Adds captions below pictures

tag_cap_images.sh

##############################################
# tag_cap_images.sh
#
# Create a new JPEG image from an old one with 
# 1.	A white border with extra space at the bottom
# 2.	A generalized caption made up of the following metadata from the original photo,
#	 perhaps added or edited in Lightroom or other software:
# 	a.	title
# 	b.	caption (may be identical to “description” metadata)
# 	c.	the keywords/tags (a.k.a. “subject” metadata)
# 	d.	The originating filename (from within Lightroom) and the final filename
# 3.	The final image with caption is larger than the original photo. 
#	But with the bonus that if you crop down to the photo, 
#	the dimensions are the same as the original photo. 
# 4.	The final image’s metadata has been automatically copied over from the original photo,
#	i.e., the title, caption, keywords, filename, etc. .
# 
# Does not work with input *.HEIC and raw files *.dng, *.ARW and *.CR2. 
# Seems to only work with JPEG.
#
# Usage
# % bash tag_cap_images.sh image1, image2, ...
#
# For example. Input could be most any image file format. 
#  % cd yourname/whereYourPicturesAre
#  % bash ~/bin/tag_cap_images.sh *.jpg
#
# output is always JPEG and is in 
# yourname/whereYourPicturesAre-captioned/capsh_*.jpg.  
#
# If you don't like the output folder location or the output file name, change the script.
##############################################

#!/bin/bash

FONT="/System/Library/Fonts/Supplemental/Times New Roman.ttf"
#FONT="/System/Library/Fonts/Supplemental/Arial Unicode.ttf"

# Exit on error
set -e

# output to subdirectory
#OUTPUTPATH=captioned

# output dir from the command line (first argument is directory)
#OUTPUTPATH=$1
#shift 1 

# output to sister directory ...-captioned
OUTPUTPATH=$PWD-captioned

echo OUTPUTPATH $OUTPUTPATH

mkdir -p "$OUTPUTPATH"
#echo Files: "$@"
for var in "$@"; do
    echo Processing $var
    OUTVAR="capsh_"$var
    WIDTH=$(exiftool -s -s -s -ExifImageWidth "$var")
    HEIGHT=$(exiftool -s -s -s -ExifImageHeight "$var")
    if test z"$WIDTH" = z; then
        WIDTH=$(exiftool -s -s -s -ImageWidth "$var")
        HEIGHT=$(exiftool -s -s -s -ImageHeight "$var")
    fi
    echo WIDTH: $WIDTH HEIGHT: $HEIGHT
    # assume larger dimension is mapped to 10" for approximate 8X10 image.
    DPI=$(python3 -c "print(max($WIDTH,$HEIGHT)//10.0)") 
    #echo DPI $DPI
    BORDER=$(python3 -c "print(int(round(0.025*max($WIDTH,$HEIGHT))))")
    FONTSIZE=$(python3 -c "print(int(round(0.015*($DPI*10.0))))") # in pixels
    FONTSIZE=$(python3 -c "print(int(min(99,$FONTSIZE)))")        # max is 99 pixels
    TITLE=$(exiftool -s -s -s -Title "$var")
    echo short TITLE: $TITLE
    if test z"$TITLE" = z; then
        LABEL=$(exiftool -s -s -s -Description -Subject -FileName "$var")
        LABEL="$LABEL -> $OUTVAR   tag_cap_images.sh"
#        LABEL=$(exiftool -s -s -s -Description -Subject -FileName "$var")
    else
        LABEL="\"$TITLE\"\n$(exiftool -s -s -s -Description -Subject -FileName "$var")"
        LABEL="$LABEL -> $OUTVAR    tag_cap_images.sh"
#        LABEL="\"$TITLE\"\n$(exiftool -s -s -s -Description -Subject -FileName "$var")"
    fi
    echo long LABEL: $LABEL
    echo Font: $FONTSIZE pixels  Border: $BORDER pixels
    magick convert "$var" \
    -pointsize $FONTSIZE \
    -font "$FONT" \
    -background white \
    \( -size $WIDTH "caption:$LABEL" \) \
    -bordercolor white \
    -border ${BORDER}x$BORDER \
    -smush -$BORDER \
    "$OUTPUTPATH/$OUTVAR"
    echo " "
done