imagemagick.sh

#!/bin/bash

max=3000000
maxWidth=2000
maxHeight=1000

for file in `\find ./docs -maxdepth 2 -name '*.png'`; do

  hoge=$(identify -format "%w %h" $file)
  IFS=' '
  set -- $hoge
  imageSize=$(($1*$2))
  newFile=${file%.*}".jpg"
  
  if [ $imageSize -gt $max ]; then
    diff=$(($imageSize-$max))

    if [ $1 -gt $2 ]; then
      #横の方が大きい
      convert $file -resize ${maxwidth}x -quality 100 $newFile
    else
      #縦の方が大きい
      convert $file -resize x${maxHeight} -quality 100 $newFile
    fi
  else
    convert $file -quality 100 $newFile
  fi

done

exit 0