Generate thumbnails

generate_thumbnails.py

#!/usr/bin/env python
# With the provided src and dest locations, will generate all the remaining
# thumbnails in the desired size.  Use --force to regenerate
import argparse
from PIL import Image
import glob, os

def debug_display_files(files, debug_level=1):
    files = list(files)
    if args.debug >= 1:
        print('Display files')

    if args.debug >= 2:
        print('\n'.join(files[0:10]))
        print("... %d total ..." % len(files))
    elif args.debug >= 3:
        print('\n'.join(files))
        print("===")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Generate square thumbnails for folder')
    parser.add_argument('--src', dest='src', help='Location of large images')
    parser.add_argument('--dest', dest='dest', help='Location of thumbnails')
    parser.add_argument('--size', dest='size', default="small", help='small 150x150, medium 300x300')
    parser.add_argument('--force', dest='force', action="store_true", help='Regenerate thumbnails for all files, even if it exists')
    parser.add_argument('--debug', dest="debug", type=int, default=1, help='Show debug level messages')

    args = parser.parse_args()

    if args.debug:
        print("===")
        print("Large: %s" % args.src)
        print("Thumbs: %s" % args.dest)
        print("===")

    # Select size
    if args.size == "small":
        size = 150, 150
    elif args.size == "medium":
        size = 300, 300
    else:
        size = 150, 150

    if args.debug >= 1:
        print("Selecting size: %s" % args.size, size)
        print("===")

    # Identify list of large files
    large_files = os.listdir(args.src)
    debug_display_files(large_files, debug_level=args.debug)

    existing_thumbs = os.listdir(args.dest)
    debug_display_files(existing_thumbs, debug_level=args.debug)

    # Find the list of thumbnails that have not been generated yet
    thumbnails_to_generate = set(large_files) - set(existing_thumbs)
    debug_display_files(thumbnails_to_generate, debug_level=args.debug)
    if args.force:
        thumbnails_to_generate = large_files
    else:
        thumbnails_to_generate = list(thumbnails_to_generate)

    # Generate the thumbs
    if args.debug >= 1:
        print ("Generating %d thumbnails!" % len(thumbnails_to_generate))

    for f in thumbnails_to_generate:
        #file, ext = os.path.splitext(large_file)
        infile = os.path.join(args.src, f)
        outfile = os.path.join(args.dest, f)
        if args.debug >= 2:
            print("Generating thumbnails for %s" % f)
            print("Output %s" % outfile)
        im = Image.open(infile)
        im.thumbnail(size)
        im.save(outfile)