Sometimes we need to resize multiple images in a folder, using PHP script we can achieve just that. Just point to folder where your images are located and execute following PHP script to resize your images.
Modify source and destination folder location on top of script, you can also set width and height of Images. All resized images will be proportional. I have re-sized 300 images with this script, each 2-3 MB and took me about 8/10 minutes.