pad_to_3_x_2.sh

#! /bin/bash

# Requires imagemagick (brew install imagemagick)

# Usage:
# ./pad_to_3_x_2.sh [image-name]
# 
# produces resized-[image-name]
#
# Example:
#
# ./pad_to_3_x_2.sh screenshot_whut.png
# 


ORIGINAL_DIMENSIONS=`magick identify $1 | cut -d " " -f3`;
WIDTH=`echo -n $ORIGINAL_DIMENSIONS | cut -d"x" -f1`
HEIGHT=`echo -n $ORIGINAL_DIMENSIONS | cut -d"x" -f2`
NEWWIDTH=$WIDTH
NEWHEIGHT=$HEIGHT

if [ "$WIDTH" -ge "$HEIGHT" ]
then
  NEWHEIGHT=$(($WIDTH * 2 / 3))
else
  NEWWIDTH=$(($HEIGHT * 2 / 3))
fi

echo "Original Width:  $WIDTH"
echo "Original Height: $HEIGHT"
echo "New Width:       $NEWWIDTH"
echo "New Height:      $NEWHEIGHT"
echo -n "Resizing to   ${NEWWIDTH}x${NEWHEIGHT}"

NEWDIMS="${NEWWIDTH}x${NEWHEIGHT}"

convert $1 -gravity center -background transparent -extent $NEWDIMS resized-$1

open "resized-$1";