Files
Gymnasium/gym/wrappers/pixel_observation.py
Justin Terry bdf95c1adc Python 3.9 support (#2088)
* try changes in pr 1804

* fix classifiers

* typo
2020-12-17 11:55:52 -08:00

132 lines
4.7 KiB
Python

"""An observation wrapper that augments observations by pixel values."""
import collections
from collections.abc import MutableMapping
import copy
import numpy as np
from gym import spaces
from gym import ObservationWrapper
STATE_KEY = 'state'
class PixelObservationWrapper(ObservationWrapper):
"""Augment observations by pixel values."""
def __init__(self,
env,
pixels_only=True,
render_kwargs=None,
pixel_keys=('pixels', )):
"""Initializes a new pixel Wrapper.
Args:
env: The environment to wrap.
pixels_only: If `True` (default), the original observation returned
by the wrapped environment will be discarded, and a dictionary
observation will only include pixels. If `False`, the
observation dictionary will contain both the original
observations and the pixel observations.
render_kwargs: Optional `dict` containing keyword arguments passed
to the `self.render` method.
pixel_keys: Optional custom string specifying the pixel
observation's key in the `OrderedDict` of observations.
Defaults to 'pixels'.
Raises:
ValueError: If `env`'s observation spec is not compatible with the
wrapper. Supported formats are a single array, or a dict of
arrays.
ValueError: If `env`'s observation already contains any of the
specified `pixel_keys`.
"""
super(PixelObservationWrapper, self).__init__(env)
if render_kwargs is None:
render_kwargs = {}
for key in pixel_keys:
render_kwargs.setdefault(key, {})
render_mode = render_kwargs[key].pop('mode', 'rgb_array')
assert render_mode == 'rgb_array', render_mode
render_kwargs[key]['mode'] = 'rgb_array'
wrapped_observation_space = env.observation_space
if isinstance(wrapped_observation_space, spaces.Box):
self._observation_is_dict = False
invalid_keys = set([STATE_KEY])
elif isinstance(wrapped_observation_space,
(spaces.Dict, MutableMapping)):
self._observation_is_dict = True
invalid_keys = set(wrapped_observation_space.spaces.keys())
else:
raise ValueError("Unsupported observation space structure.")
if not pixels_only:
# Make sure that now keys in the `pixel_keys` overlap with
# `observation_keys`
overlapping_keys = set(pixel_keys) & set(invalid_keys)
if overlapping_keys:
raise ValueError("Duplicate or reserved pixel keys {!r}."
.format(overlapping_keys))
if pixels_only:
self.observation_space = spaces.Dict()
elif self._observation_is_dict:
self.observation_space = copy.deepcopy(wrapped_observation_space)
else:
self.observation_space = spaces.Dict()
self.observation_space.spaces[STATE_KEY] = wrapped_observation_space
# Extend observation space with pixels.
pixels_spaces = {}
for pixel_key in pixel_keys:
pixels = self.env.render(**render_kwargs[pixel_key])
if np.issubdtype(pixels.dtype, np.integer):
low, high = (0, 255)
elif np.issubdtype(pixels.dtype, np.float):
low, high = (-float('inf'), float('inf'))
else:
raise TypeError(pixels.dtype)
pixels_space = spaces.Box(
shape=pixels.shape, low=low, high=high, dtype=pixels.dtype)
pixels_spaces[pixel_key] = pixels_space
self.observation_space.spaces.update(pixels_spaces)
self._env = env
self._pixels_only = pixels_only
self._render_kwargs = render_kwargs
self._pixel_keys = pixel_keys
def observation(self, observation):
pixel_observation = self._add_pixel_observation(observation)
return pixel_observation
def _add_pixel_observation(self, wrapped_observation):
if self._pixels_only:
observation = collections.OrderedDict()
elif self._observation_is_dict:
observation = type(wrapped_observation)(wrapped_observation)
else:
observation = collections.OrderedDict()
observation[STATE_KEY] = wrapped_observation
pixel_observations = {
pixel_key: self.env.render(**self._render_kwargs[pixel_key])
for pixel_key in self._pixel_keys
}
observation.update(pixel_observations)
return observation