        FILE_OUT=`echo "$OUTPUT_DIR/$FILE_IN" | sed "s/\..*\$/.png/"`
        CREATE_DATE_S=`exiftool -d "%s" $FILE_IN | grep "Create Date" | cut -c 35-`
        ACTUAL_DATE_S=`expr $CREATE_DATE_S + $ADD_SECONDS`
        ACTUAL_DATE_F=`date -r $ACTUAL_DATE_S "+$LABEL_FORMAT"`

        echo -n "$FILE_IN @ \"$ACTUAL_DATE_F\" -> $FILE_OUT ... "

        convert -background transparent -fill $COLOR -font $FONT -size $RESOLUTION -gravity $LOCATION -pointsize $FONT_SIZE label:"$ACTUAL_DATE_F" $FILE_OUT 2> /dev/null

        if [ $? -eq 0 ]; then
                echo "OK"
        else
                echo "FAIL"
        fi

done