mmclassification/mmpretrain/datasets/transforms/wrappers.py

98 lines
3.3 KiB
Python

# Copyright (c) OpenMMLab. All rights reserved.
import copy
from typing import Callable, List, Union
from mmcv.transforms import BaseTransform, Compose
from mmpretrain.registry import TRANSFORMS
# Define type of transform or transform config
Transform = Union[dict, Callable[[dict], dict]]
@TRANSFORMS.register_module()
class MultiView(BaseTransform):
"""A transform wrapper for multiple views of an image.
Args:
transforms (list[dict | callable], optional): Sequence of transform
object or config dict to be wrapped.
mapping (dict): A dict that defines the input key mapping.
The keys corresponds to the inner key (i.e., kwargs of the
``transform`` method), and should be string type. The values
corresponds to the outer keys (i.e., the keys of the
data/results), and should have a type of string, list or dict.
None means not applying input mapping. Default: None.
allow_nonexist_keys (bool): If False, the outer keys in the mapping
must exist in the input data, or an exception will be raised.
Default: False.
Examples:
>>> # Example 1: MultiViews 1 pipeline with 2 views
>>> pipeline = [
>>> dict(type='MultiView',
>>> num_views=2,
>>> transforms=[
>>> [
>>> dict(type='Resize', scale=224))],
>>> ])
>>> ]
>>> # Example 2: MultiViews 2 pipelines, the first with 2 views,
>>> # the second with 6 views
>>> pipeline = [
>>> dict(type='MultiView',
>>> num_views=[2, 6],
>>> transforms=[
>>> [
>>> dict(type='Resize', scale=224)],
>>> [
>>> dict(type='Resize', scale=224),
>>> dict(type='RandomSolarize')],
>>> ])
>>> ]
"""
def __init__(self, transforms: List[List[Transform]],
num_views: Union[int, List[int]]) -> None:
if isinstance(num_views, int):
num_views = [num_views]
assert isinstance(num_views, List)
assert len(num_views) == len(transforms)
self.num_views = num_views
self.pipelines = []
for trans in transforms:
pipeline = Compose(trans)
self.pipelines.append(pipeline)
self.transforms = []
for i in range(len(num_views)):
self.transforms.extend([self.pipelines[i]] * num_views[i])
def transform(self, results: dict) -> dict:
"""Apply transformation to inputs.
Args:
results (dict): Result dict from previous pipelines.
Returns:
dict: Transformed results.
"""
multi_views_outputs = dict(img=[])
for trans in self.transforms:
inputs = copy.deepcopy(results)
outputs = trans(inputs)
multi_views_outputs['img'].append(outputs['img'])
results.update(multi_views_outputs)
return results
def __repr__(self) -> str:
repr_str = self.__class__.__name__ + '('
for i, p in enumerate(self.pipelines):
repr_str += f'\nPipeline {i + 1} with {self.num_views[i]} views:\n'
repr_str += str(p)
repr_str += ')'
return repr_str