How to use the imagehash.hex_to_hash function in ImageHash

if file.endswith(('.png', '.bmp', '.jpg')):
                        movie_name = file[0:file.rfind('.bk2') + 4]
                        # skip everything which is not from a movie file
                        if movie_name == 'new' or not root.endswith('.bk2'):
                            continue
                        file_ending = file.split('.')[-1]
                        index = int(file[file.rfind('_') + 1:file.rfind('.{}'.format(file_ending))])
                        image_hash = self.calculate_img_hash(os.path.join(root, file))
                        self.all_hashes.append(image_hash)
                        self.hashes[str(image_hash)].append(self.pressed_keys[movie_name][index])
                        self.hash_to_file[image_hash].append(file)
        self.printer.log('Time for all hashes: {}'.format(time.time() - start_time))

        # if pickled we need to store all image hashes
        if len(self.all_hashes) == 0:
            self.all_hashes = [imagehash.hex_to_hash(i) for i in self.hashes.keys()]

        # pickle the hashes
        if not pickled or overwrite:
            with open(filename_hashes, 'wb') as f:
                pickle.dump(self.hashes, f, protocol=pickle.HIGHEST_PROTOCOL)
            with open(filename_hash_to_file, 'wb') as f:
                pickle.dump(self.hash_to_file, f, protocol=pickle.HIGHEST_PROTOCOL)

def from_string(cls, value):
        new = cls()
        new.hash = imagehash.hex_to_hash(value)
        return new

# Map.
        if hash_func == imagehash.average_hash:
            hash_name = "a_hash"
        elif hash_func == imagehash.phash:
            hash_name = "p_hash"
        elif hash_func == imagehash.dhash:
            hash_name = "d_hash"

        # Search.
        image_hash = imagehash.hex_to_hash(hash_value)
        similarities = list()
        for img in self.task.case.images.filter(state="C").exclude(id=self.task.id):
            if img.report and \
            "imghash" in img.report and \
            hash_name in img.report["imghash"] and \
            image_hash == imagehash.hex_to_hash(img.report["imghash"][hash_name]):
                # TODO: store also image distance.
                similarities.append(img.id)
        return similarities

def fill_images_db(self):
        self.image_by_hashes.clear()

        for row in db_get_all():
            file_name = row['file_name']
            self.image_by_hashes[file_name] = {
                x: imagehash.hex_to_hash(row[x]) for x in IMAGE_HASH_ALGO
            }

        self.model_files.set_file_list(
            list(self.image_by_hashes.keys())
        )

        self._update_states()

def get_similar_images(self, hash_value, hash_func):
        # TODO: this should be refactored in the future.

        # Map.
        if hash_func == imagehash.average_hash:
            hash_name = "a_hash"
        elif hash_func == imagehash.phash:
            hash_name = "p_hash"
        elif hash_func == imagehash.dhash:
            hash_name = "d_hash"

        # Search.
        image_hash = imagehash.hex_to_hash(hash_value)
        similarities = list()
        for img in self.task.case.images.filter(state="C").exclude(id=self.task.id):
            if img.report and \
            "imghash" in img.report and \
            hash_name in img.report["imghash"] and \
            image_hash == imagehash.hex_to_hash(img.report["imghash"][hash_name]):
                # TODO: store also image distance.
                similarities.append(img.id)
        return similarities