might have another version of this in gist already...

lr_restore.py

from __future__ import division
import multiprocessing
from multiprocessing.pool import Pool
import exifread
import arrow
import glob
import os
import records
import shutil
from PIL import Image


LR_CATALOG_PATH = '/Users/jacob/Dropbox/Photos/Lightroom/Lightroom Catalog.lrcat'
RESTORE_IMAGES_FOLDER_PATH = '/Volumes/Storage/Photos/Other/Recovered Photos'
DESTINATION_PATH = '/Volumes/Storage/Photos/Recovered_LR_Photos'


class ImageSet(object):
    def __init__(self, images):
        self._images = list(images)

    def __iter__(self):
        for image in self._images:
            yield image

    def __len__(self):
        return len(self._images)

    def _with_unique_attr(self, attr_name, is_callable=False):
        attr_value_image_map = {}
        for image in self:
            value = getattr(image, attr_name)
            if is_callable:
                value = value()
            
            if value in attr_value_image_map:
                attr_value_image_map[value] = None
            else:
                attr_value_image_map[value] = image

        return [image for image in attr_value_image_map.values() if image is not None]

    def with_unique_dimensions(self):
        return self._with_unique_attr('get_dimensions', True)

    def with_unique_capture_time(self):
        return self._with_unique_attr('capture_time')


class BaseImage(object):
    def __init__(self, capture_time, filename, folder_path, width, height):
        self.capture_time = capture_time
        self.filename = filename
        self.folder_path = folder_path
        self.width = width
        self.height = height

    def get_dimensions(self):
        return (self.width, self.height)

    def get_path(self):
        return os.path.join(folder_path, filename)


class RestoreImage(BaseImage):
    @classmethod
    def get_metadata(cls, file_path):
        with open(file_path) as f:
            return exifread.process_file(f)

    @classmethod
    def get_capture_time(cls, file_path):
        metadata = cls.get_metadata(file_path)
        capture_time_str = metadata.get('EXIF DateTimeOriginal', None)
        if capture_time_str:
            if str(capture_time_str) in ['0000:00:00 00:00:00']:
                return
            try:
                return arrow.get(str(capture_time_str), ['YYYY:MM:DD HH:mm:ss', 'YYYY:MM:DD HH:mm:'])
            except ValueError:
                pass

    @classmethod
    def get_dimensions_from_file_path(cls, file_path):
        if '.jpg' in file_path:
            with Image.open(file_path) as im:
                return im.size
        return (None, None)

    @classmethod
    def from_file_path(cls, file_path):
        folder_path, filename = os.path.split(file_path)
        width, height = cls.get_dimensions_from_file_path(file_path)
        return cls(
            capture_time=cls.get_capture_time(file_path),
            filename=filename,
            folder_path=folder_path,
            width=width,
            height=height,
        )


class LightroomImage(BaseImage):
    @classmethod
    def from_row(cls, row):
        instance = cls(
            capture_time=arrow.get(row['captureTime']),
            filename=row['idx_filename'],
            folder_path=row['pathFromRoot'],
            width=row['fileWidth'],
            height=row['fileHeight'],
        )
        return instance

    def get_destination_path(self):
        return os.path.join(DESTINATION_PATH, folder_path, filename)


def get_all_lr_images(lr_catalog_path):
    db = records.Database('sqlite:///{}'.format(lr_catalog_path))
    rows = db.query('''
        SELECT * FROM Adobe_images image
        LEFT JOIN agLibraryFile file ON image.rootFile = file.id_local
        LEFT JOIN agLibraryFolder folder ON file.folder = folder.id_local
    ''')
    return ImageSet(LightroomImage.from_row(row) for row in rows)


def get_restore_image(file_path):
    return RestoreImage.from_file_path(file_path)

def get_all_restore_images(restore_images_folder_path):
    file_paths = glob.glob('{}/**/*'.format(restore_images_folder_path))

    pool = Pool(multiprocessing.cpu_count())
    return ImageSet(pool.map(get_restore_image, file_paths))


# ...
restore_images = get_all_restore_images(RESTORE_IMAGES_FOLDER_PATH)
lr_images = get_all_lr_images(LR_CATALOG_PATH)

# match on unique capture time
lr_image_r_image_map = {}
lr_images_with_unique_capture_time = lr_images.with_unique_capture_time()
for r_image in restore_images.with_unique_capture_time():
    for lr_image in lr_images_with_unique_capture_time:
        if r_image.capture_time == lr_image.capture_time:
            print "{} ---> {}".format(r_image.filename, lr_image.filename)
            lr_image_r_image_map[lr_image] = r_image
            break
# print len(lr_image_r_image_map)  # 725

# # NOT WORKING CORRECTLY
# # match on unique dimensions
# # lr_image_r_image_map = {}
# lr_images_with_unique_dimensions = lr_images.with_unique_dimensions()
# for r_image in restore_images.with_unique_dimensions():
#     for lr_image in lr_images_with_unique_dimensions:
#         if r_image.get_dimensions() == lr_image.get_dimensions():
#             print "{} ---> {}".format(r_image.filename, lr_image.filename)
#             lr_image_r_image_map[lr_image] = r_image
#             break
# # print len(lr_image_r_image_map)  # 672

for lr_image, r_image in lr_image_r_image_map.items():
    folder_path = os.path.join(DESTINATION_PATH, lr_image.folder_path)
    if not os.path.exists(folder_path):
        os.makedirs(folder_path)
    shutil.copy2(
        os.path.join(r_image.folder_path, r_image.filename),
        os.path.join(DESTINATION_PATH, lr_image.folder_path, lr_image.filename)
    )