# Copyright 2021 The Layout Parser team. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. from typing import List, Dict, Dict, Any from abc import ABC, abstractmethod from copy import copy class BaseLayoutElement: def set(self, inplace=False, **kwargs): obj = self if inplace else copy(self) var_dict = vars(obj) for key, val in kwargs.items(): if key in var_dict: var_dict[key] = val elif f"_{key}" in var_dict: var_dict[f"_{key}"] = val else: raise ValueError(f"Unknown attribute name: {key}") return obj def __repr__(self): info_str = ", ".join([f"{key}={val}" for key, val in vars(self).items()]) return f"{self.__class__.__name__}({info_str})" def __eq__(self, other): if other.__class__ is not self.__class__: return False return vars(self) == vars(other) class BaseCoordElement(ABC, BaseLayoutElement): @property @abstractmethod def _name(self) -> str: """The name of the class""" pass @property @abstractmethod def _features(self) -> List[str]: """A list of features names used for initializing the class object""" pass ####################################################################### ######################### Layout Properties ######################### ####################################################################### @property @abstractmethod def width(self): pass @property @abstractmethod def height(self): pass @property @abstractmethod def coordinates(self): pass @property @abstractmethod def points(self): pass @property @abstractmethod def area(self): pass ####################################################################### ### Geometric Relations (relative to, condition on, and is in) ### ####################################################################### @abstractmethod def condition_on(self, other): """ Given the current element in relative coordinates to another element which is in absolute coordinates, generate a new element of the current element in absolute coordinates. Args: other (:obj:`BaseCoordElement`): The other layout element involved in the geometric operations. Raises: Exception: Raise error when the input type of the other element is invalid. Returns: :obj:`BaseCoordElement`: The BaseCoordElement object of the original element in the absolute coordinate system. """ pass @abstractmethod def relative_to(self, other): """ Given the current element and another element both in absolute coordinates, generate a new element of the current element in relative coordinates to the other element. Args: other (:obj:`BaseCoordElement`): The other layout element involved in the geometric operations. Raises: Exception: Raise error when the input type of the other element is invalid. Returns: :obj:`BaseCoordElement`: The BaseCoordElement object of the original element in the relative coordinate system. """ pass @abstractmethod def is_in(self, other, soft_margin={}, center=False): """ Identify whether the current element is within another element. Args: other (:obj:`BaseCoordElement`): The other layout element involved in the geometric operations. soft_margin (:obj:`dict`, `optional`, defaults to `{}`): Enlarge the other element with wider margins to relax the restrictions. center (:obj:`bool`, `optional`, defaults to `False`): The toggle to determine whether the center (instead of the four corners) of the current element is in the other element. Returns: :obj:`bool`: Returns `True` if the current element is in the other element and `False` if not. """ pass ####################################################################### ################# Shape Operations (intersect, union) ################ ####################################################################### @abstractmethod def intersect(self, other: "BaseCoordElement", strict: bool = True): """Intersect the current shape with the other object, with operations defined in :doc:`../notes/shape_operations`. """ @abstractmethod def union(self, other: "BaseCoordElement", strict: bool = True): """Union the current shape with the other object, with operations defined in :doc:`../notes/shape_operations`. """ ####################################################################### ############### Geometric Operations (pad, shift, scale) ############## ####################################################################### @abstractmethod def pad(self, left=0, right=0, top=0, bottom=0, safe_mode=True): """Pad the layout element on the four sides of the polygon with the user-defined pixels. If safe_mode is set to True, the function will cut off the excess padding that falls on the negative side of the coordinates. Args: left (:obj:`int`, `optional`, defaults to 0): The number of pixels to pad on the upper side of the polygon. right (:obj:`int`, `optional`, defaults to 0): The number of pixels to pad on the lower side of the polygon. top (:obj:`int`, `optional`, defaults to 0): The number of pixels to pad on the left side of the polygon. bottom (:obj:`int`, `optional`, defaults to 0): The number of pixels to pad on the right side of the polygon. safe_mode (:obj:`bool`, `optional`, defaults to True): A bool value to toggle the safe_mode. Returns: :obj:`BaseCoordElement`: The padded BaseCoordElement object. """ pass @abstractmethod def shift(self, shift_distance=0): """ Shift the layout element by user specified amounts on x and y axis respectively. If shift_distance is one numeric value, the element will by shifted by the same specified amount on both x and y axis. Args: shift_distance (:obj:`numeric` or :obj:`Tuple(numeric)` or :obj:`List[numeric]`): The number of pixels used to shift the element. Returns: :obj:`BaseCoordElement`: The shifted BaseCoordElement of the same shape-specific class. """ pass @abstractmethod def scale(self, scale_factor=1): """ Scale the layout element by a user specified amount on x and y axis respectively. If scale_factor is one numeric value, the element will by scaled by the same specified amount on both x and y axis. Args: scale_factor (:obj:`numeric` or :obj:`Tuple(numeric)` or :obj:`List[numeric]`): The amount for downscaling or upscaling the element. Returns: :obj:`BaseCoordElement`: The scaled BaseCoordElement of the same shape-specific class. """ pass ####################################################################### ################################# MISC ################################ ####################################################################### @abstractmethod def crop_image(self, image): """ Crop the input image according to the coordinates of the element. Args: image (:obj:`Numpy array`): The array of the input image. Returns: :obj:`Numpy array`: The array of the cropped image. """ pass ####################################################################### ########################## Import and Export ########################## ####################################################################### def to_dict(self) -> Dict[str, Any]: """ Generate a dictionary representation of the current object: { "block_type": <"interval", "rectangle", "quadrilateral"> , "non_empty_block_attr1": value1, ... } """ data = { key: getattr(self, key) for key in self._features if getattr(self, key) is not None } data["block_type"] = self._name return data @classmethod def from_dict(cls, data: Dict[str, Any]) -> "BaseCoordElement": """Initialize an instance based on the dictionary representation Args: data (:obj:`dict`): The dictionary representation of the object """ assert ( cls._name == data["block_type"] ), f"Incompatible block types {data['block_type']}" return cls(**{f: data[f] for f in cls._features})