Reduce JPEG image filesize to under 500K with imagemagick

reduce_jpeg_quality_magick.sh

# SETUP
# -----

### install brew
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

### install xquartz, requires system password & log out to complete
brew install xquartz

### install imagemagick
brew install imagemagick

# CONVERT FORMAT from iPhotos download
# --------------
# https://zwbetz.com/convert-heic-images-to-jpg/

mogrify -format jpg *.HEIC
rm -f !$


# REDUCE IMG SIZE
# ----------------

du -sk farm_brewery.jpg
## output:
# 2816	farm_brewery.jpg

magick identify -verbose farm_brewery.jpg  | grep ^..Quality:
## output:
#  Quality: 78

magick convert farm_brewery.jpg -quality 28 farm_brewery_28_quality.jpg

magick identify -verbose farm_brewery_28_quality.jpg  | grep ^..Quality:
## output:
#  Quality: 28

du -sk farm_brewery_28_quality.jpg
## output:
# 1604	farm_brewery_28_quality.jpg

magick convert farm_brewery.jpg -resize 50% farm_brewery_50pct_size.jpg

du -sk farm_brewery_50pct_size.jpg
## output:
# 1136	farm_brewery_50pct_size.jpg

magick convert farm_brewery_50pct_size.jpg -quality 27 farm_brewery_27_quality_50pct_size.jpg

magick identify -verbose farm_brewery_27_quality_50pct_size.jpg | grep ^..Quality:
## output:
#  Quality: 27

du -sk farm_brewery_27_quality_50pct_size.jpg
## output 
# 452	farm_brewery_27_quality_50pct_size.jpg