exifdump

#!/usr/bin/env python3

import json
import os
import random
import sys
import PIL.Image
import PIL.ExifTags
from pprint import pprint

def parse_maker_note(maker_note):
    """Split the "maker note" EXIF field from a Raspberry Pi camera image into useful parameters"""
    camera_parameters = {}
    last_key = None
    for p in maker_note.decode().split(" "):
        # The maker note contains <thing>=<thing> entries, space delimited but with spaces in some values.
        # So, if there is an = then we assume we've got key=value, but if there is no = sign, we append
        # the current chunk to the latest value, because that's where it probably belongs...
        if "=" in p:
            last_key, v = p.split("=")
            camera_parameters[last_key] = v
        else:
            camera_parameters[last_key] += " " + p
    return camera_parameters

def read_exif(fn):
    img = PIL.Image.open(fn)

    exif = {
        PIL.ExifTags.TAGS[k]: v
        for k, v in img._getexif().items()
        if k in PIL.ExifTags.TAGS
    }

    for k in exif:
        if type(exif[k]) is tuple and \
            len(exif[k]) == 2 and \
            type(exif[k][0]) is int and \
            type(exif[k][1]) is int:
            exif[k] = (exif[k][0] / exif[k][1]) if exif[k][1] != 0 else 0

        if type(exif[k]) is bytes:
            exif[k] = exif[k].decode('utf-8')

    if exif.get("MakerNote"):
        exif["MakerNote"] = parse_maker_note(exif.get("MakerNote"))

    return exif

print(json.dumps(read_exif(sys.argv[1]), indent = 4))