transpose exif orientation with PIL

exif_rotate.py

import io
import os

from PIL import Image
from PIL.JpegImagePlugin import JpegImageFile


class Orientation:
    key = 0x0112  # see: PIL.ExifTags.TAGS
    flip_horizontal = 2
    rotate_180_left = 3
    flip_vertical = 4
    flip_vertical_rotate_90_right = 5
    rotate_90_right = 6
    flip_horizontal_rotate_90_right = 7
    rotate_90_left = 8


def transpose_orientation(img: JpegImageFile):
    exif = img.getexif()
    try:
        orientation = exif[Orientation.key]
    except KeyError:
        return img

    if orientation in (Orientation.flip_horizontal, Orientation.flip_horizontal_rotate_90_right):
        img = img.transpose(Image.FLIP_LEFT_RIGHT)
    if orientation in (Orientation.flip_vertical, Orientation.flip_vertical_rotate_90_right):
        img = img.transpose(Image.FLIP_TOP_BOTTOM)
    if orientation == Orientation.rotate_180_left:
        img = img.transpose(Image.ROTATE_180)
    if orientation in (Orientation.rotate_90_right,
                       Orientation.flip_vertical_rotate_90_right,
                       Orientation.flip_horizontal_rotate_90_right):
        img = img.transpose(Image.ROTATE_270)
    if orientation == Orientation.rotate_90_left:
        img = img.transpose(Image.ROTATE_90)

    return img


def main():
    target_dir = 'exif-orientation-examples'  # http://github.com/recurser/exif-orientation-examples.git
    output_dir = 'output'
    os.makedirs(output_dir, exist_ok=True)
    for filename in os.listdir(target_dir):
        if not filename.endswith('.jpg'):
            continue
        filepath = os.path.join(target_dir, filename)
        with open(filepath, 'rb') as f:
            img_bytes = f.read()
        img = Image.open(io.BytesIO(img_bytes))
        new_img = transpose_orientation(img)
        new_img.save(os.path.join('output', filename))


if __name__ == '__main__':
    main()