Bulk Resize Images for WordPress

Here’s a python script.

import os
import subprocess

# inspired by this post
# https://guides.wp-bullet.com/batch-resize-images-using-linux-command-line-and-imagemagick/

def main():
    # the maximum length in any direction (width or height)
    # setting at 1600 because full HD (1920x1080) seems larger than necessary
    # this will allow 1600x900 (or portrait 900x1600) images.
    MAX_LEN = "1600" 
    size_parm = MAX_LEN+'x'+MAX_LEN+'>' #https://legacy.imagemagick.org/Usage/resize/#shrink
    
    # files in the input directory will (at least SHOULD) remain untouched.
    # files with identical names will be created in the output directory.
    # files in the output directory are OVERWRITTEN (if they already exist and the names match)
    IN_DIR = '/home/vince/Pictures/WordPress'
    OUT_DIR = '/home/vince/Pictures/WordPressSmall'

    # show what is about to happen
    print ('Input: ', IN_DIR)
    print ('Output:', OUT_DIR)
    print ('Resize Geometry:', size_parm)

    for filename in os.listdir(IN_DIR):
        # get full file paths
        infile =  os.path.join(IN_DIR, filename)
        outfile = os.path.join(OUT_DIR, filename)

        # this is not necessary because the ImageMagick library supports shrinking only
        # AND maintaining aspect ratio. all the logic is basically done.
        # the '>' in size_parm prevents making the image larger.
        # #get width and height
        # width = subprocess.check_output(['identify', '-format', '%w', filepath])
        # width = int(width.decode())

        # convert and print output
        subprocess.check_output(['convert', infile, '-verbose', '-resize', size_parm, outfile])

         
if __name__ == '__main__':
    main()