This tutorial shows you how to list your images in a csv file and resize every image in that list automatically.
WHOOO! AUTOMATION! 🎉

Imagemagick

ImageMagick is a free and open-source software suite for displaying, converting, and editing raster image and vector image files. 

Prepare the scripts

• Log in your Linux system
• Run the following command in your bash console to list every JPG in the specified folder recursively and save it into a csv file

find /home/project/ -name "*.jpg" -print| while read LINE; do echo "$LINE" ; done > list_with_images.csv

• Create a file named "resize_with_imagemagic.sh"

# define the settings
export MAGICK_THREAD_LIMIT=1;
export MAGICK_THROTTLE_LIMIT=100;
export MAGICK_MEMORY_LIMIT=500mb;
start=0;

end=$(cat$1 | wc -l)
loop through every line of the given file
while read file; do

echo "[x] Optimizing $file"

echo $(($end-$((++start)))) elements remaining of$end

replace="_optimized.jpg"

targetFile="${file/.jpg/_optimized.jpg}"

echo "Optimizing $file to$targetFile"

convert "$file" -resize 1920 "$targetFile"

# let the CPU rest for 10 sec

sleep 10

done < $1

You can edit the script to your liking. it doesn't replace the original image, but creates a new one with a postfix of "_optimized".
Original: test_image.jpg
Optimized: test_image_optimized.jpg

Run the script

sh resize_with_imagemagic.sh list_with_images.csv

Learn more about Linux bash tricks