Automatically create animated GIFs from a batch of photos

detect_gifs.py

#!/usr/bin/env python

"""
detect_gifs.py
==============
This script tries to automatically detect
GIF opportunities within a batch of photos.
"""

from __future__ import print_function
import argparse
import os
import glob
from PIL import Image
from datetime import datetime
import subprocess


def main():
    """Detect GIFs"""

    # Parse command-line arguments
    args = parse_args()

    # Ensure output_dir exists
    if not os.path.exists(args.output_dir):
        os.mkdir(args.output_dir)

    # Obtain list of photo files
    photos = []
    for ext in args.extensions:
        pattern = "{}/*.{}".format(args.photo_dir, ext)
        photos.extend(glob.glob(pattern))

    # Iterate over list of photos
    all_animations = []
    animation = []
    prev_photo_dict = None
    for photo in photos:
        photo_dict = analyze_photo(photo)
        # Compare with previous
        if prev_photo_dict:
            delta = (photo_dict["date"] - prev_photo_dict["date"]).seconds
            if delta <= args.max_delta and photo_dict["orient"] == prev_photo_dict["orient"]:
                animation.append(prev_photo_dict["photo"])
            else:
                animation.append(prev_photo_dict["photo"])
                if len(animation) >= 3:
                    all_animations.append(animation)
                animation = []
        # Store photo and date for future iterations
        prev_photo_dict = photo_dict

    # Create GIFs
    # convert -resize 400 -layers optimize -coalesce -delay 30 -loop 0 photos/DSC09379.jpg photos/DSC09380.jpg photos/DSC09381.jpg ./gifs/animation_1.gif
    for i, anim in enumerate(all_animations, start=1):
        photo_dict = analyze_photo(anim[0])
        resize = str(args.resize)
        if photo_dict["orient"] == "horizontal":
            resize = "x" + resize
        output = "{}/animation_{}.gif".format(args.output_dir, i)
        cmd = ["convert", "-layers",  "optimize", "-coalesce", "-resize", resize, "-delay", str(args.delay), "-loop", "0"] + anim + [output]
        print(" ".join(cmd), end="\n\n")
        subprocess.call(cmd)


def parse_args():
    """Parse command-line arguments"""
    parser = argparse.ArgumentParser()
    parser.add_argument("photo_dir", help="Input directory containing photos")
    parser.add_argument("--extensions", "-e", nargs="+", default=["jpeg", "jpg", "png"], help="File extensions for photos in input directory")
    parser.add_argument("--max_delta", "-d", default=1, help="Number of seconds allowed between successive photos to constitute a GIF")
    parser.add_argument("--delay", default=25, help="Milliseconds between GIF frames")
    parser.add_argument("--resize", default=500, help="Max width or height of output GIFs")
    parser.add_argument("--output_dir", default=".", help="Output directory for animated GIFs")
    parse_args
    args = parser.parse_args()
    return args


def analyze_photo(path):
    """Return dict of attributes"""
    photo = {"photo": path}
    op_photo = Image.open(path)
    exifdata = op_photo._getexif()
    ctime = exifdata[0x9003]
    photo["date"] = datetime.strptime(ctime, "%Y:%m:%d %H:%M:%S")
    (width, height) = op_photo.size
    if width > height:
        photo["orient"] = "horizontal"
    else:
        photo["orient"] = "vertical"
    return photo


if __name__ == '__main__':
    main()