lerobot/lerobot/common/transforms.py

101 lines
3.5 KiB
Python

import torch
from torchvision.transforms.v2 import Compose, Transform
def apply_inverse_transform(item, transform):
transforms = transform.transforms if isinstance(transform, Compose) else [transform]
for tf in transforms[::-1]:
if tf.invertible:
item = tf.inverse_transform(item)
else:
raise ValueError(f"Inverse transform called on a non invertible transform ({tf}).")
return item
class Prod(Transform):
invertible = True
def __init__(self, in_keys: list[str], prod: float):
super().__init__()
self.in_keys = in_keys
self.prod = prod
self.original_dtypes = {}
def forward(self, item):
for key in self.in_keys:
if key not in item:
continue
self.original_dtypes[key] = item[key].dtype
item[key] = item[key].type(torch.float32) * self.prod
return item
def inverse_transform(self, item):
for key in self.in_keys:
if key not in item:
continue
item[key] = (item[key] / self.prod).type(self.original_dtypes[key])
return item
# def transform_observation_spec(self, obs_spec):
# for key in self.in_keys:
# if obs_spec.get(key, None) is None:
# continue
# obs_spec[key].space.high = obs_spec[key].space.high.type(torch.float32) * self.prod
# obs_spec[key].space.low = obs_spec[key].space.low.type(torch.float32) * self.prod
# obs_spec[key].dtype = torch.float32
# return obs_spec
class NormalizeTransform(Transform):
invertible = True
def __init__(
self,
stats: dict,
in_keys: list[str] = None,
out_keys: list[str] | None = None,
in_keys_inv: list[str] | None = None,
out_keys_inv: list[str] | None = None,
mode="mean_std",
):
super().__init__()
self.in_keys = in_keys
self.out_keys = in_keys if out_keys is None else out_keys
self.in_keys_inv = self.out_keys if in_keys_inv is None else in_keys_inv
self.out_keys_inv = self.in_keys if out_keys_inv is None else out_keys_inv
self.stats = stats
assert mode in ["mean_std", "min_max"]
self.mode = mode
def forward(self, item):
for inkey, outkey in zip(self.in_keys, self.out_keys, strict=False):
if inkey not in item:
continue
if self.mode == "mean_std":
mean = self.stats[inkey]["mean"]
std = self.stats[inkey]["std"]
item[outkey] = (item[inkey] - mean) / (std + 1e-8)
else:
min = self.stats[inkey]["min"]
max = self.stats[inkey]["max"]
# normalize to [0,1]
item[outkey] = (item[inkey] - min) / (max - min)
# normalize to [-1, 1]
item[outkey] = item[outkey] * 2 - 1
return item
def inverse_transform(self, item):
for inkey, outkey in zip(self.in_keys_inv, self.out_keys_inv, strict=False):
if inkey not in item:
continue
if self.mode == "mean_std":
mean = self.stats[inkey]["mean"]
std = self.stats[inkey]["std"]
item[outkey] = item[inkey] * std + mean
else:
min = self.stats[inkey]["min"]
max = self.stats[inkey]["max"]
item[outkey] = (item[inkey] + 1) / 2
item[outkey] = item[outkey] * (max - min) + min
return item